اختلال در تصمیم گیری بر اساس هر دو اطلاعات تشویق و تنبیه در افراد مبتلا به اختلالات فکری و روانی
|کد مقاله||سال انتشار||مقاله انگلیسی||ترجمه فارسی||تعداد کلمات|
|34306||2006||11 صفحه PDF||سفارش دهید||4528 کلمه|
Publisher : Elsevier - Science Direct (الزویر - ساینس دایرکت)
Journal : Personality and Individual Differences, Volume 41, Issue 1, July 2006, Pages 155–165
In this study, we examined decision-making to rewarding or punishing stimuli in individuals with psychopathy (n = 21) and comparison individuals (n = 19) using the Differential Reward/Punishment Learning Task. In this task, the participant chooses between two objects associated with different levels of reward or punishment. Thus, response choice indexes not only reward/punishment sensitivity but also sensitivity to reward/punishment level according to inter-stimulus reinforcement distance. Individuals with psychopathy showed significant impairment when choosing between objects associated with differential levels of reward but also significantly greater impairment when choosing between objects associated with differential levels of punishment. However, the two groups were comparably affected by inter-stimulus reinforcement distance. The results are discussed with reference to current models of psychopathy.
Psychopathy is characterized by a callous, shallow and manipulative affective-interpersonal style combined with antisocial and reckless behavior (Hare, 1991). Individuals with psychopathy show little concern about the effects of their actions on other individuals or even themselves. They often commit impulsive, poorly planned crimes where the likelihood of being caught is high and fail to avoid behaviors which have previously been punished (Hare, 1991). In line with this, research has indicated that individuals with psychopathy are impaired at learning about and appropriately responding to stimuli associated with punishment. Thus, they show impairments in aversive conditioning (Flor, Birbaumer, Hermann, Ziegler, & Patrick, 2002) and passive avoidance learning (Blair, Mitchell, Leonard, et al., 2004 and Newman and Kosson, 1986). In addition, they show impaired augmentation of the startle reflex following visual threat primes (Levenston, Patrick, Bradley, & Lang, 2000), impaired recognition of negative affect emotional facial expressions (Blair, Mitchell, Peschardt, et al., 2004), and impaired skin conductance responses (SCR) to negative vocal expressions (Verona, Patrick, Curtin, Bradley, & Lang, 2004). It is less clear whether individuals with psychopathy are comparably impaired in learning about and appropriately responding to stimuli associated with reward. They do show appropriate suppression of the startle reflex following a positive visual prime (Levenston et al., 2000), suggesting that the processing of appetitive information is intact in individuals with psychopathy. However, relative to comparison individuals, individuals with psychopathy present with reduced SCRs to positive auditory cues (Verona et al., 2004) and reduced interference from positive distracters on goal-directed processing (Mitchell, Richell, Leonard, & Blair, in press). In addition, individuals with psychopathy show a generalized reduction of the affect-driven facilitation for both positive and negative words in lexical decision (Kiehl et al., 1999, Lorenz and Newman, 2002 and Williamson et al., 1991) and reduced affective priming for both positive and negative words (Blair et al., in press). These studies suggest that individuals with psychopathy are impaired in processing aversive and appetitive information. Many studies have examined aversive and appetitive stimuli in a ‘crystallized’ form where the emotional learning about, and formation of, appetitive and aversive conditioned stimuli (CS) occurred prior to the study. These studies therefore are not informative regarding the ability of individuals with psychopathy to learn about reward and punishment information. In this paper we examine decision-making on the basis of reward/punishment associations learnt within the content of the study. Emotional learning accounts of psychopathy make clear predictions regarding the ability of individuals with psychopathy to learn stimuli-punishment associations. Thus, accounts emphasizing the reduced ability to process punishing cues in individuals with psychopathy due to reduced anxiety or fear (Fowles, 1988, Lykken, 1957 and Patrick, 1994) clearly predict that they should be impaired at learning stimuli-punishment associations but not necessarily stimulus-reward associations. However, Fowles has suggested that individuals with psychopathy ‘show no deficit in reward learning’ (Fowles, 1988, p. 377). These accounts then would predict that individuals with psychopathy show impaired response choice to stimuli associated with punishment but normal or superior response choice to stimuli associated with reward. The Integrated Emotion System (IES) model can be considered an extension of the punishment positions (Blair, 2004). The model consists of a series of systems operating in specific integrated ways to perform specific tasks. The first of these systems (neural level: temporal cortex and hippocampus) consists of representational units coding potential CS. These units form weighted connections with affect units (neural level: the amygdala) representing reward and punishment. The affect units allow emotional learning to occur. The third system (neural level: the insula) stores the sensory valence representations. The fourth system (neural level: medial frontal cortex) receives information about the expected reward/punishment associated with a particular stimulus and allows decision-making between competing stimuli. Importantly, the computational properties of the ‘selection’ units within this fourth system suggest a clear prediction: error rates should be inversely related to inter-stimulus reinforcement difference. That is, participants should make more selection errors when deciding between stimuli associated with similar levels of reward/punishment than when deciding between stimuli associated with less similar levels of reward/punishment. With respect to psychopathy, the main claim of the IES model is that individuals with psychopathy have impaired affect representations; i.e., they are impaired in learning stimulus-reinforcement associations. Within the model, the system that allows affect representations (the amygdala) represents both positive and negative affect. Indeed, there is considerable data that the amygdala is implicated in the processing of both positive and negative stimuli (Baxter & Murray, 2002). Two sets of predictions can be generated from the IES model with respect to psychopathy. The system for affect representations may be generally impaired leading to reduced processing of both appetitive and aversive material, or it may only be impaired for aversive representations leading to reduced processing of aversive, but not appetitive, material. Given these contrasting sets of predictions from the emotional learning accounts of psychopathy, we designed a graded stimulus-reinforcement decision-making task: the Differential Reward/Punishment Learning Task (DRPLT). In this task, the participant chooses between two objects presented on a computer screen. The participants decisions can either involve two objects associated with different levels of reward, two objects associated with different levels of punishment or one object associated with reward and one object associated with punishment (see below). The participant has to choose the object that will gain the most points or, on trials involving two punishing objects, lose the least points. In our recent fMRI work, we have confirmed the involvement of the amygdala, anterior cingulate cortex, insula and medial frontal cortex in this task (Blair, Marsh, Morton, Drevets, & Blair, in preparation). If individuals with psychopathy have reduced ability to learn stimulus-reward and stimulus-punishment associations, they should show a general impairment relative to comparison individuals for all three decision types. In contrast, if individuals with psychopathy are impaired only at associating stimuli with punishment, they should show impairment only when choosing between stimuli associated with different levels of punishment. In addition, if they are hyper-sensitive to appetitive stimuli, they should show improved response choice between two rewarding stimuli relative to comparison individuals. The current study tests these predictions.