Cognition and Perception Commons^™

Validation Of A Virtual Auditory Space, And Its Use To Investigate How Pitch And Spatial Cues Contribute To Perceptual Segregation Of Auditory Streams, Nima Zargarnezhad

Electronic Thesis and Dissertation Repository

The human auditory system can decompose complex sound mixtures into distinct perceptual auditory objects through a process (or processes) known as Auditory Scene Analysis. Pitch and spatial cues are among the sound attributes known to influence sequential streaming (Plack 2018). In this project, the fidelity of a virtual acoustic space (the Audio Dome) in reproducing precisely located sound sources with a 9^th-order ambisonics algorithm was validated. The estimated horizontal Minimum Audible Angles aligned with previously reported values (Mills 1958) homogeneously across the space, and a robust low-frequency presentation was identified. Then, the Audio Dome was utilized to test …

Spontaneous Intrapersonal Synchrony And The Effect Of Cognitive Load, Ramkumar Jagadeesan

Electronic Thesis and Dissertation Repository

Spontaneous intrapersonal synchronization is the spontaneous synchronization of periodic behaviors within an individual. It is less investigated than spontaneous interpersonal synchronization, the synchronization of periodic behaviors that occurs spontaneously between individuals integrated into a single system through coupling, caused by the exchange of sensory feedback between them. It was therefore hypothesized that periodic behaviors produced by an individual, a single system by default, would spontaneously be more synchronous through exchange of sensory feedback, coupling and integration within the individual, when the behaviors are produced simultaneously, compared to separately. Based on a postulate that explains spontaneous interpersonal synchronization as a strategy …

Examining Age-Related Enhancement Of Multisensory Gain: The Role Of Sensory Decline And Inverse Effectiveness, Laura C. Schneeberger

Electronic Thesis and Dissertation Repository

Older adults experience a greater benefit from multisensory integration than their younger counterparts, but it is unclear why. One hypothesis is that age-related sensory decline weakens unisensory stimulus effectiveness, producing a boost in multisensory gain through inverse effectiveness. Many previous studies present stimuli at the same intensity for both younger and older adults (i.e., stimulus-matched), as opposed to accounting for each participant’s unique perceptual ability (i.e., perception-matched). This makes it difficult to discern the source of age-related differences in multisensory gain. Through a combination of stimulus-matched and perception-matched tasks, I found that older adults exhibit enhanced multisensory gain at low …

Investigating The Roles Of The Dorsal And Ventral Striatum In Humor Comprehension And Appreciation Throughout Health, Aging, And Parkinson’S Disease, Maggie Prenger

Electronic Thesis and Dissertation Repository

Humor processing is thought to involve two distinct components. The first, humor comprehension, involves detecting and resolving incongruities that are present within a humorous stimulus. This is related to cognitive processes such as ambiguity resolution, response inhibition, working memory, and cognitive flexibility, functions that are mediated in part by the dorsal portion of the striatum (DS). Humor appreciation, on the other hand, refers to the subjective amusement and mirth that one experiences in response to a joke. This is related to reward processing, which implicates the ventral portion of the striatum (VS). Across three separate studies, we investigated the involvement …

The Two Visual Processing Streams Through The Lens Of Deep Neural Networks, Aidasadat Mirebrahimi Tafreshi

Electronic Thesis and Dissertation Repository

Recent advances in computer vision have enabled machines to have high performance in labeling objects in natural scenes. However, object labeling constitutes only a small fraction of daily human activities. To move towards building machines that can function in natural environments, the usefulness of these models should be evaluated on a broad range of tasks beyond perception. Moving towards this goal, this thesis evaluates the internal representations of state-of-the-art deep convolutional neural networks in predicting a perception-based and an action-based behavior: object similarity judgment and visually guided grasping. To do so, a dataset of everyday objects was collected and used …

Perceptual Benefits From Long-Term Exposure To Naturalistic Sound Patterns, Bruno A. Mesquita

Electronic Thesis and Dissertation Repository

Our brains are proficient in learning recurring structures in the environment, in order to optimize perceptual inferences based on relevant information in a stochastic input. Sensory information is multi-dimensional, and the relationship between sound dimensions may be, in itself, a source of information. Many sounds in our environment covary dynamically, and these covariances may be learned, and therefore shape our perception, through exposure to them in our natural environment. In the present study we investigate how natural (long term), and experimental (short term), learning of statistical regularities in sounds may shape our ability to categorize them (Experiment 1) and to …

