The biological bases of unfairness: Neuroimaging evidence for the distinctiveness of procedural and distributive justice

A classic debate in the organizational justice literature concerns the question of whether procedural justice and distributive justice are independent constructs. We investigate this question by using fMRI methods to examine brain activation patterns associated with procedural and distributive unfairness. We observed a clear dissociation of activation between these two forms of justice, and only a minimal amount of shared activation in the hypothesized regions. Specifically, unfair procedures evoked greater activation in parts of the brain related to social cognition, such as the ventrolateral prefrontal cortex (VLPFC) and the superior temporal sulcus (STS), whereas unfair outcomes evoked greater activation in more emotional areas of the brain, such as the anterior cingulate cortex (ACC), anterior insula (AI) and the dorsolateral prefrontal cortex (DLPFC). We interpret the findings as supporting the notion that the two forms of justice reflect distinct constructs, while recognizing that, as forms of justice, they are closely related nomologically.     

Behavioral and neural predictors of upcoming decisions

Although it is widely known that brain regions such as the prefrontal cortex, the amygdala, and the ventral striatum play large roles in decision making, their precise contributions remain unclear. Here, we used functional magnetic resonance imaging and principles of reinforcement learning theory to investigate the relationship between current reinforcements and future decisions. In the experiment, subjects chose between high-risk (i.e., low probability of a large monetary reward) and low-risk (high probability of a small reward) decisions. For each subject, we estimated value functions that represented the degree to which reinforcements affected the value of decision options on the subsequent trial. Individual differences in value functions predicted not only trial-to-trial behavioral strategies, such as choosing high-risk decisions following high-risk rewards, but also the relationship between activity in prefrontal and subcortical regions during one trial and the decision made in the subsequent trial. These findings provide a novel link between behavior and neural activity by demonstrating that value functions are manifested both in adjustments in behavioral strategies and in the neural activity that accompanies those adjustments.     

Task difficulty modulates brain-behavior correlations in language production and cognitive control: Behavioral and fMRI evidence from a phonological go/no-go picture-naming paradigm

Language production and cognitive control are complex processes that involve distinct yet interacting brain networks. However, the extent to which these processes interact and their neural bases have not been thoroughly examined. Here, we investigated the neural and behavioral bases of language production and cognitive control via a phonological go/no-go picture-naming task. Naming difficulty and cognitive control demands (i.e., conflict monitoring and response inhibition) were manipulated by varying the proportion of naming trials (go trials) and inhibition trials (no-go trials) across task runs. The results demonstrated that as task demands increased, participants’ behavioral performance declined (i.e., longer reaction times on naming trials, more commission errors on inhibition trials) whereas brain activation generally increased. Increased activation was found not only within the language network but also in domain-general control regions. Additionally, right superior and inferior frontal and left supramarginal gyri were sensitive to increased task difficulty during both language production and response inhibition. We also found both positive and negative brain–behavior correlations. Most notably, increased activation in sensorimotor regions, such as precentral and postcentral gyri, was associated with better behavioral performance, in both successful picture naming and successful inhibition. Moreover, comparing the strength of correlations across conditions indicated that the brain–behavior correlations in sensorimotor regions that were associated with improved performance became stronger as task demands increased. Overall, our results suggest that cognitive control demands affect language production, and that successfully coping with increases in task difficulty relies on both language-specific and domain-general cognitive control regions.     

Human trace fear conditioning: right-lateralized cortical activity supports trace-interval processes

Pavlovian conditioning requires the convergence and simultaneous activation of neural circuitry that supports conditioned stimulus (CS) and unconditioned stimulus (US) processes. However, in trace conditioning, the CS and US are separated by a period of time called the trace interval, and thus do not overlap. Therefore, determining brain regions that support associative learning by maintaining a CS representation during the trace interval is an important issue for conditioning research. Prior functional magnetic resonance imaging (fMRI) research has identified brain regions that support trace-conditioning processes. However, relatively little is known about whether this activity is specific to the trace CS, the trace interval, or both periods of time. The present study was designed to disentangle the hemodynamic response produced by the trace CS from that associated with the trace interval, in order to identify learning-related activation during these distinct components of a trace-conditioning trial. Trace-conditioned activity was observed within dorsomedial prefrontal cortex (PFC), dorsolateral PFC, insula, inferior parietal lobule (IPL), and posterior cingulate (PCC). Each of these regions showed learning-related activity during the trace CS, while trace-interval activity was only observed within a subset of these areas (i.e., dorsomedial PFC, PCC, right dorsolateral PFC, right IPL, right superior/middle temporal gyrus, and bilateral insula). Trace-interval activity was greater in right than in left dorsolateral PFC, IPL, and superior/middle temporal gyrus. These findings indicate that components of the prefrontal, cingulate, insular, and parietal cortices support trace-interval processes, as well as suggesting that a right-lateralized fronto-parietal circuit may play a unique role in trace conditioning.     

