Rostrolateral prefrontal cortex (RLPFC) is part of a frontoparietal network of regions involved in relational reasoning, the mental process of working with relationships between multiple mental representations. RLPFC has shown functional and structural changes with age, with increasing specificity of left RLPFC activation for relational integration during development. Here, we used dynamic causal modeling (DCM) to investigate changes in effective connectivity during a relational reasoning task through the transition from adolescence into adulthood. We examined fMRI data of 37 healthy female participants (11–30 years old) performing a relational reasoning paradigm. Comparing relational integration to the manipulation of single relations revealed activation in five regions: the RLPFC, anterior insula, dorsolateral PFC, inferior parietal lobe, and medial superior frontal gyrus. We used a new exhaustive search approach and identified a full DCM model, which included all reciprocal connections between the five clusters in the left hemisphere, as the optimal model. In line with previous resting state fMRI results, we showed distinct developmental effects on the strength of long-range frontoparietal versus frontoinsular short-range fixed connections. The modulatory connections associated with relational integration increased with age. Gray matter volume in left RLPFC, which decreased with age, partly accounted for changes in fixed PFC connectivity. Finally, improvements in relational integration performance were associated with greater modulatory and weaker fixed PFC connectivity. This pattern provides further evidence of increasing specificity of left PFC function for relational integration compared to the manipulation of single relations, and demonstrates an association between effective connectivity and performance during development.
Externally directed cognition (EDC) involves attending to stimuli in the external environment, whereas internally directed cognition (IDC) involves attending internally to thoughts, memories and mental imagery. To date, most studies have focused on the competition or trade-offs between these modes of cognition. However, both EDC and IDC include a variety of cognitive states that differ along multiple dimensions. These dimensions may influence the way in which EDC and IDC relate to each other. In this review, we present a novel framework that considers whether cognitive resources are oriented externally or internally, and also whether a given cognitive state involves intentional (i.e., voluntary) or spontaneous (i.e., involuntary) processing. Within this framework, we examine the conditions under which EDC and IDC are expected to either compete, or co-occur without interference. We argue that EDC and IDC are not inherently antagonistic, but when both involve higher levels of intentionality they are increasingly likely to compete, due to the capacity limitations of intentional processing. In contrast, if one or both involve spontaneous processing, EDC and IDC can co-occur with minimal interference given that involuntary processes are not subject to the same capacity constraints. A review of the brain regions implicated in EDC and IDC suggests that their neural substrates are partially segregated and partially convergent. Both EDC and IDC recruit the lateral prefrontal cortex (PFC) during intentional processing, and may therefore compete over the processes and representational space it supports. However, at lower levels of intentionality, EDC and IDC rely on largely distinct neural structures, which may enable their co-occurrence without interference. The proposal that EDC and IDC can in some cases co-occur, provides a framework for understanding the complex mental states that underlie theory of mind, creativity, the influence of self-evaluative processing on cognitive control, and memory-guided attention.
Tremendous progress has been made in discerning the neurocognitive basis of value-based decision making and learning. Although the majority of studies to date have employed simple task paradigms, recent work has started to examine more complex aspects of value processing including: the value of engaging rule-based cognitive control; the integration of multiple pieces of information (e.g., reward magnitude and delay) to discern the best course of action; pursuing future rewards; valuation of abstract concepts (e.g., fairness); and comparing the value of executed versus imagined alternative actions. We provide a comprehensive review of functional neuroimaging, electrophysiological, and lesion evidence suggesting that the lateral prefrontal cortex (LPFC) plays a critical role in these complex aspects of value processing. In particular, we focus on the specific information that the LPFC represents, and argue that it includes both cognitive and value-based information. We also discuss how the role of the LPFC is distinct from other value-related regions. Finally, we articulate a framework for understanding the contribution of subregions along the rostro-caudal axis of the LPFC, and thereby bridge the cognitive control and decision making literatures.
Numerous studies have begun to address how the brain's gray and white matter may be shaped by meditation. This research is yet to be integrated, however, and two fundamental questions remain: Is meditation associated with altered brain structure? If so, what is the magnitude of these differences? To address these questions, we reviewed and meta-analyzed 123 brain morphology differences from 21 neuroimaging studies examining ?300 meditation practitioners. Anatomical likelihood estimation (ALE) meta-analysis found eight brain regions consistently altered in meditators, including areas key to meta-awareness (frontopolar cortex/BA 10), exteroceptive and interoceptive body awareness (sensory cortices and insula), memory consolidation and reconsolidation (hippocampus), self and emotion regulation (anterior and mid cingulate; orbitofrontal cortex), and intra- and interhemispheric communication (superior longitudinal fasciculus; corpus callosum). Effect size meta-analysis (calculating 132 effect sizes from 16 studies) suggests a global 'medium' effect size (Cohen's d¯=0.46; r¯=.19). Publication bias and methodological limitations are strong concerns, however. Further research using rigorous methods is required to definitively link meditation practice to altered brain morphology.
