Department of Psychology

Eyeblink classical conditioning (EBC) is a well-established model for studying the developmental neurobiology of associative learning and memory. Though extinction has been characterized extensively at the behavioral and neurobiological levels in adulthood, less is understood regarding extinction during development. This report represents the first study investigating the developmental emergence of extinction in EBC. Postnatal day (PD) 17 and 24 rats were used in the present study since cerebellar-brainstem circuitry critical for extinction in adulthood undergoes substantial maturation over this period. To overcome developmental limitations in EBC acquisition in PD 17 rats, stimulation of the proximal portion of the CS pathway – the middle cerebellar peduncle – was paired with a periorbital shock US to produce comparable rates and asymptotes of acquisition between ages. Contrary to expected results, fewer CRs were present during extinction in rats initially trained at PD 17 relative to the older group (PD24), due in part to rapid forgetting in the younger rats. Savings of initial learning was present at both ages as evidenced by rapid reacquisition to paired CS-US training following extinction. The present findings have implications for the developmental emergence of extinction and for infantile amnesia, and may be explained by age-related differences in maintenance of learning-related plasticity in the cerebellum.

Speaker: Elaine Bossard, Department of Psychology, University of Iowa Title: Do Children Become More Competent Decision Makers? Evidence from a Longitudinal Study

Speaker: Jillian O’Rourke, Department of Psychology, University of Iowa Title: The Impact of Wishful Thinking on How People Prepare for Uncontrollable Events

Speaker: Aaron Scherer, Department of Psychology, University of Iowa Title: Seeking What We Want: A Neuropsychological Test Between Conflicting Accounts of Confirmatory Information Seeking

There are at least two ways in which a C.E.P.P. model can be scaled up and expanded: one can apply the model to a larger array of tasks or one can attempt to complete the model, filling in any gaps that were previously left unspecified. Last week John S. provided a great example of the former approach; this week I will try to do the same for the latter approach. The particular task that I will attempt to completely model requires simple reactions to auditory stimuli of varying intensity and duration. The gated capacitor model that I will discuss not only produces reaction times that exhibit Bloch's Law, but it also produces response forces that mimic those of human subjects.

When interacting with infants and young children, adults modify their speech in characteristic and universal ways. Despite the multisensory nature of speech communication, most research has focused on the acoustical aspects of speech. This talk will present studies that use eye-tracking, motion-tracking, and acoustical analysis to examine the multisensory aspects of mother-infant interaction, addressing questions of how mothers’ speech is influenced by visual feedback from their infants, how infants visually process infant- and adult-directed speech, and how mothers change their visual prosody when talking to infants.

One of the challenges with formal theories is the issue of scale: it's possible to explain some local phenomenon, but how do you scale the theory up to explain a broader set of findings? In my talk, I'll discuss work examining visual cognition and our efforts to develop a theoretical framework that can address the scaling problem. I will show how Dynamic Field Theory does, in fact, scale by discussing a set of work that moves from lower-level attentional orienting and biased competition effects to simple variants of change detection and then to an updateable scene representation that knows 'what' is 'where'.

What do David Hockney, Richard Feynman, Vladimir Nabokov, Olivier Messiaen, and Stevie Wonder have in common? All experience synaesthesia, a "union of the senses," whereby two or more senses that are normally experienced separately are automatically joined together. For some synaesthetes, listening to a piece of music may cause them to see specific colors (e.g., the key of C-major may be blue), while for others letters or numbers are always tinged a certain color (e.g., ‘5’ may be green and ‘6’ may be red), or letters and numbers might be associated with personalities: The letter ‘A’ might be a woman and ‘B’ might be her husband! I will review evidence from behavioral experiments which show that synaesthetes can perform better than non-synaesthetes on a number of visual tests and from neuroimaging studies which show increased activity in regions of the brain that are essential for synaesthetic experiences. I will then discuss how learning, development, and cortical plasticity may interact with genetic factors to produce synesthetic experiences. Understanding synaesthesia may help to unlock someaspects of what makes humans creative; indeed, some synesthesia mechanisms are present in all of us. Thus, far from being a mere curiosity, synaesthesia may provide a window into perception, thought, and language. Please feel free to share this information with others you think may be interested in attending.

**CANCELLED**

Relapse to drug-seeking behavior remains a significant impediment in the treatment of drug addiction. Considerable effort has been directed toward modeling relapse in rats and investigating the neurobiology governing relapse behavior as a foundation for the development of improved treatments for drug addiction. Our work has focused on the neural circuits that regulate drug-seeking behavior in rats, with particular focus on heroin- and cocaine-seeking. Our findings indicate that regions of the prefrontal cortex are critically involved in driving drug-seeking behavior as well as inhibiting drug-seeking behavior. Indeed, we have found that a unique set of brain structures mediates the inhibition of drug-seeking in rats and appears to oppose those structures that drive the relapse to drug-seeking. Our data suggest that the infralimbic cortex and nucleus accumbens shell interact to suppress drug-seeking behavior and that this suppression of drug-seeking behavior depends on inhibition of the mesolimbic dopamine system, including the ventral tegmental area neurons. We believe that a novel circuit connecting the infralimbic cortex and accumbens shell to the ventral tegmental area is responsible for this inhibition, an issue we will discuss in this talk.

We endeavor to maximize benefit and minimize harm. To accomplish this, we must rapidly discriminate rewarding and aversive stimuli and learn to predict their occurrences. In response to predictors, we need to organize motor output to approach rewards and avoid aversive stimuli. The neurotransmitter dopamine and one of its targets – the nucleus accumbens – is thought to comprise a crucial part of the brain’s ‘reward circuit’. I will share studies in which I show that these elements are involved in both reward and aversion and in both approach and avoidance behaviors. Of course the value of a given stimulus is subject to change based on learning or motivational state. I will show that patterns of activity within the nucleus accumbens are plastic and are modulated during learning and in response to hormonal signals indicating need or satiety. This is accomplished by pairing recordings techniques possessing high temporal resolution (fast-scan cyclic voltammetry; electrophysiology) with a variety of behavioral paradigms. Taken together my work argues against the one-trick pony of a brain reward circuit and in favor of Mogenson’s characterization of this circuitry as a limbic-motor interface.

The efficiency of visual search in natural scenes is governed by memory and knowledge. We construct and organize environments for the purpose of allowing long-term memory and knowledge to guide the eyes to appropriate scene locations. For example, the reason the bottle opener is kept in a particular drawer in the kitchen is so that memory for its location can be used to find it efficiently. In addition, online forms of memory serve to guide attention toward the locations of objects that match the current template for visual search and away from locations that have been previously inspected. I will review research concerning the mechanisms by which visual memory exerts top-down control over visual search, spanning higher-level effects of scene knowledge on the global pattern of eye movements and low-level interactions between then content of visual working memory and individual saccades.

