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Full-Text Articles in Medicine and Health Sciences
Specific Contributions Of Ventromedial, Anterior Cingulate, And Lateral Prefrontal Cortex For Attentional Selection And Stimulus Valuation., Daniel Kaping, Martin Vinck, R Matthew Hutchison, Stefan Everling, Thilo Womelsdorf
Specific Contributions Of Ventromedial, Anterior Cingulate, And Lateral Prefrontal Cortex For Attentional Selection And Stimulus Valuation., Daniel Kaping, Martin Vinck, R Matthew Hutchison, Stefan Everling, Thilo Womelsdorf
Brain and Mind Institute Researchers' Publications
Attentional control ensures that neuronal processes prioritize the most relevant stimulus in a given environment. Controlling which stimulus is attended thus originates from neurons encoding the relevance of stimuli, i.e. their expected value, in hand with neurons encoding contextual information about stimulus locations, features, and rules that guide the conditional allocation of attention. Here, we examined how these distinct processes are encoded and integrated in macaque prefrontal cortex (PFC) by mapping their functional topographies at the time of attentional stimulus selection. We find confined clusters of neurons in ventromedial PFC (vmPFC) that predominantly convey stimulus valuation information during attention shifts. …
Paradoxical Reversal Learning Enhancement By Stress Or Prefrontal Cortical Damage: Rescue With Bdnf., Carolyn Graybeal, Michael Feyder, Emily Schulman, Lisa M Saksida, Timothy J Bussey, Jonathan L Brigman, Andrew Holmes
Paradoxical Reversal Learning Enhancement By Stress Or Prefrontal Cortical Damage: Rescue With Bdnf., Carolyn Graybeal, Michael Feyder, Emily Schulman, Lisa M Saksida, Timothy J Bussey, Jonathan L Brigman, Andrew Holmes
Brain and Mind Institute Researchers' Publications
Stress affects various forms of cognition. We found that moderate stress enhanced late reversal learning in a mouse touchscreen-based choice task. Ventromedial prefrontal cortex (vmPFC) lesions mimicked the effect of stress, whereas orbitofrontal and dorsolateral striatal lesions impaired reversal. Stress facilitation of reversal was prevented by BDNF infusion into the vmPFC. These findings suggest a mechanism by which stress-induced vmPFC dysfunction disinhibits learning by alternate (for example, striatal) systems.
A Model Of Intracellular Θ Phase Precession Dependent On Intrinsic Subthreshold Membrane Currents., L Stan Leung
A Model Of Intracellular Θ Phase Precession Dependent On Intrinsic Subthreshold Membrane Currents., L Stan Leung
Physiology and Pharmacology Publications
A hippocampal place cell fires at an increasingly earlier phase in relation to the extracellular theta rhythm as a rodent moves through the place field. The present report presents a compartment model of a CA1 pyramidal cell that explains the increase in amplitude and the phase precession of intracellular theta oscillations, with the assumption that the cell receives an asymmetric ramp depolarization (<10 >mV) in the place field and rhythmic inhibitory and/or excitatory synaptic driving. Intracellular subthreshold membrane potential oscillations (MPOs) increase in amplitude and frequency, and show phase precession within the place field. Theta phase precession and MPO power …
The Levels Of Analysis Revisited., Scott A Macdougall-Shackleton
The Levels Of Analysis Revisited., Scott A Macdougall-Shackleton
Brain and Mind Institute Researchers' Publications
The term levels of analysis has been used in several ways: to distinguish between ultimate and proximate levels, to categorize different kinds of research questions and to differentiate levels of reductionism. Because questions regarding ultimate function and proximate mechanisms are logically distinct, I suggest that distinguishing between these two levels is the best use of the term. Integrating across levels in research has potential risks, but many benefits. Consideration at one level can help generate novel hypotheses at the other, define categories of behaviour and set criteria that must be addressed. Taking an adaptationist stance thus strengthens research on proximate …