VictorJuiz/thesis huggingface dataset:
The Interpersonal Signature of Mindfulness
Keywords: Interpersonal Perception
Mindfulness
Person Perception

How are mindful individuals seen by others? The interpersonal signature (i.e. reputation) of mindfulness was measured across four social contexts of varying acquaintanceship (Study 1: Zero-acquaintanceship, Study 2: First impressions, Study 3: Well-known classmates, and Study 4: Well-known friends). Self-reports and peer-reports were measured for a set of outcomes including personality traits, socially desirable traits (e.g. attractive), and social outcomes (e.g. liking). It was predicted that mindful individuals would be seen in the same ways that they saw themselves, but that characteristics of the traits (observability and evaluativeness) and the social contexts (acquaintanceship and liking) would influence this pattern. There was some evidence that mindful individuals were seen by others as more extraverted, emotionally stable, open, attractive, and narcissistic, as well as less conscientious. However, the interpersonal signature of mindfulness varied across social contexts, and mindful individuals were not always seen in the same ways that they saw themselves.
The Neural Mechanisms of Face Ensemble Processing: Decoding Facial Summary Statistics from ERP Signals
Keywords: eeg
face ensembles
face processing
mvpa
summary statistics
svm

Previous behavioural work has demonstrated our ability to extract summary statistics from groups of faces such as identity. Because we know very little how the extraction of summary statistics for identity occurs in the cortex, I used electroencephalography (EEG) to explore the neural basis of identity summary statistics . I collected EEG data while participants viewed face ensembles or single faces presented one at a time. Different ensembles were designed so that they contained the same average face. Pattern analyses were then conducted across signals recorded from 12 occipitotemporal electrodes. The analyses revealed that ensembles with different averages could be decoded from one another suggesting that we possess a mechanism capable of summarizing identity well enough that the neural signal for one ensemble is decodable from that of an ensemble with a different average. This thesis investigation sheds new light on the neural basis of ensemble processing of identity.
The Dynamics of Decision Making: Attribute Evaluation and Weighting
Keywords: Cognitive Neuroscience
Computational modeling
Decision making
Multi-attribute
Neuroeconomics
Weighting

The aim of the present research was to investigate the evaluation and weighting mechanisms people employ in multi-attribute decision making. In a Primary and Supplementary Study, I developed a choice task that required subjects to assess the summed value of two attributes and, based on this value, make an accept or reject decision. The Primary Study employed a novel experimental paradigm which allowed us to dynamically track subject attention, with stimulus values that could be dynamically reweighted via the addition of â multipliersâ , which magnified attribute values on a trial-by-trial basis. I found that people were able to accurately re-weight attribute when making decisions. Results also revealed that people tend to fixate longer on stimuli that have been re-weighted. Finally, I developed a computational model of the task using drift diffusion modeling, which provides the basis for future imaging studies to extend this work in a search for neural correlates of attribute evaluation and weighting.
Feature-Based Attention to Colour and Shape: Interactions in Object Perception?
Keywords: attention
feature-based attention
perception
psychophysics

In a complex visual environment, attention is important for the selection of relevant input for further processing. Past research has established there to be robust effects of spatial attention on sensory representations, however, a newer line of research suggests there to also be feature-based attentional modulations, separate from spatial modulations. Studies have attempted to test the capacity of feature-based attentional systems by examining the efficiency of attending to multiple features simultaneously. Evidence is mixed, but there appears to be limited effectiveness in using more than one feature of the same dimension in discrimination tasks. In this study I will use object detection and discrimination paradigms to address whether attention to colour and shape can enhance task performance. I find additive effects of colour and shape manipulations, suggesting that attention to each feature facilitates perception independently. This research is important for setting realistic restrictions on models of attentional processes.
The Role of the Ventral Dentate Gyrus in Learned Approach-Avoidance Conflict Resolution
Keywords: Approach-Avoidance Conflict
Dentate Gyrus
Pattern Separation
Septotemporal Axis
Ventral Hippocampus

Approach-avoidance conflicts occur when organisms face stimuli linked to opposing affective outcomes, and must choose to either engage or disengage. It is increasingly acknowledged that the hippocampus, particularly its ventral aspect, is part of a critical network involved in recognizing and resolving approach-avoidance conflicts. Less is known about how the ventral hippocampusâ subdivisions along its transverse axis mediate affective conflicts. Using transient pharmacological lesions in Long-Evans rats, the present study observed that temporary inactivation of the ventral dentate gyrus resulted in an increased bias towards approaching affectively conflicting information, despite also being associated with aversive outcomes. Further testing showed that this could not be explained by an increased bias towards either positive or negative information alone, and was only observed when the conflicting stimuli were presented together. These findings suggest that the ventral dentate gyrus is a critical actor in resolving learned approach-avoidance conflicts.
The Impact of Exercise on Cognition and Neural Activity Under Varying Cognitive Demands in Children Treated for Brain Tumours
Keywords: Brain tumour
Childhood
Cognitive demand
Exercise
Information processing speed
MEG