Listening Effort: Separating The Subjective From The Objective, Joseph E. Rovetti

Electronic Thesis and Dissertation Repository

Challenges such as background noise may increase “listening effort.” This construct has been operationalized as the recruitment of cognitive resources during listening (objective effort) or as the self-reported feeling of effort (subjective effort). In the current study, I compared these two dimensions of listening effort directly. Normal-hearing adults listened to highly intelligible passages across several signal-to-noise ratios (SNRs), with reaction time on a secondary task (objective effort) and effort ratings (subjective effort) measured in separate blocks. As the SNR became less favourable, subjective effort appeared to increase continuously, while objective effort only began to increase at a much less favourable …

Culture And Classification: Investigating Analytic Vs. Holistic Thinking Styles, Neha Khemani

Electronic Thesis and Dissertation Repository

This paper sought to explore cultural preferences for analytic and holistic thinking in classification. Experiment 1 paired the Shepard, Hovland, and Jenkins (SHJ) tasks with the Analysis-Holism scale (AHS) and a demographics questionnaire. Effects of culture on learning rates, alongside the feasibility of online data collection, were assessed. Learning difficulty differences among the six SHJ category sets were observed. Further, as predicted, higher holistic thinking correlated positively with the family resemblance task. Experiment 2 replicated the Norenzayan et al. (2002) task. Unlike in the original study, the effect of instructional condition was not significant across our full sample. Nevertheless, the …

Temperament And Individual Differences In Category Learning, Tianshu Zhu

Electronic Thesis and Dissertation Repository

Objectives. Individuals can differ in their strategic approach in learning the same categorization task, researchers have sought to study what specific stable individual differences traits can help explain these differences. This dissertation first surveyed extant literature on the impact of trait differences on category learning then examined the effect of temperament traits on these dependent variables. Chapter 2 (scoping review): This scoping review synthesized the past literature that examined the relationship between sources of stable individual differences and category learning performance and strategy use outcomes. Five database platforms were searched to identify relevant articles, cross-referencing was also performed. Sixty-nine studies …

Seeing Thro The Musical Eye: Santo Daime, Fuke-Shū, 1960s Psychedelia, And The Antipodes Of Musical Experience, Forest Anthony-Muran

Electronic Thesis and Dissertation Repository

This thesis investigates the relationships between altered states of consciousness and the musical experience in religious tradition and practice. A common accompaniment to religious worship and ceremony, music is often used as a way of attempting to capture something of the ineffable and to help bring about a mystical experience. In this thesis, I make use of three contrasting case studies – the Brazilian syncretic religion Santo Daime, the historical branch of Zen Buddhism Fuke-shū, and the psychedelic rock of 1960s counterculture – to paint a portrait of the variety of ways that music has been used in different musical …

Movies On The Mind: Using Naturalistic Stimuli To Assess Perception, Cognition, And Awareness In Patients With Disorders Of Consciousness, Geoffrey Laforge

Electronic Thesis and Dissertation Repository

Standardized behavioural assessments of awareness remain the gold standard for patients with disorders of consciousness (DOC) and inform diagnosis, prognosis, and medical decision-making. However, recent neuroimaging research has identified a small but significant number of DOC patients who retain perceptual and cognitive abilities not evidenced by their behaviour. Therefore, it is imperative to develop assessment techniques to identify and characterize the conscious experiences of patients with DOC. This thesis presents a novel movie-based electroencephalographic (EEG) assessment of perceptual and cognitive function in DOC patients. In Chapter 2, we calculated EEG inter-subject correlations (ISCs) in healthy controls and DOC patients to …

The Role Of Top-Down Attention In Statistical Learning Of Speech, Stacey Reyes

Electronic Thesis and Dissertation Repository

Statistical learning (SL) refers to the ability to extract regularities in the environment and has been well-documented to play a key role in speech segmentation and language acquisition. Whether SL is automatic or requires top-down attention is an unresolved question, with conflicting results in the literature. The current proposal tests whether SL can occur outside the focus of attention. Participants either focused towards, or diverted their attention away from an auditory speech stream made of repeating nonsense trisyllabic words. Divided-attention participants either performed a concurrent visual task or a language-related task during exposure to the nonsense speech stream, while control …

