Quantifying the contribution of individual variation in timing to delay-discounting

Evgeniya Lukinova,Jeffrey C Erlich

doi:10.1038/s41598-021-97496-w

Evgeniya Lukinova, Jeffrey C Erlich

Open Access

https://doi.org/10.1038/s41598-021-97496-w

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Abstract

Delay-discounting studies in neuroscience, psychology, and economics have been mostly focused on concepts of self-control, reward evaluation, and discounting. Another important relationship to consider is the link between intertemporal choice and time perception. We presented 50 college students with timing tasks on the range of seconds to minutes and intertemporal-choice tasks on both the time-scale of seconds and of days. We hypothesized that individual differences in time perception would influence decisions about short experienced delays but not long delays. While we found some evidence that individual differences in internal clock speed account for some unexplained variance between choices across time-horizons, overall our findings suggest a nominal contribution of the altered sense of time in intertemporal choice.

Highlights

Delay-discounting studies in neuroscience, psychology, and economics have been mostly focused on concepts of self-control, reward evaluation, and discounting
Two groups of subjects in this study participated in intertemporal choice tasks to estimate discount factors and timing experiments to estimate internal clock speeds
We measured one aspect of timing, internal clock speed, estimated using time estimation and production tasks to test whether variation in ICS explains variation in subjects intertemporal choices between tasks where the delays are experienced versus not experienced

Summary

Results

Two groups of subjects in this study participated in intertemporal choice tasks to estimate discount factors and timing experiments to estimate internal clock speeds. We tested our second hypothesis: whether timing might account for variance in discount factor in the short task beyond what was explained by the discount factor in the long task (but not vice-versa) To this end, we ran linear regressions according to Eqs. Dropping ICSe (a proxy for ICS) resulted in a significant decrease in the likelihood for explaining short delay ( N = 26, Fig. 5C), but not long delay task in the new group. If individual differences in ICS influenced choices in the short delay-discounting task, using subjective time (ST), rather than objective time should improve our ability to predict subjects’ choices. To this end, we compared the model with objective delays (‘obj’) to four models with subjective delays:. ‘subjTel’—where delays in seconds were substituted by the linear fits based on time estimation,

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Discussion

Methods