The study of children with early occurring focal brain injury provides a model for exploring the dynamic nature of early brain and cognitive development. The children in the studies described in this talk suffered focal brain insult (typically stroke) in the perinatal period (late third trimester-neonatal), long before the acquisition of higher cognitive functions. In most, though not all cases, the injuries affect substantial portions of one cerebral hemisphere, resulting in patterns of neural damage that would compromise cognitive ability in adults. However, longitudinal behavioral studies of this population of children have revealed only mild cognitive deficits, and preliminary data from functional brain imaging studies suggest that alternative patterns of functional organization emerge in the wake of early injury. The degree of deficit varies somewhat across behavioral domains, with evolutionary older functions exhibiting greater and more persistent negative effects It is argued that the capacity for adaptation is not the result of early insult. Rather, it reflects normal developmental processes which are both dynamic and adaptive operating against a backdrop of serious perturbation of the neural substrate. Data illustrating profiles of motor development, language acquisition and spatial cognitive development will be discussed.

There will also be a roundtable discussion with Professor Stiles on Friday morning, 9:00-10:30 a.m., in 120 SLP.

Eyeblink conditioning has been used extensively as a method for examining the neural mechanisms underlying associative motor learning. Delay eyeblink conditioning requires plasticity mechanisms within the cerebellum. The cerebellum makes contributions to many aspects of behavior and cognition; its role in motor control is widely known but recent studies indicate that it also plays important roles in language, perception of timing, attention, verbal working memory, and associative learning. A key to understanding cerebellar function has been the identification of functional loops between the cerebellum and other areas of the brain. Our recent studies examining neural pathways for auditory and visual conditioned stimulus (CS) inputs to the cerebellum that are necessary for eyeblink conditioning have revealed changes in neuronal activity during learning that suggest interactions between the CS pathways and cerebellum. The auditory CS pathway includes the medial auditory thalamus (MAT) and its projection to the lateral pons. Simultaneous tetrode recordings within the MAT and anterior interpositus nucleus (AIN) demonstrated that learning-related increases in activity within the MAT follow learning-related increases in cerebellar activity across training sessions and within training trials, suggesting that cerebellar feedback may drive learning-related activity in the thalamus. The findings of this study suggest that there is a positive feedback loop between the cerebellum and its auditory CS input pathway. Visual thalamic and pontine neurons also exhibit learning-specific changes in activity that may be driven by cerebellar feedback. Associative motor learning is thus modulated by dynamic interactions between plasticity mechanisms in the cerebellum and its sensory input pathways.

A network of interconnected cell groups in the limbic forebrain regulates hypothalamic-pituitary-adrenal (HPA) activation during emotionally stressful experiences, and disruption of these systems is broadly implicated in stress-related psychiatric illnesses. A significant challenge has been to unravel the circuitry and mechanisms providing for regulation of HPA output, as these limbic forebrain regions do not provide any direct innervation of HPA effector cell groups in the paraventricular hypothalamus. Recent advances will be highlighted that endorse a discrete region within the bed nucleus of the stria terminalis that acts as a neural hub for receiving and integrating these influences, whereas the prevailing view concerning the organization of limbic forebrain over the HPA axis involves a layer of cell groups providing an array multisynaptic parallel pathways between the forebrain and PVH. A hypothesis will be advanced that accounts for the capacity of this network to constrain the magnitude and/or duration of HPA axis output in response to emotionally stressful experiences, and for how chronic stress-induced synaptic reorganization in key cell groups may lead to an attrition of these restraining influences in leading to HPA axis hyperactivity.

How does the brain develop differently to support nocturnality in some mammals, but diurnality in others? To answer this, one might look to the suprachiasmatic nucleus (SCN), which is entrained by light via the retinohypothalamic tract (RHT). However, because the SCN is more active during the day in all mammals studied thus far, it alone cannot determine circadian preference. In adult Norway rats (Rattus norvegicus), which are nocturnal, the RHT also projects to the ventral subparaventricular zone (vSPVZ), an adjacent region that expresses an in-phase pattern of SCN-vSPVZ neuronal activity. In contrast, in adult Nile grass rats (Arvicanthis niloticus), which are diurnal, an anti-phase pattern of SCN-vSPVZ neuronal activity is expressed. We hypothesized that these species differences result in part from a weak or absent RHT-to-vSPVZ projection in grass rats. Here, using a developmental comparative approach, we assessed differences in behavior, hypothalamic activity, and RHT anatomy between these two species. We report that a robust retina-to-vSPVZ projection develops in Norway rats around the end of the second postnatal week when nocturnal wakefulness and the in-phase pattern of neuronal activity emerge. In grass rats, however, such a projection does not develop and the emergence of the anti-phase pattern during the second postnatal week is accompanied by increased diurnal wakefulness. When considered within the context of previously published reports on RHT projections in a variety of other species, the current findings suggest that how and when the retina connects to the hypothalamus differentially shapes brain and behavior to produce animals that occupy opposing temporal niches.

This talk will provide an overview of the use of random-regression approaches to the analysis of two commonly encountered nested or hierarchical data structures. In one case, items are nested within participants at a single point in time. In the other case, repeated measures over time (e.g., across blocks) are nested within participants. Explicit representation of the hierarchical data structure, in combination with treatment of item, participant, and time as random rather than fixed effects, provide a number of conceptual and analytical advantages. Illustrative applications of this approach within clinical-cognitive research on men's perceptions of women's sexual-interest cues will be provided.

My talk focuses on the interactions between word learning, categorization, and the development of dimensional attention across immediate and developmental timescales. I will present research on two different developments that are each related to children¹s ability to focus on one dimension to the exclusion of others. One is an early acquired development, that of word learning biases, and the other a late-acquired development, that of dimensional similarity classification. In the case of word learning biases, we have an understanding of the mechanisms involved in this development, but in the case of similarity classification, it is still unclear how this develops. Thus, my central question is how the mechanisms involved in word learning biases, such as the role of word learning in training selective attention to dimensions, might relate to the development of similarity classification.

**SOCIAL PSYCHOLOGY BROWN BAG**

Approaches to phonics education have long ignored the value of cognitive research in crafting curricula. However, findings from computational modeling and studies of statistical learning offer promise of improving pedagogical decisions and aiding struggling readers. Unfortunately, applying these findings to the classroom is sometimes unclear. For example, there are numerous cases of variability among stimuli aiding learning performance in laboratory paradigms, but there are also a number of instances where similarity among stimuli improves performance. Using a computer-based phonics teaching tool, we investigate which of these principles better guides phonics learning in a sample of 224 first grade students. We find that variability offers a consistent benefit to student performance. We discuss the ramifications of this finding for theory and application.

