scholarly journals Saccade vigor partly reflects the subjective economic value of the visual stimulus

2019 ◽  
Author(s):  
Tehrim Yoon ◽  
Afareen Jaleel ◽  
Alaa A. Ahmed ◽  
Reza Shadmehr

AbstractDecisions are made based on the subjective value that the brain assigns to options. However, subjective value is a mathematical construct that cannot be measured directly, but rather inferred from choices. Recent results have demonstrated that reaction time and velocity of movements are modulated by reward, raising the possibility that there is a link between how the brain evaluates an option, and how it controls movements toward that option. Here, we asked people to choose among risky options represented by abstract stimuli, some associated with gain, others with loss. From their choices in decision trials we estimated the subjective value that they assigned to each stimulus. In probe trials, they were presented with a single stimulus at center and made a saccade to a peripheral location. We found that the reaction time and peak velocity of that saccade varied roughly linearly from loss to gain with the subjective value of the stimulus. Naturally, participants differed in how much they valued a given stimulus. Remarkably, those who valued a stimulus more, as evidenced by their choices in decision trials, tended to move with greater vigor in response to that stimulus in probe trials. Thus, saccade vigor partly reflected the subjective value that the brain assigned the stimulus. However, the influence of subjective value on vigor was only a modest predictor of preference: vigor in probe trials allowed us to predict choice in decision trials with roughly 60% accuracy.New and NoteworthyWe found that saccade vigor tends to vary monotonically with subjective value: smallest for stimuli that predict a loss, and highest for stimuli that predict a gain. Notably, between-subject differences in valuation could be gleaned from the between-subject differences in their patterns of vigor. However, the influence of subjective value on vigor was modest, allowing partial ability to infer subjective value for the purpose of predicting choice in decision trials.

2020 ◽  
Author(s):  
Benjamin Hayden ◽  
Yael Niv

Much of traditional neuroeconomics proceeds from the hypothesis that value is reified in the brain, that is, that there are neurons or brain regions whose responses serve the discrete purpose of encoding value. This hypothesis is supported by the finding that the activity of many neurons covaries with subjective value as estimated in specific tasks and has led to the idea that the primary function of the orbitofrontal cortex is to compute and signal economic value. Here we consider an alternative: that economic value, in the cardinal, common-currency sense, is not represented in the brain and used for choice by default. This idea is motivated by consideration of the economic concept of value, which places important epistemic constraints on our ability to identify its neural basis. It is also motivated by the behavioral economics literature, especially work on heuristics, which proposes value-free process models for much if not all of choice. Finally, it is buoyed by recent neural and behavioral findings regarding how animals and humans learn to choose between options. In light of our hypothesis, we critically reevaluate putative neural evidence for the representation of value and explore an alternative: direct learning of action policies. We delineate how this alternative can provide a robust account of behavior that concords with existing empirical data.


2021 ◽  
Author(s):  
Benjamin T. Files ◽  
Kimberly A. Pollard ◽  
Ashley H. Oiknine ◽  
Peter Khooshabeh ◽  
Antony D. Passaro

1978 ◽  
Vol 22 (1) ◽  
pp. 287-291 ◽  
Author(s):  
Christine L. Nelson ◽  
Robert M. London ◽  
Gordon H. Robinson

This experiment measured eye reaction time as a function of presence or absence of a central control task, type of command, and knowledge of target direction prior to command. It was found that eye reaction time was greater when a subject was involved in a central tracking task than when he was not; it was greater when the command was symbolic than when it was spatial; and it was longer when the target direction was unknown prior to command. These variables also interacted, so that the effect of unknown target direction was greater with a symbolic command. Results of this experiment also showed that subjects sometimes used an initial compensatory pattern of eye-head movements. There were large inter-subject differences, but use of compensation generally increased with complexity of centrally located information which required processing. It thus appears that reaction time of the eye responds to information processing variables in a manner similar to other motor response systems.


