What makes a reach movement effortful? Physical effort discounting supports common minimization principles in decision making and motor control.
When deciding between alternative options, a rational agent chooses on the basis of the desirability of each outcome, including associated costs. As different options typically result in different actions, the effort associated with each action is an essential cost parameter. How do humans discount...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Public Library of Science (PLoS)
2017-06-01
|
| Series: | PLoS Biology |
| Online Access: | http://europepmc.org/articles/PMC5460791?pdf=render |
| _version_ | 1818651986705252352 |
|---|---|
| author | Pierre Morel Philipp Ulbrich Alexander Gail |
| author_facet | Pierre Morel Philipp Ulbrich Alexander Gail |
| author_sort | Pierre Morel |
| collection | DOAJ |
| description | When deciding between alternative options, a rational agent chooses on the basis of the desirability of each outcome, including associated costs. As different options typically result in different actions, the effort associated with each action is an essential cost parameter. How do humans discount physical effort when deciding between movements? We used an action-selection task to characterize how subjective effort depends on the parameters of arm transport movements and controlled for potential confounding factors such as delay discounting and performance. First, by repeatedly asking subjects to choose between 2 arm movements of different amplitudes or durations, performed against different levels of force, we identified parameter combinations that subjects experienced as identical in effort (isoeffort curves). Movements with a long duration were judged more effortful than short-duration movements against the same force, while movement amplitudes did not influence effort. Biomechanics of the movements also affected effort, as movements towards the body midline were preferred to movements away from it. Second, by introducing movement repetitions, we further determined that the cost function for choosing between effortful movements had a quadratic relationship with force, while choices were made on the basis of the logarithm of these costs. Our results show that effort-based action selection during reaching cannot easily be explained by metabolic costs. Instead, force-loaded reaches, a widely occurring natural behavior, imposed an effort cost for decision making similar to cost functions in motor control. Our results thereby support the idea that motor control and economic choice are governed by partly overlapping optimization principles. |
| first_indexed | 2024-12-17T02:14:50Z |
| format | Article |
| id | doaj.art-d6f51621bba24e3488969573d9ab9e71 |
| institution | Directory Open Access Journal |
| issn | 1544-9173 1545-7885 |
| language | English |
| last_indexed | 2024-12-17T02:14:50Z |
| publishDate | 2017-06-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS Biology |
| spelling | doaj.art-d6f51621bba24e3488969573d9ab9e712022-12-21T22:07:27ZengPublic Library of Science (PLoS)PLoS Biology1544-91731545-78852017-06-01156e200132310.1371/journal.pbio.2001323What makes a reach movement effortful? Physical effort discounting supports common minimization principles in decision making and motor control.Pierre MorelPhilipp UlbrichAlexander GailWhen deciding between alternative options, a rational agent chooses on the basis of the desirability of each outcome, including associated costs. As different options typically result in different actions, the effort associated with each action is an essential cost parameter. How do humans discount physical effort when deciding between movements? We used an action-selection task to characterize how subjective effort depends on the parameters of arm transport movements and controlled for potential confounding factors such as delay discounting and performance. First, by repeatedly asking subjects to choose between 2 arm movements of different amplitudes or durations, performed against different levels of force, we identified parameter combinations that subjects experienced as identical in effort (isoeffort curves). Movements with a long duration were judged more effortful than short-duration movements against the same force, while movement amplitudes did not influence effort. Biomechanics of the movements also affected effort, as movements towards the body midline were preferred to movements away from it. Second, by introducing movement repetitions, we further determined that the cost function for choosing between effortful movements had a quadratic relationship with force, while choices were made on the basis of the logarithm of these costs. Our results show that effort-based action selection during reaching cannot easily be explained by metabolic costs. Instead, force-loaded reaches, a widely occurring natural behavior, imposed an effort cost for decision making similar to cost functions in motor control. Our results thereby support the idea that motor control and economic choice are governed by partly overlapping optimization principles.http://europepmc.org/articles/PMC5460791?pdf=render |
| spellingShingle | Pierre Morel Philipp Ulbrich Alexander Gail What makes a reach movement effortful? Physical effort discounting supports common minimization principles in decision making and motor control. PLoS Biology |
| title | What makes a reach movement effortful? Physical effort discounting supports common minimization principles in decision making and motor control. |
| title_full | What makes a reach movement effortful? Physical effort discounting supports common minimization principles in decision making and motor control. |
| title_fullStr | What makes a reach movement effortful? Physical effort discounting supports common minimization principles in decision making and motor control. |
| title_full_unstemmed | What makes a reach movement effortful? Physical effort discounting supports common minimization principles in decision making and motor control. |
| title_short | What makes a reach movement effortful? Physical effort discounting supports common minimization principles in decision making and motor control. |
| title_sort | what makes a reach movement effortful physical effort discounting supports common minimization principles in decision making and motor control |
| url | http://europepmc.org/articles/PMC5460791?pdf=render |
| work_keys_str_mv | AT pierremorel whatmakesareachmovementeffortfulphysicaleffortdiscountingsupportscommonminimizationprinciplesindecisionmakingandmotorcontrol AT philippulbrich whatmakesareachmovementeffortfulphysicaleffortdiscountingsupportscommonminimizationprinciplesindecisionmakingandmotorcontrol AT alexandergail whatmakesareachmovementeffortfulphysicaleffortdiscountingsupportscommonminimizationprinciplesindecisionmakingandmotorcontrol |