A Sense Of Proportion: How Humans Process Relative Magnitudes In Space And Time, Rebekka Lagace-Cusiac

Electronic Thesis and Dissertation Repository

Humans perceive ratios for different spatial magnitudes such as length, area, and numerosity, and temporal magnitudes such as duration. Previous studies have shown that spatial ratios may be processed by a common ratio processing system. The aim of the current study was to determine whether ratios across spatial and temporal domains may also be processed by a common system. Two hundred and seventy-five participants completed a series of spatial and temporal ratio estimation and magnitude discrimination tasks. Structural equation modeling (SEM) was used to analyze the relationship between ratio processing across domains when controlling for absolute magnitude processing ability. Results …

Audiovisual Integration In Cochlear Implant Users And Typical Hearing Controls: A Study Of Group Differences In Syllable Perception And Effect Of Asynchrony On Speech Intelligibility, Cailey A. Salagovic

Electronic Thesis and Dissertation Repository

This study examined audiovisual integration in cochlear implant (CI) users compared to typical (acoustic) hearing control participants and investigated the effect of audiovisual temporal asynchrony on speech intelligibility across these groups. Additionally, this study evaluated the utility of online data collection for audiovisual perception research. In Experiment 1, CI users were found to integrate audiovisual syllables comparably to controls as demonstrated by perception of the McGurk illusion. However, group differences were revealed in the processing of the unisensory components and underlying distributions of responses to incongruent audiovisual trials when the illusory fusion syllable was not reported. In Experiment 2, intelligibility …

Likelihood And Familiarity In The Simulation Of Future Events, Claudia Morales Valiente

Electronic Thesis and Dissertation Repository

Episodic future thinking is the ability to project the self forward in time to pre-experience an event (Atance & O’Neill, 2001). Understanding how people think about potential future events is an important component of human memory research. We investigated whether and how episodic future thinking is influenced by a person's belief of the likelihood of its future occurrence in their lives, as well as a person's familiarity with that type of event based on their past experience. The combined and individual effects of these variables have been minimally studied, particularly likelihood. We used three norming studies to develop participant-specific sets …

Visual Perception In Hearing Sign Language Users, Jessica M. Lammert

Electronic Thesis and Dissertation Repository

Deaf signers exhibit superior visual perception compared to hearing controls in several domains, including the perception of faces and peripheral motion. These visual enhancements are thought to compensate for an absence of auditory input. However, it is also possible that they reflect experience using a visual-manual language, where signers must process complex moving hand signs and facial cues simultaneously. Thus, the current study sought to isolate the effects of sign language experience by examining how visual perception is altered as a function of American Sign Language (ASL) proficiency in hearing individuals. Hearing signers completed an online test of ASL proficiency …

Rapid Facial Reactions Of Emotional Expressions As A Function Of Trait Sadism, Cathleen Fleury

Electronic Thesis and Dissertation Repository

Using electromyography (EMG), it has been shown that facial muscles imperceptibly mirror the facial expressions of others, a phenomenon referred to as rapid facial reactions (RFRs). It was previously believed to follow the direct-matching hypothesis, however several recent studies have demonstrated that context and individual differences may be influencing factors on RFRs. At the present, it is unclear to what extent RFRs can be modulated. In the present study, we propose to determine the effects of facial stimuli versus non-facial stimuli on RFRs through measuring the EMG response of participants with trait sadism. The participants observed dynamic facial expressions as …

The Relationship Between Schizotypal Traits And The Perceptual Processes Of Multisensory Integration, Temporal Processing, And Speech Perception, Anne-Marie Muller

Electronic Thesis and Dissertation Repository

Multisensory integration, the binding of sensory information from different sensory modalities, may contribute to perceptual symptomatology in schizophrenia, including hallucilllnations and aberrant speech perception. Differences in multisensory integration and temporal processing, an important component of multisensory integration, are consistently found in schizophrenia. Evidence is emerging that these differences extend across the schizophrenia spectrum, including individuals in the general population with higher schizotypal traits. In two studies, the relationship between schizotypal traits and perceptual functioning is investigated. We hypothesized associations between higher schizotypal traits and decreased multisensory integration, increased auditory speech distractibility, and less precise temporal processing. In Study 1, higher …

