FALL 2015 Colloquia

Thursdays, 4:00 - 5:30 pm, Elliott N119

 

September 24

Jason Mattingley, University of Queensland

"What can evoked neural oscillations reveal about visual perception and selective attention?"

Perceptual, cognitive and motor processes often unfold over extended time periods, yet many studies in cognitive neuroscience are designed to measure brain activity in response to discrete and rather brief psychological events. Here I discuss various applications of an approach that uses electroencephalography (EEG) to measure steady-state evoked potentials (SSEPs) over prolonged timescales, from seconds to minutes. In a typical SSEP paradigm, several competing stimuli are flickered continuously, and their unique neural signatures are recovered from the EEG trace using frequency-based analyses. We have used such "frequency tagging" methods to assess various aspects of visual perception and selective attention, in health and disease. At the level of early visual perception, we have used frequency tagging to reveal the neural correlates of modal and amodal completion of visual surfaces. We have used analogous approaches to show that feature-based attention spreads to ignored locations during conjunction search, but not during unique feature search, and that this spread of attention reflects active enhancement of target-coloured items at irrelevant locations. Finally, we have adapted these paradigms to investigate anomalous visual processing in patients with attention deficits after stroke, and in individuals with retinal degeneration.

 

October 1

Moin Syed, Psychology, UofM

"Narrative Identity Development: How Memories Become Selves."

Despite the fact that stories are a fundamental part of human existence, they have historically received relatively little attention as a subject of empirical psychological study. In recent years, narrative psychology has become increasingly popular within developmental and personality psychology, particularly as applied to the study of identity development, or how individuals come to understand who they are and how they fit in the world. A fundamental claim of the narrative approach to identity is that memories of past events become internalized representations of the self via a family of cognitive processes termed autobiographical reasoning. In this way, autobiographical reasoning is viewed as a major mechanism of development from late adolescence though adulthood.

In this talk, I will provide some historical background on the emergence of the narrative approach to identity development and discuss some of the key contemporary issues in the field. I will then illustrate how I apply a narrative model to understand individual differences in how young people develop a sense of ethnic identity. Finally, I will discuss my current and future work on master narratives, a new frontier in narrative psychology focused on the stories created and maintained at the cultural level, versus the purely individual level.

Suggested readings:

• McAdams, D. P., & McLean, K. C. (2013). Narrative identity. Current Directions in Psychological Science, 22(3), 233-238.
• Syed, M. (2015). Theoretical and methodological contributions of narrative psychology to ethnic identity research. In C. Santos & A. J. Umaña-Taylor (Eds.). Studying ethnic identity: Methodological advances and considerations for future research (pp. 27-54). Washington, DC: American Psychological Association.

 

 

October 8

Maria Chait, Auditory Cognitive Neuroscience Lab, University College London

"How the brain discovers patterns in sound sequences"

Sensitivity to patterns is fundamental to sensory processing, perhaps particularly so in the auditory system, since most auditory signals only have meaning as successions over time. Indeed, accumulating evidence suggests that the brain is tuned to the statistics of sensory stimulation. However, the process through which these statistical regularities are discovered in the first instance has eluded investigation. In my presentation I will review recent brain imaging and psychophysics findings in my lab that suggest that the auditory brain is a well-tuned 'pattern seeker', continuously scanning the unfolding auditory input for regularities, even when listeners' attention is focused elsewhere. Our data demonstrate that listeners are remarkably sensitive to the emergence of complex patterns within rapidly evolving sound sequences, performing on par with an ideal observer model. Brain responses reveal online processes of evidence accumulation - dynamic changes in tonic activity precisely correlate with the expected precision or predictability of ongoing auditory input. Source analysis demonstrates an interaction between primary auditory cortex, hippocampus, and inferior frontal gyrus in the process of 'discovering' the regularity within the ongoing sound sequence.

Suggested background reading:

• Winkler I, Denham SL, Nelken I (2009) Modeling the auditory scene: predictive regularity representations and perceptual objects. Trends Cogn Sci 13(12):532–540.

 

 

October 15

Paul Schrater

"A fundamental Effiency/Flexibility trade-off in learning and decision making explains why habits are easy and knowledge is hard."

Our brains evolved under pressures and constraints that form cost-benefit trade-offs. One of the key trade-offs is between the costs of developing and maintaining flexible behavior and the costs of inflexibility in a variable-demand environment. I'll discuss how the architecture of the brain is designed to adaptably handle this trade-off and its neurophysiological and cognitive implications.