Psychopathy,frustration, and reactive aggression: The role of ventromedial prefrontal cortex

Psychopathy is a developmental disorder marked by emotional hyporesponsiveness and an increased risk for instrumental and reactive aggression. The increased risk for reactive aggression is the focus of the current paper. It will be argued that the increased risk for reactive aggression does not relate to an increased sensitivity to threatening stimuli since psychopathy is associated with a reduced sensitivity to threat. Instead, it is argued that the increased risk for reactive aggression relates to an increased risk for frustration; i.e., the emotional state following the performance of an action in the expectation of a particular reward and not receiving this reward. Two impairments seen in psychopathy would increase the risk for frustration and consequent potential reactive aggression; impairments in stimulus‐reinforcement learning and reversal learning. It is argued that both are known consequences of impairment in ventromedial prefrontal cortex, one of the regions principally implicated in psychopathy.     

Reward anticipation enhances brain activation during response inhibition

The chance to achieve a reward starts up the required neurobehavioral mechanisms to adapt our thoughts and actions in order to accomplish our objective. However, reward does not equally reinforce everybody but depends on interindividual motivational dispositions. Thus, immediate reward contingencies can modulate the cognitive process required for goal achievement, while individual differences in personality can affect this modulation. We aimed to test the interaction between inhibition-related brain response and motivational processing in a stop signal task by reward anticipation and whether individual differences in sensitivity to reward (SR) modulate such interaction. We analyzed the cognitive–motivational interaction between the brain pattern activation of the regions involved in correct and incorrect response inhibition and the association between such brain activations and SR scores. We also analyzed the behavioral effects of reward on both reaction times for the “go” trials before and after correct and incorrect inhibition in order to test error prediction performance and postinhibition adjustment. Our results show enhanced activation during response inhibition under reward contingencies in frontal, parietal, and subcortical areas. Moreover, activation of the right insula and the left putamen positively correlates with the SR scores. Finally, the possibility of reward outcome affects not only response inhibition performance (e.g., reducing stop signal reaction time), but also error prediction performance and postinhibition adjustment. Therefore, reward contingencies improve behavioral performance and enhance brain activation during response inhibition, and SR is related to brain activation. Our results suggest the conditions and factors that subserve cognitive control strategies in cognitive motivational interactions during response inhibition.     

抑郁倾向对合作的影响：双人同步近红外脑成像研究

抑郁人群不但表现出注意、记忆等个体认知层面的负性偏向, 还伴随有明显的社会认知障碍。已有研究在抑郁对社会认知的影响方面还考察得不多。本研究采用囚徒困境范式考察抑郁倾向对社会合作的影响。结果显示, 高抑郁倾向组比低抑郁倾向组的合作率更低, 双侧背外侧前额叶的激活更弱, 抑郁对右侧背外侧前额叶及眶额叶的脑间同步性有调节作用; 低抑郁被试与低抑郁被试配对时右侧颞顶联合区脑间同步性强于高抑郁被试与高抑郁被试配对, 或者高抑郁被试与低抑郁被试配对时的右侧颞顶联合区脑间同步性, 该效应当且仅当双方的选择相同时显著。结果表明, 抑郁群体在社会奖赏加工、冲突控制及心理理论脑区均存在功能性缺陷, 这些结果为理解抑郁人群合作意愿下降提供了脑成像证据。     

