Value representation in the monkey hippocampus

Humans have a remarkable capacity for flexible decision-making, deliberating among actions by modeling their likely outcomes. This capacity allows us to adapt to the specific features of diverse circumstances. In real-world decision-making, however, people face an important challenge: There are often an enormous number of possibilities to choose among, far too many for exhaustive consideration. There is a crucial, understudied prechoice step in which, among myriad possibilities, a few good candidates come quickly to mind. How do people accomplish this? We show across nine experiments ( N = 3,972 U.S. residents) that people use computationally frugal cached value estimates to propose a few candidate actions on the basis of their success in past contexts (even when irrelevant for the current context). Deliberative planning is then deployed just within this set, allowing people to compute more accurate values on the basis of context-specific criteria. This hybrid architecture illuminates how typically valuable thoughts come quickly to mind during decision-making.

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Semiclassical initial value representation: From Møller to Miller

The Journal of Chemical Physics ◽

10.1063/5.0023137 ◽

2020 ◽

Vol 153 (17) ◽

pp. 174102

Author(s):

Laurent Bonnet

Keyword(s):

Initial Value ◽

Initial Value Representation ◽

Value Representation

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Delay discounting in youth at clinical high-risk for psychosis and adults with schizophrenia

Psychological Medicine ◽

10.1017/s0033291720000677 ◽

2020 ◽

pp. 1-8 ◽

Cited By ~ 1

Author(s):

Lisa A. Bartolomeo ◽

Hannah C. Chapman ◽

Ian M. Raugh ◽

Gregory P. Strauss

Keyword(s):

High Risk ◽

Delay Discounting ◽

Negative Symptoms ◽

Chronic Phase ◽

Reward Processing ◽

Positive Symptoms ◽

Clinical High Risk ◽

Symptom Scale ◽

Processing Mechanism ◽

Value Representation

Abstract Background Schizophrenia (SZ) is typically preceded by a prodromal (i.e. pre-illness) period characterized by attenuated positive symptoms and declining functional outcome. Negative symptoms are prominent among individuals at clinical high-risk (CHR) for psychosis (i.e. those with prodromal syndromes) and highly predictive of conversion to illness. Mechanisms underlying negative symptoms in the CHR population are unclear. Two studies were conducted to evaluate whether abnormalities in a reward processing mechanism thought to be core to negative symptoms in SZ, value representation, also exist in CHR individuals and whether they are associated with negative symptoms transphasically. Methods Study 1 included 33 individuals in the chronic phase of illness who have been diagnosed with schizophrenia or schizoaffective disorder (SZ) and 40 healthy controls (CN). Study 2 included 37 CHR participants and 45 CN. In both studies, participants completed the delay discounting (DD) task as a measure of value representation and the Brief Negative Symptom Scale was rated to measure negative symptoms. Results Results indicated that patients with SZ had steeper discounting rates than CN, indicating impairments in value representation. However, CHR participants were unimpaired on the DD task. In both studies, steeper discounting was associated with greater severity of negative symptoms. Conclusions These findings suggest that deficits in value representation are associated with negative symptoms transphasically.

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