Zotero Collections:
Zotero Collections:
Recent years have seen an explosion of interest in using neural oscillations to characterize the mechanisms supporting cognition and emotion. Oftentimes, oscillatory activity is indexed by mean power density in predefined frequency bands. Some investigators use broad bands originally defined by prominent surface features of the spectrum. Others rely on narrower bands originally defined by spectral factor analysis (SFA). Presently, the robustness and sensitivity of these competing band definitions remains unclear. Here, a Monte Carlo-based SFA strategy was used to decompose the tonic ("resting" or "spontaneous") electroencephalogram (EEG) into five bands: delta (1-5Hz), alpha-low (6-9Hz), alpha-high (10-11Hz), beta (12-19Hz), and gamma (>21Hz). This pattern was consistent across SFA methods, artifact correction/rejection procedures, scalp regions, and samples. Subsequent analyses revealed that SFA failed to deliver enhanced sensitivity; narrow alpha sub-bands proved no more sensitive than the classical broadband to individual differences in temperament or mean differences in task-induced activation. Other analyses suggested that residual ocular and muscular artifact was the dominant source of activity during quiescence in the delta and gamma bands. This was observed following threshold-based artifact rejection or independent component analysis (ICA)-based artifact correction, indicating that such procedures do not necessarily confer adequate protection. Collectively, these findings highlight the limitations of several commonly used EEG procedures and underscore the necessity of routinely performing exploratory data analyses, particularly data visualization, prior to hypothesis testing. They also suggest the potential benefits of using techniques other than SFA for interrogating high-dimensional EEG datasets in the frequency or time-frequency (event-related spectral perturbation, event-related synchronization/desynchronization) domains.
Zotero Collections:
<p>Successful human social interaction depends on our capacity to understand other people's mental states and to anticipate how they will react to our actions. Despite its importance to the human condition, the exact mechanisms underlying our ability to understand another's actions, feelings, and thoughts are still a matter of conjecture. Here, we consider this problem from philosophical, psychological, and neuroscientific perspectives. In a critical review, we demonstrate that attempts to draw parallels across these complementary disciplines is premature: The second-person perspective does not map directly to Interaction or Simulation theories, online social cognition, or shared neural network accounts underlying action observation or empathy. Nor does the third-person perspective map onto Theory-Theory (TT), offline social cognition, or the neural networks that support Theory of Mind (ToM). Moreover, we argue that important qualities of social interaction emerge through the reciprocal interplay of two independent agents whose unpredictable behavior requires that models of their partner's internal state be continually updated. This analysis draws attention to the need for paradigms in social neuroscience that allow two individuals to interact in a spontaneous and natural manner and to adapt their behavior and cognitions in a response contingent fashion due to the inherent unpredictability in another person's behavior. Even if such paradigms were implemented, it is possible that the specific neural correlates supporting such reciprocal interaction would not reflect computation unique to social interaction but rather the use of basic cognitive and emotional processes combined in a unique manner. Finally, we argue that given the crucial role of social interaction in human evolution, ontogeny, and every-day social life, a more theoretically and methodologically nuanced approach to the study of real social interaction will nevertheless help the field of social cognition to evolve.</p>
Zotero Collections:
<p>Imaging techniques provide ways of knowing structure and function in biology at different scales. The multidisciplinary nature and rapid advancement of imaging sciences requires imaging education to begin early in the biology curriculum. Guided by the National Institutes of Health (NIH) Roadmap initiatives, we incorporated a nanoimaging, molecular imaging, and medical imaging teaching unit into three 1-h class periods of an introductory course on ways of knowing biology. Activities were derived from NIH Roadmap initiatives in nanomedicine, regenerative medicine, and nuclear medicine. The course materials we describe contributed positively to student learning gains in quantifying and interpreting images, in characterizing imaging methods that provide ways of knowing biological structure and function, and in understanding scale in biology and imaging. The NIH Roadmap provides a useful context to educate students about the multidisciplinary imaging continuum.</p>
Zotero Collections:
Two hundred and nine pupils were randomly allocated to either a cognitive behaviourally based stress management intervention (SMI) group, or a non-intervention control group. Mood and motivation measures were administered pre and post intervention. Standardized examinations were taken 8–10 weeks later. As hypothesized, results indicated that an increase in the functionality of pupils’ cognitions served as the mechanism by which mental health improved in the SMI group. In contrast, the control group demonstrated no such improvements. Also, as predicted, an increase in motivation accounted for the SMI group's significantly better performance on the standardized, academic assessments that comprise the United Kingdom's General Certificate of Secondary Education. Indeed, the magnitude of this enhanced performance was, on average, one-letter grade. Discussion focuses on the theoretical and practical implications of these findings.
