Delay discounting of real and hypothetical rewards.

The degree to which real and hypothetical rewards were discounted across delays ranging from 6 hr to 1 year was explored in a within-subjects design. An adjusting-amounts procedure was used to estimate the subjective value of real and hypothetical rewards at each delay. A hyperbolic discounting function provided a significantly better fit to individual participants' preferences than did an exponential function. No significant effect of reward type on degree of hyperbolic discounting or area under the discounting curves was detected. These findings offer some support for the validity of using hypothetical rewards to estimate discounting rates in substance-abusing and other populations, but caution is suggested because this support is gleaned from a failure to detect an effect of reward type. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Temporal discounting of rewards in patients with bipolar disorder and schizophrenia.

Patients with bipolar disorder (BD) and schizophrenia (SZ) often show decision-making deficits in everyday circumstances. A failure to appropriately weigh immediate versus future consequences of choices may contribute to these deficits. We used the delay discounting task in individuals with BD or SZ to investigate their temporal decision making. Twenty-two individuals with BD, 21 individuals with SZ, and 30 healthy individuals completed the delay discounting task along with neuropsychological measures of working memory and cognitive function. Both BD and SZ groups discounted delayed rewards more steeply than did the healthy group even after controlling for current substance use, age, gender, and employment. Hierarchical multiple regression analyses showed that discounting rate was associated with both diagnostic group and working memory or intelligence scores. In each group, working memory or intelligence scores negatively correlated with discounting rate. The results suggest that (a) both BD and SZ groups value smaller, immediate rewards more than larger, delayed rewards compared with the healthy group and (b) working memory or intelligence is related to temporal decision making in individuals with BD or SZ as well as in healthy individuals. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Now or later? Striatum and insula activation to immediate versus delayed rewards.

Neuroimaging studies on delay discounting tasks that use reward delays ranging from minutes to days have implicated the insula and striatum in the processing of intertemporal decisions. This study aimed at assessing whether these brain regions would also be involved in decision-making when subjects have to wait through the delays within the range of seconds. Using functional MRI in 13 healthy volunteers, we repeatedly presented monetary options with delays that differed within the range of multiple seconds. Using a region-of-interest approach, we found significant activation in the bilateral anterior insula and striatum when subjects chose either the immediate (smaller) or delayed (larger) option. In particular, insular activation was observed after the response and the delay, when the outcome of the immediate or the delayed choice was shown. Significantly greater activation was observed in the ventroanterior striatum while subjects chose the immediate, as opposed to the delayed, options and also after receiving the outcome of waiting through the longer delay option. The evidence presented here indicates that both the ventral striatum and the insula are involved in the processing of choosing delay options as well as the consequences of choices with delays in the seconds' range. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparison between two measures of delay discounting in smokers.

Agreement between computer and questionnaire measures of delay discounting in smokers was compared. Correlations between measures for small, medium, or large rewards were significant. Log κ values decreased as the reward delay increased, with values lower for the computer task than the questionnaire, with significant differences for small rewards. The 2 measures were related to smoking rate but not to age, gender, or obesity. The Bland-Altman test of agreement indicated large within-subject differences in κ values between the 2 measures. The size of the difference between the log κ values and magnitude of the log κ values were positively related. Results suggest κ values from the 2 measures are related but may not be used interchangeably. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

How to fill a half-full glass: Emotion and schizophrenia.

The authors comment on the article "The primacy of cognition in schizophrenia," by R. W. Heinrichs (see record 2005-03019-003). They state that Heinrichs persuasively argued as to the primacy of cognition in schizophrenia by citing an impressive body of evidence in favor of the view that schizophrenia is a complex biobehavioral disorder that manifests itself primarily in cognition. His conclusion is something of an anticlimax. At the same time, however, he acknowledged that "the glass of evidence is half empty as well as half full" (Heinrichs, 2005, p. 238). That is to say, the symptoms that mark out schizophrenia--the hallucinations, delusions, and so forth--do not appear to map onto cognitive deficits, or at least they do not map onto those that are measured with traditional neuropsychological tests. To fill the other half of the glass, the authors propose that a focus on emotion (largely neglected in the target article) will be of crucial importance. Furthermore, they commend the methods of cognitive neuropsychiatry as being eminently suitable to guide this research. The authors briefly illustrate the value of this approach with reference to affective characteristics of hallucinations and cognitive-emotional interactions in source monitoring. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An argument against dual valuation system competition: Cognitive capacities supporting future orientation mediate rather than compete with visceral motivations.

