How choice reveals and shapes expected hedonic outcome

The role of the human ventral striatum and the medial orbitofrontal cortex in the representation of reward magnitude - an activation likelihood estimation meta-analysis of neuroimaging studies of passive reward expectancy and outcome processing

Reward maximization is a core motivation of every organism. In humans, several brain regions have been implicated in the representation of reward magnitude. Still, it is unclear whether identical brain regions consistently play a role in reward prediction and its consumption. In this study we used coordinate-based ALE meta-analysis to determine the individual roles of the ventral striatum (vSTR) and the medial orbitofrontal cortex (mOFC/VMPFC) in the representation of reward in general and of reward magnitude in particular. Specifically, we wanted to assess commonalities and differences in regional brain activation during the passive anticipation and consumption of rewards. Two independent meta-analyses of neuroimaging data from the past decade revealed a general role for the vSTR in reward anticipation and consumption. This was the case particularly when the consumed rewards occurred unexpectedly or were uncertain. In contrast, for the mOFC/VMPFC the present meta-analytic data suggested a rather specific function in reward consumption as opposed to passive anticipation. Importantly, when considering only coordinates that compared different reward magnitudes, the same parts of the vSTR and the mOFC/VMPFC showed concordant responses across studies, although areas of coherence were regionally more confined. These meta-analytic data suggest that the vSTR may be involved in both prediction and consumption of salient rewards, and may also be sensitive to different reward magnitudes, while the mOFC/VMPFC may rather process the magnitude during reward receipt. Collectively, our meta-analytic data conform with the notion that these two brain regions may subserve different roles in processing of reward magnitude.

The inherent reward of choice

Research suggests that the exercise of control is desirable and adaptive, but the precise mechanisms underlying the affective value of control are not well understood. The study reported here characterized the affective experience of personal control by examining the neural substrates recruited when individuals anticipate the opportunity to make a choice--in other words, when they anticipate the means for exercising control. We used an experimental paradigm that probed the value of having a choice. Participants reported liking cues that predicted a future opportunity to make a choice more than cues that predicted no choice. The anticipation of choice itself was associated with increased activity in corticostriatal regions, particularly the ventral striatum, involved in affective and motivational processes. This study is the first direct examination of the affective value of having the opportunity to choose. These findings have important implications for understanding the role of perception of control, and choice itself, in self-regulatory processes.

Abnormal functional lateralization and activity of language brain areas in typical specific language impairment (developmental dysphasia)

Atypical functional lateralization and specialization for language have been proposed to account for developmental language disorders, yet results from functional neuroimaging studies are sparse and inconsistent. This functional magnetic resonance imaging study compared children with a specific subtype of specific language impairment affecting structural language (n = 21), to a matched group of typically developing children using a panel of four language tasks neither requiring reading nor metalinguistic skills, including two auditory lexico-semantic tasks (category fluency and responsive naming) and two visual phonological tasks based on picture naming. Data processing involved normalizing the data with respect to a matched pairs paediatric template, groups and between-groups analysis, and laterality indices assessment within regions of interest using single and combined task analysis. Children with specific language impairment exhibited a significant lack of left lateralization in all core language regions (inferior frontal gyrus-opercularis, inferior frontal gyrus-triangularis, supramarginal gyrus and superior temporal gyrus), across single or combined task analysis, but no difference of lateralization for the rest of the brain. Between-group comparisons revealed a left hypoactivation of Wernicke's area at the posterior superior temporal/supramarginal junction during the responsive naming task, and a right hyperactivation encompassing the anterior insula with adjacent inferior frontal gyrus and the head of the caudate nucleus during the first phonological task. This study thus provides evidence that this subtype of specific language impairment is associated with atypical lateralization and functioning of core language areas.

Modular networks involving the medial frontal cortex: towards the development of neuropsychiatry

OBJECTIVES

The pathophysiology of mental disorders is largely unresolved. We propose that the identification of abnormalities in brain modular networks will provide a promising approach for the understanding of mental disorders.

METHODS

We review the current discussion on the neuroscientific basis of psychiatric diseases and review recent studies in functional neuroimaging and systems physiology on mental functions of the human brain.

