Colloquia Series 2018-19

Monday, May 6th 2019

Speaker: Dr. Jenny Saffran, Dept. of Psychology, University of Wisconsin-Madison

Title: Acquiring and Predicting Structure via Statistical Learning

Abstract:  

Infant learners are sensitive to myriad statistical patterns in their environment. These regularities facilitate the acquisition of a range of representations and structures. They also facilitate the generation of expectations and predictions about the world. In this talk, I will describe a diverse array of infant studies, primarily focused on language, that examine the role of prior learning in the generation of expectations in downstream processing. Implications for atypical development will also be considered.

Monday, April 22nd 2019

Speaker: Dr. Liana Hone, Clinical, Social, & Evolutionary Psychology, University of Buffalo

Title: Alcohol Effects on Antecedents of Human Sexual Behaviour: How Do Men and Women Differ?

Abstract:  

Alcohol impairs several perceptual processes that are antecedents of sexual behavior. My aim is to characterize how alcohol differentially influences men’s and women’s perceptions using evolutionary theory to generate hypotheses. Sexual selection has contributed to the development of elaborate, sex-specific, metabolically-costly, cognitive abilities in sexually-reproducing species. Arguably, deficits occur in these domains when exposure to toxins (e.g., alcohol) divert limited resources away from the maintenance of sexually selected cognitive advantages. To test this idea, I examined chronic alcohol effects on women’s ability to quickly and accurately perceive displays of emotion in the faces of others (a sexually selected, typically female-specific perceptual skill). As predicted, heavy drinking was related to deficits in women’s facial emotion perception abilities. I further I found that women’s deficits in reaction times predicted their experiences of sexual aggression. To expand on this idea, I am conducting an alcohol administration study to test acute alcohol effects on men’s perceptions of women’s facial displays of emotion (i.e., sexual interest), both sober and following a high alcohol dose. Alcohol decreases some men’s use of facial displays of emotion and increases use of peripheral cues (i.e., a woman’s provocativeness of dress) when assessing women’s sexual interest. Data collection is ongoing and I predict men who are high in certain personality traits (i.e. sexually unrestricted) are most likely to exhibit decreased reliance on facial displays of women’s sexual interest when intoxicated. These tests of alcohol’s chronic and acute effects on men’s and women’s perceptions help us identify targets for prevention and intervention efforts.

Monday, 18th March 2019

Speaker: Dr. Matthew Paul, Dept. of Psychology, University of Buffalo

Title: Adolescence: Are Pubertal Hormones Really to Blame?

Abstract:  

Adolescence is a time of significant neural, hormonal, and behavioral change. Alongside pubertal development, adolescents undergo remarkable development in social, emotional, and reward-associated behaviors. Many of these changes are initiated by increases in pubertal hormones (puberty-dependent), whereas others occur independently of pubertal hormone activation (puberty-independent). Disentangling puberty-dependent and puberty-independent development, however, is difficult because in most species they proceed concurrently. My lab has developed a new model that takes advantage of seasonal adaptations of Siberian hamsters to investigate puberty-dependent and puberty-independent influences on adolescent development. Siberian hamsters reared in a short, winter-like daylength (SD) delay puberty by several months compared to those reared in a long, summer-like daylength (LD), in order to synchronize breeding with the following spring. Hence, in this species daylength can be used as a tool to control the timing of puberty. Using this model, we asked whether delaying puberty also delays the behavioral and neural changes that occur during adolescence: e.g., social (social play and social interactions), affective (anxiety-like behaviors), and reward-associated (novelty-seeking) behaviors as well as dopamine innervation of the prefrontal cortex. Our data indicate that puberty-dependent and puberty-independent factors regulate different components of the developmental profile of adolescent-typical behaviors. In addition, these experiments uncovered an unexpected role for the prepubertal ovary in juvenile behaviors. This finding adds to the growing body of evidence that challenges the notion that the prepubertal ovary is functionally quiescent. Further research using this model will begin to map puberty-dependent and puberty-independent neural circuits and specify how they interact to regulate adolescent development.

