Kable, Joseph W
Now showing 1 - 10 of 36
PublicationRational Temporal Predictions Can Underlie Apparent Failures to Delay Gratification(2013-01-01) McGuire, Joseph T; Kable, Joseph WAn important category of seemingly maladaptive decisions involves failure to postpone gratification. A person pursuing a desirable long-run outcome may abandon it in favor of a short-run alternative that has been available all along. Here we present a theoretical framework in which this seemingly irrational behavior emerges from stable preferences and veridical judgments. Our account recognizes that decision makers generally face uncertainty regarding the time at which future outcomes will materialize. When timing is uncertain, the value of persistence depends crucially on the nature of a decision maker's prior temporal beliefs. Certain forms of temporal beliefs imply that a delay's predicted remaining length increases as a function of time already waited. In this type of situation, the rational, utility-maximizing strategy is to persist for a limited amount of time and then give up. We show empirically that people's explicit predictions of remaining delay lengths indeed increase as a function of elapsed time in several relevant domains, implying that temporal judgments offer a rational basis for limiting persistence. We then develop our framework into a simple working model and show how it accounts for individual differences in a laboratory task (the well-known “marshmallow test”). We conclude that delay-of-gratification failure, generally viewed as a manifestation of limited self-control capacity, can instead arise as an adaptive response to the perceived statistics of one's environment. PublicationFractionating the Left Frontal Response to Tools: Dissociable Effects of Motor Experience and Lexical Competition(2006-02-01) Kable, Joseph W; Kan, Irene P; Van Scoyoc, Amanda; Thompson-Schill, Sharon L.; Chatterjee, AnjanA number of theories about the evolution of language posit a close (and perhaps causal) relationship between tool use and speech. Consistent with this idea, neuroimaging studies have found that tool knowledge retrieval activates not only a region of the left premotor cortex involved in hand action, but also an adjacent region that is typically described as a language center. We examined whether this pattern of activation is best described as the result of a single process, related to both action and language, or the result of two independent processes. We identified two distinct neural components that jointly contribute to this response: a posterior region centered in the premotor cortex, which responds to motor knowledge retrieval, and an anterior region centered in the left frontal operculum, which responds to lexical competition. Crucial to the interpretation of the premotor response, individual variation in motor experience was highly correlated with the magnitude of the response in the premotor cortex, but not in the prefrontal cortex. PublicationThe Neural Correlated of Subjective Value During Intertemporal Choice(2007-01-01) Kable, Joseph W; Glimcher, Paul WNeuroimaging studies of decision-making have generally related neural activity to objective measures (such as reward magnitude, probability or delay), despite choice preferences being subjective. However, economic theories posit that decision-makers behave as though different options have different subjective values. Here we use functional magnetic resonance imaging to show that neural activity in several brain regions—particularly the ventral striatum, medial prefrontal cortex and posterior cingulate cortex—tracks the revealed subjective value of delayed monetary rewards. This similarity provides unambiguous evidence that the subjective value of potential rewards is explicitly represented in the human brain. PublicationFunctionally Dissociable Influences on Learning Rate in a Dynamic Environment(2014-11-19) McGuire, Joseph T; Nassar, Matthew R; Kable, Joseph W; Gold, Joshua IMaintaining accurate beliefs in a changing environment requires dynamically adapting the rate at which one learns from new experiences. Beliefs should be stable in the face of noisy data but malleable in periods of change or uncertainty. Here we used computational modeling, psychophysics, and fMRI to show that adaptive learning is not a unitary phenomenon in the brain. Rather, it can be decomposed into three computationally and neuroanatomically distinct factors that were evident in human subjects performing a spatial-prediction task: (1) surprise-driven belief updating, related to BOLD activity in visual cortex; (2) uncertainty-driven belief updating, related to anterior prefrontal and parietal activity; and (3) reward-driven belief updating, a context-inappropriate behavioral tendency related to activity in ventral striatum. These distinct factors converged in a core system governing adaptive learning. This system, which included dorsomedial frontal cortex, responded to all three factors and predicted belief updating both across trials and across individuals. PublicationDiminished Effort on a Progressive Ratio Task in Both Unipolar and Bipolar Depression(2016-05-15) Hershenberg, Rachel; Satterthwaite, Theodore D; Daldal, Aylin; Katchmar, Natalie; Moore, Tyler M; Kable, Joseph W; Wolf, Daniel HBackground Amotivation, or decisional anhedonia, is a prominent and disabling feature of depression. However, this aspect of depression remains understudied, and no prior work has applied objective laboratory tests of motivation in both unipolar and bipolar depression. Methods We assessed motivation deficits using a Progressive Ratio Task (PRT) that indexes willingness to exert effort for monetary reward. The PRT was administered to 96 adults ages 18–60 including 25 participants with a current episode of unipolar depression, 28 with bipolar disorder (current episode depressed), and 43 controls without any Axis I psychiatric disorders. Results Depressed participants exhibited significantly lower motivation than control participants as objectively defined by progressive ratio breakpoints. Both the unipolar and bipolar groups were lower than controls but did not differ from each other. Limitations Medication use differed across groups, and we did not have a separate control task to measure psychomotor activity; however neither medication effects or psychomotor slowing are likely to explain our findings. Conclusions Our study fills an important gap in the literature by providing evidence that diminished effort on the PRT is present across depressed patients who experience either unipolar or bipolar depression. This adds to growing evidence for shared mechanisms of reward and motivation dysfunction, and highlights the importance of improving the assessment and treatment of motivation deficits across the mood disorders spectrum. PublicationConceptual Representations of Action in the Lateral Temporal Cortex(2005-12-01) Kable, Joseph W; Thompson-Schill, Sharon L.; Kan, Irene P; Chatterjee, Anjan; Wilson, AshleyRetrieval of conceptual information