2020 ◽  
Author(s):  
Sebastian Bobadilla-Suarez ◽  
Olivia Guest ◽  
Bradley C. Love

AbstractRecent work has considered the relationship between value and confidence in both behavior and neural representation. Here we evaluated whether the brain organizes value and confidence signals in a systematic fashion that reflects the overall desirability of options. If so, regions that respond to either increases or decreases in both value and confidence should be widespread. We strongly confirmed these predictions through a model-based fMRI analysis of a mixed gambles task that assessed subjective value (SV) and inverse decision entropy (iDE), which is related to confidence. Purported value areas more strongly signalled iDE than SV, underscoring how intertwined value and confidence are. A gradient tied to the desirability of actions transitioned from positive SV and iDE in ventromedial prefrontal cortex to negative SV and iDE in dorsal medial prefrontal cortex. This alignment of SV and iDE signals could support retrospective evaluation to guide learning and subsequent decisions.


2018 ◽  
Author(s):  
Bruno Verschuere ◽  
Nils Köbis ◽  
yoella meyer ◽  
David Gertler Rand ◽  
Shaul Shalvi

Lying typically requires greater mental effort than telling the truth. Imposing cognitive load may improve lie detection by limiting the cognitive resources needed to lie effectively, thereby increasing the difference in speed between truths and lies. We test this hypothesis meta-analytically. Across 21 studies using response-time (RT) paradigms (11 unpublished; total N = 792), we consistently found that truth telling was faster than lying, but found no evidence that imposing cognitive load increased that difference (Control, d = 1.45; Load, d = 1.28). Instead, load significantly decreased the lie-truth RT difference by increasing the RT of truths, g = -.18, p = .027. Our findings therefore suggest that imposing cognitive load does not necessarily improve RT-based lie detection, and may actually worsen it by taxing the mental system and thus impeding people’s ability to easily—and thus quickly—tell the truth


2018 ◽  
Vol 7 (3) ◽  
pp. 462-469 ◽  
Author(s):  
Bruno Verschuere ◽  
Nils C. Köbis ◽  
Yoella Bereby-Meyer ◽  
David Rand ◽  
Shaul Shalvi

2020 ◽  
Author(s):  
Charidimos Tzagarakis ◽  
Sarah West ◽  
Giuseppe Pellizzer

AbstractVisual information about an upcoming target can be used to prepare an appropriate motor response and reduce its reaction time. However, when the anticipation is incorrect and the planned response must be changed, the reaction time is lengthened. Here, we investigated the brain mechanisms associated with the reliability and validity of visual information used for motor preparation. We recorded brain activity using magnetoencephalography (MEG) during a delayed reaching task in which a visual cue provided valid information about the location of the upcoming target with 50, 75 or 100% reliability. We found that reaction time increased as cue reliability decreased and that trials with invalid cues had longer reaction times than trials with valid cues. MEG channel analysis showed that beta-band power from left mid-anterior channels correlated with the reliability of the cue after cue onset but before target onset. This effect was source localized over a large motor-related cortical and subcortical network. In addition, during invalid-cue trials there was a phasic increase of theta-band power following target onset from left posterior channels, localized to the left occipito-parietal cortex. Furthermore, the theta-beta cross-frequency coupling between left mid-occipital and motor cortex also transiently increased before responses to invalid-cue trials. In conclusion, beta-band power in motor-related areas reflected the reliability of visual information used during motor preparation, whereas phasic theta-band activity signaled whether the target was at the expected location or not. These results elucidate mechanisms of interaction between attentional and motor processes.Significance StatementWe used magnetoencephalography to investigate how the brain mechanisms preparing a motor response take into account the reliability of information about the upcoming location of a target to reach, and how these mechanisms adjust when that information turns out to be incorrect. We found that during the response preparation, the power of motor-related beta-band oscillations changed with the reliability of the visual information. In addition, we found that after the onset of the target the power of the left occipito-parietal theta-band signaled whether the prior information was correct or not. The pattern of activity of the beta-band and theta-band explain the pattern of latency of responses in the task, and demonstrate how attentional and motor processes interact.


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