Zotero Collections:
The present study investigated the premise that individual differences in autonomic physiology could be used to specify the nature and consequences of information processing taking place in medial prefrontal regions during cognitive reappraisal of unpleasant pictures. Neural (blood oxygenation level-dependent functional magnetic resonance imaging) and autonomic (electrodermal [EDA], pupil diameter, cardiac acceleration) signals were recorded simultaneously as twenty-six older people (ages 64-66 years) used reappraisal to increase, maintain, or decrease their responses to unpleasant pictures. EDA was higher when increasing and lower when decreasing compared to maintaining. This suggested modulation of emotional arousal by reappraisal. By contrast, pupil diameter and cardiac acceleration were higher when increasing and decreasing compared to maintaining. This suggested modulation of cognitive demand. Importantly, reappraisal-related activation (increase, decrease>maintain) in two medial prefrontal regions (dorsal medial frontal gyrus and dorsal cingulate gyrus) was correlated with greater cardiac acceleration (increase, decrease>maintain) and monotonic changes in EDA (increase>maintain>decrease). These data indicate that these two medial prefrontal regions are involved in the allocation of cognitive resources to regulate unpleasant emotion, and that they modulate emotional arousal in accordance with the regulatory goal. The emotional arousal effects were mediated by the right amygdala. Reappraisal-related activation in a third medial prefrontal region (subgenual anterior cingulate cortex) was not associated with similar patterns of change in any of the autonomic measures, thus highlighting regional specificity in the degree to which cognitive demand is reflected in medial prefrontal activation during reappraisal.
Zotero Collections:
Zotero Collections:
Noninvasive recordings of electrical and magnetic fields generated by neuronal activity have helped to characterize the temporal sequencing and mechanisms underlying human cognition. Progress is being made toward the goal of localizing the intracranial loci at which many important electromagnetic signals are generated through the use of new analytic techniques and of scalp recordings of electromagnetic activity in neurological patients and through related work in animals. Such methods alone, however, do not yet have the three-dimensional spatial resolution that is necessary in order to identify the intracranial anatomical structures that are involved in the generation of externally recorded activity and, thus, cannot yet inform us with precision about the anatomical substrates of neural events. In comparison, neuroimaging methods, such as positron emission tomography and functional magnetic resonance imaging, can provide higher spatial resolution information about which brain structures are involved in perceptual, motor, and cognitive processes. However, these imaging methods do not yield much information about the time course of brain activity. One promising approach is to combine electromagnetic recordings and functional neuroimaging in order to gain knowledge about the spatiotemporal organization of human cognition. Here we review how electrophysiology and functional neuroimaging can be combined in the study of attention in normal humans.
Zotero Collections:
The ability to focus one's attention underlies success in many everyday tasks, but voluntary attention cannot be sustained for extended periods of time. In the laboratory, sustained-attention failure is manifest as a decline in perceptual sensitivity with increasing time on task, known as the vigilance decrement. We investigated improvements in sustained attention with training (~ 5 hr/day for 3 months), which consisted of meditation practice that involved sustained selective attention on a chosen stimulus (e.g., the participant's breath). Participants were randomly assigned either to receive training first (n = 30) or to serve as waiting-list controls and receive training second (n = 30). Training produced improvements in visual discrimination that were linked to increases in perceptual sensitivity and improved vigilance during sustained visual attention. Consistent with the resource model of vigilance, these results suggest that perceptual improvements can reduce the resource demand imposed by target discrimination and thus make it easier to sustain voluntary attention.
Zotero Collections:
This article explores the concept of interiority as it relates to education and contemplation. Primarily, four general dimensions of consciousness related to learning are examined: presence, clarity, detachment, and resilience. The direct experience of these states and processes are described and explored in light of contemporary research on the neuro-physiologic correlates of various contemplative practices. This neurophenomenological approach considers the evidence and argument for the value of contemplation in education.