The functional organization of brain areas supporting goal-directed behavior is debated. Some accounts suggest a rostro-caudal organization, while others suggest a broad recruitment as part of a multiple demand network. We used fMRI and an anatomical region of interest (ROI) approach to test which account better characterizes the organization of key brain areas related to goal-directed behavior: the lateral prefrontal cortex (LPFC), medial prefrontal cortex (MPFC), cingulate cortex, and insula. Subjects performed a cognitive control task with distinct trial events corresponding to rule representation, rule maintenance, action execution, and monitoring progress towards an overarching motivational goal. The use of ROIs allowed us to look for evidence of rostro-caudal gradients during each event separately. Our results provide strong evidence for rostro-caudal gradients in all regions. During the action execution period, activation was robust in caudal ROIs and decreased linearly moving to rostral ROIs in the LPFC, cingulate cortex, and MPFC. Conversely, during the goal monitoring period, activation was weak in caudal ROIs and increased linearly moving to the rostral ROIs in the aforementioned regions. The insula exhibited the reverse pattern. These findings provide evidence for rostro-caudal organization in multiple regions within the same study. More importantly, they demonstrate that rostro-caudal gradients can be observed during individual trial events, ruling out confounding factors such as task difficulty.
Dehumanizing attitudes and behaviors frequently occur in organizational settings and are often viewed as an acceptable, and even necessary, strategy for pursuing personal and organizational goals. Here I examine a number of commonly held beliefs about dehumanization and argue that there is relatively little support for them in light of the evidence emerging from social psychological and neuroscientific research. Contrary to the commonly held belief that everyday forms of dehumanization are innocent and inconsequential, the evidence shows profoundly negative consequences for both victims and perpetrators. As well, the belief that suppressing empathy automatically leads to improved problem solving is not supported by the evidence. The more general belief that empathy interferes with problem solving receives partial support, but only in the case of mechanistic problem solving. Overall, I question the usefulness of dehumanization in organizational settings and argue that it can be replaced by superior strategies that are ethically more acceptable and do not entail the severely negative consequences associated with dehumanization.
Isolated reports have long suggested a similarity in content and thought processes across mind wandering (MW) during waking, and dream mentation during sleep. This overlap has encouraged speculation that both "daydreaming" and dreaming may engage similar brain mechanisms. To explore this possibility, we systematically examined published first-person experiential reports of MW and dreaming and found many similarities: in both states, content is largely audiovisual and emotional, follows loose narratives tinged with fantasy, is strongly related to current concerns, draws on long-term memory, and simulates social interactions. Both states are also characterized by a relative lack of meta-awareness. To relate first-person reports to neural evidence, we compared meta-analytic data from numerous functional neuroimaging (PET, fMRI) studies of the default mode network (DMN, with high chances of MW) and rapid eye movement (REM) sleep (with high chances of dreaming). Our findings show large overlaps in activation patterns of cortical regions: similar to MW/DMN activity, dreaming and REM sleep activate regions implicated in self-referential thought and memory, including medial prefrontal cortex (PFC), medial temporal lobe structures, and posterior cingulate. Conversely, in REM sleep numerous PFC executive regions are deactivated, even beyond levels seen during waking MW. We argue that dreaming can be understood as an "intensified" version of waking MW: though the two share many similarities, dreams tend to be longer, more visual and immersive, and to more strongly recruit numerous key hubs of the DMN. Further, whereas MW recruits fewer PFC regions than goal-directed thought, dreaming appears to be characterized by an even deeper quiescence of PFC regions involved in cognitive control and metacognition, with a corresponding lack of insight and meta-awareness. We suggest, then, that dreaming amplifies the same features that distinguish MW from goal-directed waking thought.
