Normalized value coding explains dynamic adaptation in the human valuation process

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.

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Mirror neurons are modulated by grip force and reward expectation in the sensorimotor cortices (S1, M1, PMd, PMv)

Scientific Reports ◽

10.1038/s41598-021-95536-z ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Md Moin Uddin Atique ◽

Joseph Thachil Francis

Keyword(s):

Neural Activity ◽

Visual Information ◽

Mirror Neurons ◽

Grip Force ◽

Neural Representation ◽

Virtual Object ◽

Time Lags ◽

Subjective Value ◽

Machine Interface ◽

Definition Of

AbstractMirror Neurons (MNs) respond similarly when primates make or observe grasping movements. Recent work indicates that reward expectation influences rostral M1 (rM1) during manual, observational, and Brain Machine Interface (BMI) reaching movements. Previous work showed MNs are modulated by subjective value. Here we expand on the above work utilizing two non-human primates (NHPs), one male Macaca Radiata (NHP S) and one female Macaca Mulatta (NHP P), that were trained to perform a cued reward level isometric grip-force task, where the NHPs had to apply visually cued grip-force to move and transport a virtual object. We found a population of (S1 area 1–2, rM1, PMd, PMv) units that significantly represented grip-force during manual and observational trials. We found the neural representation of visually cued force was similar during observational trials and manual trials for the same units; however, the representation was weaker during observational trials. Comparing changes in neural time lags between manual and observational tasks indicated that a subpopulation fit the standard MN definition of observational neural activity lagging the visual information. Neural activity in (S1 areas 1–2, rM1, PMd, PMv) significantly represented force and reward expectation. In summary, we present results indicating that sensorimotor cortices have MNs for visually cued force and value.

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The relationship between physiological arousal and multiple levels of temporal context in risky choice

10.31234/osf.io/39rbs ◽

2021 ◽

Author(s):

Hayley R. Brooks ◽

Peter Sokol-Hessner

Keyword(s):

Decision Making ◽

Risk Taking ◽

Context Effects ◽

Temporal Structure ◽

Physiological Arousal ◽

Risky Choice ◽

Context Dependency ◽

Temporal Context ◽

Multiple Levels ◽

Task Level

Context-dependence is fundamental to risky monetary decision-making. A growing body of evidence suggests that temporal context, or recent events, alters risk-taking at a minimum of three timescales: immediate (e.g. trial-by-trial), neighborhood (e.g. a group of consecutive trials), and global (e.g. task-level). To examine context effects, we created a novel monetary choice set with intentional temporal structure in which option values shifted between multiple levels of value magnitude (“contexts”) several times over the course of the task. This structure allowed us to examine whether effects of each timescale were simultaneously present in risky choice behavior and the potential mechanistic role of arousal, an established correlate of risk-taking, in context-dependency. We found that risk-taking was sensitive to immediate, neighborhood, and global timescales, increasing following small (vs. large) outcome amounts, large positive (but not negative) shifts in context, and when cumulative earnings exceeded expectations. We quantified arousal with skin conductance responses, which were specifically related to the global timescale, increasing with cumulative earnings, suggesting that physiological arousal captures a task-level assessment of performance. We complimented this correlational analysis with a secondary reanalysis of risky monetary choices following the double-blind administration of propranolol and a placebo during a temporally unstructured choice task. We replicated our behavioral finding that risk-taking is context-sensitive at three timescales but found no change in temporal context-effects following propranolol administration. Our results demonstrate that risky decision-making is consistently dynamic at multiple timescales and that arousal is likely the consequence, rather than the cause, of temporal context in risky monetary decision-making.

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Subjective value and decision entropy are jointly encoded by aligned gradients across the human brain

10.1101/2020.02.18.954362 ◽

2020 ◽

Author(s):

Sebastian Bobadilla-Suarez ◽

Olivia Guest ◽

Bradley C. Love

Keyword(s):

Prefrontal Cortex ◽

Human Brain ◽

Ventromedial Prefrontal Cortex ◽

Neural Representation ◽

Retrospective Evaluation ◽

Systematic Fashion ◽

Subjective Value ◽

Fmri Analysis ◽

The Relationship ◽

The Brain

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.

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Cortical Representations of Speech in a Multi-talker Auditory Scene

10.1101/124750 ◽

2017 ◽

Cited By ~ 1

Author(s):

Krishna C. Puvvada ◽

Jonathan Z. Simon

Keyword(s):