Emotional appraisal is influenced by cardiac afferent information

Influential models highlight the central integration of bodily arousal with emotion. Some emotions, notably disgust, are more closely coupled to visceral state than others. Cardiac baroreceptors, activated at systole within each cardiac cycle, provide short-term visceral feedback. Here we explored how phasic baroreceptor activation may alter the appraisal of brief emotional stimuli and consequent cardiovascular reactions. We used functional MRI (fMRI) to measure brain responses to emotional face stimuli presented before and during cardiac systole. We observed that the processing of emotional stimuli was altered by concurrent natural baroreceptor activation. Specifically, facial expressions of disgust were judged as more intense when presented at systole, and rebound heart rate increases were attenuated after expressions of disgust and happiness. Neural activity within prefrontal cortex correlated with emotionality ratings. Activity within periaqueductal gray matter reflected both emotional ratings and their interaction with cardiac timing. Activity within regions including prefrontal and visual cortices correlated with increases in heart rate evoked by the face stimuli, while orbitofrontal activity reflected both evoked heart rate change and its interaction with cardiac timing. Our findings demonstrate that momentary physiological fluctuations in cardiovascular afferent information (1) influence specific emotional judgments, mediated through regions including the periaqueductal gray matter, and (2) shape evoked autonomic responses through engagement of orbitofrontal cortex. Together these findings highlight the close coupling of visceral and emotional processes and identify neural regions mediating bodily state influences on affective judgment.     

Neuronal representations of cognitive state: reward or attention?

The effects of spatial or featural attention on the activity of neurons have been studied in many experiments that have used a variety of neurophysiological approaches. Other experiments have examined how expectations about reward are represented in neuronal activity in various brain regions. Although attention and reward are distinct concepts, I argue here that many neurophysiological experiments on attention and reward do not permit a clean dissociation between the two. This problem arises in part because reward contingencies are the only parameter manipulated in any of these experiments. I describe how attention and reward expectations have been confounded, giving rise to uncertainty about how signals related to attention and reward are distributed in the brain.     

Peers influence adolescent reward processing,but not response inhibition

Most adolescent risk taking occurs in the presence of peers. Prior research suggests that peers alter adolescents’ decision making by increasing reward sensitivity and the engagement of regions involved in the processing of rewards, primarily the striatum. However, the potential influence of peers on the capacity for impulse control, and the associated recruitment of the brain’s control circuitry, has not yet been adequately examined. In the current study, adolescents underwent functional neuroimaging while they completed interleaved rounds of risk-taking and response-inhibition tasks. Social context was manipulated such that the participants believed they were either playing alone and unobserved, or watched by an anonymous peer. Compared to those who completed the tasks alone, adolescents in the peer condition took more risks during the risk-taking task and exhibited relatively heightened activation of the striatum. Activity within this striatal region also predicted individual differences in overall risk taking. In contrast, the presence of peers had no effect on behavioral response inhibition and had minimal impact on the engagement of typical cognitive control regions. In a subregion of the anterior insula engaged mutually by both tasks, activity was again found to be sensitive to social context during the risk-taking task, but not during the response-inhibition task. These findings extend the evidence that the presence of peers biases adolescents towards risk taking by increasing reward sensitivity rather than disrupting cognitive control.     

Adolescents' Reward‐related Neural Activation: Links to Thoughts of Nonsuicidal Self‐Injury

Adolescence is a critical developmental period marked by an increase in risk behaviors, including nonsuicidal self‐injury (NSSI). Heightened reward‐related brain activation and relatively limited recruitment of prefrontal regions contribute to the initiation of risky behaviors in adolescence. However, neural reward processing has not been examined among adolescents who are at risk for future engagement for NSSI specifically, but who have yet to actually engage in this behavior. In the current fMRI study (N = 71), we hypothesized that altered reward processing would be associated with adolescents' thoughts of NSSI. Results showed that NSSI youth exhibited heightened activation in the bilateral putamen in response to a monetary reward. This pattern of findings suggests that heightened neural sensitivity to reward is associated with thoughts of NSSI in early adolescence. Implications for prevention are discussed.     

A Brain-Based Account of the Development of Rule Use in Childhood

ABSTRACT— The ability to follow explicit rules improves dramatically during the course of childhood, but relatively little is known about the changes in brain structure and function that underlie this behavioral improvement. Drawing from neuroscientific studies in human adults and other animals, as well as from an emerging literature in developmental cognitive neuroscience, we propose a brain-based account of the development of rule use in childhood. This account focuses on four types of rules represented in different parts of the prefrontal cortex: simple rules for reversing stimulus–reward associations, pairs of conditional stimulus–response rules (both univalent and bivalent), and higher-order stimulus–response rules for selecting among task sets. It is hypothesized that the pattern of developmental changes in rule use reflects the different rates of development of specific regions within the prefrontal cortex.     