The dynamic inconsistency of preference is well documented in behavioral research, but its basis remains controversial. In this article, the authors summarize recent functional MRI (fMRI) work in the domain of intertemporal choice, specifically considering evidence bearing on the hypothesis that delay discounting in humans is determined by competition between an evolutionarily older system that discounts precipitously with delay (System 1) and a newer system that exhibits very little discounting (System 2). The authors argue that neuroimaging evidence does not support the hypothesized separate and competing value systems. While it is clear that the sophisticated cognitive capacities that lead to greater valuation of larger later alternatives (e.g., selective attention and self-signaling) depend critically on neocortical structures, these capacities affect intertemporal choice through mediation of (rather than competition with) older cortical and subcortical structures central to reward and motivation. Taken together, neuroimaging evidence supports the alternative hypothesis that intertemporal choice is guided by a single valuation system. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Narrating emotional events in schizophrenia.

Research has indicated that schizophrenia patients report similar amounts of experienced emotion in response to emotional material compared with nonpatients. However, less is known about how schizophrenia patients describe and make sense of their emotional life events. We adopted a narrative approach to investigate schizophrenia patients' renderings of their emotional life experiences. In Study 1, patients' (n = 42) positive and negative narratives were similarly personal, tellable, engaged, and appropriate. However, negative narratives were less grammatically clear than positive narratives, and positive narratives were more likely to involve other people than negative narratives. In Study 2, emotional (positive and negative) narratives were less tellable and detached, yet more linear and social compared with neutral narratives for both schizophrenia patients (n = 24) and healthy controls (n = 19). However, patients' narratives about emotional life events were less appropriate to context and less linear, and patients' narratives, whether emotional or not, were less tellable and more detached compared with controls' narratives. Although schizophrenia patients are capable of recounting life events that trigger different emotions, the telling of these life events is fraught with difficulty. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Time estimation in process-reactive schizophrenia.

Process and reactive schizophrenics, and reactive schizophrenics and normals were compared as to their responses on a perceptual time-estimation task. Null hypotheses being tested were that groups would not differ in variability or accuracy of response. Schizophrenic (45) and normal (15) subjects were selected from the male patient population and hospital employees, respectively, of a Veteran's Administration hospital. Schizophrenics selected for the study were classified by means of the Abbreviated Becker Elgin Scale. Subjects were individually administered a time-estimation task consisting of seven stimulus cards which were tachistoscopically presented, with exposure speeds at 10, 20, and 30 seconds for each card. Judgments of exposure times were converted into scores based upon ratios of estimated time to actual time. Scores (three) for each card were totaled. Groups were then compared on each of the stimulus cards by means of two-tailed t tests. In accuracy of estimation, process schizophrenics demonstrated significantly less accuracy than did reactives on four of the seven cards; no differences were shown between reactives and normals in accuracy of estimation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Delusional thinking and cognitive organization in schizophrenia.

A delusion can be conceptualized as a form of cognitive reorganization; according to this interpretation a delusion serves to integrate into a meaningful and acceptable whole data which otherwise would be anxiety provoking. On the assumption that the utilization of delusions is representative of a generalized cognitive technique for dealing with ambiguous inputs it was hypothesized that delusional schizophrenics should manifest a stronger tendency to integrate ambiguous stimuli in a laboratory situation than nondelusional schizophrenics. To test the hypothesis 24 delusional and 25 nondelusional schizophrenics were compared on the McGill Closure Test. The results supported the hypothesis. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The role of the nucleus accumbens core in impulsive choice, timing, and reward processing.

The present series of experiments aimed to pinpoint the source of nucleus accumbens core (AcbC) effects on delay discounting. Rats were trained with an impulsive choice procedure between an adjusting smaller sooner reward and a fixed larger later reward. The AcbC-lesioned rats produced appropriate choice behavior when the reward magnitude was equal. An increase in reward magnitude resulted in a failure to increase preference for the larger later reward in the AcbC-lesioned rats, whereas a decrease in the larger later reward duration resulted in normal alterations in choice behavior in AcbC-lesioned rats. Subsequent experiments with a peak timing (Experiments 2 and 3) and a behavioral contrast (Experiment 4) indicated that the AcbC-lesioned rats suffered from decreased incentive motivation during changes in reward magnitude (Experiments 2 and 4) and when expected rewards were omitted (Experiments 2 and 3), but displayed intact anticipatory timing of reward delays (Experiments 2 and 3). The results indicate that the nucleus accumbens core is critical for determining the incentive value of rewards, but does not participate in the timing of reward delays. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Intertemporal choice: Neuronal and psychological determinants of economic decisions.