Children treated with cranial radiation for brain tumours exhibit substantial deficits in information processing (IP) over time. Slower IP speed appears to underlie the inability to recruit cognitive resources required to meet greater task demands and is related to aberrant brain function. Exercise has been shown to improve IP speed and enhance neural activity. We assessed the influence of exercise on IP speed and the underlying functional mechanisms during increasingly demanding conditions by examining visual-motor reaction-time (RT) and regional neural activation during varying task loads using MEG. Immediate and longer-term changes in RT and local neural activity in 4 frequency bands was investigated. After exercise, patients demonstrated stable visual-motor RT under varying task demands and decreased high gamma (60-100Hz) power when task load was minimal. Our findings suggest exercise mitigates declines in IP speed and enhances underlying functional mechanisms under varying cognitive demands in children treated for brain tumours.
Alpha Oscillatory Synchrony underlying Working Memory Maintenance in Children
Keywords: Alpha Oscillations
Development
Funcitonal Connectivity
MEG
Working Memory

Working Memory (WM) is a critical ability that supports a wide range of cognitive functions, and is highly associated with general intelligence and academic achievement. Although functional MRI studies have highlighted a network of regions involved in WM in adults, little is known about how these networks develop in children to support successful WM performance. Using MEG, we examined the dynamic network structures underlying the maintenance of visual information in WM in 6-year-old children. We observed stronger and more stable connectivity in the alpha frequency band (8 to 14 Hz) during the retention interval associated with correct compared to incorrect trials. Additionally, our network analysis revealed elevated alpha synchronization during WM maintenance compared to baseline, in a distributed network of frontal, parietal, and temporal regions. Our results suggest that alpha inter-regional synchrony is an important mechanism for sustaining memory of visual stimuli and is already active in young children.
“Don’t Look Down”: Alpha-Band Activity Reveals Selection Prior to Suppression of to-be-Ignored Locations
Keywords: Attention
Distraction
EEG
Suppression
Visual Search

To examine behavioural and electrophysiological effects associated with the intentional suppression of spatial locations, a task was employed which cued to-be-ignored locations prior to stimulus presentation. Over three experiments, participants were faster to respond to targets when such stimuli were presented alongside salient distractors at cued locations compared to uncued locations. This distractor cueing benefit, however, was time dependent as it was only observed when sufficient time was provided between cue and target displays. Possibly underlying the distractor cueing benefit, hemispheric differences in alpha-band activity gradually emerged between cue and target displays in accordance with the position of cued locations. While it was expected that electrophysiological markers associated with reactive suppression would also be influenced by distractor cueing, this was not the case; only a late stage of effortful processing was affected. Further, findings were present to suggest that both endogenous and exogenous processes contributed to the distractor cueing benefit.
Mechanisms of Ensemble Face Processing: Extraction of Summary, but not Single, Identity Shows Sensitivity to Non-Frontal Global Viewpoints
Keywords: cognitive mechanisms
ensemble processing
face processing
object processing
statistical summary
visual cognition

The recognition and perception of faces – both alone and in groups – is an important biological function, enabling humans to effectively engage with one another socially. This thesis describes viewpoint and identity interactions in processing face ensembles, helping vision scientists to understand the cognitive mechanisms taking place. I manipulated viewpoint or identity across two experiments. The first experiment had participants report an average or single viewpoint or identity, and the second experiment had participants report an average identity or a single identity across a wide range of viewpoints. I find that efficiency in average – but not single – identity extraction decreases as viewpoints are progressively non-frontal. Viewers also extract summary viewpoint better than a single viewpoint, and this ability also decreases as global viewpoints are non-frontal. The implications in the face ensemble processing system, general ensemble processing models, and future research are discussed below.
A Peer E-Mentoring Employment Program for Youth With Physical Disabilities: What are the Social Supports That are Needed and Provided?
Keywords: content analysis
employment
peer e-mentoring
physical disabiltiy
qualitative research
social support

Background: The employment readiness of youth with physical disabilities may improve from social support offered through peer e-mentoring. Little is known regarding the nature of social support within a randomized control trial (RCT) of peer e-mentoring. Objective: To explore the social support needs of youth with physical disabilities with regards to employment readiness and to explore the nature of social support in a peer e-mentoring intervention. Methods: Through a focus group, youthsâ social support needs were analyzed. Through content analysis of discussion forums the nature of social support in the RCT was explored. Results: Youth suggested they required informational support. In the intervention, the mentored group offered varied social support in comparison to the non-mentored group. Conclusions: This research contributes to knowledge about informational support needs of youth with physical disabilities in the area of employment readiness; and presents the types of social support provided in a peer e-mentoring RCT.
Examining the Validity of Accelerometry for Measuring Arm Movements in Children
Keywords: accelerometry
arm use
assessment
cerebral palsy
hemiparesis
pediatric

