Microsaccade direction reflects the economic value of potential saccade goals and predicts saccade choice

2016 ◽  
Vol 115 (2) ◽  
pp. 741-751 ◽  
Author(s):  
Gongchen Yu (余功臣) ◽  
Baijie Xu (徐佰杰) ◽  
Yuchen Zhao (赵宇晨) ◽  
Beizhen Zhang (张倍祯) ◽  
Mingpo Yang (杨明坡) ◽  
...  
Keyword(s):  
Small Amplitude ◽  
Human Subjects ◽  
Economic Value ◽  
Decision Processes ◽  
Complete Darkness ◽  
Sensory Stimuli ◽  
Attentional Processes ◽  
Cognitive States ◽  
Subjective Value ◽  
Voluntary Choice

Microsaccades are small-amplitude (typically <1°), ballistic eye movements that occur when attempting to fixate gaze. Initially thought to be generated randomly, it has recently been established that microsaccades are influenced by sensory stimuli, attentional processes, and certain cognitive states. Whether decision processes influence microsaccades, however, is unknown. Here, we adapted two classic economic tasks to examine whether microsaccades reflect evolving saccade decisions. Volitional saccade choices of monkey and human subjects provided a measure of the subjective value of targets. Importantly, analyses occurred during a period of complete darkness to minimize the known influence of sensory and attentional processes on microsaccades. As the time of saccadic choice approached, microsaccade direction became the following: 1) biased toward targets as a function of their subjective value and 2) predictive of upcoming, voluntary choice. Our results indicate that microsaccade direction is influenced by and is a reliable tell of evolving saccade decisions. Our results are consistent with dynamic decision processes within the midbrain superior colliculus; that is, microsaccade direction is influenced by the transition of activity toward caudal saccade regions associated with high saccade value and/or future saccade choice.

scholarly journals Normalized value coding explains dynamic adaptation in the human valuation process

2017 ◽  
Vol 114 (48) ◽  
pp. 12696-12701 ◽  
Author(s):  
Mel W. Khaw ◽  
Paul W. Glimcher ◽  
Kenway Louie
Keyword(s):  
Context Effects ◽  
Human Subjects ◽  
Neural Representation ◽  
Dynamic Adaptation ◽  
Temporal Context ◽  
Decision Variable ◽  
Average Value ◽  
Subjective Value ◽  
Valuation Process ◽  
Value Coding

The notion of subjective value is central to choice theories in ecology, economics, and psychology, serving as an integrated decision variable by which options are compared. Subjective value is often assumed to be an absolute quantity, determined in a static manner by the properties of an individual option. Recent neurobiological studies, however, have shown that neural value coding dynamically adapts to the statistics of the recent reward environment, introducing an intrinsic temporal context dependence into the neural representation of value. Whether valuation exhibits this kind of dynamic adaptation at the behavioral level is unknown. Here, we show that the valuation process in human subjects adapts to the history of previous values, with current valuations varying inversely with the average value of recently observed items. The dynamics of this adaptive valuation are captured by divisive normalization, linking these temporal context effects to spatial context effects in decision making as well as spatial and temporal context effects in perception. These findings suggest that adaptation is a universal feature of neural information processing and offer a unifying explanation for contextual phenomena in fields ranging from visual psychophysics to economic choice.

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
Keyword(s):  
Reaction Time ◽  
Peak Velocity ◽  
Economic Value ◽  
Single Stimulus ◽  
Peripheral Location ◽  
Subjective Value ◽  
Abstract Stimuli ◽  
The Brain ◽  
Mathematical Construct ◽  
Subject Differences

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.

scholarly journals Reward-specific satiety affects subjective value signals in orbitofrontal cortex during multicomponent economic choice

2021 ◽  
Vol 118 (30) ◽  
pp. e2022650118
Author(s):  
Alexandre Pastor-Bernier ◽  
Arkadiusz Stasiak ◽  
Wolfram Schultz
Keyword(s):  
Orbitofrontal Cortex ◽  
Economic Value ◽  
Revealed Preference ◽  
Value Change ◽  
Neuronal Coding ◽  
Preference Theory ◽  
Subjective Value ◽  
Reward Value ◽  
Value Loss ◽  
Reward Functions