This introductory article provides a short overview of empirical and theoretical articles presented in the special issue on psychological and neural models of intertemporal decision making, which is divided into 2 parts. The first part consists of contributions presenting different models of intertemporal choice. These contributions provide an overview of current conceptualizations; that is, providing several psychological and neural frameworks, investigating how memory processes are related to the anticipation of time, and showing how the perception of time underlies our decisions about the future. A final article deals with factors that influence choices on environmental policies where the consequences of decisions are delayed by decades or more. The second upcoming part is concerned with functional neuroimaging of intertemporal decision making. Two reviews of studies in neuroimaging and 2 empirical articles examine the questions of which brain regions (and associated functions) are involved in deciding on options with different temporal consequences. We hope this volume will be conducive in developing a better understanding of intertemporal decision making as part of complex sets of neural processes as well as psychological factors that include cognitive reasoning, emotional states, and the interconnected perception of time. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Everyday action in schizophrenia: Performance patterns and underlying cognitive mechanisms.

Everyday action is impaired among individuals with schizophrenia, yet few studies have characterized the nature of this deficit using performance-based measures. This study examined the performance of 20 individuals with schizophrenia or schizoaffective disorder on the Naturalistic Action Test (M. F. Schwartz, L. J. Buxbaum, M. Ferraro, T. Veramonti, & M. Segal, 2003). Performance was coded to examine overall impairment, task accomplishment, and error patterns and was compared with that of healthy controls (n = 28) and individuals with mild dementia (n = 23). Additionally, 2 competing accounts of everyday action deficits, the resource theory and an executive account, were evaluated. When compared with controls, the participants with schizophrenia demonstrated impaired performance. Relative to dementia patients, participants with schizophrenia obtained higher accomplishment scores but committed comparable rates of errors. Moreover, distributions of error types for the 2 groups differed, with the participants with schizophrenia demonstrating greater proportions of errors associated with executive dysfunction. This is the 1st study to show different Naturalistic Action Test performance patterns between 2 neurologically impaired populations. The distinct performance pattern demonstrated by individuals with schizophrenia reflects specific deficits in executive function. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Time perception and conflict arousal in schizophrenia.

The hypothesis that schizophrenics would exhibit greater distortion in estimation of duration time for stimuli relevant to their major conflicts than for other stimuli was investigated. 3 groups, each with 16 Ss who were homogeneous with respect to experiencing primary conflicts with either aggression, sex, or dependency, were formed. A factorial Latin square design was used in which Ss estimated stimuli durations following the tachistoscopic presentation at 4 exposure times of 4 pictorial stimuli, 1 of which represented their major conflict area. Results demonstrated that greatest distortions occurred for conflict pictures at the .001 level. Distortion elicitation of the aggression stimulus was greater than other stimuli at .001 for the combined schizophrenics, an effect not found with normal control Ss. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Neurocognition in first-episode schizophrenia: A meta-analytic review.

Compromised neurocognition is a core feature of schizophrenia. Following Heinrichs and Zakzanis’s (1998) seminal meta-analysis of middle-aged and predominantly chronic schizophrenia samples, the aim of this study is to provide a meta-analysis of neurocognitive findings from 47 studies of first-episode (FE) schizophrenia published through October 2007. The meta-analysis uses 43 separate samples of 2,204 FE patients with a mean age of 25.5 and 2,775 largely age- and gender-matched control participants. FE samples demonstrated medium-to-large impairments across 10 neurocognitive domains (mean effect sizes from ?0.64 to ?1.20). Findings indicate that impairments are reliably and broadly present by the FE, approach or match the degree of deficit shown in well-established illness, and are maximal in immediate verbal memory and processing speed. Larger IQ impairments in the FE compared to the premorbid period, but comparable to later phases of illness suggests deterioration between premorbid and FE phases followed by deficit stability at the group level. Considerable heterogeneity of effect sizes across studies, however, underscores variability in manifestations of the illness and a need for improved reporting of sample characteristics to support moderator variable analyses. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Intrinsic motivation in schizophrenia: Relationships to cognitive function, depression, anxiety, and personality.

The goal of the current project was to assess subjective reports of intrinsic motivation and their relationship to cognitive function, mood, and personality in schizophrenia. The authors used the Motivational Trait Questionnaire to examine 3 components of intrinsic motivation (personal mastery, competitive excellence, motivation related to anxiety). They also examined fluid intelligence, context processing, and working memory, as well as self-reports of mood and personal traits related to motivation. Participants were 66 individuals with schizophrenia or schizoaffective disorder and 44 healthy controls. Self-reports of personal mastery and competitive excellence did not differ between controls and individuals with schizophrenia, though patients did report significantly higher motivation related to anxiety. Among controls, but not patients, self-reports of intrinsic motivation were strongly related to cognitive performance. In contrast, both controls and patients showed similar strong relationships between self-reports of intrinsic motivation and related measures of mood and personality. These results are not consistent with the hypothesis that motivational deficits in schizophrenia reflect impairments in intrinsic motivation. However, they do suggest that the normal relationship between self-reports of intrinsic motivation and cognitive function is disrupted in schizophrenia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Direct measurement of differential cognitive deficit in acute schizophrenia.

