Is the short-latency dopamine response too short to signal reward error?

Unexpected stimuli that are behaviourally significant have the capacity to elicit a short-latency, short-duration burst of firing in mesencephalic dop aminergic neurones. An influential interpretation of the experimental data that characterize this response proposes that: dopaminergic neurones have a crucial role in reinforcement learning because they signal error in the pr ediction of future reward. In this article we propose a different functiona l role for this 'short-latency dopamine response' in the mechanisms that un derlie associative learning. We suggest that the initial burst of dopaminer gic-neurone firing could represent an essential component in the process of switching attentional and behavioural selections to unexpected, behavioura lly important stimuli. This switching response could be a crucial prerequis ite for associative learning and might be part of a general short-latency r esponse that is mediated by catecholamines and prepares the organism for an appropriate reaction to biologically significant events.