Miguel Remondes and Matt Wilson show that theta synchrony between the hippocampus and anterior cingulate during a task in which rats chose one of four trajectories. Theta coherence at 8 Hz lowers slightly (by 1 Hz) when rats enter the decision phase of the task and hippocampal processing of trajectory information precedes that of the anterior cingulate. Thus, lowering of theta synchrony may coordinate the integration of hippocampal information by neurons in the anterior cingulate.
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Brown University researchers show how increases in sigma and delta brain oscillations during sleep correlate with learning new visual and motor skills. The sigma oscillations in particular were traced to the occipital representation of the visual quadrant where the learning took place.
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The all-star team of Buzaki, Logothetis, and Singer discuss how the hierarchy of brain oscillations is remarkably consistent despite huge differences in brain size across different animals. This may allow for multiple time-scale communication and may be a key factor in time management in the brain. They discuss the implications for mental disease and therapy.
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Peters et al used functional imaging in humans to examine the effects of the contents of working memory on extrastriate visual cortex. Subjects performed a visual search task. The target item in working memory enhanced processing of a matching visual input whereas other “accessory” items held in working memory suppressed extrastriate activity. These dual effects may help focus on relevant tasks while avoiding distractions.
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Michale Fee and crew review and synthesize three major models of basal ganglia output (disinhibition, rebound, and entrainment).
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The title says it all. Theta oscillations in humans increased with prediction error and predicted the subject’s learning rates.
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Miller Lab alumnus Jon Wallis and crew studied two different types of cost-benefit decisions (delay vs effort). They found that different neurons in the dorsolateral prefrontal cortex, orbitofrontal, and anterior cingulate encoded the different types of decisions. Thus, rather than have neurons encode decisions on an abstract level, frontal cortex neurons encode stimuli based on their exact consequences.
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Bradley Voytek walks us through a brain surgery (with video)
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Bob Desimone (Director of the McGovern Institute for Brain Research at MIT) demonstrates auto-synchronization of metronomes
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Behavior can be fast and automatic, but inflexible (model-free) vs slower, more deliberate, and flexible (model-based) Ray Dolan and crew show that disruption of the prefrontal cortex by transcranial magnetic stimulation (TMS) pushes humans towards more inflexible, model-free, behavior.