2023-2024 Psychology Department
Colloquium Speaker Series

presents

Lindsey Glickfeld
Associate Professor of Neurobiology
Duke University

Synaptic Mechanisms for Normalization
in the Visual Cortex

Normalization, or the rescaling of neural activity to account for the total input, is a fundamental computation that is performed at each stage of sensory processing to maintain activity within the appropriate dynamic range. While there is strong foundational knowledge about the kinds of normalization that occur in the visual system, the underlying circuit and synaptic mechanisms are largely unknown. In this talk I will discuss two fundamental forms of normalization: adaptation and contrast gain. First, we investigate the mechanisms underlying rapid adaptation in primary visual cortex (V1). Neurons in L2/3, but not in L4, are exquisitely sensitive to recent experience, such that even a 100 ms stimulus can suppress responses to similar stimuli for seconds. We find that these brief visual inputs drive a balanced reduction in both excitation and inhibition due to short-term depression at the L4 to L2/3 synapse. This mechanism allows for stimulus-specific input normalization in L2/3 that is engaged at short timescales, whereas a less selective output normalization is imposed after prolonged adaptation. Second, we investigate the circuit and synaptic mechanisms underlying contrast gain control in primary visual cortex. Inhibition stabilized networks have long been proposed to mediate gain control as sensory inputs increase, yet under what conditions these networks are recruited is unknown. Using a novel cell-type specific pharmacological approach to block AMPA receptors on somatostatin expressing interneurons, we find that inhibition stabilization increases as a function of both contrast and behavioral state. Together, these studies provide a mechanistic understanding of sensory normalization in V1.

Monday, January 22, 2024
12:30-1:45pm
390 Gilmer Hall

2023-2024 Psychology Department
Colloquium Speaker Series co-sponsored by the School of Education
and Human Development and the UVA Grand Challenge

presents

Candice Odgers
Associate Dean for Research and Professor of
Psychological Science and Informatics
University of California, Irvine

The Science behind the Story of Teen Mental
Health and Digital Technology Use

Adolescents spend much of their lives online and fears are high that digital technology use, and social media in particular, is harming their social and emotional development. The narrative around social media and adolescent development has been negative, but, surprisingly, the empirical support for the story of increased deficits and disconnection is limited. This talk will synthesize findings from large-scale reviews of the associations between digital technology use and adolescent well-being and present new findings from our large-scale longitudinal study of adolescents followed daily via their mobile devices. Recommendations for next steps for improving science and practice for young people growing up in an increasingly digital and uncertain age will be provided.

Monday, January 29, 2024
12:30-1:45pm
390 Gilmer Hall

Candice Odgers is Associate Dean for Research and Professor of Psychological Science and Informatics at the University of California Irvine. She currently Co-directs the Child & Brain Development Program at the Canadian Institute for Advanced Research and CERES, an international network working to enhance evidence-based and developmentally informed design and evaluation of new technologies for children and adolescents. Her team has been capturing the daily lives and mental health of adolescents using mobile phones and sensors for more than a decade. Odgers is the author of over 100 peer-reviewed publications and her research has been disseminated widely outside of academia. More information about her work can be found on adaptlab.org.

2023-2024 Psychology Department

Colloquium Speaker Series

presents

Laura Bustamante

 Postdoctoral Fellow

 Washington University in St. Louis

Computational Approaches to Individual Differences in Cognitive Control and Effort-based Decision Making

Cognitive control is foundational to positive life outcomes. Enhancing cognitive control to support individuals in achieving their goals has long been an objective in psychological research. This objective has remained elusive, with interventions typically targeting cognitive control ability. My research focuses on a promising alternative target for intervention; willingness to exert cognitive effort. I will present results from three studies using a novel individual differences measure of effort costs (i.e., avoidance). The Effort Foraging Task embedded cognitive or physical effort into a patch foraging sequential decision task, to isolate and quantify the cost of both cognitive and physical effort using a foraging theory computational model. 

In the first study, we found that cognitive and physical effort costs were positively correlated in a large online sample, suggesting that these are perceived and processed in common terms. In the second study, surprisingly, we found that participants with greater overall symptoms of major depression were more willing to exert cognitive effort, but less willing to exert physical effort. In the third study we found that participants became more willing to exert cognitive effort under excitatory transcranial direct current stimulation to the frontopolar cortex, relative to sham. I will conclude with a discussion of the future directions for my laboratory, which aims to enhance cognitive control by targeting willingness to exert cognitive effort. My lab will accomplish this by investigating the computational and neural basis of inter-individual differences in cognitive control decision making, as well as intra-individual fluctuations in willingness to exert effort.

Wednesday, January 31, 2024

3:30pm

301 Gilmer Hall