In everyday life, we use perception to guide our actions and our actions to inform our perception. My work focuses on the integrated study of perception and action in order to better understand the complex reciprocal relationship that exists between the two. The talk covers two lines of my research. I will begin by discussing a study in which we examined the actions infants direct towards two- and three-dimensional objects in order to understand how infants perceive these objects and the different ways in which they can interact with them. I will then describe my dissertation research on the recalibration of perception and action in children and adults. In this line of research, we examine the link between perception and action by changing the normal relationship between perception and action and then measuring the errors that occur when feedback is withheld. Both lines of research aim to better understand how organisms use perception and action in order to interact with a dynamically changing environment.

In primates, neurons sensitive to figure-ground status are located in striate cortex (area V1) and extrastriate cortex (area V2). Although much is known about anatomical structure and connectivity of the avian visual pathway, the functional organization of the avian brain remain relatively unexplored. To pinpoint areas associated with figure-ground segregation in avian brain, in a first experiment we used a radioactively labeled glucose analog to compare differences in glucose uptake after figure-ground, color, and shape discriminations. In addition, we used a control group that received food on variable-interval schedule but was not required to perform visual discrimination. Although the response requirements depended on group assignment, the stimulus displays were identical for all three experimental groups ensuring that all animals were processing the same visual input. A second experiment explored the role of visual modulatory areas on figure-ground, color and shape discriminations by lesioning the nucleus subpretectalis. In this experiment each bird was train to master the three discrimination task. After reaching criterion, animals were subject to bilateral ibotenic acid lesions in the n. subpretectalis. After recovery birds were request to perform the discrimination task again. Our analysis in the first experiment concentrated on a primary thalamic nucleus associated with visual processing, nucleus rotundus, and two nuclei providing regulatory feedback, pretectum and nucleus subpretectalis/ interstitio-pretecto-subpretectalis complex. We found that figure-ground discrimination was associated with strong nonlateralized activity of nucleus rotundus, while color discrimination produced strong activation of nucleus in right hemisphere but not in left hemisphere. In contrast, shape discrimination was associated with significantly lower activity of nucleus rotundus in comparison to control group. In the second experiment we found that lesioning the n. subpretectalis result in a selective impairment of the figure-ground and shape discrimination, with no effect on color discrimination. Taken together, our results suggest that figure-ground segregation in avian brain may occur significantly earlier than in primate brain.

Perceptual learning refers to improvements in perceptual abilities through training. It has been a topic of growing interest over the last two decades. Perceptual learning is a valuable tool for studying the organization of the visual system and the mechanisms of brain plasticity. The improvements, however, are often specific to the particular stimuli used in training. This stimulus specificity is universally recognized as a key property of perceptual learning, but is still poorly understood. In this talk, a detailed computational model will be presented that accounts for some (but not all) forms of specificity. After presenting the model in some detail, I will outline some of its limitations and finish with some ideas on how the model can be improved.

Selective reweighting model (Petrov, Dosher, & Lu, 2005): Growing evidence suggests that selective reweighting of the read-out connections from the sensory representations plays a major role in perceptual learning. Here we instantiate this idea in a computational model that takes grayscale images as inputs and learns on a trial-by-trial basis. The stimuli are processed by standard orientation- and frequency-tuned representational units, divisively normalized. Learning occurs only in the read-out connections to a decision unit; the stimulus representations never change. An incremental Hebbian rule tracks the task-dependent predictive value of each unit, thereby improving the signal-to-noise ratio of their weighted combination. Each abrupt change in the environmental statistics induces a switch cost in the learning curves as the system temporarily works with suboptimal weights. In this situation, self-generated feedback seems sufficient for learning. The model accounts for a complex pattern of context-induced switch costs in a non-stationary training environment.

As a developmentalist my primary goal is to understand how learning and behavior in one moment lead to cascading developmental effects across future moments of learning and behavior. My talk focuses on interactions between word learning, attention, and categorization across immediate and developmental timescales. My research questions primarily concern 1) how we initially learn the scope of a novel category, 2) how learning more about a category and its members influences how we perceive the structure of that particular category, and 3) how this subsequently influences how we judge similarity in general.

The hippocampus is necessary for the normal formation of enduring declarative memories, but its role in cognitive processes spanning short intervals is less well understood. Within the last decade several reports have described modest behavioral deficits in MTL-lesion patients when they perform tasks that do not seem likely to rely on enduring memory. An intriguing but sparsely-tested implication of such results is that the MTL is involved in the on-line representation of information, possibly of an associative/relational nature, irrespective of delay. I have tested this proposition in my work by examining the behavior and eye movements of healthy participants, amnesic patients with hippocampal damage, and brain-damaged comparison participants. My colleagues and I have found that damage to the hippocampus disrupts performance of many tasks that are completed within seconds, implying that in healthy individuals the hippocampus is continuously influencing ongoing cognition in subtle but important ways.

Depressive and anxiety disorders in the postpartum period cause significant suffering for women and are associated with delays in socio-emotional and cognitive development and increased risk for internalizing and externalizing disorders among offspring. State public health officials across the country use the Centers for Disease Control and Prevention sponsored Pregnancy Risk Assessment Monitoring System (PRAMS) questionnaire to assess health behaviors and conditions that occur around the time of pregnancy for the purpose of program and policy planning. Although some questions were already in use to detect depression and anxiety on the PRAMS survey, they had not been validated with postpartum women. The purpose of the present study was to validate two to three items that could be included on the PRAMS questionnaire to detect depression and anxiety among postpartum women in a surveillance environment. A comprehensive set of items was developed and tested in three phases. We identified several combinations of items that showed acceptable psychometric performance in detecting depression and anxiety in postpartum women. Depression and anxiety can be detected using very few items, which makes assessment feasible in surveillance systems like PRAMS and in primary care settings.

The Simon Effect, discovered by Dick Simon at the University of Iowa in the late 1960s, is a widely studied form of response competition that continues to inform our understanding of response selection processes. Toby Mordkoff and I have been examining sequential modulations of the Simon Effect to determine what they can tell us about the central operations that translate stimuli into voluntary motor movements. By using four-choice versions of the Simon task, we assess various potential sources of the effect, including conflict adaptation, feature binding, and feature adaptation. The results indicate that many of these phenomena play a role in sequential modulations. However, while the histories of individual stimulus and response features are contributors, the congruency of the previous trial – even when it shares no features with the present trial – affects the magnitude of the congruency effect on the present trial. The results are discussed in relation to their implications for theories of response selection.

Visual working memory (VWM) refers to a limited-capacity storage system used for temporary maintenance of task-relevant visual information. An important issue in VWM research is the mechanism by which information is selected for encoding into VWM. We tested the roles of overt and covert attention in the encoding of items into VWM. Attention was manipulated during the retention interval of a change-detection task by asking participants to either overtly or covertly attend to a distractor. We found that executing a saccade to the distractor resulted in its automatic encoding in VWM whereas covertly attending to the distractor did not interfere with the contents of VWM. These results challenge the view that spatial attention and VWM reflect the same mechanism while supporting the view that perceptual gaps created by saccades necessitate automatic encoding of the saccade-target item.