RESULTS

We propose that brain functional units are organized in modular networks. Modular networks allow for flexibility within the modular processing units and across interconnected modules affording optimization of task performance and deficit compensation in disease. As an example it will be shown that differentiated modules in medial frontal cortex play a critical role for the control of behaviour. This will be contrasted to recent studies in neurological and psychiatric patients revealing behavioural abnormalities due to lesions or reversibly deprived functions in the medial frontal cortex.

CONCLUSIONS

These findings are conceptualized as starting points for a neuroscience based diagnosis and treatment of brain diseases at the border of psychiatry and neurology.

A role for the striatum in regret-related choice repetition

"Regret aversion" is proposed to explain a tendency to avoid future choices that have induced past regret. However, regret might also motivate us to repeat previous regret-related choices to make up for their previous selection, a behavior resembling "chasing" in the context of gambling. In the current experiment, we acquired fMRI brain data while participants placed monetary bets on repeated gambles. Behaviorally, participants showed a tendency to repeat previously regret-related choices (operationalized as those leading to an outcome worse than what might have been), an effect restricted to early runs of the task. At gamble outcome, we show a reduction in ventral striatal activity for regret-related relative to relief-related outcomes. Critically, this modulation was only seen when subjects were responsible for the bet choice. Activity in dorsal striatum was associated with an influence of previous regret on participants' subsequent choices, which is evident in increased activity when regret-related choices were repeated, relative to avoided, on the next trial. Our findings indicate that regret can lead to choice repetition as if seeking to make up for our mistakes and in so doing may lead to subsequent chasing behavior.

Choice from non-choice: predicting consumer preferences from blood oxygenation level-dependent signals obtained during passive viewing

Decision-making is often viewed as a two-stage process, where subjective values are first assigned to each option and then the option of the highest value is selected. Converging evidence suggests that these subjective values are represented in the striatum and medial prefrontal cortex (MPFC). A separate line of evidence suggests that activation in the same areas represents the values of rewards even when choice is not required, as in classical conditioning tasks. However, it is unclear whether the same neural mechanism is engaged in both cases. To address this question we measured brain activation with functional magnetic resonance imaging while human subjects passively viewed individual consumer goods. We then sampled activation from predefined regions of interest and used it to predict subsequent choices between the same items made outside of the scanner. Our results show that activation in the striatum and MPFC in the absence of choice predicts subsequent choices, suggesting that these brain areas represent value in a similar manner whether or not choice is required.

Born to choose: the origins and value of the need for control

Belief in one's ability to exert control over the environment and to produce desired results is essential for an individual's wellbeing. It has repeatedly been argued that perception of control is not only desirable, but is also probably a psychological and biological necessity. In this article, we review the literature supporting this claim and present evidence of a biological basis for the need for control and for choice-that is, the means by which we exercise control over the environment. Converging evidence from animal research, clinical studies and neuroimaging suggests that the need for control is a biological imperative for survival, and a corticostriatal network is implicated as the neural substrate of this adaptive behavior.

Insula and striatum mediate the default bias

Humans are creatures of routine and habit. When faced with situations in which a default option is available, people show a consistent tendency to stick with the default. Why this occurs is unclear. To elucidate its neural basis, we used a novel gambling task in conjunction with functional magnetic resonance imaging. Behavioral results revealed that participants were more likely to choose the default card and felt enhanced emotional responses to outcomes after making the decision to switch. We show that increased tendency to switch away from the default during the decision phase was associated with decreased activity in the anterior insula; activation in this same area in reaction to "switching away from the default and losing" was positively related with experienced frustration. In contrast, decisions to choose the default engaged the ventral striatum, the same reward area as seen in winning. Our findings highlight aversive processes in the insula as underlying the default bias and suggest that choosing the default may be rewarding in itself.

Neural correlates of cognitive dissonance and choice-induced preference change

According to many modern economic theories, actions simply reflect an individual's preferences, whereas a psychological phenomenon called "cognitive dissonance" claims that actions can also create preference. Cognitive dissonance theory states that after making a difficult choice between two equally preferred items, the act of rejecting a favorite item induces an uncomfortable feeling (cognitive dissonance), which in turn motivates individuals to change their preferences to match their prior decision (i.e., reducing preference for rejected items). Recently, however, Chen and Risen [Chen K, Risen J (2010) J Pers Soc Psychol 99:573-594] pointed out a serious methodological problem, which casts a doubt on the very existence of this choice-induced preference change as studied over the past 50 y. Here, using a proper control condition and two measures of preferences (self-report and brain activity), we found that the mere act of making a choice can change self-report preference as well as its neural representation (i.e., striatum activity), thus providing strong evidence for choice-induced preference change. Furthermore, our data indicate that the anterior cingulate cortex and dorsolateral prefrontal cortex tracked the degree of cognitive dissonance on a trial-by-trial basis. Our findings provide important insights into the neural basis of how actions can alter an individual's preferences.