from action pictures causes greater activation than from object pictures bilaterally in human motion areas (MT/MST) and nearby temporal regions. By contrast, retrieval of conceptual information from action words causes greater activation in left middle and superior temporal gyri, anterior and dorsal to the MT/MST. We performed two fMRI experiments to replicate and extend these findings regarding action words. In the first experiment, subjects performed conceptual judgments of action and object words under conditions that stressed visual semantic information. Under these conditions, action words again activated posterior temporal regions close to, but not identical with, the MT/MST. In the second experiment, we included conceptual judgments of manipulable object words in addition to judgments of action and animal words. Both action and manipulable object judgments caused greater activity than animal judgments in the posterior middle temporal gyrus. Both of these experiments support the hypothesis that middle temporal gyrus activation is related to accessing conceptual information about motion attributes, rather than alternative accounts on the basis of lexical or grammatical factors. Furthermore, these experiments provide additional support for the notion of a concrete to abstract gradient of motion representations with the lateral occipitotemporal cortex, extending anterior and dorsal from the MT/MST towards the peri-sylvian cortex. PublicationVentromedial Frontal Lobe Damage Disrupts Value Maximization in Humans(2011-05-18) Camille, Nathalie; Griffiths, Cathryn A; Vo, Khoi; Fellows, Lesley K; Kable, Joseph WRecent work in neuroeconomics has shown that regions in orbitofrontal and medial prefrontal cortex encode the subjective value of different options during choice. However, these electrophysiological and neuroimaging studies cannot demonstrate whether such signals are necessary for value-maximizing choices. Here we used a paradigm developed in experimental economics to empirically measure and quantify violations of utility theory in humans with damage to the ventromedial frontal lobe (VMF). We show that people with such damage are more likely to make choices that violate the generalized axiom of revealed preference, which is the one necessary and sufficient condition for choices to be consistent with value maximization. These results demonstrate that the VMF plays a critical role in value-maximizing choice. PublicationPreference Reversals in Decision Making Under Risk Are Accompanied by Changes in Attention to Different Attributes(2012-07-19) Kim, Betty E; Seligman, Darryl; Kable, Joseph WRecent work has shown that visual fixations reflect and influence trial-to-trial variability in people’s preferences between goods. Here we extend this principle to attribute weights during decision making under risk. We measured eye movements while people chose between two risky gambles or bid on a single gamble. Consistent with previous work, we found that people exhibited systematic preference reversals between choices and bids. For two gambles matched in expected value, people systematically chose the higher probability option but provided a higher bid for the option that offered the greater amount to win. This effect was accompanied by a shift in fixations of the two attributes, with people fixating on probabilities more during choices and on amounts more during bids. Our results suggest that the construction of value during decision making under risk depends on task context partly because the task differentially directs attention at probabilities vs. amounts. Since recent work demonstrates that neural correlates of value vary with visual fixations, our results also suggest testable hypotheses regarding how task context modulates the neural computation of value to generate preference reversals. PublicationDecision Makers Calibrate Behavioral Persistence on the Basis of Time-Interval Experience(2012-08-01) McGuire, Joseph T; Kable, Joseph WA central question in intertemporal decision making is why people reverse their own past choices. Someone who initially prefers a long-run outcome might fail to maintain that preference for long enough to see the outcome realized. Such behavior is usually understood as reflecting preference instability or self-control failure. However, if a decision maker is unsure exactly how long an awaited outcome will be delayed, a reversal can constitute the rational, utility-maximizing course of action. In the present behavioral experiments, we placed participants in timing environments where persistence toward delayed rewards was either productive or counterproductive. Our results show that human decision makers are responsive to statistical timing cues, modulating their level of persistence according to the distribution of delay durations they encounter. We conclude that temporal expectations act as a powerful and adaptive influence on people’s tendency to sustain patient decisions. Highlights ► Participants decided how long to wait for temporally uncertain rewards. ► The distribution of possible delays determines whether persistence is productive. ► Different conditions, matched for reward rate, required high or low persistence. ► With experience, decision makers appropriately adjusted their willingness to wait. ► Apparent failures of persistence can reflect adaptive temporal judgments. PublicationIndividual Differences in the Neural Signature of Subjective Value Among Older Adults(2015-06-17) Halfmann, Kameko; Hedgcock, William; Kable, Joseph W; Denburg, Natalie LSome healthy older adults show departures from standard decision-making patterns exhibited by younger adults. We asked if such departures are uniform or if heterogeneous aging processes can designate which older adults show differing decision patterns. Thirty-three healthy older adults with varying decision-making patterns on a complex decision task (the Iowa Gambling Task) completed an intertemporal choice task while undergoing functional magnetic resonance imaging. We examined whether value representation in the canonical valuation network differed across older adults based on complex decision-making ability. Older adults with advantageous decision patterns showed increased activity in the valuation network, including the ventromedial prefrontal cortex (VMPFC) and striatum. In contrast, older adults with disadvantageous decision patterns showed reduced or absent activation in the VMPFC and striatum, and these older adults also showed greater blood oxygen level dependent signal temporal variability in the striatum. Our results suggest that a reduced representation of value in the brain, possibly driven by increased neural noise, relates to suboptimal decision-making in a subset of older adults, which could translate to poor decision-making in many aspects of life, including finance, health and long-term care. Understanding the connection between suboptimal decision-making and neural value signals is a step toward mitigating age-related decision-making impairments.