Converging evidence points toward large genetic contributions to attention-deficit hyperactivity disorder. Despite this finding, the main effects of the observable genetic markers account for only a small fraction of the substantial heritability observed in twin studies. This discrepancy has been the main impetus for investigation of gene x environment interactions (GxE) for ADHD, which have yielded some promising positive findings thus far (see Nigg, Nikolas, & Burt, 2010). Traditionally, GxE effects have been assumed to follow a traditional diathesis-stress framework. However, recent theorists have proposed that an alternative model of ‘differential susceptibility’ may be operating for psychiatric conditions, including ADHD. Investigations of GxE effects involving candidate genes in the dopamine and serotonin neurotransmission systems and characteristics of the family environment revealed initial support for an etiological model of ‘differential susceptibility’ for ADHD. I will describe how research in my laboratory will seek to further evaluate GxE effects in this framework, including extension to adult ADHD populations and examination of the impact of adolescent development on these relationships.

Spoken language contains numerous dimensions of acoustic variability, but only some of those dimensions actually signal word meaning. Acquiring speech sound categories is often construed as a search for linguistic “signal” in acoustic “noise,” where the noise consists of acoustic attributes that include talker-related properties—gender, regional or foreign accent, identity. Children within the first year of life begin to show adult-like, language-specific discrimination patterns of speech sounds. But what happens to the rest of the information? I present evidence from preschoolers and adults suggesting that this acoustic detritus is actually a gold mine of information that is necessary for everyday language processing.

I describe current projects in my lab examining how 3-to-5-year-olds utilize acoustic variability in speech, specifically, talker variability and accent variability. In addition to overt responses, I use eye tracking as a dependent measure to allow connection to a literature on even younger (pre-verbal) children. Results suggest that young children flexibly use the acoustic specifics of speech to predict what a talker will refer to, and they tolerate atypical pronunciations (at least for familiar words), though they are less adept than adults at identifying individual voices. These results support a perspective in which perceptual learning of speech (1) is not limited to linguistic information, (2) may extend well past infancy, and (3) shapes language processing at multiple levels of analysis.

There will also be a roundtable discussion with Dr. Creel on Friday 9/30 morning, 9:00-10:30 a.m., in 120 SLP.

In a typical transposition task, an animal is presented with a single pair of stimuli (for example, S3+ S4-, where plus and minus denote reward and nonreward and digits denote stimulus location on a sensory dimension such as size). Subsequently, an animal is presented with a testing pair that contains a previously reinforced or nonreinforced stimulus and a novel stimulus (for example, S2-S3 and S4-S5). Does the choice of a novel S2 instead of previously reinforced S3 in a testing pair S2-S3 indicate that the animal has learned a relation (i.e., “select smaller”)? I will review empirical evidence and theoretical accounts demonstrating that organism’s behavior in a transposition task is undoubtedly influenced by prior reinforcement history of the training stimuli (Spence, 1937). However, our recent data show that it is also affected by two other factors—a similarity of two testing stimuli to each other and an overall similarity of the testing pair as a whole to the training pair as a whole. Finally, I will present a new experimental approach that employs a modification of a multiple-object tracking task to study implicit relational learning in adult humans.

The Dimensional Change Card Sort (DCCS) task is widely used to study the early development of task switching and cognitive flexibility. In the DCCS, children must flexibly switch from sorting cards either by shape or color to sorting by the other dimension. Typically, 3-year-olds, but not 4-year-olds, lack the flexibility to do so and perseverate on the first set of rules when instructed to switch. I present a Dynamic Neural Field (DNF) model that captures both behavioral and neural dynamics in early childhood. In the first study, we explored the neural grounding of the DNF model by testing hemodynamic predictions with 3- and 4-year-olds. In the second study, we formally link task-switching in early childhood and adulthood by developing an adult version of the DCCS task that retains the critical aspects of the child task. Finally, I discuss future directions in developing the DNF model.

Social impairments are the most defining and chronic symptoms of autism spectrum disorders (ASD). Three theoretical models (i.e., Joint attention (JA), Theory of mind (ToM), and Weak central coherence (WCC)) have been proposed to account for the root of social impairments in individuals with ASD. The present review investigates to what extent the theoretical models have been examined in relation to real-world social deficits in ASD. Six social correlates have been examined in relation to the theories. Social interaction was associated with the 2 theories, JA and ToM. Event scheme was related to the 2 theories, ToM and WCC. Intention understanding and social motivation were associated with JA. Pragmatic language and emotion recognition were associated with ToM. Clinical implications of the empirical associations are discussed.

An emerging area of research in my lab focuses on understanding what controls the contents of our thoughts and how the experience of control affects us. I will present data from three projects. In the first project, we looked at difficult insight problems and showed that the likelihood of participants spontaneously solving these problems was substantially improved by manipulations that asked participants to move their arms or eyes in manners that were spatially compatible with the problem’s solution. Crucially, participants were unaware of any connection between the body movements and the problems at hand. In a second project, we examined what role attention plays in maintaining a thought active in our minds over prolonged periods of time. We showed that, contrary to most theories of sustained attention, attention does not exhaust over time. Rather, it is our thoughts and goals that simply become habituated over time. This “goal habituation” phenomenon makes us lose control over our immediate goals. Finally, I will talk about the phenomenon known as Illusion of Control, the feeling that we may experience control over external events, even when we do not directly affect them. We showed that the salience of external events directly impacts the degree of control that we feel over them. And we further showed that the experience of control, even when illusory, actually alters how we perceive the world: feeling control over aversive events shrinks the perceived duration of these events.

Join us tomorrow for a data blitz from our colleagues in the BCN area.

Women are at increased risk for several psychological disorders, and the period of increased risk begins during puberty and ends after menopause. Moreover, certain psychological symptoms have been shown to fluctuate during the menstrual cycle according to predictable patterns. However, the direct influence of ovarian hormones on psychological symptoms has not been widely studied. The current program of research has focused on detecting associations between hormones and mood, and specifically, the influence of estradiol and progesterone on eating, mood, and addiction. Results across a number of studies suggest that estradiol and progesterone influence psychological symptoms. For example, among women with bulimia nervosa, decreasing estradiol (r=-.25, p<.01) and increasing progesterone (r=.37,p<.001) were associated with an exacerbation of binge eating and purging. In a translational study of postpartum depression, estradiol withdrawal was associated with depression-like behavior in rodents (t=2.26, p=.02) and negative affect in women (r=-0.34, p<.001). Among nicotine dependent women, changes in estradiol (r=-.21, p=.03) and progesterone (r=-.20, p=.03) predicted increased smoking. Taken together, these results suggest that ovarian hormones modulate the frequency and intensity of pathological behavior in women. Results of this research contribute to evidence of a neurobiological basis for psychopathology among women, and estradiol withdrawal represents a promising candidate for further study.

One of the central questions that modern language research set out to answer is the search for the biological and cognitive causes that determine the distribution of linguistic structures across the languages of world. In other words: why do human languages have the features they have and why are some features more frequently observed across languages than others?

