The current study investigated the effects of an 8-week mindfulness-based meditation training (MMT) intervention on attentional bias, engagement and disengagement of pain-related threat in fibromyalgia patients as compared to an age-matched control group. A well validated dot-probe task was used to explore early versus later stages of attentional processing through the use of two stimulus exposure durations (100, 500 ms) of pain-related threat words. The enduring effects of MMT were assessed 6-months after completion of MMT. Preliminary results suggest that MMT reduces avoidance of pain-related threat at early levels of processing, and facilitates disengagement from threat at later stages of processing. Furthermore, it appears that effects of MMT on early attentional threat processing do not remain stable after long-term follow-up.
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Selective attention has been shown to bias sensory processing in favor of relevant stimuli and against irrelevant or distracting stimuli in perceptual tasks. Increasing evidence suggests that selective attention plays an important role during working memory maintenance, possibly by biasing sensory processing in favor of to-be-remembered items. In the current study, we investigated whether selective attention may also support working memory by biasing processing against irrelevant and potentially distracting information. Event-related potentials (ERPs) were recorded while subjects (n = 22) performed a delayed-recognition task for faces and shoes. The delay period was filled with face or shoe distractors. Behavioral performance was impaired when distractors were congruent with the working memory domain (e.g., face distractor during working memory for faces) relative to when distractors were incongruent with the working memory domain (e.g., face distractor during shoe working memory). If attentional biasing against distractor processing is indeed functionally relevant in supporting working memory maintenance, perceptual processing of distractors is predicted to be attenuated when distractors are more behaviorally intrusive relative to when they are nonintrusive. As such, we predicted that perceptual processing of distracting faces, as measured by the face-sensitive N170 ERP component, would be reduced in the context of congruent (face) working memory relative to incongruent (shoe) working memory. The N170 elicited by distracting faces demonstrated reduced amplitude during congruent versus incongruent working memory. These results suggest that perceptual processing of distracting faces may be attenuated due to attentional biasing against sensory processing of distractors that are most behaviorally intrusive during working memory maintenance.
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The tensor-based morphometry (TBM) has been widely used in characterizing tissue volume difference between populations at voxel level. We present a novel computational framework for investigating the white matter connectivity using TBM. Unlike other diffusion tensor imaging (DTI) based white matter connectivity studies, we do not use DTI but only T1-weighted magnetic resonance imaging (MRI). To construct brain network graphs, we have developed a new data-driven approach called the e-neighbor method that does not need any predetermined parcellation. The proposed pipeline is applied in detecting the topological alteration of the white matter connectivity in maltreated children.
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BACKGROUND: Hypothalamic-pituitary-adrenal (HPA) system activation is adaptive in response to stress, and HPA dysregulation occurs in stress-related psychopathology. It is important to understand the mechanisms that modulate HPA output, yet few studies have addressed the neural circuitry associated with HPA regulation in primates and humans. Using high-resolution F-18-fluorodeoxyglucose positron emission tomography (FDG-PET) in rhesus monkeys, we assessed the relation between individual differences in brain activity and HPA function across multiple contexts that varied in stressfulness.
METHODS: Using a logical AND conjunctions analysis, we assessed cortisol and brain metabolic activity with FDG-PET in 35 adolescent rhesus monkeys exposed to two threat and two home-cage conditions. To test the robustness of our findings, we used similar methods in an archival data set. In this data set, brain metabolic activity and cortisol were assessed in 17 adolescent male rhesus monkeys that were exposed to three stress-related contexts.
RESULTS: Results from the two studies revealed that subgenual prefrontal cortex (PFC) metabolism (Brodmann's area 25/24) consistently predicted individual differences in plasma cortisol concentrations regardless of the context in which brain activity and cortisol were assessed.
CONCLUSIONS: These findings suggest that activation in subgenual PFC may be related to HPA output across a variety of contexts (including familiar settings and novel or threatening situations). Individuals prone to elevated subgenual PFC activity across multiple contexts may be individuals who consistently show heightened cortisol and may be at risk for stress-related HPA dysregulation.
