Increasing motivation can positively impact cognitive performance. Here we employed a cognitive timing task that allows us to detect changes in cognitive performance that are not influenced by general activity or arousal factors such as the speed or persistence of responding. This approach allowed us to manipulate motivation using three different methods; molecular/genetic, behavioral and pharmacological. Increased striatal D2Rs resulted in deficits in temporal discrimination. Switching off the transgene improved motivation in earlier studies, and here partially rescued the temporal discrimination deficit. To manipulate motivation behaviorally, we altered reward magnitude and found that increasing reward magnitude improved timing in control mice and partially rescued timing in the transgenic mice. Lastly, we manipulated motivation pharmacologically using a functionally selective 5-HT2C receptor ligand, SB242084, which we previously found to increase incentive motivation. SB242084 improved temporal discrimination in both control and transgenic mice. Thus, while there is a general intuitive belief that motivation can affect cognition, we here provide a direct demonstration that enhancing motivation, in a variety of ways, can be an effective strategy for enhancing temporal cognition. Understanding the interaction of motivation and cognition is of clinical significance since many psychiatric disorders are characterized by deficits in both domains.
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