One school of thought has focused on the possibility of cognitively arbitrary linguistic universals. Another school of thought hypothesizes that many if not all properties of language as well as the preference for certain structures over others can be derived from functional pressures, such as memory limitations, a preference for efficient communication, and so on. This latter view is intriguing in that it potentially offers a parsimonious account of cross-linguistic patterns in that it reduces at least some of these patterns to more general principles that are not specific to linguistic systems. Initial support for these accounts comes from the observation that gradient processing preferences *within* a given language seem to be reflected in the distribution of categorical grammatical constraints *across* languages.

However, one pivotal assumption has remained virtually unaddressed: in order for functional pressures to explain typological distributions, functional pressures need to shape languages over time. But how does this happen? In this talk, I present work that addresses two possibilities: (1) it is possible that functional pressures operate during language acquisition, so that language learners deviate ever so subtly from their input in the direction of a functionally more preferred system; (2) it is also possible that functional pressures operate during language production in such a way that the linguistic system continuously changes throughout adult life, which would mean that the language input to the next generation will change in the direction of a functionally preferred system.

I present artificial language learning studies on adults addressing possibility (1) and experiments on implicit learning over linguistic structures in adults addressing possibility (2). The latter presents a first step (interesting in its own right) to explore the plasticity of the adult *comprehension* system (although, ultimately, production studies are more relevant to address (2)).

http://www.hlp.rochester.edu/

Traditionally, word learning is thought to be a bottom-up process. Listeners hear a word and extract the abstract units that comprise this word (e.g. phonemes, features). However, many other domains show that the perceptual primitives used for categorization vary depending on the categorization task. We ask whether adult word learning shows similar top-down influences of category structure on the process of encoding the stimuli. Through teaching adults a set of words that is comprised of either highly overlapping or highly dissimilar words, we show that the way words are encoded is greatly affected by the similarity of the words being learned. Specifically, words with greater overlap engender more precise representations, and those learning these words exhibit sharpening of phonological categories. This contrasts with traditional accounts of word learning and suggests that the precision with which words are encoded is determined by the nature of the learning task.

The claim that infants can track statistical patterns in their linguistic environment, once controversial, is now widely accepted. However, the relationship between infant statistical learning and the process of language acquisition remains unclear. In this talk, I will present results from multiple lines of research that converge to support the claim that statistical learning processes play a role in at least some aspects of language acquisition, including the discovery of word boundaries in unfamiliar natural languages, mapping novel words to their referents and to lexical categories, and individual differences in native language attainment.

There will also be a roundtable discussion with Professor Saffran on Friday morning, 9:00-10:30 a.m., in 120 SLP.

In the process of determining the meaning of a new word children rely on previous experience with similar situations and prior knowledge about words and categories. The current work examines the influence of children’s prior knowledge and experience with stimuli from different ontological kinds on word learning in fast-mapping tasks. This work is motivated by our Dynamic Neural Field model of word learning which suggests that retention of newly mapped name-referent links will be higher when stimuli are from a domain with minimal represented structure from experience, such as non-solids. This is because new name-referent mappings have less competition with prior representations when initially being formed. We test this prediction with 24-month-old children in a traditional fast-mapping paradigm using both familiar (e.g. applesauce) and novel (e.g. pickle relish) substances. The findings confirm the predictions of the model and demonstrate that the lack of structure in an unfamiliar domain can sometimes facilitate word learning.

Dr. Savage-Rumbaugh is former Director of Bonobo Research at the Great Ape Trust in Des Moines, IA, a world-class center for research into the intelligence of primates. She helped pioneer the use of technologies, including a keyboard which allows the animals to communicate using spoken English, and a "primate friendly" computer-based joystick terminal that permitted the automated presentation of computerized tasks. Information regarding the abilities of non-human primates to acquire symbols, comprehend spoken words, decode simple syntactical structures, learn concepts of number and quantity, and to perform complex perceptual-motor tasks, helped change the way humans view other members of the primate order. She authored several books including Apes, Language and the Human Mind (Oxford). Her honors include speaking at the Nobel Conference, Honorary Doctorates of Science from the University of Chicago and Missouri State University, and an Anthropology Award from Indiana University.

In many areas of research and clinical assessment, it is common for the same test to be administered on more than one occasion in order to measure changes in cognition. However, the interpretation of retest scores is complicated by practice effects, score gains related to factors such as memory for specific test items, learned strategies, or general experience and comfort with testing. In this review, meta-analyses of test-retest changes were conducted for 18 common neuropsychological tests used to assess several domains of cognitive functioning. The use of alternate forms, participant age, and the length of the test-retest interval were all associated with the sizes of many of the changes in performance. The implications of these findings will be discussed.

Speech and hand gesture form a temporally coordinated system. Listeners are affected by information presented in the spontaneous hand gestures that accompany speech. One question is what cues promote listeners to integrate visual information from gesture with speech. I will present data suggesting that one important cue is the synchrony of visual and auditory information. Listeners are less likely to integrate asynchronous information than synchronous information. However, they are likely to integrate synchronous information, even when this information is not clearly produced by a human speaker.

Abstract: How does stimulus and response information influence response selection over learning? I provide evidence from two separate lines of research. First, I examine evidence from a motor learning task where subjects produced simultaneous finger keypresses (similar to playing a chord on a piano) to spatially compatible stimuli. We manipulated item similarity and found that more similar chords were learned more slowly than dissimilar chords. Perceptual similarity was eliminated (by assigning each chord to a Chinese character), which resulted in no difference in learning between similar and dissimilar chords, indicating that perceptual competition affects learning rate. Second, we examined the relative contributions of stimulus uncertainty and response uncertainty to the Hick-Hyman Law, which holds that reaction time increases linearly with the log of the number of stimulus-response alternatives. Across three experiments we have evidence that reducing the number of responses consistently affected reaction time more than reducing the number of stimuli. I will discuss ways in which these competing pieces of evidence, that in one case stimulus information is more important and in another response information is more important, can be integrated and the implications for theories of response selection.

Most people in close relationships experience hurt feelings from time to time and families are no exception. In fact, people report being the most intensely hurt by family members (Vangelisti & Crumley, 1998) and hurtful messages between parents and children have significant consequences on individual and relational wellbeing. This talk will focus on how relational inferences drawn from a family member’s communication may be at the heart of hurtful experiences. In other words, it is what a parent or child is seen as communicating about the relationship that leads an individual to feel hurt. Furthermore, it will focus on the characteristics and consequences associated with hurtful communication between parents and adolescents.