How choice modifies preference: neural correlates of choice justification

When making a difficult choice, people often justify the choice by increasing their liking for the chosen object and decreasing their liking for the rejected object. To uncover the neural signatures of choice justification, we used functional magnetic resonance imaging to monitor neural activity when subjects rated their preference for chosen and rejected musical CDs before and after they made their choices. We observed that the trial-by-trial attitude change (i.e., increase of preference for chosen items and decrease of preference for rejected items) was predicted by post-choice activity in the ventral medial prefrontal cortex (MPFC), right temporal-parietal junction, anterior insula, and bilateral cerebellum. Furthermore, individual difference in choice justification (i.e., increased preference for chosen items minus decreased preference for rejected items) was predicted by post-choice neural activity in the dorsal MPFC, left lateral prefrontal cortex, and right precentral cortex positively. In addition, interdependent self-construal was correlated with decreased activity in the ventral MPFC in the post-choice than pre-choice sessions. These findings suggest that both negative arousal/regulation and self-reflection are associated with choice justification. This provides evidence for the self-threat theory of choice justification.

The role of the left head of caudate in suppressing irrelevant words

Suppressing irrelevant words is essential to successful speech production and is expected to involve general control mechanisms that reduce interference from task-unrelated processing. To investigate the neural mechanisms that suppress visual word interference, we used fMRI and a Stroop task, using a block design with an event-related analysis. Participants indicated with a finger press whether a visual stimulus was colored pink or blue. The stimulus was either the written word "BLUE," the written word "PINK," or a string of four Xs, with word interference introduced when the meaning of the word and its color were "incongruent" (e.g., BLUE in pink hue) relative to congruent (e.g., BLUE in blue) or neutral (e.g., XXXX in pink). The participants also made color decisions in the presence of spatial interference rather than word interference (i.e., the Simon task). By blocking incongruent, congruent, and neutral trials, we identified activation related to the mechanisms that suppress interference as that which was greater at the end relative to the start of incongruency. This highlighted the role of the left head of caudate in the control of word interference but not spatial interference. The response in the left head of caudate contrasted to bilateral inferior frontal activation that was greater at the start than at the end of incongruency, and to the dorsal anterior cingulate gyrus which responded to a change in the motor response. Our study therefore provides novel insights into the role of the left head of caudate in the mechanisms that suppress word interference.

Born to choose: the origins and value of the need for control

Belief in one's ability to exert control over the environment and to produce desired results is essential for an individual's wellbeing. It has repeatedly been argued that perception of control is not only desirable, but is also probably a psychological and biological necessity. In this article, we review the literature supporting this claim and present evidence of a biological basis for the need for control and for choice-that is, the means by which we exercise control over the environment. Converging evidence from animal research, clinical studies and neuroimaging suggests that the need for control is a biological imperative for survival, and a corticostriatal network is implicated as the neural substrate of this adaptive behavior.

Do decisions shape preference? Evidence from blind choice

Psychologists have long asserted that making a choice changes a person's preferences. Recently, critics of this view have argued that choosing simply reveals preexisting preferences, and that all studies claiming that choice shapes preferences suffer from a fundamental methodological flaw. Here we address this question directly by dissociating preexisting preferences from decision making. We studied participants who rated different vacation destinations both before and after making a blind choice that could not be guided by preexisting preferences. As an additional control, we elicited ratings in a condition in which a computer made the decision for the participants. We found that preferences were altered after participants made a blind choice, but not after a computer dictated the decision. The results suggest that just as preferences form choices, choices shape preferences.