Auditory Cortex ◽

Human Subjects ◽

Higher Order ◽

Neural Representation ◽

Cortical Areas ◽

Auditory Scene ◽

Global Representation ◽

Stimulus Reconstruction ◽

Background Object ◽

Cortical Representations

AbstractThe ability to parse a complex auditory scene into perceptual objects is facilitated by a hierarchical auditory system. Successive stages in the hierarchy transform an auditory scene of multiple overlapping sources, from peripheral tonotopically-based representations in the auditory nerve, into perceptually distinct auditory-objects based representation in auditory cortex. Here, using magnetoencephalography (MEG) recordings from human subjects, both men and women, we investigate how a complex acoustic scene consisting of multiple speech sources is represented in distinct hierarchical stages of auditory cortex. Using systems-theoretic methods of stimulus reconstruction, we show that the primary-like areas in auditory cortex contain dominantly spectro-temporal based representations of the entire auditory scene. Here, both attended and ignored speech streams are represented with almost equal fidelity, and a global representation of the full auditory scene with all its streams is a better candidate neural representation than that of individual streams being represented separately. In contrast, we also show that higher order auditory cortical areas represent the attended stream separately, and with significantly higher fidelity, than unattended streams. Furthermore, the unattended background streams are more faithfully represented as a single unsegregated background object rather than as separated objects. Taken together, these findings demonstrate the progression of the representations and processing of a complex acoustic scene up through the hierarchy of human auditory cortex.Significance StatementUsing magnetoencephalography (MEG) recordings from human listeners in a simulated cocktail party environment, we investigate how a complex acoustic scene consisting of multiple speech sources is represented in separate hierarchical stages of auditory cortex. We show that the primary-like areas in auditory cortex use a dominantly spectro-temporal based representation of the entire auditory scene, with both attended and ignored speech streams represented with almost equal fidelity. In contrast, we show that higher order auditory cortical areas represent an attended speech stream separately from, and with significantly higher fidelity than, unattended speech streams. Furthermore, the unattended background streams are represented as a single undivided background object rather than as distinct background objects.

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Memory for temporal context: Effects of ageing, encoding instructions, and retrieval strategies

Memory ◽

10.1080/09658210344000611 ◽

2005 ◽

Vol 13 (1) ◽

pp. 95-109 ◽

Cited By ~ 13

Author(s):

Christine Bastin ◽

Martial Van der Linden

Keyword(s):

Context Effects ◽

Temporal Context ◽

Retrieval Strategies

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Temporal context effects with two judgmental languages

Psychonomic Science ◽

10.3758/bf03328002 ◽

1966 ◽

Vol 6 (4) ◽

pp. 151-152 ◽

Cited By ~ 6

Author(s):

William G. Braud ◽

Stephen W. Holborn

Keyword(s):

Context Effects ◽

Temporal Context

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Temporal context effects in pigeons' memory for event duration

Learning and Motivation ◽

10.1016/0023-9690(92)90013-c ◽

1992 ◽

Vol 23 (2) ◽

pp. 117-144 ◽

Cited By ~ 44

Author(s):

Marcia L. Spetch ◽

Benjamin Rusak

Keyword(s):

Context Effects ◽

Temporal Context ◽

Event Duration

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Valence biases in reinforcement learning shift across adolescence and modulate subsequent memory

10.31234/osf.io/n3vsr ◽

2020 ◽

Author(s):

Gail Rosenbaum ◽

Hannah Grassie ◽

Catherine A. Hartley

Keyword(s):

Reinforcement Learning ◽

Trial And Error ◽

Independent Dataset ◽

Age Related ◽

Subjective Value ◽

Valuation Process ◽

Incidental Memory ◽

Past Experiences ◽

Expected Outcomes ◽

Better Than

Individuals learn differently through trial and error, with some more influenced by good outcomes, and others weighting bad outcomes more heavily. Such valence biases may also influence memory for past experiences. Here, we examined whether valence asymmetries in reinforcement learning change across adolescence, and whether individual learning asymmetries bias the content of subsequent memory. Participants ages 8-27 learned the values of “point machines”, after which their memory for trial-unique images presented with choice outcomes was assessed. Relative to children and adults, adolescents overweighted worse-than-expected outcomes during learning. Individuals’ valence biases modulated incidental memory, such that those who prioritized worse- (or better-) than-expected outcomes during learning were also more likely to remember images paired with these outcomes, an effect reproduced in an independent dataset. Collectively, these results highlight age-related changes in the computation of subjective value, and demonstrate that a valence-asymmetric valuation process influences how information is prioritized in episodic memory.

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Context Effects in Temporal Differentiation: Some Data and a Model

International Journal of Comparative Psychology ◽

10.46867/ijcp.2015.28.02.11 ◽

2015 ◽

Vol 28 ◽

Author(s):

Marilia Pinheiro de Carvalho ◽

Armando Machado ◽

Marco Vasconcelos

Keyword(s):

Context Effects ◽

Phase 1 ◽

Temporal Context ◽

Model Parameters ◽

Time Interval ◽

Interval Duration ◽

Phase 2 ◽

Time Model ◽

Temporal Differentiation ◽

Range Of Values

We examined whether temporal context influences how animals produce a time interval. Six pigeons pecked one key to start an interval and then another key to end the interval. Reinforcement followed whenever the interval duration fell within a range of values signaled by the keylight colors. During Phase 1, keylight colors S1 and L1, intermixed across trials, signaled the ranges (0.5-1.5 s) and (1.5- 4.5 s), respectively. During Phase 2, colors S2 and L2 signaled the ranges (1.5-4.5 s) and (4.5-13.5 s), respectively. We asked whether the intervals produced in the presence of L1 and S2, stimuli signalling the same range, varied with their temporal context, short in Phase 1, long in Phase 2. The results showed that a) the intervals produced in the presence of the different keylight colors accorded with the main properties of temporal differentiation, including Weber’s law, b) the L1 intervals had slightly higher means than the S2 intervals, a weak contrast effect, c) the L1 intervals also had higher variability than the S2 intervals. An extension of the learning-to-time model to temporal differentiation tasks reproduced some of the major features of the data but left unanswered how context might change the model parameters.

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