Psychiatric disorders are highly prevalent in patients with migraine. Depression is at least three times more common among migraineurs than in the general population. The depression-migraine relationship is bidirectional, with each disorder increasing the risk for the onset of the other. Depression-Migraine comorbidity is a major health concern as it results in poorer prognosis, remission rate, and response to treatment. Acceptance and Commitment Therapy (ACT) is an empirically based behavioral therapy that incorporates acceptance and mindfulness strategies with behavioral change strategies. ACT is effective in treating psychiatric disorders like depression and anxiety and in improving outcomes of chronic medical conditions. Importantly, ACT has resulted in positive outcomes even when presented in brief form. Method: Patients with migraine completed an assessment of psychiatric symptoms and functioning. Those meeting criteria for depression were assigned to a 1-day ACT + illness management (ACT-IM) group intervention or to a Wait List Control. Each ACT-IM group included 4-10 patients and lasted 5-6 hours. Three broad areas of Behavioral Change Training, Mindfulness and Acceptance, and Illness Management were covered. Assessment of psychiatric symptoms, functioning, and migraine frequency were completed at 2-, 6-, and 12 weeks post-intervention. Results: Patients in the treatment group showed greater reduction in depressive symptoms and greater improvement in migraine-related quality of life than patients in the wait-list group.

Approximately 355,000 patients with end-stage renal disease receive treatment with center hemodialysis. The management of this chronic condition requires patients to adhere to a restrictive fluid and dietary regimen. Despite the deleterious effects of nonadherence, 40-60% of patients have difficulty limiting their fluid intake. The current study was designed to test the efficacy of a behavioral intervention for improving fluid-intake adherence among hemodialysis patients. Individuals who demonstrated a consistent pattern of nonadherence (i.e., fluid weight gains over the recommended 2.5kg between treatments for at least one month) were recruited from hemodialysis centers across the state of Iowa. Interested patients were randomized to a Self-Regulation intervention or a Support & Discussion attention placebo control group. Conditions were balanced such that both included 7 one hour weekly meetings in groups of 3-8 patients led by trained master’s level clinicians. The focus of the intervention group was on reducing fluid-intake, and self-regulation techniques (monitoring, goal-setting and reinforcement) were used. In contrast, the control group provided psychoeducation, support, and discussion of issues related to managing renal disease, excluding the specific behavioral techniques taught to intervention patients. Fluid weight gains were the primary outcome measure, and these values were collected at pre- and post-treatment, as well as 3 and 6 months following the end of the intervention.

The suprachiasmatic nucleus (SCN) modulates circadian rhythms via direct neural connections and humoral factors. Here we explore the development of these influences on sleep and wakefulness in infant rats. To remove direct neural connections from the SCN to downstream brainstem structures, we performed precollicular transections at P2 and P8. In an additional experiment, we lesioned the SCN at P1 and tested pups at P2. In all experiments, sleep and wakefulness were monitored by measuring nuchal muscle activity during the day and night. Although precollicular transections at P2 did not alter day-night differences in sleep and wakefulness, transections at P8 did eliminate day-night differences in sleep and wakefulness. In contrast with transections, SCN lesions eliminated day-night differences in sleep and wakefulness in pups tested at P2. These results suggest that direct neural connections from the SCN appear to gain control over brainstem structures in the first postnatal week. Finally, to explore the influences of the SCN on ultradian and circadian rhythms after direct neural connections to downstream structures have been established, we lesioned the SCN at P8 and tested pups at P15 and P21. As we have found previously, control subjects exhibited nocturnal wake behavior and power-law distributions of wake bout durations whereas subjects with SCN lesions exhibited a lack of circadian rhythmicity and an exponential distribution of wakefulness. Altogether, these results suggest that neural connections from the SCN develop over the first postnatal week, and after this connectivity becomes established the SCN is also necessary for the normal expression of power-law wake behavior.

Angela Fagerlin, Center for Behavioral and Decision Sciences in Medicine, University of Michigan, and Ann Arbor VA HSR&D, will present a Psychology department colloquium on March 4th:

Patients making medical decision are often plagued by poor numeracy (i.e., inability to understand and work with numbers) and their decisions are often affected by traditional heuristics and biases. In this talk, I will describe how biases (e.g., framing) affect patient decision making and discuss strategies to reduce these biases. Much of the research discussed will be in the context of cancer risk communication.

Humans have a difficult time performing two distinct tasks simultaneously. Dual-task studies conducted in laboratory settings have been used to test the limitations of the cognitive mechanisms that underlie response selection, and the decrements in performance that arise from doing two tasks at the same time are often interpreted as reflecting the operation of at least one stage of processing that cannot be shared by two concurrent tasks (Pashler, 1994). This stage is usually referred to as a processing bottleneck, which some researchers have used to suggest that humans can never actually carry out two tasks at the same time. Although dual-task costs are very robust and can be found in many different situations, a small number of studies have shown evidence of two tasks being performed concurrently without performance suffering in either task. Among these are tasks that use ideomotor-compatible stimuli, which have led some researchers to argue that there are a few situations in which perfect time-sharing can be achieved within a single session (Greenwald, 2003). However, these findings have been disputed in recent publications (see e.g. Lien, Proctor and Ruthruff, 2003). In a series of experiments, we tested the way in which task structure affects dual-task performance by manipulating whether or not an SOA was used, the type of instructions participants received and the type of ideomotor-compatible stimuli. We also included mixed blocks in which only one stimulus was presented on each trial, but participants did not know which task would be presented on a given trial. In general, RTs were shortest for single-task blocks, but there were no significant differences between the dual-task blocks and the mixed blocks. These results suggest that typical dual-task costs might arise from task structure rather than response limitations.

The affect regulation model of binge eating, which posits that patients binge eat to reduce negative affect (NA), has received support from cross-sectional and laboratory-based studies. Ecological momentary assessment (EMA) involves momentary ratings and repeated assessments over time and is ideally suited to identify temporal antecedents and consequences of binge eating. This meta-analytic review includes EMA studies of affect and binge eating. Electronic database and manual searches produced 36 EMA studies with N = 968 participants (89% Caucasian women). Meta-analyses examined changes in affect before and after binge eating using within-subjects standardized mean gain effect sizes (ES). Results supported greater NA preceding binge eating relative to average affect (ES = .63) and affect before regular eating (ES = .68). However, NA increased further following binge episodes (ES = .50). Preliminary findings suggested that NA decreased following purging in Bulimia Nervosa (ES = -.46). Moderators included diagnosis (with significantly greater elevations of NA prior to bingeing in Binge Eating Disorder compared to Bulimia Nervosa) and binge definition (with significantly smaller elevations of NA before binge versus regular eating episodes for the DSM definition compared to lay definitions of binge eating). Overall, results fail to support the affect regulation model of binge eating and challenge reductions in NA as a maintenance factor for binge eating. However, limitations of this literature include unidimensional analyses of NA and inadequate examination of affect during binge eating as binge eating may regulate only specific facets of affect or may reduce NA only during the episode.