Multisensory Associative Learning And Multisensory Integration, Sebastien Lauzon

Electronic Thesis and Dissertation Repository

Human multisensory experiences with the world rely on a combination of top-down and bottom-up influences, a process that changes throughout development. The present study explored the relationship between multisensory associative learning and multisensory integration using encephalography (EEG) and behavioural measures. While recording EEG activity, participants were exposed to novel pairings of non-sociolinguistic audiovisual stimuli of varying presentation probability while performing a detection task. The same stimuli were then used in another detection task, which was followed by an analogous behavioural speeded-response task, both of which kept probabilities equal and tested for multisensory integration. Significant relationships were found in fronto-central and …

Exploring Cognitive Maps Through Sketching, Melissa M. Nantais

Electronic Thesis and Dissertation Repository

Abstract

Periodic testing has been found to improve the accuracy of participants’ cognitive maps when an onscreen map is provided, however, it is unclear whether the same results would occur without the onscreen map. The current study investigated whether drawing a map periodically while exploring the virtual environment Silcton would improve cognitive map accuracy. Participants explored Silcton and were stopped every 4 minutes to either sketch a map of Silcton, identify items seen in Silcton, or colour an unrelated picture, and a baseline group was not stopped. All groups drew a final sketch map and completed a direction estimation task. …

How Does The Brain Represent Digits? Investigating The Neural Correlates Of Symbolic Number Representation Using Fmri-Adaptation, Celia Goffin

Electronic Thesis and Dissertation Repository

How does the brain represent numerical symbols (e.g., Arabic digits)? Activity in left parietal regions correlates with symbolic number processing. Research with functional resonance imaging adaptation (fMRI-A) indicates that the intraparietal sulcus (IPS) exhibits a rebound (increase in activation) effect when a repeatedly presented number is followed by a new number. Importantly, this rebound effect is modulated by numerical ratio as well as the difference between presented numbers (distance). This ratio-dependent rebound effect could reflect a link between symbolic numerical representation and an approximate number system (ANS). In this doctoral dissertation, fMRI-A is used to investigate mechanisms underlying symbolic number …

The Impact Of Statistical Learning On Language And Social Competency In Asd And Adhd: Divergent Findings, Kaitlyn M.A Parks

Electronic Thesis and Dissertation Repository

Statistical learning is a process that allows individuals to extract regularities from the environment and plays an important role in language acquisition, speech segmentation, and aspects of social behaviour. Little is known about the contribution of statistical learning impairments on Autism Spectrum Disorder (ASD) and Attention-Deficit/Hyperactivity Disorder (ADHD) related traits. The current study examined whether impairments in auditory and visual statistical learning are related to ASD and ADHD traits, language, and social competency. Decreased auditory, but not visual statistical learning abilities was related to increased autism traits and visual statistical learning and social competency abilities were mediated by language comprehension. …

Interpreting Intentions: Evidence For Cross-Language Influences In Bilinguals, Maziyah Mohamed

Electronic Thesis and Dissertation Repository

In Malay, accidental actions are marked with the prefix -ter. Malay speakers typically assume a deliberate intent when the prefix is absent. I investigated whether Malay-English bilinguals are more likely than English monolinguals to interpret actions in English sentences as deliberate when they are not clearly indicated as being accidental. In Experiment 1, Malay speakers completed a recognition memory task. The results showed that Malay speakers remembered unintentionality accurately. This accuracy in remembering unintentionality suggests that Malay speakers encode the intentions of others. In Experiment 2, participants completed a cross-modal priming task. They first heard scenarios in which a …

Improving Stimulus Realism: The Effect Of Visual Dimension On Affective Responding, Shannon Compton

Electronic Thesis and Dissertation Repository

For decades researchers have used 2D stimuli under the assumption that they accurately represent real objects. This assumption has been challenged by recent vision and neuroeconomics research which has found that 2D images can evoke different neural and behavioural responses than real objects. The current study continues this line of research in the field of affective cognitive neuroscience; a field where small effect sizes are common and rapid habituation to affective stimuli used in the lab often occurs. The present study uses realistic 2D and 3D emotional images to determine the impact of visual dimension on affective responding. Subjective ratings …