A goal of rehabilitation for children with hemiparesis is improved arm use during daily life. However, paediatric outcome measures do not objectively measure arm use in natural environments. Accelerometers, which quantitatively measure movement, may provide some missing information. This thesis examines the criterion, convergent and discriminative validity of accelerometry as a measure of paediatric arm movement. The results from a sample of 26 typically-developing (TD) participants and 13 participants with hemiplegic cerebral palsy (CP) indicate arm-accelerometry has: i) criterion validity, based on its sensitivity, specificity (Youdenâ s Index, J > .63) and agreement (> 84%), with reference to video-based observations; ii) moderate convergent validity, based on the correlation between arm ratios and QUEST scores (rs = 0.662, p = .026); and iii) discriminative validity, based on differences in arm ratios (p
Characterizing Cortical and Spinal Markers of Lower Limb Movement Preparation
Keywords: Brain stimulation
Central set
Movement preparation
Nerve stimulation
Reaction time

Preparation for an action involves a variety of inhibitory and excitatory processes that influence the efficiency and scaling of the movement. The purpose of this thesis was to identify the cortical and spinal contributions regulating excitability while preparing for differentially cued lower limb tasks and how individual strategy influences these measures. Twenty-six participants were presented with two reaction time tasks (simple and complex) using a GO/NO-GO paradigm. During the foreperiod, transcranial magnetic stimulation and/or percutaneous electrical stimulation were performed to evoke a muscle response in tibialis anterior as measures of corticospinal and spinal excitability, respectively. Analyses showed no significant effect of task predictability or strategy on cortical and spinal measures; corticospinal and spinal excitability were modulated to a similar extent irrespective of the task. Future work should investigate other potential modifiers of preparatory excitability such as arousal and environment.
Effect of Local Estrogen Therapy on Vaginal Tissue Remodeling in Post-Menopausal Women with Severe Pelvic Organ Prolapse
Keywords: Estrogen
Estrogen Therapy
Immune system
Menopause
Pelvic Organ Prolapse
Vagina

Pelvic Organ Prolapse (POP) is a major health issue, affecting up to half of post-menopausal women. Women with POP have dysregulation of ECM synthesis and breakdown, and a weakened pelvic support. Epidemiological studies reveal that menopause is one of the major risk factors for POP suggesting that ovarian hormones play a protective role in maintaining the strength of a healthy pelvic floor. Loss of this support, due to menopause-related hypoestrogenism, may promote fast deterioration of pelvic connective tissue and facilitates the development of POP. I hypothesized that local intravaginal administration of estrogen in postmenopausal women with severe POP would influence the expression of ECM structural proteins and remodeling enzymes in the vagina and would modulate immune response, resulting in an overall improvement in the quality of the vaginal tissue. I found that following treatment with local estrogen therapy, vaginal tissue of women with POP demonstrated increased ECM synthesis and local activation of the immune system that could ameliorate menopause-related changes and increase urogenital tract tissue regeneration.
Physical Activity Participation in Mild Cognitive Impairment and Alzheimer's Disease.
Keywords: Aging
Behavioural Psychology
Dementia
Mild Cognitive Impairment
Physical Activity
Qualitative Research

This document explores how older adults with cognitive impairment and their caregivers experience and perceive physical activity (PA) and their health beliefs concerning PA. Ten care dyads, consisting of one community-dwelling adult aged 65 years or older diagnosed with Mild Cognitive Impairment (MCI) or mild-to-moderate Alzheimerâ s Disease (AD) and one familial caregiver, were selected to participate in this qualitative study. Information on weekly PA levels, apathy, and apathy-associated distress were collected using questionnaires. Semi-structured interviews were used to explore the PA experiences, beliefs, and perceptions of dyad members. Thematic analysis of interview transcripts yielded four emergent themes: (1) PA as a meaningful activity, (2) Feeling is more important than thinking, (3) Participation is possible despite dementia, and (4) Caregivers as enablers. Findings from this thesis address a current gap in the literature concerning the value and use of PA for health promotion by older adults with cognitive impairment.
Behaviorally Measuring Mindfulness: Evaluating Effort as an Index of Emotional Acceptance
Keywords: acceptance
effort
emotion regulation
mindfulness