Sensitivity to satiety constitutes a basic requirement for neuronal coding of subjective reward value. Satiety from natural ongoing consumption affects reward functions in learning and approach behavior. More specifically, satiety reduces the subjective economic value of individual rewards during choice between options that typically contain multiple reward components. The unconfounded assessment of economic reward value requires tests at choice indifference between two options, which is difficult to achieve with sated rewards. By conceptualizing choices between options with multiple reward components (“bundles”), Revealed Preference Theory may offer a solution. Despite satiety, choices against an unaltered reference bundle may remain indifferent when the reduced value of a sated bundle reward is compensated by larger amounts of an unsated reward of the same bundle, and then the value loss of the sated reward is indicated by the amount of the added unsated reward. Here, we show psychophysically titrated choice indifference in monkeys between bundles of differently sated rewards. Neuronal chosen value signals in the orbitofrontal cortex (OFC) followed closely the subjective value change within recording periods of individual neurons. A neuronal classifier distinguishing the bundles and predicting choice substantiated the subjective value change. The choice between conventional single rewards confirmed the neuronal changes seen with two-reward bundles. Thus, reward-specific satiety reduces subjective reward value signals in OFC. With satiety being an important factor of subjective reward value, these results extend the notion of subjective economic reward value coding in OFC neurons.

The case against economic values in the orbitofrontal cortex (or anywhere else in the brain)

2020 ◽  
Author(s):  
Benjamin Hayden ◽  
Yael Niv
Keyword(s):  
Orbitofrontal Cortex ◽  
Economic Value ◽  
Brain Regions ◽  
Process Models ◽  
Neural Basis ◽  
Economic Concept ◽  
Free Process ◽  
Subjective Value ◽  
Epistemic Constraints ◽  
The Brain

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.

scholarly journals Spatial Directionality Found in Frontal-Parietal Attentional Networks

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Gahangir Hossain ◽  
Mark H. Myers ◽  
Robert Kozma
Keyword(s):  
Cognitive Processing ◽  
Human Subjects ◽  
Sensory Stimulation ◽  
Beta Phase ◽  
Neural Oscillations ◽  
Beta Activity ◽  
Scalp Eeg ◽  
Cognitive States ◽  
Eyes Open ◽  
Higher Cognitive Functions

Research in last few years on neurophysiology focused on several areas across the cortex during cognitive processing to determine the dominant direction of electrical activity. However, information about the frequency and direction of episodic synchronization related to higher cognitive functions remain unclear. Our aim was to determine whether neural oscillations carry perceptual information as spatial patterns across the cortex, which could be found in the scalp EEG of human subjects while being engaged in visual sensory stimulation. Magnitude squared coherence of neural activity during task states that “finger movement with Eyes Open (EO) or Eyes Wandering (EW)” among all electrode combinations has the smallest standard deviation and variations. Additionally, the highest coherence among the electrode pairs occurred between alpha (8-12 Hz) and beta (12-16 Hz) ranges. Our results indicate that alpha rhythms seem to be regulated during activities when an individual is focused on a given task. Beta activity, which has also been implicated in cognitive processing to neural oscillations, is seen in our work as a manner to integrate external stimuli to higher cognitive activation. We have found spatial network organization which served to classify the EEG epochs in time with respect to the stimuli class. Our findings suggest that cortical neural signaling utilizes alpha-beta phase coupling during cognitive processing states, where beta activity has been implicated in shifting cognitive states. Significance. Our approach has found frontoparietal attentional mechanisms in shifting brain states which could provide new insights into understanding the global cerebral dynamics of intentional activity and reflect how the brain allocates resources during tasking and cognitive processing states.

scholarly journals Non-selective inhibition of the motor system following unexpected and expected infrequent events

2020 ◽  
Author(s):  
Carly Iacullo ◽  
Darcy A. Diesburg ◽  
Jan R. Wessel
Keyword(s):  
Motor System ◽  
Human Subjects ◽  
Reaction Time Task ◽  
Selective Inhibition ◽  
Motor Inhibition ◽  
Simple Reaction Time Task ◽  
Movement Initiation ◽  
Sensory Stimuli ◽  
Behavioral Adaptations ◽  
Environmental Events

AbstractMotor inhibition is a key control mechanism that allows humans to rapidly adapt their actions in response to environmental events. One of the hallmark signatures of rapidly exerted, reactive motor inhibition is the non-selective suppression of cortico-spinal excitability (CSE): unexpected sensory stimuli lead to a suppression of CSE across the entire motor system, even in muscles that are inactive. Theories suggest that this reflects a fast, automatic, and broad engagement of inhibitory control, which facilitates behavioral adaptations to unexpected changes in the sensory environment. However, it is an open question whether such non-selective CSE suppression is truly due to the unexpected nature of the sensory event, or whether it is sufficient for an event to be merely infrequent (but not unexpected). Here, we report data from two experiments in which human subjects experienced both unexpected and expected infrequent events during a simple reaction time task while CSE was measured from a task-unrelated muscle. We found that expected infrequent events can indeed produce non-selective CSE suppression – but only when they occur during movement initiation. In contrast, unexpected infrequent events produce non-selective CSE suppression even in the absence of movement initiation. Moreover, CSE suppression due to unexpected events occurs at shorter latencies compared to expected infrequent events. These findings demonstrate that unexpectedness and stimulus infrequency have qualitatively different suppressive effects on the motor system. They also have key implications for studies that seek to disentangle neural and psychological processes related to motor inhibition and stimulus detection.