Monday, January 28th 2019

Speakerr: Dr. Rosemary Bagot, Dept. of Psychology, McGill University

Title: Circuit Mechanisms of Stress Susceptibility

Abstract:  

Evidence in both humans and animals point to dysregulated circuit function in depression, but the molecular mechanisms are unknown. Recent functional studies suggest that opposing alterations in prefrontal cortex and ventral hippocampus regulate resilience and susceptibility to chronic social defeat stress (CSDS), a highly validated mouse model of depression. Integrative network analysis of a large-scale RNA-sequencing data set from multiple brain regions in control, susceptible and resilient mice identified transcriptional networks that regulate susceptibility or resilience in distinct brain regions. In vivo manipulations of multiple key regulators confirmed the functional significance of these networks by assessing the effects of viral-mediated over-expression of identified network hub-genes in mice exposed to CSDS on depression associated behavioral assays, electrophysiological assays of synaptic function and transcriptional regulation of gene networks. These results demonstrate that states of resilience and susceptibility are driven by distinct circuit-level transcriptional networks and confirm the utility of a systems biology approach in identifying novel transcriptional mechanisms of stress susceptibility and resilience that may offer new targets to reverse susceptibility or induce resilience.

Monday, November 19, 2018

Speaker: Dr. Cheryl Sisk, Neuroscience Program, Michigan State University 

Title: Not The Usual Place & Time: New Neurons & Glia Are Added To Sexually Dimoprhic Brain Regions During Puberty

Abstract:  

There is growing evidence that postnatally born neurons and glial cells are added to the rodent hypothalamus and amygdala. My talk will focus on the pubertal addition of cells to the anteroventral periventricular nucleus (AVPV) and posterodorsal medial amygdala (MePD), two sexually dimorphic cell groups that contribute to sex differences in reproductive function and social behaviors. Using BrdU as a cell birthdate marker, we initially observed sex differences in the pubertal addition of new cells that parallel sex differences in AVPV and MePD volume in rats: more pubertally born cells are added to the AVPV in females, whereas more are added to the MePD in males. These sex differences are eliminated by prepubertal gonadectomy, indicating that gonadal hormones drive sex differences in the pubertal maturation of AVPV and MePD. Using tfm mice that lack functional androgen receptors, we found that the sex difference in pubertally born MePD cells is androgen receptor-dependent. Other experiments investigated whether pubertally born cells are functionally incorporated into neural circuits mediating sex-specific behaviors. These experiments provide evidence that pubertally born AVPV cells contribute to the ovarian-hormone induced LH surge in female rats, and that pubertally born MePD cells are are activated by social interactions in male hamsters and mice. We propose that the pubertal addition of new neurons and glia to sexually dimorphic cell groups is a potential mechanism underlying adolescent maturation of sex-specific reproductive function and social behaviors.

Monday, October 15, 2018

Speaker: Dr. Andrew Leber, Department of Psychology, Ohio State University

Title: Toward An Individual Profile of Goal-Directed Attention Control

Abstract:  

As humans, we are tremendously adept at controlling how we perceive the world around us.  We can choose to strategically attend to red things, round things, moving things, etc., and the choices we make effectively determine the world we experience.  While decades of research have focused on cataloging and quantifying the various attentional control abilities at our disposal, the choice part of the process has been largely understudied.  That is, how do people decide which attentional strategy to use?  Consider that lab studies typically tell people which strategy to use, which leaves much to be desired: first, participants may fail to comply, and, second, this lacks ecological validity, as we rarely are provided instructions when confronting the sensory environment in our daily lives.  To begin to address the question of choice and attentional control, we recently created the Adaptive Choice Visual Search paradigm.  In this paradigm, observers can freely choose between two search strategies on each trial, while we vary the relative efficacy of each strategy.  That is, on some trials it is faster to use the “search for red” strategy than the “search for blue” strategy, while on other trials the opposite is true.  Results using this paradigm have shown that choice behavior is far from optimal, and it appears largely determined by competing drives to maximize performance and minimize effort.  Further, individual differences in performance are stable across sessions while also being malleable to experimental manipulations that emphasize one competing drive (e.g., reward, which motivates individuals to maximize performance).  This research represents an initial step toward characterizing an individual profile of goal-directed control that extends beyond the classic understanding of attentional abilities and promises to contribute to a more accurate framework of attentional control.

Monday, September 10, 2018 

Speaker:  Dr. David Samson, Assistant Professor of Anthropology, University of Toronto Mississauga 

Title: Wild Nights: Sleep and Human Evolution 

Abstract:  

What does how you sleep have to do with human evolution? Our immune strength, working memory, attention, decision-making, and visual-motor performance all depend on sleep. How then could elders’ insomnia and teenagers’ penchant for staying up late have evolved?

Find out at this free public lecture by sleep anthropologist David Samson, whose work has been featured on the BBC, Time, the New York Times, New Scientist, and the CBC. Dr. Samson describes his research using pioneering, non-invasive technology to study sleep across human cultures and primate species to answer evolutionary questions.

 


More information:
Mahnoor Mukhtar (mahnoor.mukhtar@utoronto.ca)