We found that average RT correlations calculated during groups

HDAC activity assay of trials when beta-band power was relatively constant (R = 0.32) were significantly lower than correlations calculated in the same way when beta-band power varied (R = 0.37). The difference in RT correlation was significant (p < 0.05, rank-sum test). An average of 18% of the correlation between saccade and reach RTs could be explained by variations in beta-band power in area LIP. At some sites, beta-band power could explain over 60% of the RT correlations. Since SRT and RRT are less correlated when beta-band power does not vary, variation in the level of beta-band activity can contribute to RT correlations. Beta-band power is selective for RT in other areas of posterior parietal cortex and is not selective for RT in nearby occipital cortex. We analyzed a complementary data set of 122 LFP recordings in PRR and 36 visually responsive recordings in V3d, located along the lunate sulcus, with at least 60 trials in each condition, and we plotted RT selectivity from all three areas as the trial progressed (Figure 7).

Beta-band LFP activity selleck products in area LIP was increasingly selective for RT as the memory period progressed (Figures 7A and 7B). The RT effect was also robust in PRR where 28/122 sessions (23%) were significantly selective when trials were sorted by RRT, and 18/122 sessions (15%) were significantly selective when trials were sorted as a function of SRT (Figures 7C and 7D). In comparison, at 45 Hz, only 12/122 sessions (10%, data not shown) were significantly selective for RRT, and 7/122 sessions (6%, data not shown) were selective for SRT, which is not statistically significant (Binomial test). Beta-band power in the visual areas we studied, in contrast, is not selective throughout the trial (Figures 7E and 7F). PRR LFP recordings also showed Target Selective Inhibitor Library RT selectivity for both movements at the same site (data not shown). As in area LIP, LFP activity at 15 Hz in PRR was significantly selective

for both SRT and RRT at 22/122 sites (18%; p < 0.01), while at 45 Hz, LFP was selective for both RTs at only 4/122 sites (3%) which, as in area LIP, is not statistically significant. Therefore, LFP beta-band RT selectivity is a feature of areas within the intraparietal sulcus of the posterior parietal cortex and is not present in nearby visual cortex. To be involved in guiding movements, neural activity should be selective for the properties of the movement, such as the direction of the movement and the type of movement (coordinated or isolated). Therefore, we examined the directional and movement type selectivity of LFP power in all 105 recordings in area LIP and compared this with LFP power in the 135 recordings from PRR and 36 visually responsive recordings from nearby V3d (Figure 8).