Frontal brain asymmetry and reward responsiveness: a source-localization study

The influence of approach and avoidance tendencies on affect, reasoning, and behavior has attracted substantial interest from researchers across various areas of psychology. Currently, frontal electroencephalographic (EEG) asymmetry in favor of left prefrontal regions is assumed to reflect the propensity to respond with approach-related tendencies. To test this hypothesis, we recorded resting EEG in 18 subjects, who separately performed a verbal memory task under three incentive conditions (neutral, reward, and punishment). Using a source-localization technique, we found that higher task-independent alpha2 (10.5-12 Hz) activity within left dorsolateral prefrontal and medial orbitofrontal regions was associated with stronger bias to respond to reward-related cues. Left prefrontal resting activity accounted for 54.8% of the variance in reward bias. These findings not only confirm that frontal EEG asymmetry modulates the propensity to engage in appetitively motivated behavior, but also provide anatomical details about the underlying brain systems.     

Neural correlates of lexicon and grammar: evidence from the production, reading, and judgment of inflection in aphasia

Are the linguistic forms that are memorized in the mental lexicon and those that are specified by the rules of grammar subserved by distinct neurocognitive systems or by a single computational system with relatively broad anatomic distribution? On a dual-system view, the productive -ed-suffixation of English regular past tense forms (e.g., look-looked) depends upon the mental grammar, whereas irregular forms (e.g., dig-dug) are retrieved from lexical memory. On a single-mechanism view, the computation of both past tense types depends on associative memory. Neurological double dissociations between regulars and irregulars strengthen the dual-system view. The computation of real and novel, regular and irregular past tense forms was investigated in 20 aphasic subjects. Aphasics with non-fluent agrammatic speech and left frontal lesions were consistently more impaired at the production, reading, and judgment of regular than irregular past tenses. Aphasics with fluent speech and word-finding difficulties, and with left temporal/temporo-parietal lesions, showed the opposite pattern. These patterns held even when measures of frequency, phonological complexity, articulatory difficulty, and other factors were held constant. The data support the view that the memorized words of the mental lexicon are subserved by a brain system involving left temporal/temporo-parietal structures, whereas aspects of the mental grammar, in particular the computation of regular morphological forms, are subserved by a distinct system involving left frontal structures.     

Unpacking Response Contingent Positive Reinforcement: Reward Probability,but Not Environmental Suppressors,Prospectively Predicts Depressive Symptoms via Behavioral Activation

Behavioral models of depression conceptualize the development and maintenance of depressive symptoms as occurring within a system of response-contingent positive reinforcement (RCPR). Such models propose a negative cycle in which a decrease in positive reinforcement of adaptive, approach-oriented behaviors (i.e., RCPR) results in reduced behavioral activation and increased depressive symptoms, which in turn feeds back into further decreases in positive reinforcement and maintains the cycle. Previous research indicates that RCPR has two lower-order constructs, reward probability and environmental suppressors. The present study evaluated a hypothesized mediational model in which the paths from each of the two domains of RCPR to depressive symptoms are mediated by behavioral activation. The sample consisted of 150 college students (78.0% women), ranging in age from 18 to 47 years (M = 20.81, SD = 3.96), who endorsed moderate to severe depressive symptoms at a baseline (time 1) evaluation. Findings from a path analysis provide support for the mediated path between reward probability at time 1 and depressive symptoms at time 3, via behavioral activation at time 2. In contrast, environmental suppressors at time 1 demonstrated a direct impact on depressive symptoms at time 3, and this relationship was not mediated by behavioral activation at time 2. These findings provide a partial test of behavioral frameworks and provide evidence of separate pathways between domains of RCPR and depressive symptoms.     

The reward of a good joke: neural correlates of viewing dynamic displays of stand-up comedy

Humor is enjoyable, yet few studies to date have reported that humor engages brain regions involved in reward processing (i.e., the mesolimbic reward system). Even fewer have investigated socially relevant, dynamic displays of real actors telling jokes. Instead, many studies have focused on responses to static cartoons or written jokes in isolation. In the present investigation, we used functional magnetic resonance imaging (fMRI) to examine brain activation in response to video clips of comedians performing stand-up comedy, a more socially relevant task than reading jokes or cartoons in isolation. Participants watched video clips of eight stand-up comedians, half female/half male, that were prerated by a separate group of participants from the same population as eliciting either high or low levels of amusement, thereby allowing us to control for comedian attributes and comedic style. We found that high-funny clips elicited more activation in several brain regions involved with reward responses, including the nucleus accumbens, caudate, and putamen. A regression with participants’ own ratings of humor revealed similar activity in reward areas as well as in regions involved in theory of mind. These findings indicate that dynamic social displays of humor do engage reward responses. The rewarding nature of humor may help explain why it is so valued socially.     