Mindfulness has received an increasingly large amount of attention in academic research. While the benefits of mindfulness are often cited, certain methodological issues significantly limit interpretation across findings. Here, we seek to address this concern through the development of a behavioral measure of emotional acceptance (i.e., a fundamental component of mindfulness). Drawing on behavioral economics, we attempt to develop a measure of emotion regulation choice behavior called the Willingness to Experience Task (WILTEX) in which participants make a series of binary choices between accepting emotion or engaging it with an alternative strategy. Across 5 studies, we demonstrate that individuals are no less likely to avoid emotional acceptance than they are to avoid other emotion regulation strategies. Implications for conceptualizing and measuring mindfulness are discussed.
It Doesn't Hurt to Try: The Impact of a Search for Structure in Artificial Grammar Learning
Keywords: Artificial Grammar Learning
Cognitive Control
Explicit Memory
Implicit Memory
Learning
Memory

Some research suggests children are less susceptible to the influence of top-down cognitive processes than adults, and rather, children learn through unbiased sensitivity to information in the environment. One potential means of testing this theory is by manipulating the cognitive processes used in an artificial grammar learning task. Some evidence indicates that adults' success in this task can be reduced by engaging in a deliberate search for the rules underlying stimuli organization. If children are truly less biased learners, it should be the case that they would be less susceptible to the negative effects of a search for structure. In two experiments, we tested how a search for structure affects adult learning of an artificial grammar, and contrary to prediction, the results suggest that searching for structure is beneficial for adults. Therefore, the use of an artificial grammar learning paradigm in exploring developmental questions may be unwarranted, without additional work.
On the Nature of Functional Reserve: Experience in Activities of Daily Living may be Associated with Sex Differences and Delayed Functional Impairment
Keywords: Activities of daily living
Alzheimer's
Functional impairment
Functional reserve
Mild cognitive impairment
Sex differences

Given the limited research comparing men and women in terms of instrumental activities of daily living (IADLs), this research examined sex differences cross-sectionally and longitudinally with data from the Alzheimerâ s Disease Neuroimaging Initiative (ADNI). Furthermore, the influence of IADL experience was included as a proxy measure of functional reserve. All participants had mild cognitive impairment (MCI) at baseline. Linear regression, mixed-effects modeling, and chi-square analyses were conducted. Female sex was associated with superior IADL functioning at baseline, although no sex difference was found in the rate of decline. However, once IADL experience was included in regression analysis, this baseline sex difference was no longer significant. Furthermore, IADL experience was associated with superior functioning at baseline and a slower decline longitudinally. Moreover, experience within specific IADLs was associated with independence in other, unrelated activities. This research supports the notion that performing IADLs may have a protective influence on functioning with neurodegeneration.
Alcohol Consumption and Family History as Correlates of Neuroanatomy and Cognition
Keywords: Alcohol consumption
Cognition
Family history
Magnetic resonance imaging
Neuroanatomy

Neuroanatomical and cognitive differences between individuals with and without a family history of alcohol dependence (FHA) have been noted, however, results are inconsistent. Similarly, the relationship between alcohol consumption and neuroanatomy in young adults without an alcohol use disorder remains unclear. The current study examined the association between alcohol consumption and family history with neuroanatomical and cognitive outcomes in a sample of sixty-nine young adults. Participants with a recent history of heavy episodic drinking completed structural magnetic resonance imaging (MRI) and cognitive testing (WASI-II). Factorial ANOVAs were used to compare FHA and sex groups on neuroanatomy and cognition; linear regression analyses were used to examine the relationship between alcohol consumption and neuroanatomy. Neuroanatomical and cognitive outcomes did not significantly vary as a factor of FHA or sex. Alcohol consumption indices did not significantly predict neuroanatomy. Differences in data analysis and study design are hypothesized to contribute discrepancies in the literature.
The Assessment and Detection Feigned Symptoms that may persist after a Mild Traumatic Brain Injury: An Analogue Investigation
Keywords: assessment
mild traumatic brain injury
MMPI-2-RF
PAI
performance validity
symptom validity

Psychologists have available to them different instruments to assess the non-credible over-reporting of symptoms that can persist after a mild traumatic brain injury (mTBI), including symptom validity tests (SVTs) and performance validity tests (PVTs). The comparative predictive capacity of SVTs “embedded” in the Minnesota Multiphasic Personality Inventory 2 Restructured Form (MMPI-2-RF) and the Personality Assessment Inventory (PAI) versus three “stand alone” PVTs were examined in a simulation study. Participants were administered the MMPI-2-RF, PAI and PVTs and instructed to either feign symptoms that can persist after an mTBI or “respond honestly.” Using a series of hierarchical logistic regression analyses, the performance of SVTs and PVTs to differentiate feigners from honest responders was examined. The Response Bias Scale (RBS) of the MMPI-2-RF was the best predictor relative to all other SVTs and the PVTs. Although the results need to be replicated in other experimental studies and in clinical contexts, those assessing the possible feigning of mTBI would be well served by including the MMPI-2-RF in their psychological test battery.