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The scientific discovery of novel training paradigms has yielded better understanding of basic mechanisms underlying cortical plasticity, learning and development. This study is a first step in evaluating Tai Chi (TC), the Chinese slow-motion meditative exercise, as a training paradigm that, while not engaging in direct tactile stimulus training, elicits enhanced tactile acuity in long-term practitioners. The rationale for this study comes from the fact that, unlike previously studied direct-touch tactile training paradigms, TC practitioners focus specific mental attention on the body’s extremities including the fingertips and hands as they perform their slow routine. To determine whether TC is associated with enhanced tactile acuity, experienced adult TC practitioners were recruited and compared to age–gender matched controls. A blinded assessor used a validated method (Van Boven et al. in Neurology 54(12): 2230–2236, 2000) to compare TC practitioners’ and controls’ ability to discriminate between two different orientations (parallel and horizontal) across different grating widths at the fingertip. Study results showed that TC practitioners’ tactile spatial acuity was superior to that of the matched controls (P < 0.04). There was a trend showing TC may have an enhanced effect on older practitioners (P < 0.066), suggesting that TC may slow age related decline in this measure. To the best of our knowledge, this is the first study to evaluate a long-term attentional practice’s effects on a perceptual measure. Longitudinal studies are needed to examine whether TC initiates or is merely correlated with perceptual changes and whether it elicits long-term plasticity in primary sensory cortical maps. Further studies should also assess whether related somatosensory attentional practices (such as Yoga, mindfulness meditation and Qigong) achieve similar effects.
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<p>Explains the TCT-DP by discussing (a) the need for the TCT-DP, (b) the justification for and purpose of the test, (c) the meaning and limitations of the test construct, (d) design, (e) evaluation criteria, (f) the 1st results, and (g) prognostics. The TCT-DP testing sheet includes stimuli, in the form of figural elements or fragments, intentionally designed in an incomplete and irregular fashion to achieve maximum flexibility as an imperative for creativity. The TCT-DP allows potentially gifted students to interpret and to complete what they conceive to be significant for the development of a creative product.</p>
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We investigated the top-down influence of working memory (WM) maintenance on feedforward perceptual processing within occipito-temporal face processing structures. During event-related potential (ERP) recordings, subjects performed a delayed-recognition task requiring WM maintenance of faces or houses. The face-sensitive N170 component elicited by delay-spanning task-irrelevant grayscale noise probes was examined. If early feedforward perceptual activity is biased by maintenance requirements, the N170 ERP component elicited by probes should have a greater N170 amplitude response during face relative to house WM trials. Consistent with this prediction, N170 elicited by probes presented at the beginning, middle, and end of the delay interval was greater in amplitude during face relative to house WM. Thus, these results suggest that WM maintenance demands may modulate early feedforward perceptual processing for the entirety of the delay duration. We argue based on these results that temporally early biasing of domain-specific perceptual processing may be a critical mechanism by which WM maintenance is achieved.
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In recent years, three attentional networks have been defined in anatomical and functional terms. These functions involve alerting, orienting, and executive attention. Reaction time measures can be used to quantify the processing efficiency within each of these three networks. The Attention Network Test (ANT) is designed to evaluate alerting, orienting, and executive attention within a single 30-min testing session that can be easily performed by children, patients, and monkeys. A study with 40 normal adult subjects indicates that the ANT produces reliable single subject estimates of alerting, orienting, and executive function, and further suggests that the efficiencies of these three networks are uncorrelated. There are, however, some interactions in which alerting and orienting can modulate the degree of interference from flankers. This procedure may prove to be convenient and useful in evaluating attentional abnormalities associated with cases of brain injury, stroke, schizophrenia, and attention-deficit disorder. The ANT may also serve as an activation task for neuroimaging studies and as a phenotype for the study of the influence of genes on attentional networks.
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The information processing capacity of the human mind is limited, as is evidenced by the attentional blink-a deficit in identifying the second of two targets (T1 and T2) presented in close succession. This deficit is thought to result from an overinvestment of limited resources in T1 processing. We previously reported that intensive mental training in a style of meditation aimed at reducing elaborate object processing, reduced brain resource allocation to T1, and improved T2 accuracy [Slagter, H. A., Lutz, A., Greischar, L. L., Francis, A. D., Nieuwenhuis, S., Davis, J., et al. Mental training affects distribution of limited brain resources. PloS Biology, 5, e138, 2007]. Here we report EEG spectral analyses to examine the possibility that this reduction in elaborate T1 processing rendered the system more available to process new target information, as indexed by T2-locked phase variability. Intensive mental training was associated with decreased cross-trial variability in the phase of oscillatory theta activity after successfully detected T2s, in particular, for those individuals who showed the greatest reduction in brain resource allocation to T1. These data implicate theta phase locking in conscious target perception, and suggest that after mental training the cognitive system is more rapidly available to process new target information. Mental training was not associated with changes in the amplitude of T2-induced responses or oscillatory activity before task onset. In combination, these findings illustrate the usefulness of systematic mental training in the study of the human mind by revealing the neural mechanisms that enable the brain to successfully represent target information.