This is a longitudinal study in which 11 standardized tests of cognitive function were administered to 20,000 normal Ss and at a later point in time readministered to those Ss of the original group (N=15) who became schizophrenic and were hospitalized. The tests were also readministered to part of the original group (N=40) who, at the same point in time, were still normal. The results, which revealed significant differential deficit on 5 of the measures, suggest that lack of motivation to reach out and actively manipulate stimuli or experience new learning produced the differences observed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Remembering the past and imagining the future in schizophrenia.

It has been suggested that patients with schizophrenia experience a distorted sense of continuity of self across time. However, temporal aspects of self-processing have received little empirical attention in schizophrenia. In this study, the authors investigated schizophrenic patients' ability to generate specific mental images of their personal past and future. Results showed that patients recalled fewer specific past events than did healthy controls and were even more impaired in generating specific future events. These deficits were associated with positive symptoms but were not associated with negative symptoms or with performances on verbal fluency tasks. It is suggested that schizophrenic patients' failures to project themselves into specific past and future episodes might be related to difficulties in retrieving contextual details from memory, as well as disturbance of the sense of subjective time. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Impairment of probabilistic reward-based learning in schizophrenia.

Recent models assume that some symptoms of schizophrenia originate from defective reward processing mechanisms. Understanding the precise nature of reward-based learning impairments might thus make an important contribution to the understanding of schizophrenia and the development of treatment strategies. The present study investigated several features of probabilistic reward-based stimulus association learning, namely the acquisition of initial contingencies, reversal learning, generalization abilities, and the effects of reward magnitude. Compared to healthy controls, individuals with schizophrenia exhibited attenuated overall performance during acquisition, whereas learning rates across blocks were similar to the rates of controls. On the group level, persons with schizophrenia were, however, unable to learn the reversal of the initial reward contingencies. Exploratory analysis of only the subgroup of individuals with schizophrenia who showed significant learning during acquisition yielded deficits in reversal learning with low reward magnitudes only. There was further evidence of a mild generalization impairment of the persons with schizophrenia in an acquired equivalence task. In summary, although there was evidence of intact basic processing of reward magnitudes, individuals with schizophrenia were impaired at using this feedback for the adaptive guidance of behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of methylphenidate on discounting of delayed rewards in attention deficit/hyperactivity disorder.

Impulsivity is a central component of attention deficit/hyperactivity disorder (ADHD). Delay discounting, or a preference for smaller, immediate rewards over larger, delayed rewards, is considered an important aspect of impulsivity, and delay-related impulsivity has been emphasized in etiological models of ADHD. In this study, we examined whether stimulant medication, an effective treatment for ADHD, reduced discounting of delayed experiential and hypothetical rewards among 49 children (ages 9–12 years) with ADHD. After a practice day, participants completed a 3-day double-blind placebo-controlled acute medication assessment. Active doses were long-acting methylphenidate (Concerta), with the nearest equivalents of 0.3 and 0.6 mg/kg TID immediate-release methylphenidate. On each testing day, participants completed experiential (real-world money in real time) and hypothetical discounting tasks. Relative to placebo, methylphenidate reduced discounting of delayed experiential rewards but not hypothetical rewards. Broadly consistent with etiological models that emphasize delay-related impulsivity among children with ADHD, these findings provide initial evidence that stimulant medication reduces delay discounting among those with the disorder. The results also draw attention to task parameters that may influence the sensitivity of various delay discounting measures to medication effects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Scanning-control mechanism and "cognitive filtering" in paranoid and non-paranoid schizophrenia.

Recent studies of individual consistencies in cognitive behavior, termed studies of "cognitive controls," have emphasized the importance of differing characterological response dispositions which also serve ego defensive functions. This report concerned 2 such response dispositions—extensiveness of scanning and breadth of categorization. Highly significant differences in scanning behavior, inferred from performances on a certain form of size-estimation procedure, were found between paranoid and nonparanoid schizophrenics. Significant differences were also found between the groups on a measure of breadth of categorization. These findings were discussed in terms of some developmental aspects of the 2 cognitive controls and also in terms of the relevance of these findings to a theory of delusional thinking. (22 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)