While goal-directed thinking has received the lions share of neuroscientific attention, its counterpart--the undirected thought flow that comes to mind unbidden and without effort--has remained largely on the sidelines of scientific research. Such undirected thought, however, forms a large part of our mental experience. The last decade of neuroscientific investigations marked a resurgence of interest and work into the neural basis of undirected thought. This article reviews the current status of the field and examines the research on the three most frequently discussed categories of undirected thought: spontaneous thought, stimulus-independent thought, and mind wandering. The terminology and paradigms for investigating undirected thought are still being developed, while research is gradually moving beyond strictly task- and rest-based paradigms and towards incorporating introspective first-person reports in order to better understand this phenomenon. It is impossible to say at this point that undirected thinking is preferentially linked to any one particular brain system. Although its connection to the default network has been disproportionately emphasized in the literature, other brain networks such as the executive system and the temporal lobe memory network appear to be equally involved. In addition to reviewing the literature, this article also presents novel findings regarding the functional connectivity between large-scale brain networks during mind wandering. These findings reveal the presence of positive functional connectivity between regions of the default and executive networks and negative functional connectivity between the default network and primary sensory cortices. Thus, the default and executive networks can closely cooperate in supporting undirected thought processes, and seem to do so at times when the primary sensory cortices are not busy with the processing of perceptual information from the external environment. This article is part of a Special Issue entitled The Cognitive Neuroscience of Thought.
Mind wandering (i.e. engaging in cognitions unrelated to the current demands of the external environment) reflects the cyclic activity of two core processes: the capacity to disengage attention from perception (known as perceptual decoupling) and the ability to take explicit note of the current contents of consciousness (known as meta-awareness). Research on perceptual decoupling demonstrates that mental events that arise without any external precedent (known as stimulus independent thoughts) often interfere with the online processing of sensory information. Findings regarding meta-awareness reveal that the mind is only intermittently aware of engaging in mind wandering. These basic aspects of mind wandering are considered with respect to the activity of the default network, the role of executive processes, the contributions of meta-awareness and the functionality of mind wandering.
Psychological theories have suggested that creativity involves a twofold process characterized by a generative component facilitating the production of novel ideas and an evaluative component enabling the assessment of their usefulness. The present study employed a novel fMRI paradigm designed to distinguish between these two components at the neural level. Participants designed book cover illustrations while alternating between the generation and evaluation of ideas. The use of an fMRI-compatible drawing tablet allowed for a more natural drawing and creative environment. Creative generation was associated with preferential recruitment of medial temporal lobe regions, while creative evaluation was associated with joint recruitment of executive and default network regions and activation of the rostrolateral prefrontal cortex, insula, and temporopolar cortex. Executive and default regions showed positive functional connectivity throughout task performance. These findings suggest that the medial temporal lobe may be central to the generation of novel ideas and creative evaluation may extend beyond deliberate analytical processes supported by executive brain regions to include more spontaneous affective and visceroceptive evaluative processes supported by default and limbic regions. Thus, creative thinking appears to recruit a unique configuration of neural processes not typically used together during traditional problem solving tasks.
Cognitive neuroscience investigations of self-experience have mainly focused on the mental attribution of features to the self (self-related processing). In this paper, we highlight another fundamental, yet neglected, aspect of self-experience, that of being an agent. We propose that this aspect of self-experience depends on self-specifying processes, ones that implicitly specify the self by implementing a functional self/non-self distinction in perception, action, cognition and emotion. We describe two paradigmatic cases - sensorimotor integration and homeostatic regulation - and use the principles from these cases to show how cognitive control, including emotion regulation, is also self-specifying. We argue that externally directed, attention-demanding tasks, rather than suppressing self-experience, give rise to the self-experience of being a cognitive-affective agent. We conclude with directions for experimental work based on our framework.
Non-linear changes in behaviour and in brain activity during adolescent development have been reported in a variety of cognitive tasks. These developmental changes are often interpreted as being a consequence of changes in brain structure, including non-linear changes in grey matter volumes, which occur during adolescence. However, very few studies have attempted to combine behavioural, functional and structural data. This multi-method approach is the one we took in the current study, which was designed to investigate developmental changes in behaviour and brain activity during relational reasoning, the simultaneous integration of multiple relations. We used a relational reasoning task known to recruit rostrolateral prefrontal cortex (RLPFC), a region that undergoes substantial structural changes during adolescence. The task was administered to female participants in a behavioural (N = 178, 7-27 years) and an fMRI study (N = 37, 11-30 years). Non-linear changes in accuracy were observed, with poorer performance during mid-adolescence. fMRI and VBM results revealed a complex picture of linear and possibly non-linear changes with age. Performance and structural changes partly accounted for changes with age in RLPFC and medial superior frontal gyrus activity but not for a decrease in activation in the anterior insula/frontal operculum between mid-adolescence and adulthood. These functional changes might instead reflect the maturation of neurocognitive strategies.
