Psychology Commons^™

Exploring Cross-Linguistic Speech Perception In Hindi, English, And Romance-Language Through Temporal Dynamics Of Neural Activity, Yuga Kothari

Dissertations, Theses, and Capstone Projects

This study examines the effect of linguistic experience on the neural processing of Voice Onset Time (VOT) in Hindi and Romance language (Spanish and Portuguese) individuals who are bilingual in English and monolingual English speakers using the event-related potential (ERP) Mismatch Negativity (MMN) response. VOT is a linguistic property that measures the time elapsed between the release of a stop consonant and the beginning of voicing, that is, vocal fold vibration of a following vowel. In a double-oddball paradigm, participants’ (n = 41) ERP were recorded while listening to speech sounds differing in VOT. The bilabial short lag stop [p] …

Characterizing The Brain Dynamics And Eye Movement Behavior Of Memory-Guided Saccades: A Preliminary Investigation Of Distractor Influence On Memory-Guided Saccades, Angelo V. Colmenero

Dissertations, Theses, and Capstone Projects

Research has helped to shed light on the functional organization and neural mechanisms of distractors on memory-guided saccades. In our current study we have utilized eye tracking and EEG technology to simultaneously record the changes in saccadic eye movement (SEM) behavior and event-related potentials (ERPs) associated with performance on a memory-guided saccade task with distractor conditions. Thirteen healthy control participants (n = 13; 6 female) were tasked to complete 864 memory-guided saccade trials with both visible (white) and invisible (black) distractors presented on a black background before saccade initiation. Compared with the control (black) distractor condition, distractor presentation produced a …

The Temporal Dynamics Of Ensemble Perception, Michael L. Epstein

Dissertations, Theses, and Capstone Projects

The striking disparity between the subjective richness of experience and the considerable limitations of perceptual processing has emerged as an essential, enduring question in both vision science and philosophy of mind. A potential solution to this issue is ensemble perception: the ability for the visual system to compute the statistical summaries of object groups, effectively compressing an otherwise overwhelming amount of information. Previous work has supported that ensemble statistics can be perceived quickly and accurately for a wide range of object features. This has motivated models of ensemble perception as an early process in vision, providing an initial sense of …

The Time Course Of Moral Perception: An Erp Investigation Of The Moral Pop-Out Effect, Ana Gantman, Sayeed Devraj-Kizuk, Peter Mende-Siedlecki, Jay J. Van Bavel, Kyle E. Mathewson

Publications and Research

Humans are highly attuned to perceptual cues about their values. A growing body of evidence suggests that people selectively attend to moral stimuli. However, it is unknown whether morality is prioritized early in perception or much later in cognitive processing. We use a combination of behavioral methods and electroencephalography to investigate how early in perception moral words are prioritized relative to non-moral words. The behavioral data replicate previous research indicating that people are more likely to correctly identify moral than non-moral words in a modified lexical decision task. The electroencephalography data reveal that words are distinguished from non-words as early …

Mechanisms Of Value-Biased Prioritization In Fast Sensorimotor Decision Making, Kivilcim Afacan-Seref

Dissertations and Theses

In dynamic environments, split-second sensorimotor decisions must be prioritized according to potential payoffs to maximize overall rewards. The impact of relative value on deliberative perceptual judgments has been examined extensively, but relatively little is known about value-biasing mechanisms in the common situation where physical evidence is strong but the time to act is severely limited. This research examines the behavioral and electrophysiological indices of how value biases split-second perceptual decisions and the possible mechanisms underlying the process. In prominent decision models, a noisy but statistically stationary representation of sensory evidence is integrated over time to an action-triggering bound, and value-biases …

Visual Modulation Of Resting State Α Oscillations, Kelly Webster, Tony Ro

Publications and Research

Once thought to simply reflect passive cortical idling, recent studies have demonstrated that α oscillations play a causal role in cognition and perception. However, whether and how cognitive or sensory processes modulate various components of the α rhythm is poorly understood. Sensory input and resting states were manipulated in human subjects while electroencephalography (EEG) activity was recorded in three conditions: eyes-open fixating on a visual stimulus, eyes-open without visual input (darkness), and eyes-closed without visual input (darkness). We show that α power and peak frequency increase when visual input is reduced compared to the eyes open, fixating condition. These results …

Visual Entrainment Of Perception-Related Neural Oscillations As A Mechanism For Maintaining Rhythmic Temporal Expectations Across A Wide Range Of Frequencies, Michael James Gray

Dissertations, Theses, and Capstone Projects

Visual sensitivity fluctuates rhythmically, in-synch with ongoing, EEG-recorded neural oscillations across a wide range of frequencies (~1-25hz). Some recent work has suggested that these perception-related neural oscillations can be entrained by rhythmic visual stimulation. Evidence is also emerging that the entrainment of ongoing oscillations in visual and auditory cortices is involved in rhythmic temporal expectations. In the introduction chapter, I attempt to bridge these bodies of literature and hypothesize that rhythmic visual stimuli automatically entrain ongoing, perception-related neural oscillations and that this mechanism supports the maintenance of rhythmic temporal expectations. Chapters 2 and 3 address this hypothesis from different angles. …

Neural Correlates Of Automatic Emotional Processing And Emotion Regulation In Empathy And Psychopathy-Related Coldheartedness, Danielle Difilipo

