Fig. 7: Summary of results.

During the early evoked period, interactions between areas tend to be feedforward-dominated. Later during the evoked period and during the spontaneous period, interactions between areas become feedback-dominated. Furthermore, feedforward- and feedback-dominated interactions involve different population activity patterns. Larger ellipses represent the set of all activity patterns one might observe in either the V1 or the V2/V4 populations. The smaller ellipses represent the activity patterns most related across the two areas.