Females in the forefront: time-based intervention effects on impulsive choice and interval timing in female rats

Sarah L Stuebing,Ashton Triplett,Kimberly Kirkpatrick,Andrew T Marshall

doi:10.1007/s10071-018-1208-9

Abstract

Impulsive choice has been implicated in substance abuse, gambling, obesity, and other maladaptive behaviors. Deficits in interval timing may increase impulsive choices, and therefore, could serve as an avenue through which suboptimal impulsive choices can be moderated. Temporal interventions have successfully attenuated impulsive choices in male rats, but the efficacy of a temporal intervention has yet to be assessed in female rats. As such, this experiment examined timing and choice behavior in female rats, and evaluated the ability of a temporal intervention to mitigate impulsive choice behavior. The temporal intervention administered in this study was successful in reducing impulsive choices compared to a control group. Results of a temporal bisection task indicated that the temporal intervention increased long responses at the shorter durations. Further, results from the peak trials within the choice task combined with the progressive interval task suggest that the intervention increased sensitivity to delay and enhanced timing confidence. Overall, these results indicate that a temporal intervention can be a successful avenue for reducing impulsive choice behavior in female rats, and could contribute to the development of behavioral interventions to prevent impulsive choice and maladaptive behaviors that can be applied to both sexes.

Highlights

Impulsive choice behavior entails placing a higher value on smaller sooner (SS) rewards than on larger later (LL) rewards, when LL rewards provide greater reward earning over time (Mazur 1987)
Past research has focused on several psychological mechanisms that contribute to individual differences in impulsive choice behavior, including individual differences in interval timing and delay aversion (Baumann and Odum 2012; Kim and Zauberman 2009; Marshall et al 2014; McClure et al 2014)
These results indicate that poor time discrimination, delay tolerance, and impulsive choice are interrelated, and suggest that mechanisms within the core timing system may be important targets for understanding the origins of impulsive choice

Summary

Introduction

Impulsive choice behavior entails placing a higher value on smaller sooner (SS) rewards than on larger later (LL) rewards, when LL rewards provide greater reward earning over time (Mazur 1987). Past research has focused on several psychological mechanisms that contribute to individual differences in impulsive choice behavior, including individual differences in interval timing and delay aversion (Baumann and Odum 2012; Kim and Zauberman 2009; Marshall et al 2014; McClure et al 2014). Marshall et al (2014) found that impulsive rats demonstrated poor time discrimination relative to non-impulsive individuals (see McClure et al 2014) and that impulsive rats were less tolerant of longer delays These results indicate that poor time discrimination, delay tolerance, and impulsive choice are interrelated, and suggest that mechanisms within the core timing system may be important targets for understanding the origins of impulsive choice

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