Abstract

This chapter considers how dynamic brain states continuously fine-tune processing to accommodate changes in behavioural context and task goals. First, the authors review the extant literature suggesting that content-specific patterns of preparatory activity bias competitive processing in visual cortex to favour behaviourally relevant input. Next, they consider how higher-level brain areas might provide a top-down attentional signal for modulating baseline visual activity. Extensive evidence suggests that working memory representations in prefrontal cortex are especially important for generating and maintaining biases in preparatory visual activity via modulatory feedback. Although it is often proposed that such working memory representations are maintained via persistent prefrontal activity, the authors review more recent evidence that rapid short-term synaptic plasticity provides a common substrate for maintaining the content of past experience and the rules for guiding future goal-directed processing.