Figure 4

Within-channel (MUA) stabilities of left-ECR-related activity over time. X-axis denotes time scale of comparison (H: hours; D: days). Y-axis measures are normalized to the range [0, 1], higher values denoting greater stability. Bars show mean values + /- 1 SE. (*), (**), and (***) denote significance levels of 0.05, 0.01, and 0.001 respectively. (A) Firing strength stability significantly decreased from hours to days, and was higher for contralateral than ipsilateral channels. There was a significant hemisphere—by–timescale interaction, with a significant decrease in contralateral channel stability as the period between recordings varied from hours to days, but no corresponding significant difference in ipsilateral stability over timescale. (B) Firing dynamic stability (cross-correlation between z-scored PETHs) did not significantly decrease from hours to days in both hemispheres. There was a significant main effect of brain hemisphere, with contralateral channels being more stable than ipsilateral across hours and days. (C–D) Comparative stability across areas, pooled over brain hemisphere. (C) Firing strength stability (relative change in z-score of firing rate) by cortical area, over time. Stability significantly decreased over time from hours to days, with no significant difference between cortical areas. (D) Firing dynamic stability was invariant within areas from hours to days, but was significantly higher in sensory than motor channels.