Social and Behavioral Sciences Commons^™

Scene Search Guidance Under Salience-Driven And Memory-Driven Demands, Jenn Ha’Aheo Olejarczyk

Theses and Dissertations

Visual search involves selecting relevant information while ignoring irrelevant information. Most search models predict what relevant features attract gaze; yet few consider search guidance from previous knowledge of scenes. This dissertation used eye movements to examine the guidance of attention when an immediate or delayed distractor appeared during novel and repeated searches.

The experiments showed efficient search for repeated scenes, a classic result of contextual cueing. During repeated searches, an immediate attentional bias was found for distractors close to the target location. Automatic and controlled selective attention processes, measured using the antisaccade, were found within search behavior. The final experiment …

Dimensionality And Instrument Validation In Factor Analysis: Effect Of The Number Of Response Alternatives, Alexander G. Hall

Theses and Dissertations

Despite the great prevalence in both research and application of Factor Analysis (FA), widespread misinterpretation continues to pervade the psychological community in its application for the development and evaluation of psychometric tools. Fundamental measurement questions such as the number of response alternatives needed, and the power to detect poor model fit in non-normal or misspecified data, still remain in need of further investigation. For example, the power of the chi-square statistic used in structural equation modeling decreases as the absolute value of excess kurtosis of the observed data increases. This issue is further compounded with discrete variables, where increasing kurtosis …

The Neural Representation Of Duration In Event Concepts, Christopher Todd Hackett

Theses and Dissertations

Little is known about the neural basis of temporal concepts. Some have suggested that temporal concepts are grounded in spatial or temporal processes. Here we aimed to examine the representation of duration of event concepts, and compare them with judgments of object size, which may entail spatial processing. A 2x2 block design used event and object nouns as stimuli that were presented during functional imaging. Participants made judgments about event duration, object size, and event and object valence. In addition to whole-brain analyses, we examined activations in areas known to be involved in temporal processing and spatial processing. Knowledge of …

Iv Prenatal Nicotine Exposure Modulates Α6, Α7, And Α4Β2 Nicotinic Acetylcholinergic Receptor Subunit Expression In Male And Female Neonatal And Adolescent Rat Offspring: An Autoradiographical Analysis, Amanda Morgan

Theses and Dissertations

Maternal smoke exposure produces long-term adverse cognitive and behavioral outcomes in offspring, including an increased likelihood of attention problems (e.g., attention deficit hyperactivity disorder; ADHD) and drug abuse. Preclinical research shows that gestational exposure to nicotine, the primary psychoactive compound in tobacco smoke, influences the neurodevelopment of attention and reward neuronal circuits. This study investigated hypotheses about five brain regions, to determine if prenatal nicotine (PN) exposure altered expression of nicotinic acetylcholine receptors (nAChRs). A low dose, intravenous nicotine (IV) exposure method was used to administer nicotine (0.05 mg/kg/injection) or saline, 3x/day on gestational days 8–21 (Treatment). Brain tissue was …

The Syntax-Space Effect, Timothy W. Boiteau

Theses and Dissertations

Previous research has linked the concept of number and other ordinal series to space via a spatially-oriented number line. Other researchers have shown that language as well may have an underlying spatial representation, though this seems to be tied to visual scene recognition and production and is potentially an idiosyncratic effect of a limited set of concrete verbs. In this dissertation, employing a novel method that measures the underlying spatial biases of actors in transitive sentences, I show that findings from previous studies showing a relationship between transitivity and space reflect an interaction between word order in the sentence, order …

Sleep Extension And Stable Sleep Schedules In Older Adults, Alexandria M. Reynolds

Theses and Dissertations

There is consistent evidence demonstrating a “U-shaped” association between sleep duration and mortality, as well as several morbidities, such as increased systemic inflammation, decreased cognitive performance, and mood disturbances. Much of the information on long sleep is epidemiological in nature. The present study examined the associations between sleep duration and extension on mood, inflammation, and cognition. Ten (50-79 y) healthy adults who report sleeping 6-8 h were assessed on cognitive, emotional, and inflammatory measures in a cross-over design. Following a baseline week, participants were randomized to one of two three-week treatments: (1) a control treatment of habitual time in bed; …

Representation Of Affect From Fmri Data As A Function Of Stimulus Modality And Judgment Task, Jongwan Kim

Theses and Dissertations

The theory of core affect posits that the neural system processes affective aspects of stimuli encountered by the organism quickly and automatically, resulting in a unified affective state described along the dimensions of valence and arousal. Core affect theory posits two functional subsystems that guide affective processing: a sensory integration and a visceramotor network. The proposed study investigates how the representation of affective dimensions depends on sensory modality, features of the task, and brain regions. A series of behavioral studies was run to develop an experimental stimulus set of silent videos and musical clips that met requirements of equating valence …