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Spatial working memory is a cognitive brain mechanism that enables the temporary maintenance and manipulation of spatial information. Recent neuroimaging and behavioral studies have led to the proposal that directed spatial attention is the mechanism by which location information is maintained in spatial working memory. Yet it is unclear whether attentional involvement is required throughout the period of active maintenance or is only invoked during discrete task-phases such as mnemonic encoding. In the current study, we aimed to track the time-course of attentional involvement during spatial working memory by recording event-related brain potentials (ERPs) from healthy volunteers. In Experiment 1, subjects performed a delayed-recognition task. Each trial began with the presentation of a brief stimulus (S1) that indicated the relevant location that subjects were to maintain in working memory. A 4.8-5.3 sec delay interval followed during which a single task-irrelevant probe was presented. The delay interval concluded with a test item (S2) to which subjects made a response indicating whether the S2-location was the same as the S1-memory location. To determine if attention was differentially engaged during discrete phases of the trial, task-irrelevant probes were presented early (400-800 msec following S1-offset) or late (2600-3000 msec following S1-offset) during the delay interval. Sensory-evoked ERPs (P1 and N1) elicited by these irrelevant probes showed attention-like modulations with greater amplitude responses for probes occurring at the S1-memory locations in comparison to probes presented at other locations. This pattern was obtained for both early- and late-delay probes. Probe-evoked activity during delayed-recognition trials was similar to activity observed when spatial attention was explicitly focused on a location in visual space (Experiment 2). These results are consistent with a model of spatial working memory in which perceptual level selective attention is utilized throughout the entire period of active maintenance to keep relevant spatial information in mind.
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<p>This study is an open clinical trial that examined the feasibility and acceptability of a mindfulness training program for anxious children. We based this pilot initiative on a cognitively oriented model, which suggests that, since impaired attention is a core symptom of anxiety, enhancing self-management of attention should effect reductions in anxiety. Mindfulness practices are essentially attention enhancing techniques that have shown promise as clinical treatments for adult anxiety and depression (Baer, 2003). However, little research explores the potential benefits of mindfulness to treat anxious children. The present study provided preliminary support for our model of treating childhood anxiety with mindfulness. A 6-week trial was conducted with five anxious children aged 7 to 8 years old. The results of this study suggest that mindfulness can be taught to children and holds promise as an intervention for anxiety symptoms. Results suggest that clinical improvements may be related to initial levels of attention.</p>
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Attention is a central theme in cognitive science — it exemplifies the links between the brain and behaviour, and binds psychology to the techniques of neuroscience. A visionary model suggested by Michael Posner described attention as a set of independent control networks. This challenged the previously held view of attention as a uniform concept. The idea that disparate attentional networks correlate with discrete neural circuitry and can be influenced by focal brain injuries, mental state and specific drugs has since been supported by converging data from several modern methodologies. Given the recent explosion in empirical data, attentional typologies provide powerful conceptual tools with which to contextualize and integrate these findings.
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Planned and reflexive behaviors often occur in the presence of emotional stimuli and within the context of an individual's acute emotional state. Therefore, determining the manner in which emotion and attention interact is an important step toward understanding how we function in the real world. Participants in the current investigation viewed centrally displayed, task-irrelevant, face distractors (angry, neutral, happy) while performing a lateralized go/no-go continuous performance task. Lateralized go targets and no-go lures that did not spatially overlap with the faces were employed to differentially probe processing in the left (LH) and right (RH) cerebral hemispheres. There was a significant interaction between expression and hemisphere, with an overall pattern such that angry distractors were associated with relatively more RH inhibitory errors than neutral or happy distractors and happy distractors with relatively more LH inhibitory errors than angry or neutral distractors. Simple effects analyses confirmed that angry faces differentially interfered with RH relative to LH inhibition and with inhibition in the RH relative to happy faces. A significant three-way interaction further revealed that state anxiety moderated relations between emotional expression and hemisphere. Under conditions of low cognitive load, more intense anxiety was associated with relatively greater RH than LH impairment in the presence of both happy and threatening distractors. By contrast, under high load, only angry distractors produced greater RH than LH interference as a function of anxiety.
