Figure 4.

Spiking activity recorded during the orthogonal task. A–D, First column, Population PSTHs showing the firing rate during the two stimulus presentations (S1 and S2) of repetition trials in repetition blocks (red) and alternation blocks (blue), as well as alternation trials in repetition blocks (orange) and alternation blocks (light blue). Second column, AIs for each trial × block combination (positive values mean suppression for S2), stimulus-specific effects (AI repetition trials − AI alternation trials), and block effects (difference in stimulus specific effect: repetition block − adaptation block). Third column, Scatter plot of AIs for repetition trials in repetition blocks (abscissa) and alternation blocks (ordinate). Triangles on axes indicate mean values. Fourth column, Scatter plot of AIs for alternations trials (see third column). A, Monkey G single-unit results; B, Monkey G multiunit results; C, Monkey D single-unit results; D, Monkey D multiunit results.