赌博障碍的认知功能缺陷及神经基础

赌博障碍是指持续且反复的赌博行为,给个人、家庭和社会都带来了严重后果,近年来受到越来越多研究者的关注。本研究总结了赌博障碍的认知功能缺陷及其神经基础,主要集中在如下四个方面：①认知扭曲、②奖赏和惩罚敏感性、③注意偏向和④决策。未来研究应多从认知神经科学角度深入探究赌博障碍的发生机制和发展过程,关注大脑结构变化及功能网络改变,并将其整合到一个统一的神经生物机制框架中,找到更加有效的干预和治疗手段。     

Investigating the modality specificity of response selection using a temporal flanker task

The neurocognitive architecture for response selection is uncertain. Some theorists suggest that it is mediated by an amodal central mechanism, whereas others propose a set of independent control mechanisms. In a functional neuroimaging experiment, we investigated the nature of response selection by examining how its underlying brain mechanisms are affected by stimulus modality. To do this, we used a modified flanker task, in which the target and flanker (distractor) stimuli differed in time rather than space, making it accessible for both visual and auditory stimuli. As in the traditional flanker task, larger reaction times were observed for incongruent than congruent trials (i.e., a congruency effect) for both modalities. Congruency affected brain activation for both modalities in prefrontal cortex, parietal cortex, and the putamen. Modality-dependent activation was found in additional prefrontal and parietal regions for the visual modality and in left inferior prefrontal cortex for the auditory modality. Modality-dependent activity specifically related to response congruency was also found in sensory cortical regions. These data suggest that modality affects the brain regions throughout the cortex mediating response selection even for conceptually identical stimuli and tasks. They are consistent with the hypothesis that (at least partially) independent brain networks mediate response selection and that input modality may be a powerful factor for organizing neural activity to support task performance.     

赌博障碍的认知功能缺陷及神经基础

赌博障碍是指持续且反复的赌博行为,给个人、家庭和社会都带来了严重后果,近年来受到越来越多研究者的关注。本研究总结了赌博障碍的认知功能缺陷及其神经基础,主要集中在如下四个方面：①认知扭曲、②奖赏和惩罚敏感性、③注意偏向和④决策。未来研究应多从认知神经科学角度深入探究赌博障碍的发生机制和发展过程,关注大脑结构变化及功能网络改变,并将其整合到一个统一的神经生物机制框架中,找到更加有效的干预和治疗手段。     

Longitudinal changes in behavioral approach system sensitivity and brain structures involved in reward processing during adolescence

[Correction Notice: An Erratum for this article was reported in Vol 48(5) of Developmental Psychology (see record 2012-09244-001). Figure 2 was distorted in production. The correct version is presented in the erratum.] Adolescence is a period of radical normative changes and increased risk for substance use, mood disorders, and physical injury. Researchers have proposed that increases in reward sensitivity (i.e., sensitivity of the behavioral approach system [BAS]) and/or increases in reactivity to all emotional stimuli (i.e., reward and threat sensitivities) lead to these phenomena. The present study is the first longitudinal investigation of changes in reward (i.e., BAS) sensitivity in 9- to 23-year-olds across a 2-year follow-up. Support was found for increased reward sensitivity from early to late adolescence, and evidence was found for decline in the early 20s. This decline is combined with a decrease in left nucleus accumbens (Nacc) volume, a key structure for reward processing, from the late teens into the early 20s. Furthermore, we found longitudinal increases in sensitivity to reward to be predicted by individual differences in the Nacc and medial orbitofrontal cortex (OFC) volumes at baseline in this developmental sample. Similarly, increases in sensitivity to threat (i.e., behavioral inhibition system sensitivity) were qualified by sex, with only females participants experiencing this increase, and predicted by individual differences in lateral OFC volumes at baseline. (PsycINFO Database Record (c) 2012 APA, all rights reserved).