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Facial expressions of pain are an important part of the pain response, signaling distress to others and eliciting social support. To evaluate how voluntary modulation of this response contributes to the pain experience, 29 subjects were exposed to thermal stimulation while making standardized pain, control, or relaxed faces. Dependent measures were self-reported negative effect (valence and arousal) as well as the intensity of nociceptive stimulation required to reach a given subjective level of pain. No direct social feedback was given by the experimenter. Although the amount of nociceptive stimulation did not differ across face conditions, subjects reported more negative effects in response to painful stimulation while holding the pain face. Subsequent analyses suggested the effects were not due to preexisting differences in the difficulty or unpleasantness of making the pain face. These results suggest that voluntary pain expressions have no positively reinforcing (pain attenuating) qualities, at least in the absence of external contingencies such as social reinforcement, and that such expressions may indeed be associated with higher levels of negative affect in response to similar nociceptive input.
PERSPECTIVE: This study demonstrates that making a standardized pain face increases negative affect in response to nociceptive stimulation, even in the absence of social feedback. This suggests that exaggerated facial displays of pain, although often socially reinforced, may also have unintended aversive consequences.
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Research on temporal-order judgments, reference frames, discrimination tasks, and links to oculomotor control suggest important differences between inhibition of return (IOR) and attentional costs and benefits. Yet, it is generally assumed that IOR is an attentional effect even though there is little supporting evidence. The authors evaluated this assumption by examining how several factors that are known to influence attentional costs and benefits affect the magnitude of IOR: target modality, target intensity, and response mode. Results similar to those previously reported for attention were observed: IOR was greater for visual than for auditory targets, showed an inverse relationship with target intensity, and was equivalent for manual and saccadic responses. Important parallels between IOR and attentional costs and benefits are indicated, suggesting that, like attention, IOR may in part affect sensory-perceptual processes.
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Who benefits most from making sacrifices for others? The current study provides one answer to this question by demonstrating the intrinsic benefits of sacrifice for people who are highly motivated to respond to a specific romantic partner's needs noncontingently, a phenomenon termed communal strength. In a 14-day daily-experience study of 69 romantic couples, communal strength was positively associated with positive emotions during the sacrifice itself, with feeling appreciated by the partner for the sacrifice, and with feelings of relationship satisfaction on the day of the sacrifice. Furthermore, feelings of authenticity for the sacrifice mediated these associations. Several alternative hypotheses were ruled out: The effects were not due to individuals higher in communal strength making qualitatively different kinds of sacrifices, being more positive in general, or being involved in happier relationships. Implications for research and theory on communal relationships and positive emotions are discussed.
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The Star Counting Test (SCT) has been developed to measure the regulatory function of attention. In a previous study it was shown that the SCT is suited for assessment of this attentional aspect with children. The present study concerns a more difficult version aimed at young adults. In the literature, the regulatory function of attention is increasingly stressed and it has been linked to working memory functioning. In order to further determine the validity of the SCT, performance was checked against two kinds of measures relating to working memory, i.e. Digit Span and Computational Span. These tasks both call for storage but differ in their claims on the processing component of working memory. Using confirmatory factor analysis substantial correlations were demonstrated with either of these measures. As expected, the correlations tended to rise with increasing demands on the processing component. Test scores were further compared with self-reported cognitive failures. No significant relation appeared to exist. The results are interpreted in terms of demands on the regulatory function of attention.
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Dynamic adjustments in cognitive control are well documented in conflict tasks, wherein competition from irrelevant stimulus attributes intensifies selection demands and leads to subsequent performance benefits. The current study investigated whether mnemonic demands, in a working memory (WM) task, can drive similar online control modifications. Demand levels (high vs. low) of WM maintenance (memory load of 2 items vs. 1 item) and delay-spanning distractor interference (confusable vs. not confusable with memoranda) were manipulated using a factorial design during a WM delayed-recognition task. Performance was best subsequent to trials in which both maintenance and distractor interference demands were high, followed by trials with high demand in either of these 2 control domains, and worst following trials with low demand in both domains. These results suggest that dynamic adjustments in cognitive control are not triggered exclusively by conflict-specific contexts but are also triggered by WM demands, revealing a putative mechanism by which this system configures itself for successful task performance.
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