Recent real-time fMRI (rt-fMRI) training studies have demonstrated that subjects can achieve improved control over localized brain regions by using real-time feedback about the level of fMRI signal in these regions. It has remained unknown, however, whether subjects can gain control over anterior prefrontal cortex (PFC) regions that support some of the most complex forms of human thought. In this study, we used rt-fMRI training to examine whether subjects can learn to regulate the rostrolateral prefrontal cortex (RLPFC), or the lateral part of the anterior PFC, by using a meta-cognitive awareness strategy. We show that individuals can achieve improved regulation over the level of fMRI signal in their RLPFC by turning attention towards or away from their own thoughts. The ability to achieve improved modulation was contingent on observing veridical real-time feedback about the level of RLPFC activity during training; a sham-feedback control group demonstrated no improvement in modulation ability and neither did control subjects who received no rt-fMRI feedback but underwent otherwise identical training. Prior to training, meta-cognitive awareness was associated with recruitment of anterior PFC subregions, including both RLPFC and medial PFC, as well as a number of other midline and posterior cortical regions. Following training, however, regulation improvement was specific to RLPFC and was not observed in other frontal, midline, or parietal cortical regions. These results demonstrate the feasibility of acquiring control over high-level prefrontal regions through rt-fMRI training and offer a novel view into the correspondence between observable neuroscientific measures and highly subjective mental states.
The literature on dysregulated sexuality, whether theoretical, clinical or empirical, has failed to differentiate the construct from high sexual desire. In this study, we tested three hypotheses which addressed this issue. A sample of 6458 men and 7938 women, some of whom had sought treatment for sexual compulsivity, addiction or impulsivity, completed an online survey comprised of various sexuality measures. Men and women who reported having sought treatment scored significantly higher on measures of dysregulated sexuality and sexual desire. For men, women, and those who had sought treatment, dysregulated sexuality was associated with increased sexual desire. Confirmatory factor analysis supported a one-factor model, indicating that, in both male and female participants, dysregulated sexuality and sexual desire variables loaded onto a single underlying factor. The results of this study suggest that dysregulated sexuality, as currently conceptualized, labelled, and measured, may simply be a marker of high sexual desire and the distress associated with managing a high degree of sexual thoughts, feelings, and needs.
Although mind wandering occupies a large proportion of our waking life, its neural basis and relation to ongoing behavior remain controversial. We report an fMRI study that used experience sampling to provide an online measure of mind wandering during a concurrent task. Analyses focused on the interval of time immediately preceding experience sampling probes demonstrate activation of default network regions during mind wandering, a finding consistent with theoretical accounts of default network functions. Activation in medial prefrontal default network regions was observed both in association with subjective self-reports of mind wandering and an independent behavioral measure (performance errors on the concurrent task). In addition to default network activation, mind wandering was associated with executive network recruitment, a finding predicted by behavioral theories of off-task thought and its relation to executive resources. Finally, neural recruitment in both default and executive network regions was strongest when subjects were unaware of their own mind wandering, suggesting that mind wandering is most pronounced when it lacks meta-awareness. The observed parallel recruitment of executive and default network regions--two brain systems that so far have been assumed to work in opposition--suggests that mind wandering may evoke a unique mental state that may allow otherwise opposing networks to work in cooperation. The ability of this study to reveal a number of crucial aspects of the neural recruitment associated with mind wandering underscores the value of combining subjective self-reports with online measures of brain function for advancing our understanding of the neurophenomenology of subjective experience.
The prefrontal cortex (PFC) plays a crucial role in cognitive control and higher mental functions by maintaining working memory representations of currently relevant information, thereby inducing a mindset that facilitates the processing of such information. Using fMRI, we examined how the human PFC implements mindsets for information at varying levels of abstraction. Subjects solved anagrams grouped into three kinds of blocks (concrete, moderately abstract, and highly abstract) according to the degree of abstraction of their solutions. Mindsets were induced by cuing subjects at the beginning of every block as to the degree of abstraction of solutions they should look for. Different levels of abstraction were matched for accuracy and reaction time, allowing us to examine the effects of varying abstraction in the absence of variations in cognitive complexity. Mindsets for concrete, moderately abstract, and highly abstract information were associated with stronger relative recruitment of ventrolateral, dorsolateral, and rostrolateral PFC regions, respectively, suggesting a functional topography whereby increasingly anterior regions are preferentially associated with representations of increasing abstraction. Rather than being a structural property of the neurons in different prefrontal subregions, this relative specialization may reflect one of the principles according to which lateral PFC adaptively codes and organizes task-relevant information.
