Bea Luna and colleagues used graph theory to examine the development of functional hubs in the human brain. The hub architecture develops earlier, but connections between the hubs and “spokes” continue to develop and change into adulthood.
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Adam Gazzaley and company show, for the first time, that training on a video game results in benefits that transfer to other tests of cognition. Training on the NeuroRacer game produced long-lasting improvements in cognitive abilities of older adults (age 65-80). How did they do it? Their trick was to focus on multitasking and attention.
Anguera et al (2013) Nature -
Matt Chafee and colleagues used multiple-electrode recording in the prefrontal and parietal cortices to examine the temporal dynamics of their neural activity during a categorization task. They decoded category signals from patterns of simultaneously recorded in small bins and asked whether the resulting information time series in one area could predict the other. This showed that “executive” top-down signals flow from the prefrontal to parietal cortex.
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Ranulfo Romo and crew show delta band (1-4 Hz) synchrony between frontal and parietal cortex that varies with decisions. When there were no decisions to be made, frontal-parietal delta was reduced.
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An article in MIT’s Technology Review magazine about our work on how multitasking “mixed selectivity” neurons may be key for cognition.
Do-It-All Neurons – A key to cognitive flexibility by Anne Trafton -
Ann Graybiel and crew show that the role of dopamine in reinforcement learning is not so straightforward. Rather than just give short bursts tied to reward prediction errors, dopamine ramps up as rats near a goal. It could reflect a motivational drive.
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Arimura et al compared neural responses in the globus pallidus (GP), prefrontal cortex (PFC) and premotor cortex (PMC) during a task in which a visual cue instructed a goal and then another cue instructed which action to perform. The GP reflected the visual cue and goal as soon as the cortex. However, action selection occurred later in the GP than cortex. Thus, the GP seems to play a more important role in goal determination than action selection.
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Lee, Whittington, and Kopell review recent studies of the role of beta-band oscillations in top-down control of attention and model it. In their model, top-down beta rhythms activate layer-specific ascending projections that mediate biased competition. Interneurons resonate with the beta oscillations and help modulate superficial layer activity according to attentional demands.
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Christian Ruff pays tribute to the late, great, Jon Driver by reviewing neural mechanisms of top-down control of attention and memory.
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Shenhav, Botvinick, and Cohen tie together a number of observations and notions into a new theory of ACC function: allocation of control based on an evaluation of the expected value of control (EVC).