Dissertations, Theses, and Capstone Projects

Psychopathy is a personality disorder that is defined, in part, by a lack of empathy. Psychopathy-related empathic deficits have been associated with atypical behavioral and neural responses to emotional facial expressions. Although the mirror neuron system (MNS) has been implicated in empathy, very few studies have examined the role of MNS functioning as it pertains to empathy impairments in psychopathy. Moreover, there is very little empirical research regarding emotion regulation in psychopathy, and specifically whether emotional responses can be intentionally upregulated. The present study sought to clarify whether the MNS is functionally intact in adults with subclinical psychopathic traits, particularly …

Competitive Frontoparietal Interactions Mediate Implicit Inferences, Martijn E. Wokke, Tony Ro

Publications and Research

Frequent experience with regularities in our environment allows us to use predictive information to guide our decision process. However, contingencies in our environment are not always explicitly present and sometimes need to be inferred. Heretofore, it remained unknown how predictive information guides decision-making when explicit knowledge is absent and how the brain shapes such implicit inferences. In the present experiment, 17 human participants (9 females) performed a discrimination task in which a target stimulus was preceded by a predictive cue. Critically, participants had no explicit knowledge that some of the cues signaled an upcoming target, allowing us to investigate how …

Semantic Attention: Effects Of Modality, Lexicality And Semantic Content, David Britton

Dissertations, Theses, and Capstone Projects

Since the discovery of the Stroop Effect in 1935 questions about the role of language vs. non-lexical stimuli in selective attention remain. Early researchers attributed the powerful distracting influence shown in the Stroop task, naming the color in which a spelled word is printed when incongruent with the color name the word spells, to an automaticity of language that gives it privileged access to meaning, but many others since have shown various ways to reduce or even reverse this distracting effect of an incongruent word. This study addresses this by using EEG to record neural activity along with reaction time …

The Effects Of Alpha Oscillations On Touch Perception And Visuo-Tactile Integration, Lei Ai

Dissertations, Theses, and Capstone Projects

Previous studies have shown that touch perception and visuo-tactile integration have large inter-subject/intra-subject variations. For example, touch perception varies across trials and the temporal binding windows of visuo-tactile integration varies across subjects. I hypothesized that the variations might be due to the change of power, phase and peak frequency of brain alpha oscillations. In the first set of experiments, I examined whether the power and phase of alpha oscillations predict successful conscious touch perception. Near-threshold tactile stimuli were applied to the left hand while electroencephalographic (EEG) activity and fast signal optical imaging were recorded over the somatosensory cortex. Alpha power …

The Neurophysiology Of Intersensory Selective Attention And Task Switching, Jeremy W. Murphy

Dissertations, Theses, and Capstone Projects

Our ability to selectively attend to certain aspects of the world and ignore others is fundamental to our day-to-day lives. The need for selective attention stems from capacity limitations inherent in our perceptual and cognitive processing architecture. Because not every elemental piece of our environment can be fully processed in parallel, the nervous system must prioritize processing. This prioritization is generally referred to as selective attention. Meanwhile, we are faced with a world that is constantly in flux, such that we have to frequently shift our attention from one piece of the environment to another and from one task to …

Biological Motion Processing In Typical Development And In The Autism Spectrum, Aaron Krakowski

Dissertations, Theses, and Capstone Projects

Biological motion (BM) analysis and interpretation is a fundamental process of human neurocognition that has been only minimally explored neurophysiologically. In addition to its importance in understanding the underlying roots and development of social cognition, BM processing is a prime candidate domain for exploring the underlying etiology of social cognitive disorders such as the autism spectrum.

In an initial experiment, typical adults observed BM point-light displays of a human actor (UM) as well as their spatially scrambled counterparts (SM), in both an unattended distractor task as well as an explicit attention task. Results showed a neurophysiological response manifested as three …

Brief Monocular Deprivation As An Assay Of Short-Term Visual Sensory Plasticity In Schizophrenia - "The Binocular Effect", John J. Foxe, Sheralyn Yeap, Victoria M. Leavitt

Publications and Research

Background: Visual sensory processing deficits are consistently observed in schizophrenia, with clear amplitude reduction of the visual evoked potential (VEP) during the initial 50-150 of processing. Similar deficits are seen in unaffected first-degree relatives and drug-naïve first-episode patients, pointing to these deficits as potential endophenotypic markers. Schizophrenia is also associated with deficits in neural plasticity, implicating dysfunction of both glutamatergic and GABAergic systems. Here, we sought to understand the intersection of these two domains, asking whether short-term plasticity during early visual processing is specifically affected in schizophrenia.

Methods: Brief periods of monocular deprivation (MD) induce relatively rapid changes …

Newborn Infants Learn During Sleep, William P. Fifer, Dana L. Byrd, Michelle Kaku, Inge-Marie Eigsti, Joseph R. Isler, Jillian Grose-Fifer, Amanda R. Tarullo, Peter D. Balsam

Publications and Research

Newborn infants must rapidly adjust their physiology and behavior to the specific demands of the novel postnatal environment. This adaptation depends, at least in part, on the infant’s ability to learn from experiences. We report here that infants exhibit learning even while asleep. Bioelectrical activity from face and scalp electrodes was recorded from neonates during an eye movement conditioning procedure in which a tone was followed by a puff of air to the eye. Sleeping newborns rapidly learned the predictive relationship between the tone and the puff. Additionally, in the latter part of training, these infants exhibited a frontally maximum …