Figure 1.
Task and recording sites (A) Time-line of the memory-guided center-out reach task in an example trial with early context (colored square, instructing pro- or antireach) and early spatial (white disc at 0, 90, 180, or 270o position) cueing (ECES condition). Set of all 4 possible cueing conditions, depending on the timing of the context and the spatial cue during the pre-cue and go-cue period, respectively. (B) Cognitive processes required at different times in the 4 cueing conditions (MGS – motor-goal selection, WME, working memory encoding (S: spatial, C: context), WMR, working memory retrieval) and relevant comparisons for identifying which process best explains any observed neural modulations between cueing conditions. (C) Hypotheses and corresponding predictions for the times at which frontoparietal interaction should occur according to its hypothesized role in motor-goal selection (= space-context integration), motor initiation (motor-goal confirmation, efference copy), spatial WM encoding, or spatial WM retrieval. Note that our hypotheses do not make predictions about the direction of interaction (PMd→PRR or PRR→PMd), the relative amplitudes of functional interaction, the relevant LFP signal frequency band, or the precise temporal dynamics, but mostly about the timing within the trial. (D) Position of recording sites in parietal and premotor cortices in monkey A for all n recording sessions (n = 48) based on post-surgical MR imaging. Color coded legend indicates the number of electrode penetrations at each site. See Supplementary Figure S1 for an explanation of the tilted projections and corresponding data from monkey S. ips, intraparietal sulcus; cis, cingulate sulcus; pos, parieto-occipital sulcus; as, arcuate sulcus; cs, central sulcus.