Neural responses to unattended products predict later consumer choices

Imagine you are standing at a street with heavy traffic watching someone on the other side of the road. Do you think your brain is implicitly registering your willingness to buy any of the cars passing by outside your focus of attention? To address this question, we measured brain responses to consumer products (cars) in two experimental groups using functional magnetic resonance imaging. Participants in the first group (high attention) were instructed to closely attend to the products and to rate their attractiveness. Participants in the second group (low attention) were distracted from products and their attention was directed elsewhere. After scanning, participants were asked to state their willingness to buy each product. During the acquisition of neural data, participants were not aware that consumer choices regarding these cars would subsequently be required. Multivariate decoding was then applied to assess the choice-related predictive information encoded in the brain during product exposure in both conditions. Distributed activation patterns in the insula and the medial prefrontal cortex were found to reliably encode subsequent choices in both the high and the low attention group. Importantly, consumer choices could be predicted equally well in the low attention as in the high attention group. This suggests that neural evaluation of products and associated choice-related processing does not necessarily depend on attentional processing of available items. Overall, the present findings emphasize the potential of implicit, automatic processes in guiding even important and complex decisions.

Experience and choice shape expected aversive outcomes

The value assigned to aversive events is susceptible to contextual influences. Here, we asked whether a change in the valuation of negative events is reflected in an altered neuronal representation of their expected aversive outcome. We show that experiencing an aversive event in the past, and choosing to experience it in the future, reduces its aversive value. This psychological change is mirrored in an altered neural representation of aversive value in the caudate nucleus and anterior cingulate cortex. Our findings indicate that subcortical regions known to track expected value such as the caudate nucleus, together with anterior cingulate cortical regions implicated in emotional modulation, mediate a revaluation in expectancies of aversive states. The results provide a striking example of a contextual sensitivity in how the brain ascribes value to events, in a manner that may foster resilience in the face of adversity.

The neural basis of rationalization: cognitive dissonance reduction during decision-making

People rationalize the choices they make when confronted with difficult decisions by claiming they never wanted the option they did not choose. Behavioral studies on cognitive dissonance provide evidence for decision-induced attitude change, but these studies cannot fully uncover the mechanisms driving the attitude change because only pre- and post-decision attitudes are measured, rather than the process of change itself. In the first fMRI study to examine the decision phase in a decision-based cognitive dissonance paradigm, we observed that increased activity in right-inferior frontal gyrus, medial fronto-parietal regions and ventral striatum, and decreased activity in anterior insula were associated with subsequent decision-related attitude change. These findings suggest the characteristic rationalization processes that are associated with decision-making may be engaged very quickly at the moment of the decision, without extended deliberation and may involve reappraisal-like emotion regulation processes.

I'm no longer torn after choice: how explicit choices implicitly shape preferences of odors

Several studies have shown that preferences can be strongly modulated by cognitive processes such as decision making and choices. However, it is still unclear whether choices can influence preferences of sensory stimuli implicitly. This question was addressed here by asking participants to evaluate odors, to choose their preferred odors within pairs, to reevaluate the odors, and to perform an unexpected memory test. Results revealed, for the first time in the study of olfaction, the existence of postchoice preference changes, in the sense of an overvaluation of chosen odors and a devaluation of rejected ones, even when choices were forgotten. These results suggest that chemosensory preferences can be modulated by explicit choices and that such modulation might rely on implicit mechanisms. This finding rules out any explanation of postchoice preference changes in terms of experimental demand and strongly challenges the classical cognitive-dissonance-reduction account of such preference changes.

Behavioral and neural evidence of incentive bias for immediate rewards relative to preference-matched delayed rewards

Several theories of self-control [including intertemporal bargaining (Ainslie, 1992) and self-signaling (Bodner and Prelec, 2001)] imply that intertemporal decisions can be more farsighted than would be predicted by the incentive associated with rewards outside a decision context. We examined this hypothesis using behavior and functional neuroimaging. First, subjects expressed preferences between amounts of money delayed by 4 months and smaller amounts available that day. This allowed us to establish "indifference pairs" individualized to each participant: immediate and delayed amounts that were equally preferred. Participants subsequently performed a reaction time functional magnetic resonance imaging task (Knutson et al., 2001a) that provided them with distinct opportunities to win each of the rewards that comprised the indifference pairs. Anatomical region of interest analysis as well as whole-brain analysis indicated greater response recruited by the immediate rewards (relative to the preference-matched delayed rewards) in regions previously implicated as sensitive to incentive value using the same task (including bilateral putamen, bilateral anterior insula, and midbrain). Reaction time to the target was also faster during the immediate relative to delayed reward trials (p < 0.01), and individual differences in reaction time between immediate versus delayed reward trials correlated with variance in magnetic resonance signal in those clusters that responded preferentially to immediate rewards (r = 0.33, p < 0.05). These findings indicate a discrepancy in incentive associated with the immediate versus the preference-matched delayed rewards. This discrepancy may mark the contribution of self-control processes that are recruited during decision-making but that are absent when rewards are individually anticipated.

