Browsing by Author "Goghari, Vina M."

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    In the Eye Movements of the Beholder: Manipulating Visual Scanpaths During Facial Emotion Perception Modulates Functional Brain Activation in Schizophrenia Patients and Controls
    (2018-10-20) Spilka, Michael; Bray, Signe L.; Goghari, Vina M.; Achim, Amélie M.; Kopala-Sibley, Daniel C.; MacMaster, Frank P.; Sears, Christopher R.
    Individuals with schizophrenia exhibit deficits in the ability to perceive and recognize emotions from faces, and these deficits are significant predictors of functional outcome. Research into the origins of facial emotion recognition deficits in schizophrenia has identified abnormalities in visual gaze behaviour and functional brain activation in patients during facial emotion perception; however, these two aspects of facial emotion processing have previously been studied in isolation. Nonetheless, several studies with healthy individuals and other clinical populations suggest a relationship between gaze behaviour and functional activation in regions also implicated in facial emotion processing deficits in schizophrenia (e.g., fusiform gyrus). These findings raise the important question of whether gaze behaviour abnormalities in schizophrenia contribute to reported functional activation abnormalities during facial emotion perception. In this dissertation, I examined whether manipulating visual scanpaths during facial emotion perception would modulate blood-oxygen-level dependent (BOLD) signal change in a sample of schizophrenia patients and community controls. Patients and controls underwent functional magnetic resonance imaging (fMRI) while viewing pictures of emotional faces. During the Typical Viewing condition, a fixation cue directed participants’ gaze primarily to the eyes and mouth, while gaze was directed to peripheral features during the Atypical Viewing condition. Participants additionally completed a practice version of the task outside the scanner and a traditional facial emotion discrimination task, while gaze behaviour was recorded with an eye tracker. Patients had reduced percentage of fixations to salient facial features during facial emotion discrimination, similar to previous findings. During the fMRI task, both viewing conditions elicited BOLD signal change throughout regions of the neural system for face perception. Typical Viewing led to greater activation in visual association cortex including the right “occipital face area”, while Atypical Viewing elicited greater activation in primary visual cortex and regions involved in attentional control, including the intraparietal sulcus and frontal eye fields. There were no group differences in functional activation, in contrast to previous findings. The results of this study indicate that gaze behaviour modulates activation in early face-processing regions, suggesting that abnormal gaze behaviour in schizophrenia may contribute to the documented activation abnormalities in these regions during facial emotion perception.
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    Manipulating visual scanpaths during facial emotion perception modulates functional brain activation in schizophrenia patients and controls
    (2019-09) Spilka, Michael J.; Pittman, Daniel J.; Bray, Signe L.; Goghari, Vina M.
    Individuals with schizophrenia exhibit deficits in facial emotion processing, which have been associated with abnormalities in visual gaze behaviour and functional brain activation. However, the relationship between gaze behaviour and brain activation in schizophrenia remains unexamined. Studies in healthy individuals and other clinical samples indicate a relationship between gaze behaviour and functional activation in brain regions implicated in facial emotion processing deficits in schizophrenia (e.g., fusiform gyrus), prompting the question of whether a similar relationship exists in schizophrenia. This study examined whether manipulating visual scanpaths during facial emotion perception would modulate functional brain activation in a sample of 23 schizophrenia patients and 26 community controls. Participants underwent functional magnetic resonance imaging while viewing pictures of emotional faces. During the typical viewing condition, a fixation cue directed participants’ gaze primarily to the eyes and mouth, whereas during the atypical viewing condition gaze was directed to peripheral features. Both viewing conditions elicited a robust response throughout face-processing regions. Typical viewing led to greater activation in visual association cortex including the right inferior occipital gyrus/occipital face area, whereas atypical viewing elicited greater activation in primary visual cortex and regions involved in attentional control. There were no between-group activation differences in response to faces or interaction between group and gaze manipulation. The results indicate that gaze behaviour modulates functional activation in early face-processing regions in individuals with and without schizophrenia, suggesting that abnormal gaze behaviour in schizophrenia may contribute to activation abnormalities during facial emotion perception.
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    Measuring Fluid Intelligence in Healthy Older Adults
    (2017-01) Shakeel, Mohammed K.; Goghari, Vina M.
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    Measuring Fluid Intelligence in Healthy Older Adults
    (2017-01-30) Shakeel, Mohammed K.; Goghari, Vina M.
    The present study evaluated subjective and objective cognitive measures as predictors of fluid intelligence in healthy older adults. We hypothesized that objective cognitive measures would predict fluid intelligence to a greater degree than self-reported cognitive functioning. Ninety-three healthy older (>65 years old) community-dwelling adults participated. Raven’s Advanced Progressive Matrices (RAPM) were used to measure fluid intelligence, Digit Span Sequencing (DSS) was used to measure working memory, Trail Making Test (TMT) was used to measure cognitive flexibility, Design Fluency Test (DFT) was used to measure creativity, and Tower Test (TT) was used to measure planning. The Cognitive Failures Questionnaire (CFQ) was used to measure subjective perceptions of cognitive functioning. RAPM was correlated with DSS, TT, and DFT. When CFQ was the only predictor, the regression model predicting fluid intelligence was not significant. When DSS, TMT, DFT, and TT were included in the model, there was a significant change in the model and the final model was also significant, with DFT as the only significant predictor. The model accounted for approximately 20% of the variability in fluid intelligence. Our findings suggest that the most reliable means of assessing fluid intelligence is to assess it directly.
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    Neuroanatomical Changes Associated with Working Memory Training in Healthy Adults
    (2018-06-26) Savage, Linette; Goghari, Vina M.; Campbell, Tavis S.; Bodner, Glen E.; Lebel, Catherine A.; MacMaster, Frank P.; Yang, Lixia
    The potential for working memory training to enhance cognitive and intellectual abilities is alluring across scientific disciplines and the general public. However, the field has been fraught with inconsistency and controversy. Heterogeneous methodological implementations have led to a divided and contrasting body of literature, which has collectively limited scientific transparency and advancement in the field. However, neuroimaging has the potential to clarify what, if any, benefit working memory training has on the adult human brain. A recent series of studies used functional neuroimaging to investigate neural activations associated with working memory training. This dissertation uses structural imaging to address another theoretical area: the neuroanatomical correlates of working memory training. Forty-eight healthy community dwelling adults, aged 18 - 40 years, completed a series of cognitive tasks and underwent magnetic resonance imaging (MRI) before and after completing a 6-week trial of working memory training (experimental condition) or processing speed training (active control condition). Group by time repeated measures Analyses of Variance (rm-ANOVAs) were conducted on MRI data to identify changes in surface area, thickness, and volume in theoretically relevant gray matter regions of interest, as well as overall gray and white matter volumes, associated with working memory training. Similar analyses were conducted to investigate changes in cognitive task performance in this sample. Null results were present across all neuroanatomical metrics after correction for multiple comparisons, and findings from cognitive tasks were consistent with the subset of literature suggesting that working memory training does not meaningfully benefit cognitive performance. Albeit limited by low statistical power and the confines of available technology, findings of this study, in consort with recently published investigations, strongly support the idea that working memory training is not an effective method for enhancing cognitive performance or inducing neoplastic changes in brain structure. We suggest that future studies continue attempts to resolve heterogeneity and polarization in this field, or alternatively, concentrate resources on identifying and refining mechanisms of change in populations who may benefit from rehabilitative forms of cognitive training.