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Is Working More Costly than Waiting in Monkeys?

We studied how value for instrumental action is discounted by predicted effort and delay. The monkeys were trained to perform instrumental trials that required a bar release when a visual target changed from red-to-green. There were two trial conditions. In delay trials, after the monkeys performed...

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Autores principales: Minamimoto, Takafumi, Hori, Yukiko, Richmond, Barry J.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2012
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3492350/
https://www.ncbi.nlm.nih.gov/pubmed/23144881
http://dx.doi.org/10.1371/journal.pone.0048434
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author Minamimoto, Takafumi
Hori, Yukiko
Richmond, Barry J.
author_facet Minamimoto, Takafumi
Hori, Yukiko
Richmond, Barry J.
author_sort Minamimoto, Takafumi
collection PubMed
description We studied how value for instrumental action is discounted by predicted effort and delay. The monkeys were trained to perform instrumental trials that required a bar release when a visual target changed from red-to-green. There were two trial conditions. In delay trials, after the monkeys performed one instrumental trial correctly a reward was delivered 0–7 seconds later. In work trials, the monkeys had to perform 0, 1, or 2 additional instrumental trials to obtain a reward. The lengths of trials in delay matched the time it took to complete work trials. The length of delay or number of trials was indicated by a visual cue presented throughout the trial. Our hypothesis was that the monkeys would all show temporal discounting of reward in the delay trials, and that in the work trials the monkeys’ performance might reflect an additional cost due to working. The error rate increased linearly as remaining cost increased for all 8 monkeys. For 4 monkeys the error rate was significantly larger in work trials than in delay trials (effort sensitive monkeys). For the other 4 monkeys there was no significant difference in error rate (effort insensitive monkeys). Since the error rate has an inverse relation with value for action, these results suggest that value is discounted hyperbolically by effort as well as by delay. Error rates generally increased as the testing sessions progressed and the total reward accumulated (i.e., effect of reward devaluation). The relative impact of delay and effort on error rates was reasonably stable within subjects. Thus, within the monkey population there seems to be a significant dichotomy in the sensitivity governing whether working is more costly than waiting, possibly arising from a constitutional or genetic trait.
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spelling pubmed-34923502012-11-09 Is Working More Costly than Waiting in Monkeys? Minamimoto, Takafumi Hori, Yukiko Richmond, Barry J. PLoS One Research Article We studied how value for instrumental action is discounted by predicted effort and delay. The monkeys were trained to perform instrumental trials that required a bar release when a visual target changed from red-to-green. There were two trial conditions. In delay trials, after the monkeys performed one instrumental trial correctly a reward was delivered 0–7 seconds later. In work trials, the monkeys had to perform 0, 1, or 2 additional instrumental trials to obtain a reward. The lengths of trials in delay matched the time it took to complete work trials. The length of delay or number of trials was indicated by a visual cue presented throughout the trial. Our hypothesis was that the monkeys would all show temporal discounting of reward in the delay trials, and that in the work trials the monkeys’ performance might reflect an additional cost due to working. The error rate increased linearly as remaining cost increased for all 8 monkeys. For 4 monkeys the error rate was significantly larger in work trials than in delay trials (effort sensitive monkeys). For the other 4 monkeys there was no significant difference in error rate (effort insensitive monkeys). Since the error rate has an inverse relation with value for action, these results suggest that value is discounted hyperbolically by effort as well as by delay. Error rates generally increased as the testing sessions progressed and the total reward accumulated (i.e., effect of reward devaluation). The relative impact of delay and effort on error rates was reasonably stable within subjects. Thus, within the monkey population there seems to be a significant dichotomy in the sensitivity governing whether working is more costly than waiting, possibly arising from a constitutional or genetic trait. Public Library of Science 2012-11-07 /pmc/articles/PMC3492350/ /pubmed/23144881 http://dx.doi.org/10.1371/journal.pone.0048434 Text en © 2012 Minamimoto et al http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.
spellingShingle Research Article
Minamimoto, Takafumi
Hori, Yukiko
Richmond, Barry J.
Is Working More Costly than Waiting in Monkeys?
title Is Working More Costly than Waiting in Monkeys?
title_full Is Working More Costly than Waiting in Monkeys?
title_fullStr Is Working More Costly than Waiting in Monkeys?
title_full_unstemmed Is Working More Costly than Waiting in Monkeys?
title_short Is Working More Costly than Waiting in Monkeys?
title_sort is working more costly than waiting in monkeys?
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3492350/
https://www.ncbi.nlm.nih.gov/pubmed/23144881
http://dx.doi.org/10.1371/journal.pone.0048434
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