Cognitive Psychology Commons^™

One Giant Leap For Categorizers: One Small Step For Categorization Theory, David J. Smith, Shawn W. Ell

Psychology Faculty Scholarship

We explore humans’ rule-based category learning using analytic approaches that highlight their psychological transitions during learning. These approaches confirm that humans show qualitatively sudden psychological transitions during rule learning. These transitions contribute to the theoretical literature contrasting single vs. multiple category-learning systems, because they seem to reveal a distinctive learning process of explicit rule discovery. A complete psychology of categorization must describe this learning process, too. Yet extensive formal-modeling analyses confirm that a wide range of current (gradient-descent) models cannot reproduce these transitions, including influential rule-based models (e.g., COVIS) and exemplar models (e.g., ALCOVE). It is an important theoretical conclusion …

Impaired Executive Function In Concussed Athletes, Marisa Gretz

Neuroscience Summer Fellows

Concussions are classified as mild traumatic brain injuries (mTBI). An individual that has sustained a concussion will experience symptoms such as nausea, possible memory loss, blurry vision, or loss of balance. Most symptoms subside within a few days, but a large pool of research raises concern for the recovery of executive function, specifically impulse control. Executive function relates to all tasks that require deliberate attention. Past research has shown adolescents record the highest number of sports concussions when compared to collegiate and professional athletes. The frontal lobe, which controls executive function, is not fully developed during the time of adolescence. …

An Exploratory High-Density Eeg Investigation Of The Misinformation Effect: Attentional And Recollective Differences Between True And False Perceptual Memories, John E. Kiat, Robert F. Belli

Department of Psychology: Faculty Publications

The misinformation effect, a phenomenon in which eyewitness memories are altered via exposure to post-event misinformation, is one of the most important paradigms used to investigate the reconstructive nature of human memory. The aim of this study was to use the misinformation effect paradigm to investigate differences in attentional and recollective processing between true and false event memories. Nineteen participants completed a variant of the misinformation paradigm in which recognition responses to true and misinformation based event details embedded within a narrative context, were investigated using high-density (256-channel) EEG with a 1-day delay between event exposure and test. Source monitoring …

Spike Field Coherence (Sfc) For Ripples In Rat Hippocampus, Pranav Singla

Honors Scholar Theses

The aim of this project was to determine coherence between two types of neural recordings which can be obtained from the rat hippocampus: spikes and local field potentials. Extracellular recording makes it possible to determine spiking activity from individual neurons in the vicinity of the recording electrode. Local field potential recording gives a combined activity of many neurons (thousands) at once to determine an overall picture of the coordination of the cells in real time. Here we examine the relationship between these two signals, focusing on place cells which spike at their maximal rate only at certain positions in physical …

Design, Programming, And User-Experience, Kaila G. Manca

Honors Scholar Theses

This thesis is a culmination of my individualized major in Human-Computer Interaction. As such, it showcases my knowledge of design, computer engineering, user-experience research, and puts into practice my background in psychology, com- munications, and neuroscience.

I provided full-service design and development for a web application to be used by the Digital Media and Design Department and their students.This process involved several iterations of user-experience research, testing, concepting, branding and strategy, ideation, and design. It lead to two products.

The first product is full-scale development and optimization of the web appli- cation.The web application adheres to best practices. It was …

Electrophysiological Changes Of N100 Latency And Amplitude In Healthy Participants Performing The Jitter Orientated Visual Integration Task: A Multi-Block Design Study, Fariya Naz

University Scholar Projects

The present study investigated the differences in processing during visual integration in healthy adults. The visual N100 indexes early visual discrimination and in this case, was hypothesized to show differences in both latency and amplitude depending on the level of difficulty which corresponds to orientational jitter in a visual integration task. Four blocks with pseudo-random levels of jitter were presented to participants in the Jitter Oriented Visual Integration (JOVI) task. Results looking at the Oz channel showed significant reduction in amplitude in the visual N100 during the more difficult levels condition of the task. The multi-block design, originally expected to …

Prevalence Of Learned Grapheme-Color Pairings In A Large Online Sample Of Synesthetes, Nathan Withhoft, Jonathan Winawer, David M. Eagleman

Faculty Publications

In this paper we estimate the minimum prevalence of grapheme-color synesthetes with letter-color matches learned from an external stimulus, by analyzing a large sample of English-speaking grapheme-color synesthetes. We find that at least 6% (400/6588 participants) of the total sample learned many of their matches from a widely available colored letter toy. Among those born in the decade after the toy began to be manufactured, the proportion of synesthetes with learned letter-color pairings approaches 15% for some 5-year periods. Among those born 5 years or more before it was manufactured, none have colors learned from the toy. Analysis of the …

Belief About Nicotine Selectively Modulates Value And Reward Prediction Error Signals In Smokers, Xiaosi Gu, Terry Lohrenz, Ramiro Salas, Philip R. Baldwin, Alireza Soltani

Dartmouth Scholarship

Little is known about how prior beliefs impact biophysically described processes in the presence of neuroactive drugs, which presents a profound challenge to the understanding of the mechanisms and treatments of addiction. We engineered smokers' prior beliefs about the presence of nicotine in a cigarette smoked before a functional magnetic resonance imaging session where subjects carried out a sequential choice task. Using a model-based approach, we show that smokers' beliefs about nicotine specifically modulated learning signals (value and reward prediction error) defined by a computational model of mesolimbic dopamine systems. Belief of "no nicotine in cigarette" (compared with "nicotine in …