Dopamine enhances expectation of pleasure in humans

Human action is strongly influenced by expectations of pleasure. Making decisions, ranging from which products to buy to which job offer to accept, requires an estimation of how good (or bad) the likely outcomes will make us feel [1]. Yet, little is known about the biological basis of subjective estimations of future hedonic reactions. Here, we show that administration of a drug that enhances dopaminergic function (dihydroxy-L-phenylalanine; L-DOPA) during the imaginative construction of positive future life events subsequently enhances estimates of the hedonic pleasure to be derived from these same events. These findings provide the first direct evidence for the role of dopamine in the modulation of subjective hedonic expectations in humans.

Neural representation of subjective value under risk and ambiguity

Risk and ambiguity are two conditions in which the consequences of possible outcomes are not certain. Under risk, the probabilities of different outcomes can be estimated, whereas under ambiguity, even these probabilities are not known. Although most people exhibit at least some aversion to both risk and ambiguity, the degree of these aversions is largely uncorrelated across subjects, suggesting that risk aversion and ambiguity aversion are distinct phenomena. Previous studies have shown differences in brain activations for risky and ambiguous choices and have identified neural mechanisms that may mediate transitions from conditions of ambiguity to conditions of risk. Unknown, however, is whether the value of risky and ambiguous options is necessarily represented by two distinct systems or whether a common mechanism can be identified. To answer this question, we compared the neural representation of subjective value under risk and ambiguity. fMRI was used to track brain activation while subjects made choices regarding options that varied systematically in the amount of money offered and in either the probability of obtaining that amount or the level of ambiguity around that probability. A common system, consisting of at least the striatum and the medial prefrontal cortex, was found to represent subjective value under both conditions.

An automatic valuation system in the human brain: evidence from functional neuroimaging

According to economic theories, preference for one item over others reveals its rank value on a common scale. Previous studies identified brain regions encoding such values. Here we verify that these regions can valuate various categories of objects and further test whether they still express preferences when attention is diverted to another task. During functional neuroimaging, participants rated either the pleasantness (explicit task) or the age (distractive task) of pictures from different categories (face, house, and painting). After scanning, the same pictures were presented in pairs, and subjects had to choose the one they preferred. We isolated brain regions that reflect both values (pleasantness ratings) and preferences (binary choices). Preferences were encoded whatever the stimulus (face, house, or painting) and task (explicit or distractive). These regions may therefore constitute a brain system that automatically engages in valuating the various components of our environment so as to influence our future choices.

Dopamine enhances expectation of pleasure in humans

Human action is strongly influenced by expectations of pleasure. Making decisions, ranging from which products to buy to which job offer to accept, requires an estimation of how good (or bad) the likely outcomes will make us feel [1]. Yet, little is known about the biological basis of subjective estimations of future hedonic reactions. Here, we show that administration of a drug that enhances dopaminergic function (dihydroxy-L-phenylalanine; L-DOPA) during the imaginative construction of positive future life events subsequently enhances estimates of the hedonic pleasure to be derived from these same events. These findings provide the first direct evidence for the role of dopamine in the modulation of subjective hedonic expectations in humans.

Neural activity predicts attitude change in cognitive dissonance

When our actions conflict with our prior attitudes, we often change our attitudes to be more consistent with our actions. This phenomenon, known as cognitive dissonance, is considered to be one of the most influential theories in psychology. However, the neural basis of this phenomenon is unknown. Using a Solomon four-group design, we scanned participants with functional MRI while they argued that the uncomfortable scanner environment was nevertheless a pleasant experience. We found that cognitive dissonance engaged the dorsal anterior cingulate cortex and anterior insula; furthermore, we found that the activation of these regions tightly predicted participants' subsequent attitude change. These effects were not observed in a control group. Our findings elucidate the neural representation of cognitive dissonance, and support the role of the anterior cingulate cortex in detecting cognitive conflict and the neural prediction of attitude change.