Dotson NM, Salazar RF, Gray CM (2014). Fronto-parietal correlation dynamics reveal interplay between integration and segregation during visual working memory. J Neuroscience, 34(41):13600-13.

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Abstract

Working memory requires large-scale cooperation among widespread cortical and subcortical brain regions. Importantly, these processes must achieve an appropriate balance between functional integration and segregation, which are thought to be mediated by task-dependent spatiotemporal patterns of correlated activity. Here, we used cross-correlation analysis to estimate the incidence, magnitude, and relative phase angle of temporally correlated activity from simultaneous local field potential recordings in a network of prefrontal and posterior parietal cortical areas in monkeys performing an oculomotor, delayed match-to-sample task. We found long-range intraparietal and frontoparietal correlations that display a bimodal distribution of relative phase values, centered near 0° and 180°, suggesting a possible basis for functional segregation among distributed networks. Both short- and long-range correlations display striking task-dependent transitions in strength and relative phase, indicating that cognitive events are accompanied by robust changes in the pattern of temporal coordination across the frontoparietal network.

Monosov IE, Sheinberg DL, Thompson KG (2011). The effects of prefrontal cortex inactivation on object responses of single neurons in the inferotemporal cortex during visual search...

 J Neuroscience, 31, 15956-15961.

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Abstract

Inferotemporal cortex (IT) is believed to be directly involved in object processing and necessary for accurate and efficient object recognition. The frontal eye field (FEF) is an area in the primate prefrontal cortex that is involved in visual spatial selection and is thought to guide spatial attention and eye movements. We show that object selective responses of IT neurons and behavioral performance are affected by changes in frontal eye field activity. This was found in monkeys performing a search classification task by temporarily inactivating sub-regions of FEF while simultaneously recording the activity from single neurons in IT. The effect on object selectivity and performance was specific, occurring in a predictable spatially dependent manner and was strongest when the IT neuron’s preferred target was presented in the presence of distractors. FEF inactivation did not affect IT responses on trials in which the non-preferred target was presented in the search array.

Keywords: visual search, perception, attention, object recognition, monkey, physiology