Psychology Commons^™

Mental Blocks: The Behavioural Effects And Neural Encoding Of Obstacles When Reaching And Grasping, Craig S. Chapman

Electronic Thesis and Dissertation Repository

The ability to adeptly interact with a cluttered and dynamic world requires that the brain simultaneously encode multiple objects. Theoretical frameworks of selective visuomotor attention provide evidence for parallel encoding (Baldauf & Deubel, 2010; Cisek & Kalaska, 2010; Duncan, 2006) where concurrent object processing results in neural competition. Since the end goal of object representation is usually action, these frameworks argue that the competitive activity is best characterized as the development of visuomotor biases. While some behavioural and neural evidence has been accumulated in favour of this explanation, one of the most striking, yet deceptively common, demonstrations of this capacity …

When Bad Stress Goes Good: Increased Threat Reactivity Predicts Improved Category Learning Performance, Shawn W. Ell, Brandon Cosley, Shannon L. Mccoy

Psychology Faculty Scholarship

The way in which we respond to everyday stressors can have a profound impact on cognitive functioning. Maladaptive stress responses in particular are generally associated with impaired cognitive performance. We argue, however, that the cognitive system mediating task performance is also a critical determinant of the stress-cognition relationship. Consistent with this prediction, we observed that stress reactivity consistent with a maladaptive, threat response differentially predicted performance on two categorization tasks. Increased threat reactivity predicted enhanced performance on an information-integration task (i.e., learning is thought to depend upon a procedural-based memory system), and a (nonsignificant) trend for impaired performance on a …

Alternation Rate In Perceptual Bistability Is Maximal At And Symmetric Around Equi-Dominance, Rubén Moreno-Bote, Asya Shpiro, John Rinzel, Nava Rubin

Publications and Research

When an ambiguous stimulus is viewed for a prolonged time, perception alternates between the different possible interpretations of the stimulus. The alternations seem haphazard, but closer inspection of their dynamics reveals systematic properties in many bistable phenomena. Parametric manipulations result in gradual changes in the fraction of time a given interpretation dominates perception, often over the entire possible range of zero to one. The mean dominance durations of the competing interpretations can also vary over wide ranges (from less than a second to dozens of seconds or more), but finding systematic relations in how they vary has proven difficult. Following …

Rule-Based Categorization Deficits In Focal Basal Ganglia Lesion And Parkinson’S Disease Patients, Shawn W. Ell, Andrea Weinstein, Richard Ivry

Psychology Faculty Scholarship

Patients with basal ganglia (BG) pathology are consistently found to be impaired on rule-based category learning tasks in which learning is thought to depend upon the use of an explicit, hypothesis-guided strategy. The factors that influence this impairment remain unclear. Moreover, it remains unknown if the impairments observed in patients with degenerative disorders such as Parkinson’s disease (PD) are also observed in those with focal BG lesions. In the present study, we tested patients with either focal BG lesions or PD on two categorization tasks that varied in terms of their demands on selective attention and working memory. Individuals with …

A Longitudinal Study Of Neurocognitive Deficits And Functional Outcome In Bipolar Disorder, Brian D. Leany

UNLV Theses, Dissertations, Professional Papers, and Capstones

Bipolar disorder is an affective disorder that, in addition to being characterized by depressive and expansive mood symptoms, often presents with neuropsychological deficits. Bipolar disorder not only impairs an individual’s cognitive abilities, but these cognitive impairments may also impact day-to-day activities causing functional impairment. In other psychiatric disorders such as schizophrenia, it has been shown that the neuropsychological deficits are predictive of poor, long term treatment outcome and functioning. However, while bipolar disorder affects nearly 1 - 2% of the U.S. population (Keck, McElroy, & Arnold, 2001), little is known about the extent that neurocognitive deficits may play in the …

The Effects Of Handedness And Bilateral Saccadic Eye Movements On False Alarms In Recognition Memory, Lisa Weinberg

Psychology Honors Projects

Handedness can be used as a marker for interhemispheric interaction, which can produce memory benefits. Bilateral saccadic eye movements can be used to manipulate levels of interhemispheric interaction. This study measured the effects of handedness and bilateral saccadic eye movement on memory using the Deese-Roediger-McDermott paradigm. This study predicted a memory advantage for left-handers and mixed-handers without eye movements and an advantage for right-handers with the eye movements. The results do not support these predictions but do suggest that handedness is a factor in episodic memory performance. The analyses for this study were run using A’ to compare false alarm …

Locus Of Control And The Age Difference In Free Recall From Episodic Memory, Paul Amrhein, Judith K. Bond, Derek Hamilton

Department of Psychology Faculty Scholarship and Creative Works

The authors investigated the relation of locus of control (LOC) to age differences in free-recall memory performance. Older and younger participants completed P. C. Duttweiler's (1984) Internal Control Index (ICI) and subsequently performed free-recall memory tasks. Compared with the younger participants, the older participants exhibited poorer recall with more intrusions and uncorrected repetition errors as well as reduced categorical clustering. For the older participants with less internal LOC, recall proportion and item-pair associative recall clustering were lower than for the older participants with more internal LOC. By contrast, the younger participants did not exhibit any LOC effects in their recall …

Amygdala And Dorsomedial Prefrontal Cortex Responses To Appearance-Based And Behavior-Based Person Impressions., Sean Baron, M Gobinni, Andrew Engell, Alex Todorov

Andrew Engell

Distributed Representations Of Dynamic Facial Expressions In The Superior Temporal Sulcus., Chris Said, Chris Moore, Andrew Engell, Alex Todroov, James Haxby

Andrew Engell

Influence Of Perinatal Exposure To A Polychlorinated Biphenyl Mixture On Learning And Memory, Hippocampal Size, And Estrogen Receptor-Beta Expression, Howard Cromwell

Howard Casey Cromwell

Abstract. Perinatal exposure to PCB has been reported to cause a variety of health effects including endocrine disruption, and immunologic, reproductive, neurologic, and behavioral deficits. In the present study, a mixture of two PCB congeners, one non-coplanar (PCB 47) and one coplanar (PCB 77), were administered to young female Sprague-Dawley rats by route of maternal dietary consumption (either 12.5 ppm or 25.0 ppm, w/w). Impact on learning and memory were examined by radial arm maze on postnatal day 24-27. After behavioral tests were completed, the rats were transcardially perfused, and brains were excised. Immunohistochemistry for ER- β was carried out …

Cortical Underconnectivity Coupled With Preserved Visuospatial Cognition In Autism: Evidence From An Fmri Study Of An Embedded Figures Task, Saudamini Damarla, Timothy A. Keller, Rajesh K. Kana, Vladimir L. Cherkassky, Diane L. Williams, Nancy J. Minshew, Marcel Adam Just

Marcel Adam Just

No abstract provided.

A Neurosemantic Theory Of Concrete Noun Representation Based On The Underlying Brain Codes, Marcel Adam Just, Vladimir L. Cherkassky, Sandesh Aryal, Tom M. Mitchell

Marcel Adam Just

No abstract provided.