 

 

October 22

Kathleen Vohs

"What do people want? Everyday Temptations: An Experience Sampling Study on People and Their Desires"

Suggested readings:

• Hofmann W, Baumeister RF, Förster G, Vohs KD (2012) Everyday temptations: An experience sampling study of desire, conflict, and self-control. J Pers Soc Psychol, 102(6), 1318–1335. doi:10.1037/a0026545
• Hofmann W, Vohs KD, Baumeister RF (2012) What People Desire, Feel Conflicted About, and Try to Resist in Everyday Life (458 kb pdf). Psychol Sci, 23(6), 582–588. doi:10.1177/0956797612437426

 

 

October 29

Colin DeYoung

"Cybernetic Big Five Theory: Explaining the Psychological and Neurobiological Sources of Personality"

The Big Five emerged empirically as a descriptive model of personality structure. To increase scientific understanding of the Big Five now requires moving beyond description to the development of theories that explain the sources of these five personality dimensions. Cybernetics, the study of goal-directed, adaptive systems, is a promising framework for an integrative theory of personality. Cybernetic Big Five Theory attempts to provide a comprehensive, synthetic, and mechanistic explanatory model. Constructs that describe psychological individual differences are divided into personality traits, reflecting variation in the parameters of the evolved cybernetic mechanisms that govern common patterns of motivation, emotion, cognition, and behavior, and characteristic adaptations, representing goals, interpretations, and strategies defined in relation to an individual's particular life circumstances. Based on research in psychology and neuroscience, the theory identifies mechanisms in which variation is responsible for traits in the top three levels of a hierarchical taxonomy based on the Big Five and describes the causal dynamics between traits and characteristic adaptations.

Suggested readings:

• DeYoung CG (2014) Cybernetic Big Five Theory. J Res Pers, 56, 33-58.
• Allen TA, Deyoung CG (in press) Personality Neuroscience and the FFM, Widiger, T. A. (Ed.). Oxford Handbook of the Five Factor Model. New York: Oxford University Press.

 

 

November 12

Aldo Rustichini, Economics

"Intelligence and strategic behavior"

Intelligence affects the behavior of individuals in strategic situation. In strictly competitive games with a single Nash equilibrium the insight that subjects with higher intelligence play closer to the Equilibrium prediction is broadly true. In games where efficiency gains are possible the relation is much more complex, and individuals with higher intelligence seem to be able to coordinate on higher efficiency equilibria. We study in particular the issue of social outcomes of groups in games where these gains are possible; the systematic study of the link is provided in an experiment where two groups of subjects with different levels of intelligence, but otherwise similar, play a repeated prisoner's dilemma. Initial cooperation rates are similar, but increase in the groups with higher intelligence to reach almost full cooperation, while they decline in the groups with lower intelligence. Cooperation of higher intelligence subjects is payoff sensitive and not automatic: in a treatment with lower continuation probability there is no difference between different intelligence groups.

 

 

 

December 3

Yaoda Xu, Harvard University

"Multi-level and dynamic visual information representation in the human brain"

The human vision is fundamentally a reconstruction process. As reflected in the hierarchical structure of the human ventral visual system, complex visual inputs are broken down into simple features and then reassembled to form increasingly complex representations. Through this process, we gain access to visual information at multiple distinctive levels, such as lines, edges, parts, and objects. Yet at any given moment, we are able to navigate through these different levels of visual processing and extract information at the appropriate level for the task at hand. This highlights two important issues that are critical to understanding visual information processing in the human brain: (1) how are simple features combined to give rise to increasingly complex representations at multiple distinctive levels? And (2) how is the moment-to-moment goal-driven visual information processing accomplished? Using fMRI and multi-voxel pattern analysis, our research attempts to address these two questions by examining how parts, objects and ensembles are represented in the human ventral visual cortex and the role of the human parietal cortex in dynamic visual information representation.

 

 

December 10
This will be a discussion-format session as we debrief the semester's talks. We will discuss common themes and unifying threads across the talks; we will make note of interdisciplinary connections and practical applications of the research, whether they are already in place (i.e., the presenter talked about them) or there is a fruitful potential for them to be implemented. We will discuss how the talks and topic connect to our own interest and research, and we will share ideas and suggestions for fruitful, collaborative research. Attendance is required for registered students; everyone is welcome! Come with your ideas!