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CBB talk series

The Cognitive Brown Bag (CBB) is a graduate student organized talk series, primarily attended by the faculty, graduate students, and staff from the cognitive labs at Dartmouth College. The talks are typically held on Thursdays from 12:15-1pm, in Moore 302.

 Spring 2019

 

 Speaker

 Title

 Abstract

 Wed, Apr 10

 

 

 

 

Shih-Wei Wu, National Yang-Ming University

Probability estimation and its neurocompuational substrates

Many decisions we make depend on how we evaluate potential outcomes and estimate their probabilities of occurrence. Outcome valuation is subjective – it requires consulting the decision maker’s internal preferences and is sensitive to context. Probability estimation is also subjective – but requires the decision maker to first extract statistics from the environment before using them to estimate probability. Currently, it is unclear whether the two computations share similar algorithms and neural-algorithmic implementations.

I will present our recent work on context-dependent probability estimation, which we identified both similarities and differences in computational mechanisms between valuation and probability estimation. I will also talk about work on modeling probability estimation as Bayesian inference, which focuses on examining how and how well people estimate probability of reward in the presence of prior and likelihood information. Here we found suboptimal performance similar to base-rate neglect, which surprisingly is robust across a wide variety of setups that try to eliminate this behavior. Together, these results suggest many interesting aspects of probability estimation that have yet to be fully understood at the behavioral, computational, and neural algorithmic levels.

Thurs, Apr 18

 

 

 

 

Sarah Herald, Dartmouth College

 

What is the role of the left-hemisphere face areas?

Over the past two decades, neuroimaging studies have revealed a bilateral network of face-selective areas. Despite the presence of left hemisphere face areas, only a few cases of acquired prosopagnosia (AP) resulting from left hemisphere damage have been reported, and most of those cases involved left-handed individuals. Indeed, almost all cases of AP result from unilateral right or bilateral hemisphere damage. Given the apparent right-hemisphere dominance of face-processing from the lesion literature, what might be the role of the left hemisphere face areas? I will review the lesion, neuroimaging, microsimulation, and intracranial recording literature to summarize our current understanding, or lack thereof, about the left hemisphere face areas. Additionally, I will provide suggestions for how future face perception studies can better address the shortcomings of prior studies and fill in the gaps in our knowledge. 

Thurs, May 2

 

 

 

 

Vassiki Chauhan, Dartmouth College

 

 Acquisition of person knowledge is pivotal for carrying out successful social interactions. Not only do we need to recognize people in different environments and circumstances, we also need to efficiently integrate information about them across different modalities. In my presentation, I will go over a range of approaches we have employed to investigate the system for recognizing familiar individuals. First, I will discuss the dominant theories about person knowledge and share some empirical evidence for prioritized processing of faces of familiar individuals. I will also share some recent neuroimaging results probing the recognition of identities across different modalities. Then, I will present preliminary neuroimaging results from a sample of children who were born blind but whose sight has been recently restored, allowing us to investigate how the face processing network evolves over time. Finally, I will go over the possibility of using naturalistic stimuli in order to identify common face selective regions in the brain across different participants.

 

Thurs, May 23

     

 

 

Kay Alfred, Dartmouth College

   

 

 

 Shiva Ghaanifarashahi, Dartmouth College

   

Thurs, May 30

     

 

 

Malinda McPherson, Harvard University

Multiple pitch mechanisms in music and speech perception

Pitch conveys critical information in speech, music and other natural sounds, and is conventionally defined as the perceptual correlate of a sound's fundamental frequency (F0). Although pitch perception is widely assumed to rely on a single F0 estimation process, real-world pitch tasks vary enormously, raising the possibility of underlying mechanistic diversity. I will present evidence that at least two different pitch mechanisms can be dissociated across tasks. One mechanism appears to help listeners summarize the frequencies of sounds with their F0, creating a compact code for memory storage. I will also discuss the use of singing to confirm and extend these results in populations where traditional psychophysical judgments may be difficult to elicit (e.g. young children or remote cultures without formal educational systems).

 Winter 2019

 

 Speaker

 Title

Feb 21

 

 

 

Sarah Oh, Dartmouth College

 

Mar 14

   
 

Jonathan Freeman, NYU

More than meets the eye: Split-second social perception

Mar 21

   
 

Lucy Owen, Dartmouth College

Decrypting the neural code

Last Updated: 5/14/19