The goals of this study were to examine the effectiveness of emotional reappraisal in regulating male sexual arousal and to investigate a set of variables theoretically linked to sexual arousal regulation success. Participants first completed a series of online sexuality questionnaires. Subsequently, they were assessed for their success in regulating sexual arousal in the laboratory. Results showed that the ability to regulate emotion may cross emotional domains; those men best able to regulate sexual arousal were also the most skilled at regulating their level of amusement to humorous stimuli. Participants, on average, were somewhat able to regulate their physiological and cognitive sexual arousal, although there was a wide range of regulation success. Whereas some men were very adept at regulating their sexual arousal, others became more sexually aroused while trying to regulate. Age, sexual experience, and sexual compulsivity were unrelated to sexual arousal regulation. Conversely, sexual excitation, inhibition, and desire correlated with sexual arousal regulation success. Increased sexual excitation and desire were associated with poorer regulatory performance, whereas a propensity for sexual inhibition due to fear of performance consequences was related to regulatory success.
Relational reasoning is an essential component of fluid intelligence, and is known to have a protracted developmental trajectory. To date, little is known about the neural changes that underlie improvements in reasoning ability over development. In this event-related functional magnetic resonance imaging (fMRI) study, children aged 8-12 and adults aged 18-25 performed a relational reasoning task adapted from Ravens Progressive Matrices. The task included three levels of relational reasoning demands: REL-0, REL-1, and REL-2. Children exhibited disproportionately lower accuracy than adults on trials that required integration of two relations (REL-2). Like adults, children engaged lateral prefrontal cortex (PFC) and parietal cortex during task performance; however, they exhibited different time courses and activation profiles, providing insight into their approach to the problems. As in prior studies, adults exhibited increased rostrolateral PFC (RLPFC) activation when relational integration was required (REL-2 > REL-1, REL-0). Children also engaged RLPFC most strongly for REL-2 problems at early stages of processing, but this differential activation relative to REL-1 trials was not sustained throughout the trial. These results suggest that the children recruited RLPFC while processing relations, but failed to use it to integrate across two relations. Relational integration is critical for solving a variety of problems, and for appreciating analogies; the current findings suggest that developmental improvements in this function rely on changes in the profile of engagement of RLPFC, as well as dorsolateral PFC and parietal cortex.
Cognitive control is a fundamental skill reflecting the active use of task-rules to guide behavior and suppress inappropriate automatic responses. Prior work has traditionally used paradigms in which subjects are told when to engage cognitive control. Thus, surprisingly little is known about the factors that influence individuals initial decision of whether or not to act in a reflective, rule-based manner. To examine this, we took three classic cognitive control tasks (Stroop, Wisconsin Card Sorting Task, Go/No-Go task) and created novel free-choice versions in which human subjects were free to select an automatic, pre-potent action, or an action requiring rule-based cognitive control, and earned varying amounts of money based on their choices. Our findings demonstrated that subjects decision to engage cognitive control was driven by an explicit representation of monetary rewards expected to be obtained from rule-use. Subjects rarely engaged cognitive control when the expected outcome was of equal or lesser value as compared to the value of the automatic response, but frequently engaged cognitive control when it was expected to yield a larger monetary outcome. Additionally, we exploited fMRI-adaptation to show that the lateral prefrontal cortex (LPFC) represents associations between rules and expected reward outcomes. Together, these findings suggest that individuals are more likely to act in a reflective, rule-based manner when they expect that it will result in a desired outcome. Thus, choosing to exert cognitive control is not simply a matter of reason and willpower, but rather, conforms to standard mechanisms of value-based decision making. Finally, in contrast to current models of LPFC function, our results suggest that the LPFC plays a direct role in representing motivational incentives.
The accuracy of subjective reports, especially those involving introspection of ones own internal processes, remains unclear, and research has demonstrated large individual differences in introspective accuracy. It has been hypothesized that introspective accuracy may be heightened in persons who engage in meditation practices, due to the highly introspective nature of such practices. We undertook a preliminary exploration of this hypothesis, examining introspective accuracy in a cross-section of meditation practitioners (1-15,000 hrs experience). Introspective accuracy was assessed by comparing subjective reports of tactile sensitivity for each of 20 body regions during a body-scanning meditation with averaged, objective measures of tactile sensitivity (mean size of body representation area in primary somatosensory cortex; two-point discrimination threshold) as reported in prior research. Expert meditators showed significantly better introspective accuracy than novices; overall meditation experience also significantly predicted individual introspective accuracy. These results suggest that long-term meditators provide more accurate introspective reports than novices.
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