Zotero Collections:
Lesions of the dorsal hippocampus have been shown to disrupt both the acquisition and the consolidation of memories associated with contextual fear (fear of the place of conditioning), but do not affect fear conditioning to discrete cues (e.g., a tone). Blockade of central muscarinic cholinergic receptor activation results in selective acquisition deficits of contextual fear conditioning, but reportedly has little effect on consolidation. Here we show for the first time that direct infusion of the muscarinic cholinergic receptor antagonist, scopolamine, into the dorsal hippocampus produces a dose-dependent deficit in both acquisition and consolidation of contextual fear conditioning, while having no impact on simple tone conditioning.
Zotero Collections:
We investigated whether mindfulness training (MT) influences information processing in a working memory task with complex visual stimuli. Participants were tested before (T1) and after (T2) participation in an intensive one-month MT retreat, and their performance was compared with that of an age- and education-matched control group. Accuracy did not differ across groups at either time point. Response times were faster and significantly less variable in the MT versus the control group at T2. Since these results could be due to changes in mnemonic processes, speed-accuracy trade-off, or nondecisional factors (e.g., motor execution), we used a mathematical modeling approach to disentangle these factors. The EZ-diffusion model (Wagenmakers, van der Maas, & Grasman, Psychonomic Bulletin & Review 14:(1), 3-22, 2007) suggested that MT leads to improved information quality and reduced response conservativeness, with no changes in nondecisional factors. The noisy exemplar model further suggested that the increase in information quality reflected a decrease in encoding noise and not an increase in forgetting. Thus, mathematical modeling may help clarify the mechanisms by which MT produces salutary effects on performance.
Zotero Collections:
To monitor the environment for social threat humans must build affective evaluations of others. These evaluations are malleable and to a high degree shaped by responses engendered by specific social encounters. The precise neuronal mechanism by which these evaluations are constructed is poorly understood. We tested a hypothesis that conjoint activity in amygdala and fusiform gyrus would correlate with acquisition of social stimulus value. We tested this using a reinforcement learning algorithm, Q-learning, that assigned values to faces as a function of a history of pairing, or not pairing, with aversive shocks. Behaviourally, we observed a correlation between conditioning induced changes in skin conductance response (SCR) and subjective ratings for likeability of faces. Activity in both amygdala and fusiform gyrus (FG) correlated with the output of the reinforcement learning algorithm parameterized by these ratings. In amygdala, this effect was greater for averted than direct gaze faces. Furthermore, learning-related activity change in these regions correlated with SCR and subjective ratings. We conclude that amygdala and fusiform encode affective value in a manner that closely approximates a standard computational solution to learning.
Zotero Collections:
Zotero Collections:
This paper briefly reviews the evidence for multistore theories of memory and points out some difficulties with the approach. An alternative framework for human memory research is then outlined in terms of depth or levels of processing. Some current data and arguments are reexamined in the light of this alternative framework and implications for further research considered.
Zotero Collections:
To better understand the neurobiological mechanisms by which mindfulness-based practices function in a psychotherapeutic context, this article details the definition, techniques, and purposes ascribed to mindfulness training as described by its Buddhist tradition of origin and by contemporary neurocognitive models. Included is theory of how maladaptive mental processes become habitual and automatic, both from the Buddhist and Western psychological perspective. Specific noting and labeling techniques in open monitoring meditation, described in the Theravada and Western contemporary traditions, are highlighted as providing unique access to multiple modalities of awareness. Potential explicit and implicit mechanisms are discussed by which such techniques can contribute to transforming maladaptive habits of mind and perceptual and cognitive biases, improving efficiency, facilitating integration, and providing the flexibility to switch between systems of self-processing. Finally, a model is provided to describe the timing by which noting and labeling practices have the potential to influence different stages of low- and high-level neural processing. Hypotheses are proposed concerning both levels of processing in relation to the extent of practice. Implications for the nature of subjective experience and self-processing as it relates to one's habits of mind, behavior, and relation to the external world, are also described.
