During this task, monkeys were presented with a model object R428 cell line consisting of a varying configuration of square components (Fig. 6A; ‘Model’), and were required to remember the model configuration during a subsequent delay period. At the end of the delay, they were presented with a copy of the preceding model object, identical except that a single component was missing (Fig. 6A; ‘Copy’). The task was for monkeys to localize and replace the missing component, which they did by timing when they pressed a single response key in relation to a choice sequence

(Fig. 6A; ‘1st choice’, ‘2nd choice’) at the end of the trial. The sequential choice method of behavioural report ensured that the locations of object components were not confounded with the direction of the upcoming movement. This facilitated identification of neural signals related to a cognitive analysis of object structure, and made it possible to differentiate these signals from others present in parietal cortex that code the direction of forthcoming movements. However,

it is important to note that, as the construction task did not require monkeys to physically assemble objects, how signals in parietal cortex that PR-171 in vivo reflect object structure ultimately shape motor commands to direct object construction has yet to be addressed. During the copy period when monkeys were required to localize the component that was missing from the copy object relative to the preceding model, the activity of single neurons in area 7a reflected Cytoskeletal Signaling inhibitor this spatial computation by signalling the location of the missing component (Fig. 6B; Chafee et al., 2005). This neural signal did not reflect the spatial features of the visual input, as neural activity varied to reflect the location of the missing component even when the form and position of the copy object remained constant (Fig. 6B; top row). Neurons were similarly

activated by diverse pairs of model and copy objects that jointly localized the missing component to each neurons preferred position (Fig. 6B; second column from left). Nor did activity reflect a spatial motor plan, as the spatial information coded by neural activity was uncorrelated with the direction of the forthcoming motor response (which did not vary across trials). Rather, the signal appeared to be a cellular correlate of a spatial cognitive process analyzing object structure in order to direct the construction operation, without being correlated with the spatial aspects of individual stimuli presented or movements made during the trial.