Fig. 6.
Changes in correlated activity in ABL during intertrial intervals in the early (white bars) and late (black bars) phases of precriterion training, during postcriterion performance (gray bars), and after reversal (striped bars). A, Correlated activity at short latency (within 2 msec of a spike in the reference cell) did not change significantly during training in ABL (F(2,78) = 0.48; p= 0.62). A separate analysis of neuron pairs recorded during reversals also revealed no change in correlated activity at this latency (F(1,19) = 2.31; p= 0.14). B, Changes in correlated activity at longer latency (2–10 msec after a spike in the reference cell) increased significantly during initial training (F(2,78) = 6.29; p= 0.0029). Post hoc comparisons revealed that efficacy increased between the early and late precriterion phases (p = 0.0147) but did not increase in the postcriterion phase relative to the late precriterion phase (p = 0.924). Efficacy of correlated firing within the longer latency interval did not change further after reversal (F(1,19) = 2.3;p = 0.14). C, Activity in cell pairs with correlated activity in ABL. Average firing rate is shown for both neurons within each pair that was included in the analyses presented inA and B. Note the difference in both pattern and magnitude between the minimal changes in activity and the changes in correlated firing across the training phases.