When people talk, they gesture. We now know that these gestures are associated with learning. They can index moments of cognitive instability and reflect thoughts not yet found in speech. What I hope to do in this talk is raise the possibility that gesture might do more than just reflect learning -- it might be involved in the learning process itself. I consider two non-mutually exclusive possibilities. First, gesture could play a role in the learning process by displaying, for all to see, the learner's newest, and perhaps undigested, thoughts. Parents, teachers, and peers would then have the opportunity to react to those unspoken thoughts and provide the learner with the input necessary for future steps in mastering the problem. Second, gesture could play a role in the learning process more directly by providing another representational format, one that would allow the learner to explore, perhaps with less effort, ideas that may be difficult to think through in a verbal format. Thus gesture has the potential to contribute to cognitive change directly by influencing the learner and indirectly by influencing the learning environment.

There will also be a roundtable discussion with Professor Goldin-Meadow on Friday morning, 9:00-10:30 a.m., in 120 SLP.

Dorsal temporal pole (dTP), a cortical region at the rostral portion of the superior temporal gyrus, has been associated with auditory perception for complex sound stimuli (Poremba and Mishkin, 2007; Olson et al., 2007), and it is particularly sensitive to species-specific vocalizations in humans and monkeys (Belin et al., 2002; Poremba et al., 2004). Evidence related to neural mechanisms of auditory processing and memory function is less well-known for dTP compared to other auditory association areas. The present study employed single-unit recording techniques to examine neuronal activity of dTP when two monkeys performed an auditory version of a delayed matching-to-sample (DMTS) task. Results show that dTP encodes various task-related events during the DMTS task, cue presentations, memory delays, behavioral responses, and food rewards. Population response to sample stimuli is crucial for correct memory performance, regardless of match and nonmatch rules. Importantly, dTP showed effects of match suppression to familiar sound stimuli when monkeys correctly identified two matching sounds. Delay-related activity revealed in dTP was short-lived and irregular. During passive listening, neurons of dTP were sound-selective, and mostly responsive to up to four sound stimuli although no strong relationship was identified between unit responsiveness to sounds and acoustic properties of sounds estimated from spectral and amplitude envelopes. Current findings suggest that dTP is a higher-order region for auditory processing, and it is compatible to a hierarchical organization of information flow in the auditory nervous system of non-human primates. Dorsal temporal pole demonstrates match suppression in the current recognition memory task, similar to the activity observed in the visual object identification pathway located more ventrally than dTP, inferior temporal cortex and ventral temporal pole. However, sustained delay activity, one of the important hallmarks for models of visual working/short-term memory, is very limited and transient in dTP. It may therefore provide preliminary evidence for why monkeys have less robust auditory memory and short thresholds of forgetting, compared to their visual memory functions.

Child informants routinely participate in forensic and social service investigations and are often a critical source of information. However, across research domains high levels of discrepancy between parents' reports and children's reports have been documented, which has led researchers to question children's abilities to provide accurate information about others' behavior. To date research examining parent–child discrepancies has focused on discrepancies in reports of child behavior. The aim of the present review is to examine children's abilities to provide veridical accounts of parental behaviors, drawing on developmental and clinical research to delineate factors likely to enhance or impede accuracy. Among the factors examined, age appears to have the strongest influence on the accuracy of children's reports in general. A clear distinction also emerged in the literature between children's abilities to report objective data versus information regarding abstract concepts. Although available evidence provides mixed support for the veridicality of children's reports of parenting, factors that influence children's accuracy have generally been overlooked. Namely, researchers have largely failed to discriminate between assessment of child-rearing behaviors and children's perceptions of those behaviors. The present review proposes that such failure likely accounts for a notable portion of parent–child discrepancies in reports of parenting.

Considerable evidence demonstrates that manipulation of the endocannabinoid system regulates nausea and vomiting in humans and other animals. Recently, animal evidence suggests that cannabinoids may be especially useful in treating the more difficult to control symptom of nausea which is less well controlled by the currently available conventional pharmaceutical agents. Although rats and mice are incapable of vomiting, they display a distinctive conditioned gaping response when re-exposed to cues (flavors or contexts) paired with a nauseating treatment. Direct and indirect cannabinoid agonists suppress conditioned gaping reactions (nausea-like behavior) in rats as they suppress vomiting in emetic species. Inverse agonists, but not neutral antagonists, of the CB1 receptor promote nausea, and at subthreshold doses potentiate nausea produced by other toxins (LiCl). The primary non-psychoactive compound in cannabis, cannabidiol (CBD), also suppresses nausea and vomiting within a limited dose range. Preclinical research indicates that cannabinioids, including CBD, may be effective therapeutic agents for treating both nausea and vomiting produced by chemotherapy treatment or produced by other therapeutic treatments. Considerable evidence demonstrates that manipulation of the endocannabinoid system regulates nausea and vomiting in humans and other animals. Recently, animal evidence suggests that cannabinoids may be especially useful in treating the more difficult to control symptom of nausea which is less well controlled by the currently available conventional pharmaceutical agents. Although rats and mice are incapable of vomiting, they display a distinctive conditioned gaping response when re-exposed to cues (flavors or contexts) paired with a nauseating treatment. Direct and indirect cannabinoid agonists suppress conditioned gaping reactions (nausea-like behavior) in rats as they suppress vomiting in emetic species. Inverse agonists, but not neutral antagonists, of the CB1 receptor promote nausea, and at subthreshold doses potentiate nausea produced by other toxins (LiCl). The primary non-psychoactive compound in cannabis, cannabidiol (CBD), also suppresses nausea and vomiting within a limited dose range. Preclinical research indicates that cannabinioids, including CBD, may be effective therapeutic agents for treating both nausea and vomiting produced by chemotherapy treatment or produced by other therapeutic treatments.

The psychosocial context in which a mother attempts to parent her child has regularly been found to predict the mother's appraisal of the parenting process. Negative life events and lack of social support in particular have shown associations with increased parenting stress. This study aimed to address the reliance of previous research on self-report measures of stress and support, and to test the role of negative affect as a mediator. A total of 150 women with toddlers completed interviews on life adversity, social support, psychopathology, and attitudes towards parenting as well as self-report measures of negative affect and parenting stress. Structural equation modeling showed that life adversity over the past 6 months was positively associated with parenting stress and that this association was entirely mediated by negative affect. Social support was not directly associated with parenting stress but moderated the association between adversity and negative affect. The role of affect and environmental circumstances in determining parenting stress are discussed

Cancelled due to weather. Check back for re-scheduled time.

In our society, the psychological stress (the anticipation of threats to homeostasis), such as the possibility of losing one’s job and then one’s home, can be protracted and without physical stress ( a direct threat to homeostasis). To develop a better understanding of the neural and behavioral consequences of prolonged psychological stress, we have developed a rodent model of stress that is restricted to psychological stress and excludes physical stress. In the model, rats have the ability to control their approach to a position of threat, but cannot predict the timing of threat. I will present data illustrating the need for such a model, data to validate the model, and the behavioral consequences of the model. The behavioral consequences of our model raise the possibility that resilience may occur at a cost to memory.

