Medicine and Health Sciences Commons^™

Human Parietal "Reach Region" Primarily Encodes Intrinsic Visual Direction, Not Extrinsic Movement Direction, In A Visual Motor Dissociation Task., Juan Fernandez-Ruiz, Herbert C Goltz, Joseph F X Desouza, Tutis Vilis, J Douglas Crawford

Brain and Mind Institute Researchers' Publications

Posterior parietal cortex (PPC) participates in the planning of visuospatial behaviors, including reach movements, in gaze-centered coordinates. It is not known if these representations encode the visual goal in retinal coordinates, or the movement direction relative to gaze. Here, by dissociating the intrinsic retinal stimulus from the extrinsic direction of movement, we show that PPC employs a visual code. Using delayed pointing and event-related functional magnetic resonance imaging, we identified a cluster of PPC regions whose activity was topographically (contralaterally) related to the direction of the planned movement. We then switched the normal visual-motor spatial relationship by adapting subjects to …

Alcohol Slows Interhemispheric Transmission, Increases The Flash-Lag Effect, And Prolongs Masking: Evidence For A Slowing Of Neural Processing And Transmission., Sarah A Khan, Brian Timney

Brain and Mind Institute Researchers' Publications

While the alcohol literature is extensive, relatively little addresses the relationship between physiological effects and behavioural changes. Using the visual system as a model, we examined alcohol's influence on neural temporal processing as a potential means for alcohol's effects. We did this by using tasks that provided a measure of processing speed: Poffenberger paradigm, flash-lag, and backward masking. After moderate alcohol, participants showed longer interhemispheric transmission times, larger flash-lags, and prolonged masking. Our data are consistent with the view that alcohol slows neural processing, and provide support for a reduction in processing efficiency underlying alcohol-induced changes in temporal visual processing.

Relevance To Self: A Brief Review And Framework Of Neural Systems Underlying Appraisal, Taylor W. Schmitz, Sterling C. Johnson

Brain and Mind Institute Researchers' Publications

We argue that many similar findings observed in cognitive, affective, and social neuroimaging research may compose larger processes central to generating self-relevance. In support of this, recent findings from these research domains were reviewed to identify common systemic activation patterns. Superimposition of these patterns revealed evidence for large-scale supramodal processes, which are argued to mediate appraisal of self-relevant content irrespective of specific stimulus types (e.g. words, pictures) and task domains (e.g. induction of reward, fear, pain, etc.). Furthermore, we distinguish between two top-down sub-systems involved in appraisal of self-relevance, one that orients pre-attentive biasing information (e.g. anticipatory or mnemonic) to …

Perceptual Functions Of Perirhinal Cortex In Rats: Zero-Delay Object Recognition And Simultaneous Oddity Discriminations., Susan J Bartko, Boyer D Winters, Rosemary A Cowell, Lisa M Saksida, Timothy J Bussey

Brain and Mind Institute Researchers' Publications

The perirhinal cortex (PRh) is widely accepted as having an important role in object recognition memory in humans and animals. Contrary to claims that PRh mediates declarative memory exclusively, previous evidence suggests that PRh has a role in the perceptual processing of complex objects. In the present study, we conducted an examination of the possible role of PRh in perceptual function in rats. We examined whether bilateral excitotoxic lesions of PRh or PPRh (perirhinal plus postrhinal cortices) in the rat would cause deficits in a zero-delay object-recognition task and a simultaneous oddity discrimination task. Both of these tasks measured spontaneous …

Anosognosia In Mild Cognitive Impairment: Relationship To Activation Of Cortical Midline Structures Involved In Self-Appraisal, Michele L. Ries, Britta M. Jabbar, Taylor W. Schmitz, Mehul A. Trivedi, Carey E. Gleason, Cynthia M. Carlsson, Howard A. Rowley, Sanjay Asthana, Sterling C. Johnson

Brain and Mind Institute Researchers' Publications

Awareness of cognitive dysfunction shown by individuals with Mild Cognitive Impairment (MCI), a condition conferring risk for Alzheimer's disease (AD), is variable. Anosognosia, or unawareness of loss of function, is beginning to be recognized as an important clinical symptom of MCI. However, little is known about the brain substrates underlying this symptom. We hypothesized that MCI participants' activation of cortical midline structures (CMS) during self-appraisal would covary with level of insight into cognitive difficulties (indexed by a discrepancy score between patient and informant ratings of cognitive decline in each MCI participant). To address this hypothesis, we first compared 16 MCI …

Learning From The Grandmothers: Incorporating Indigenous Principles Into Qualitative Research, Charlotte Loppie

Aboriginal Policy Research Consortium International (APRCi)

In this article, the author describes the process she undertook to incorporate Indigenous principles into her doctoral research about the midlife health experiences of elder Aboriginal women in Nova Scotia, Canada. By employing qual- itative methods within the context of an Indigenous worldview, she gained knowledge of and developed competence in Aboriginal health research. The emergent partnership among Aboriginal community research facilitators, participating Mi’kmaq women, and the researcher provided many opportunities for the researcher to incorporate the paradigmatic and methodological traditions of Western science and Indigenous cultures. The application of these principles to this study might provide a useful example …

Social Support And Thriving Health: A New Approach To Understanding The Health Of Indigenous Canadians, Chantelle A.M. Richmond, Nancy A. Ross, Grace E. Egeland

Aboriginal Policy Research Consortium International (APRCi)

Objectives. We examined the importance of social support in promoting thriv- ing health among indigenous Canadians, a disadvantaged population.

Methods. We categorized the self-reported health status of 31 625 adult indig- enous Canadians as thriving (excellent, very good) or nonthriving (good, fair, poor). We measured social support with indices of positive interaction, emotional support, tangible support, and affection and intimacy. We used multivariable lo- gistic regression analyses to estimate odds of reporting thriving health, using social support as the key independent variable, and we controlled for educational attainment and labor force status.

Results. Compared with women reporting low levels of …

Public Health Decision Makers’ Informational Needs And Preferences For Receiving Research Evidence, Maureen Dobbins, Susan Jack, Helen Thomas, Anita Kothari

Anita Kothari

Objectives: The purpose of this study was to identify decision-makers’ preferences for the transfer and exchange of research knowledge. This article is focused on how the participants define evidence-based decision-making and their preferences for receiving research evidence to integrate into the decision-making process.

Methods: Semistructured interviews were conducted with a purposive sample of 16 Ontario public health decision-makers from six Ontario public health units in this fundamental qualitative descriptive study. The sample included nine program managers, six directors, and one Medical Officer of Health. Participants were asked to define the term evidence-based decision-making and identify preferred research dissemination strategies. The …