Jan Peters

Episodic Future Thinking Reduces Reward Delay Discounting through an Enhancement of Prefrontal-Mediotemporal Interactions

Humans discount the value of future rewards over time. Here we show using functional magnetic resonance imaging (fMRI) and neural coupling analyses that episodic future thinking reduces the rate of delay discounting through a modulation of neural decision-making and episodic future thinking networks. In addition to a standard control condition, real subject-specific episodic event cues were presented during a delay discounting task. Spontaneous episodic imagery during cue processing predicted how much subjects changed their preferences toward more future-minded choice behavior. Neural valuation signals in the anterior cingulate cortex and functional coupling of this region with hippocampus and amygdala predicted the degree to which future thinking modulated individual preference functions. A second experiment replicated the behavioral effects and ruled out alternative explanations such as date-based processing and temporal focus. The present data reveal a mechanism through which neural decision-making and prospection networks can interact to generate future-minded choice behavior.

Boys do it the right way: sex-dependent amygdala lateralization during face processing in adolescents.

Previous studies have observed a sex-dependent lateralization of amygdala activation related to emotional memory. Specifically, it was shown that the activity of the right amygdala correlates significantly stronger with memory for images judged as arousing in men than in women, and that there is a significantly stronger relationship in women than in men between activity of the left amygdala and memory for arousing images. Using a large sample of 235 male adolescents and 235 females matched for age and handedness, we investigated the sex-specific lateralization of amygdala activation during an emotional face perception fMRI task. Performing a formal sex by hemisphere analysis, we observed in males a significantly stronger right amygdala activation as compared to females. Our results indicate that adolescents display a sex-dependent lateralization of amygdala activation that is also present in basic processes of emotional perception. This finding suggests a sex-dependent development of human emotion processing and may further implicate possible etiological pathways for mental disorders most frequent in adolescent males (i.e., conduct disorder).

Don’t Look Back in Anger! Responsiveness to Missed Chances in Successful and Nonsuccessful Aging

Emotionally healthy older adults show a reduced responsiveness to regret when performing a sequential decision task. No Regrets As people grow older, the possibility to think about “missed chances” increases. When we are young, thinking about missed opportunities may help to optimize future behavior. However, the older we get the probability of “second chances” decreases and thus the benefit of ruminating upon them disappears. Brassen et al. (p. 612, published online 19 April) studied the behavioral and neural response to missed chances in young adults, the healthy elderly subjects and late-life depressed volunteers. Compared with young and depressed subjects, the healthy elderly subjects showed a reduced sensitivity to missed opportunities. The findings suggest a potential mechanism for preserved emotional health in older age. Life-span theories explain successful aging with an adaptive management of emotional experiences like regret. As opportunities to undo regrettable situations decline with age, a reduced engagement into these situations represents a potentially protective strategy to maintain well-being in older age. Yet, little is known about the underlying neurobiological mechanisms supporting this claim. We used a multimodal psychophysiological approach in combination with a sequential risk-taking task that induces the feeling of regret and investigated young as well as emotionally successfully and unsuccessfully (i.e., late-life depressed) aged participants. Responsiveness to regret was specifically reduced in successful aging paralleled by autonomic and frontostriatal characteristics indicating adaptive shifts in emotion regulation. Our results suggest that disengagement from regret reflects a critical resilience factor for emotional health in older age.

Cue-Induced Craving Increases Impulsivity via Changes in Striatal Value Signals in Problem Gamblers

Impulsive behavior such as steep temporal discounting is a hallmark of addiction and is associated with relapse. In pathological gamblers, discounting may be further increased by the presence of gambling-related cues in the environment, but the extent to which the gambling relatedness of task settings affects reward responses in gambling addiction is debated. In the present study, human problem gamblers made choices between immediate rewards and individually tailored larger-but-later rewards while visual gambling-related scenes were presented in the background. N = 17 participants were scanned using fMRI, whereas N = 5 additional participants completed a behavioral version of the task. Postscan craving ratings were acquired for each image, and behavioral and neuroimaging data were analyzed separately for high- and low-craving trials (median split analysis). Discounting was steeper for high versus low craving trials. Neuroimaging revealed a positive correlation with model-based subjective value in midbrain and striatum in low-craving trials that was reversed in high-craving trials. These findings reveal a modulation of striatal reward responses in gamblers by addiction-related cues, and highlight a potentially important mechanism that may contribute to relapse. Cue-induced changes in striatal delayed reward signals may lead to increased discounting of future rewards, which might in turn affect the likelihood of relapse.

Reward-based decision making in pathological gambling: the roles of risk and delay.

Pathological gambling (PG) is a non-substance based addiction that shares many behavioral and neural features with substance based addictions. However, in PG behavioral and neural changes are unlikely to be confounded by effects of acute or chronic drug exposure. Changes in reward based decision-making in particular increases in impulsivity are hallmark features of addictions. Here we review studies in PG that applied three reward-related decision tasks: the Iowa Gambling Task, probability discounting and delay discounting. We discuss the findings and focus on the impact of addiction severity and the relation of effects to impulsivity measures. While there is evidence that PGs differ from healthy controls on all three tasks, there is only little support for a further modulation of impairments by addiction severity. Conceptually, delay discounting is related to impulsivity measures and findings in this task show a considerable correlation with e.g. questionnaire-based measures of impulsivity. Taken together, impairments in PG on these three tasks are relatively well replicated, although impairments appear to be largely uncorrelated between tasks. An important next step will be to conceptualize a process-based account of behavioral impairments in PG.