How does attention know where to go in a complex visual scene? Theories of attentional control have divided control into a stimulus-based component and a goal-based component, and much of the literature has been devoted to debating which component is most important. Recent work from my laboratory has examined control from orthogonal directions, asking how attentional control (capture) is affected by perceptual load (complexity) and learning or experience (contingency). Our findings indicate that attentional capture can be eliminated in complex, high perceptual load displays. But a supression of capture depends on experience, suggesting a new dimension to consider in attentional control. I hypothesize that with little experience, attentional control is stimulus driven, but control shifts to goal driven as task parameters are learned through experience with visual displays.

Maternal responsiveness has been shown to influence many aspects of children’s behavior during development. In particular, sensitive maternal responses have been associated with positive developmental outcomes in socioemotional, attentional, linguistic and cognitive development. Specific to language development, maternal responses have been shown to affect phonological, vocabulary and pragmatic development. Few studies have examined paternal responsiveness, and of those that have, most are qualitative and do not consider parallel influences of mothers and fathers on development. The purpose of this study was to determine if fathers and mothers respond differently to infants’ vocalizations and whether caregiver responses differentially relate to language and early communicative development. We observed mothers and fathers with their infants (10 and 12 months) in free play interactions to examine differences in infant vocal behavior (vocal type and directedness) with mothers and fathers. In addition, caregiver responses to vocalizations (overall levels and styles) were compared. Preliminary analyses indicate that mothers and fathers showed distinct styles, but similar levels, of responsiveness to infant vocalizations. We are currently examining the relationship between styles of responding and language measures on the MCDI.

Although learning of phonological word forms is important for mastering a language, little is known about the factors influencing it. We examined such factors by comparing phonological word form learning in two typical learning situations: learning novel word forms through incidental exposure to the word forms alone, without any referents (incidental word form learning); and learning novel word forms as the labels for referents (deliberate word learning). Phonological word form learning as measured by stem completion ability was found to be better in the second than in the first situation. We then systematically examined the effects of key task differences between these two situations, as a means of identifying factors influencing phonological word form learning. The variables examined included: deliberate memorization; the availability of a unique associate to a word form; treatment of the visual image as the referent of a word form; and testing. The results are discussed in terms of what they suggest about the processes involved in the learning of phonological word forms.

Since species-typical behavior emerges from complex developmental interactions, studying the ontogeny of circadian rhythms in animals with opposing phenotypes may provide insight into evolutionary mechanisms that contributed to their development. Whereas progress has been made in our understanding of the development of sleep-wake rhythms in nocturnal Norway rats (Rattus norvegicus), less is known about their development in diurnal rodents. Here we analyzed the ontogeny of day-night differences in sleep-wake behavior and Fos-immunoreactivity (IR) in diurnal Nile grass rats (Arvicanthis niloticus) and nocturnal Norway rats. Grass rats expressed diurnal wakefulness as early as P2. Additionally, they exhibited a dramatic increase in daytime wake bout durations at P15 that was mirrored by the development of increased nighttime Fos-IR in the ventral subparaventricular zone (vSPVZ), a region implicated in the control of phase preference. Contrastingly, the emergence of nocturnal wakefulness at P15 in Norway rats was mirrored by a significant increase in daytime Fos-IR in vSPVZ. Finally, developmental emergence of retinal projections to structures involved in the circadian modulation of wakefulness was analyzed after invitreal injections of fluorescently labeled anterograde tracer. We found that labeling in vSPVZ of Norway rats followed a similar developmental trajectory as nocturnal wakefulness, whereas grass rats showed little or no labeling in vSPVZ across development. Apparently, vSPVZ plays an antagonistic role on wakefulness as it becomes more active during each species inactive phase. Additionally, retinal projections to vSPVZ in Norway rats, and their virtual absence in grass rats, represents a developmental and anatomical difference that may be fundamental to species differences in phase preference.

Sodium is the body’s most abundant extracellular ion. This ion serves as the "backbone" for the body's interstitial and vascular fluids, and its extracellular concentration is largely responsible for establishing the distribution between the cellular and extracellular fluid compartments. The process of evolution has given rise to numerous physiological and behavioral control mechanisms to ensure consistency in the balance and distribution of sodium in the body. Dysregulation of sodium can lead to numerous physiological and psychological disorders. In the early history of humans, problems of sodium deficiency were more serious than those of excess. Humans evolved in an environment bereft of sodium. As a consequence, there was great selection pressure for both physiological mechanisms to minimize sodium loss, a sensory modality that could identify sources of sodium and behavioral systems that could respond by initiating salt seeking and ingestion, particularly in states of deficit. The state of salt associated with the sensing of a sodium deficit and the activation of behaviors to acquire and ingest salty substances is present in many species and is defined as salt appetite. The generation of salt appetite requires the neural integration of different types of information arising from various body sources. In effect, salt appetite is a perceived need that arises as a result of a synthetic process. With regard to salt appetite, the current presentation will first describe the nature of the information the brain receives and where it is processed to generate the motivational state of salt appetite. Then the discussion will turn to a more detailed presentation of new research implicating brain systems not usually associated with body fluid and cardiovascular homeostasis. These systems involve brain structures and pathways more typically associated with reward and mood. These affect-related neural systems are likely to play greater pivotal roles in generating the powerful motivation to seek and ingest salt. This motivational state of salt appetite coupled with the pleasure of ingesting sodium when it is perceived to be needed may in large part account for why salt may be the world’s most abused substances and consumed in quantities far in excess of that necessary to satisfy homeostatic needs.

The purpose of this study is to examine whether a social partner’s eye gaze would influence children’s pro-social behaviors. We presented forty-eight children (half of them were 3-4 years old, and the other half were 5-6 years old) with two tasks (choosing task and sorting task) under two gaze conditions. In the choosing task, children could choose between two allocations, and decide to deliver stickers to themselves only, or to both themselves and another person. In the sorting task, the participant divided stickers into two piles, one for themselves, and one for another person. The potential recipient either alternated her eye gaze between the child and the stickers, or did not look to the child. Results showed that eye gaze influenced 3-4-year-old children to be more likely to make pro-social choices in the choosing task, and 5-6-year-old children to share more stickers in the sorting task. However, no significant effects of eye gaze were found in older children’s choices in the choosing game and younger children’s distribution in the sorting game. In addition, in a final task, the experimenter chose between two allocations as the child did before. Children who had been influenced by eye gaze were more likely to exchange eye gaze with the experimenter. The results suggest that eye gaze affects children’s pro-social behaviors, but that this interacts with children’s age and task formats. The related ability to understand the meaning of eye gaze, and the competitive nature of the tasks are discussed.

The schedule of speakers for this year will soon be available on the web at: http://www.psychology.uiowa.edu/events/ If you are interested in presenting at the Lunchtime Brown Bag, please contact Susan Wagner Cook: susan-cook@uiowa.edu.