Top-Down Versus Bottom-Up Control of Attention in the Prefrontal and Posterior Parietal Cortices

@article{citeulike:1197981, abstract = {Attention can be focused volitionally by "top-down" signals derived from task demands and automatically by "bottom-up" signals from salient stimuli. The frontal and parietal cortices are involved, but their neural activity has not been directly compared. Therefore, we recorded from them simultaneously in monkeys. Prefrontal neurons reflected the target location first during top-down attention, whereas parietal neurons signaled it earlier during bottom-up attention. Synchrony between frontal and parietal areas was stronger in lower frequencies during top-down attention and in higher frequencies during bottom-up attention. This result indicates that top-down and bottom-up signals arise from the frontal and sensory cortex, respectively, and different modes of attention may emphasize synchrony at different frequencies. 10.1126/science.1138071}, author = {Buschman, Timothy J. and Miller, Earl K. }, citeulike-article-id = {1197981}, comment = {* multielectrode examination of prefrontal (PFC and FEF) and parietal (LIP) cortices during top-down and bottom-up attention tasks, primary goal is to examine the relative timing of attention-related activity * in the pop-out task, the target stimuli differed in both color and orientation from the other stimuli; such salience draws bottom-up attention * in the visual search task, each distractor differed independently from the target and the target had to be identified by its remembered appearance (top-down control); accordingly, RTs were larger in the visual search compared to the pop-out paradigm * each recording session contained <50 simultaneous electrodes, stimuli were not optimized for RF activity and neurons were not preselected (802 neurons in 24 sessions) * the authors determined when each neuron selected the target location using a "mutual information statistic" (which is never defined) * in the pop-out task, each area contained a population of neurons that found the target early an d a separate population later, post saccade; during pop-out, LIP neurons found the target first, followed by PFC and then FEF * ''the two populations may correspond to peripheral and central RFs, respectively'' * during visual search, the order was reversed: PFC and FEF found the target first, followed by LIP; most neurons found the target late, either peri- or post-saccadically * during both search and pop-out there was an increase in LIP-frontal cortex LFP coherence in a middle (22-34 Hz) and an upper (35-55 Hz) band; these frequency bands showed task selectivity, as the middle band showed higher coherence during top-down search and the upper band showed higher coherence during pop-out * the authors suggest that bottom-up signals first appear in LIP (from lower order visual cotices), but top-down signals appear first in frontal cortex * ''in a commentary, Schall et al argue that the reported LIP neural latencies are too short and take issue with the simultaneous multiple electrode approach, particularly the inability to optimize stimuli for each neuron'' * ''Miller and Buschman respond by emphasizing that their analysis reported the leading edge of selectivity rather than average latencies, and defending their recording technique as an unbiased approach''}, doi = {http://dx.doi.org/10.1126/science.1138071}, journal = {Science}, keywords = {\_note, attention, fef, lip, monkey, neurophysiology, prefrontal}, month = {March}, number = {5820}, pages = {1860--1862}, posted-at = {2007-03-30 14:29:30}, priority = {2}, title = {Top-Down Versus Bottom-Up Control of Attention in the Prefrontal and Posterior Parietal Cortices}, url = {http://dx.doi.org/10.1126/science.1138071}, volume = {315}, year = {2007} }

TY - JOUR ID - citeulike:1197981 L3 - citeulike-article-id:1197981 TI - Top-Down Versus Bottom-Up Control of Attention in the Prefrontal and Posterior Parietal Cortices JF - Science VL - 315 IS - 5820 SP - 1860 EP - 1862 N2 - Attention can be focused volitionally by "top-down" signals derived from task demands and automatically by "bottom-up" signals from salient stimuli. The frontal and parietal cortices are involved, but their neural activity has not been directly compared. Therefore, we recorded from them simultaneously in monkeys. Prefrontal neurons reflected the target location first during top-down attention, whereas parietal neurons signaled it earlier during bottom-up attention. Synchrony between frontal and parietal areas was stronger in lower frequencies during top-down attention and in higher frequencies during bottom-up attention. This result indicates that top-down and bottom-up signals arise from the frontal and sensory cortex, respectively, and different modes of attention may emphasize synchrony at different frequencies. 10.1126/science.1138071 KW - _note KW - attention KW - fef KW - lip KW - monkey KW - neurophysiology KW - prefrontal N1 - * multielectrode examination of prefrontal (PFC and FEF) and parietal (LIP) cortices during top-down and bottom-up attention tasks, primary goal is to examine the relative timing of attention-related activity * in the pop-out task, the target stimuli differed in both color and orientation from the other stimuli; such salience draws bottom-up attention * in the visual search task, each distractor differed independently from the target and the target had to be identified by its remembered appearance (top-down control); accordingly, RTs were larger in the visual search compared to the pop-out paradigm * each recording session contained <50 simultaneous electrodes, stimuli were not optimized for RF activity and neurons were not preselected (802 neurons in 24 sessions) * the authors determined when each neuron selected the target location using a "mutual information statistic" (which is never defined) * in the pop-out task, each area contained a population of neurons that found the target early an d a separate population later, post saccade; during pop-out, LIP neurons found the target first, followed by PFC and then FEF * ''the two populations may correspond to peripheral and central RFs, respectively'' * during visual search, the order was reversed: PFC and FEF found the target first, followed by LIP; most neurons found the target late, either peri- or post-saccadically * during both search and pop-out there was an increase in LIP-frontal cortex LFP coherence in a middle (22-34 Hz) and an upper (35-55 Hz) band; these frequency bands showed task selectivity, as the middle band showed higher coherence during top-down search and the upper band showed higher coherence during pop-out * the authors suggest that bottom-up signals first appear in LIP (from lower order visual cotices), but top-down signals appear first in frontal cortex * ''in a commentary, Schall et al argue that the reported LIP neural latencies are too short and take issue with the simultaneous multiple electrode approach, particularly the inability to optimize stimuli for each neuron'' * ''Miller and Buschman respond by emphasizing that their analysis reported the leading edge of selectivity rather than average latencies, and defending their recording technique as an unbiased approach'' AU - Buschman, Timothy AU - Miller, Earl PY - 2007/03/30/ UR - http://dx.doi.org/10.1126/science.1138071 ER -