Zotero Collections:
<p>This article describes the design and advocacy of the Bachelor of Fine Arts in Jazz and Contemplative Studies curriculum at The University of Michigan School of Music. The curriculum combines meditation practice and related studies with jazz and overall musical training and is part of a small but growing movement in academia that seeks to integrate contemplative disciplines within the educational process. The article considers issues such as the structure of the curriculum, the reconciliation of contemplative studies and conventional notions of academic rigor, the avoidance of possible conflicts between church and state, and other challenges encountered in gaining support for this plan, after weeks of intensive debate, from a 2/3 majority of the faculty.</p>
Zotero Collections:
Those with high baseline stress levels are more likely to develop mild cognitive impairment (MCI) and Alzheimer's Disease (AD). While meditation may reduce stress and alter the hippocampus and default mode network (DMN), little is known about its impact in these populations. Our objective was to conduct a "proof of concept" trial to determine whether Mindfulness Based Stress Reduction (MBSR) would improve DMN connectivity and reduce hippocampal atrophy among adults with MCI. 14 adults with MCI were randomized to MBSR vs. usual care and underwent resting state fMRI at baseline and follow-up. Seed based functional connectivity was applied using posterior cingulate cortex as seed. Brain morphometry analyses were performed using FreeSurfer. The results showed that after the intervention, MBSR participants had increased functional connectivity between the posterior cingulate cortex and bilateral medial prefrontal cortex and left hippocampus compared to controls. In addition, MBSR participants had trends of less bilateral hippocampal volume atrophy than control participants. These preliminary results indicate that in adults with MCI, MBSR may have a positive impact on the regions of the brain most related to MCI and AD. Further research with larger sample sizes and longer-follow-up are needed to further investigate the results from this pilot study.
Those with high baseline stress levels are more likely to develop mild cognitive impairment (MCI) and Alzheimer's Disease (AD). While meditation may reduce stress and alter the hippocampus and default mode network (DMN), little is known about its impact in these populations. Our objective was to conduct a “proof of concept” trial to determine whether Mindfulness Based Stress Reduction (MBSR) would improve DMN connectivity and reduce hippocampal atrophy among adults with MCI. 14 adults with MCI were randomized to MBSR vs. usual care and underwent resting state fMRI at baseline and follow-up. Seed based functional connectivity was applied using posterior cingulate cortex as seed. Brain morphometry analyses were performed using FreeSurfer. The results showed that after the intervention, MBSR participants had increased functional connectivity between the posterior cingulate cortex and bilateral medial prefrontal cortex and left hippocampus compared to controls. In addition, MBSR participants had trends of less bilateral hippocampal volume atrophy than control participants. These preliminary results indicate that in adults with MCI, MBSR may have a positive impact on the regions of the brain most related to MCI and AD. Further research with larger sample sizes and longer-follow-up are needed to further investigate the results from this pilot study.
Zotero Collections:
In this article the author examines the use of meditation as an aid to conventional medicine, examines the increased research on the subject, and offers a critique of Mindfulness-Based Stress Reduction (MBSR), the therapeutic meditation method developed by molecular biologist Jon Kabat-Zinn. A number of topics are addressed including Kabat-Zinn's perception of MBSR as Buddhist meditation without a religious element, the moral framework of yoga and meditation, and the lack of interaction and community in the practice of MBSR.
Zotero Collections:
This study investigated the link between meditation, self-reported mindfulness and cognitive flexibility as well as other attentional functions. It compared a group of meditators experienced in mindfulness meditation with a meditation-naïve control group on measures of Stroop interference and the “d2-concentration and endurance test”. Overall the results suggest that attentional performance and cognitive flexibility are positively related to meditation practice and levels of mindfulness. Meditators performed significantly better than non-meditators on all measures of attention. Furthermore, self-reported mindfulness was higher in meditators than non-meditators and correlations with all attention measures were of moderate to high strength. This pattern of results suggests that mindfulness is intimately linked to improvements of attentional functions and cognitive flexibility. The relevance of these findings for mental balance and well-being are discussed.
Zotero Collections:
<p>Covering both theory and practice, this work provides a guide to reflection and meditation in school, showing how to relate such principles to the curriculum as a whole.</p>
Zotero Collections:
Pages |