Characterizing The Familiar-Voice Benefit To Intelligibility, Beatriz Ysabel Domingo

Electronic Thesis and Dissertation Repository

Everyday listening often occurs in the presence of background noise. Listeners with normal hearing can often successfully segregate competing sounds from the signal of interest. To do this, listeners exploit a variety of cues to facilitate the separation of simultaneous sounds into separate sources, and group sequential sounds into intelligible speech streams. One of the cues that has been shown to be an effective facilitator of speech intelligibility is familiarity with a talker’s voice. A recent study by Johnsrude et al. (2013) measured speech intelligibility of a naturally familiar voice (i.e., that of a long-term spouse) and showed a …

Neural Entrainment Indexes Statistical Learning In Children, Christine Moreau

Electronic Thesis and Dissertation Repository

Statistical learning is proposed as a mechanism for discovering structural patterns in speech through incidental exposure. However, studies have largely relied on assessing explicit memory after learning has occurred, which does not capture the time course and process of statistical learning per se. To better understand the dynamics of statistical learning, we assessed 8- to 12-year-old children using an EEG measure of learning, which captures changes in neural entrainment to words embedded in a continuous artificial language. Statistical learning was assessed post-learning using implicit and explicit behavioural tests. The neural entrainment results demonstrated rapid learning of word-level information, while post-learning …

A Study Of Multiple Predictors Of Cognitive Fatigue In Individuals With Multiple Sclerosis, Leila M. Mackay

Electronic Thesis and Dissertation Repository

Persons with multiple sclerosis (PwMS) commonly experience cognitive fatigue (CF), defined as a decrease in cognitive performance over a sustained activity and measured objectively or subjectively. In the present research, we evaluated the extent to which depression, anxiety, information processing speed, sleep quality, and disease severity predict subjective and objective CF, in a sample of 55 PwMS (37 females, M = 44.23). Although no statistically significant predictors of objective CF were demonstrated, all variables predicted subjective CF, R2adj = .384 [F (6, 40) = 5.783, p = .0002]. In particular, depression and information processing speed were found to be significant …

The Effects Of Linguistic Labels On Object Categorization And Perception, Xuan Pan

Electronic Thesis and Dissertation Repository

The linguistic relativity hypothesis (Whorf, 1956) claims that speakers of different languages perceive and conceptualize the world differently. Language-thought interaction is likely to be more complex in bilinguals because they have two languages that could influence their cognitive and perceptual processes.Lupyan’s (2012) Label-feedback Hypothesis proposes a mechanism underpinning language-thought interactions, arguingthat linguistic labels affect our conceptual and perceptual representations through top-down feedback.This thesis tested the Label-feedback Hypothesis by capitalizing on an interesting feature of Chinese. In English, most nouns do not provide linguistic clues to their categories (an exception issunflower), whereas in Chinese, some nouns provide explicit category …

The Effects Of Semantic Priming On Lexical Processing, Alexander Taikh

Electronic Thesis and Dissertation Repository

The present experiments were designed to investigate the locus of the semantic priming effect, a phenomenon that has received much research attention. Semantically related primes (e.g., cat) might activate the lexical representations of their targets (e.g., DOG) through automatic spreading activation at short stimulus onset asynchronies (SOAs) between the prime and target, or through generation of words expected to follow the prime at long SOAs. Alternately, semantically related primes might be used strategically to aid responding after target identification. The effects of masked orthographic primes (e.g., judpe-JUDGE), in contrast, are assumed to be strictly lexical and automatic. Lexical processing of …

The Effects Of Emotionally Salient Unimodal And Multimodal Stimuli On Low-Level Visual Perception, Stephen Raymond Pierzchajlo

Electronic Thesis and Dissertation Repository

Sensory information can both impair and enhance low-level visual feature processing, and this can be significantly modulated depending on the whether this information matches the visual sensory modality. Emotionally significant visual and auditory stimuli can have opposing effects on attention. While task-irrelevant emotionally salient visual stimuli can often impair task attention, task-irrelevant emotionally salient auditory stimuli have been shown to enhance aspects of attention. To date, no study has directly compared how emotionally salient information presented to different sensory modalities can affect low-level vision. Using Gabor patches of differing contrasts to measure the threshold of visual perception, we hypothesized that …