scholarly journals Reliable population utility signal from diverse economic value coding in orbitofrontal neurons

2021 ◽  
Author(s):  
Simone Ferrari-Toniolo ◽  
Wolfram Schultz
Keyword(s):  
Reward Magnitude ◽  
Economic Value ◽  
Population Level ◽  
Axiomatic Approach ◽  
Neuronal Population ◽  
Risk Attitudes ◽  
Probability Weighting ◽  
Value Functions ◽  
Single Neurons ◽  
Subjective Value

Economic value encapsulates the subjective combination of reward magnitude and probability. We investigated the mechanism for subjective value computation in single neurons using an economic axiomatic approach. We found that single neurons in the macaque orbitofrontal cortex, known to be sensitive to reward magnitude and probability, encode the economic value functions (utility and probability weighting) in a heterogeneous manner, such that the activity of individual neurons did not match the animal's choices. However, the utility and probability weighting code from a population of these varied neurons reliably matched the animals' choices and risk attitudes. Thus, the neuronal population code for economic value amounted to a distributional representation of the formal economic functions. With a diverse single-unit economic value code converging into a reliable population-level utility code, this scheme suggests a brain mechanism for the flexible accommodation of multiple choice patterns and risk attitudes.

Fluctuations of Attentional Networks and Default Mode Network during the Resting State Reflect Variations in Cognitive States: Evidence from a Novel Resting-state Experience Sampling Method

2017 ◽  
Vol 29 (1) ◽  
pp. 95-113 ◽  
Author(s):  
Laurens Van Calster ◽  
Arnaud D'Argembeau ◽  
Eric Salmon ◽  
Frédéric Peters ◽  
Steve Majerus
Keyword(s):  
Default Mode Network ◽  
Resting State ◽  
Experience Sampling ◽  
Resting State Fmri ◽  
Mental States ◽  
Network Activity ◽  
Attentional Processes ◽  
Default Mode ◽  
Cognitive States ◽  
Attentional Networks

Neuroimaging studies have revealed the recruitment of a range of neural networks during the resting state, which might reflect a variety of cognitive experiences and processes occurring in an individual's mind. In this study, we focused on the default mode network (DMN) and attentional networks and investigated their association with distinct mental states when participants are not performing an explicit task. To investigate the range of possible cognitive experiences more directly, this study proposes a novel method of resting-state fMRI experience sampling, informed by a phenomenological investigation of the fluctuation of mental states during the resting state. We hypothesized that DMN activity would increase as a function of internal mentation and that the activity of dorsal and ventral networks would indicate states of top–down versus bottom–up attention at rest. Results showed that dorsal attention network activity fluctuated as a function of subjective reports of attentional control, providing evidence that activity of this network reflects the perceived recruitment of controlled attentional processes during spontaneous cognition. Activity of the DMN increased when participants reported to be in a subjective state of internal mentation, but not when they reported to be in a state of perception. This study provides direct evidence for a link between fluctuations of resting-state neural activity and fluctuations in specific cognitive processes.

What Is a Neuronal Ensemble?

2020 ◽  
Author(s):  
Luis Carrillo-Reid ◽  
Rafael Yuste
Keyword(s):  
Neuronal Activity ◽  
Causal Relation ◽  
Brain Activity ◽  
Building Blocks ◽  
Neural Code ◽  
Sensory Stimuli ◽  
Neuronal Ensembles ◽  
Cognitive States ◽  
Neuroscience Research ◽  
And Behavior

Despite over a century of neuroscience research, the nature of the neural code, that is, how neuronal activity underlies motor, sensory, and cognitive functions, remains elusive. Understanding the causal relation between neuronal activity and behavior requires a new conceptual paradigm that considers groups of neurons, instead of individual neurons, as the functional building blocks of the brain. These “neuronal ensembles,” defined as groups of neurons with coordinated activity that are reliably recalled by sensory stimuli, motor programs, or cognitive states, could be basic modular functional units of neural circuits. This hypothesis is consistent with past and present neuroscience results and could provide a broader framework to more effectively decipher the neural code in normal brains and provide new insights into how abnormal brain activity could lead to mental and neurological disease.

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