The basal ganglia are known to control behavior using reward information; however, recent experiments have revealed that the basal ganglia contribute to the processing of salient non-rewarding events as well. Here, we suggest that the temporal dynamics of the response of dopaminergic neurons (DANs) enable the basal ganglia to have a dual role. The fast DAN response to salient events is mediated thorough the brainstem-basal ganglia loop. Forebrain loops enable the second phase of the dopaminergic responses that require highly processed information. The convergent encoding of fast/salient and slow/detailed information suggests that the basal ganglia control the tradeoff between fast and immediate responses to environmental events and slow responses that are only executed after substantial environmental information has been gathered.
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