Formal Comparison of Dual-Parameter Temporal Discounting Models in Controls and Pathological Gamblers

Temporal or delay discounting refers to the phenomenon that the value of a reward is discounted as a function of time to delivery. A range of models have been proposed that approximate the shape of the discount curve describing the relationship between subjective value and time. Recent evidence suggests that more than one free parameter may be required to accurately model human temporal discounting data. Nonetheless, many temporal discounting studies in psychiatry, psychology and neuroeconomics still apply single-parameter models, despite their oftentimes poor fit to single-subject data. Previous comparisons of temporal discounting models have either not taken model complexity into account, or have overlooked particular models. Here we apply model comparison techniques in a large sample of temporal discounting datasets using several discounting models employed in the past. Among the models examined, an exponential-power model from behavioural economics (CS model, Ebert & Prelec 2007) provided the best fit to human laboratory discounting data. Inter-parameter correlations for the winning model were moderate, whereas they were substantial for other dual-parameter models examined. Analyses of previous group and context effects on temporal discounting with the winning model provided additional theoretical insights. The CS model may be a useful tool in future psychiatry, psychology and neuroscience work on inter-temporal choice.

Impairment of verbal recollection following ischemic damage to the right anterior hippocampus

Damage to the left medial temporal lobe (MTL) leads to an impairment of verbal recognition memory, affecting both the process of conscious recollection and familiarity-based recognition. Neuroimaging evidence, on the other hand, suggests a bilateral MTL contribution to verbal recollection. We investigated verbal recognition memory in three patients with focal ischemic lesions to the right MTL. The dual-process signal detection model and the process-dissociation procedure were applied to assess the contributions of recollection and familiarity to recognition memory. Compared to a group of 27 healthy age-matched controls, patients were impaired at recollection while familiarity was intact, and this effect was found for both estimation procedures. Detailed single-case analyses confirmed this pattern in two of the three right MTL patients. The findings suggest that, when task demands are high, as during recollective recognition, the right anterior hippocampus may also contribute to verbal recollection, thereby confirming neuroimaging evidence of a joint involvement of the left and the right MTL in verbal recollection.

Structure-function relationships in the processing of regret in the orbitofrontal cortex

The influence of counterfactual thinking and regret on choice behavior has been widely acknowledged in economic science (Bell in Oper Res 30:961–981, 1982; Kahneman and Tversky in Judgment under uncertainty: heuristics and biases. Cambridge University Press, Cambridge, pp 201–210, 1982; Loomes and Sugden in Econ J 92:805–824, 1982). Neuroimaging studies have only recently begun to explore the neural correlates of this psychological factor and orbitofrontal cortex (OFC) activity was observed in several of them depending of the exact characteristics of the employed paradigm. This selective OFC involvement and, moreover, a consistently found dissociation of medial and lateral OFC activity clusters allow inferences to the function of this structure in counterfactual thinking and regret. Vice versa, the differential contribution of OFC subregions to these processes also adds evidence to the current debate on the function of this cortical structure in decision-making that attracted increasing attention in recent years.

Episodic Future Thinking Is Related to Impulsive Decision Making in Healthy Adolescents

Delay discounting is a stable trait measure of impulsivity. Engaging in episodic future thinking (EFT) can reduce discounting, but whether individual differences in discounting are associated with differences in future thinking remains unclear. Here, this association was tested in healthy adolescents (n = 49, age range = 12-16 years, fluent German speakers, from a large German city). Data collection was between December 2011 and December 2012. Vividness of EFT (assessed via the Autobiographical Memory Interview) was negatively correlated with discounting (r = -.41, 95% CI [-.63, -.13], r(2) = .17). Regression analyses confirmed that this association was stable when controlling for additional variables, including hormonal measures of pubertal maturation and intelligence. EFT may attenuate impulsivity in young people at risk of engaging in problematic behavior.

Elevated functional connectivity in a striatal-amygdala circuit in pathological gamblers.

Both substance-based addiction and behavioural impulse control disorders (ICDs) have been associated with dysfunctions of the ventral striatum. Recent studies using functional connectivity techniques have revealed increased coupling of the ventral striatum with other limbic regions such as amygdala and orbitofrontal cortex in patients with substance abuse disorders and attention-deficit hyperactivity disorder. In the present study, we re-analyzed previously published functional magnetic resonance imaging data acquired in pathological gamblers and controls during value-based decision-making to investigate whether PG is associated with similar functional connectivity effects. In line with previous studies in other ICDs, we observed reliable increases in functional coupling between striatum and bilateral amygdala in gamblers vs. controls. Implications of these findings for neural models of self-control and addiction are discussed.