Collective Correlations of Brodmann Areas fMRI Study with RMT-Denoising

We study collective behavior of Brodmann regions of human cerebral cortex using functional Magnetic Resonance Imaging (fMRI) and Random Matrix Theory (RMT). The raw fMRI data is mapped onto the cortex regions corresponding to the Brodmann areas with the aid of the Talairach coordinates. Principal Component Analysis (PCA) of the Pearson correlation matrix for 41 different Brodmann regions is carried out to determine their collective activity in the idle state and in the active state stimulated by tapping. The collective brain activity is identified through the statistical analysis of the eigenvectors to the largest eigenvalues of the Pearson correlation matrix. The leading eigenvectors have a large participation ratio. This indicates that several Broadmann regions collectively give rise to the brain activity associated with these eigenvectors. We apply random matrix theory to interpret the underlying multivariate data

Trait Mindfulness and Functional Connectivity in Cognitive and Attentional Resting State Networks

Mindfulness has been described as an orienting of attention to the present moment, with openness and compassion. Individuals displaying high trait mindfulness exhibit this tendency as a more permanent personality attribute. Given the numerous physical and mental health benefits associated with mindfulness, there is a great interest in understanding the neural substrates of this trait. The purpose of the current research was to examine how individual differences in trait mindfulness associated with functional connectivity in five resting-state networks related to cognition and attention: the default mode network (DMN), the salience network (SN), the central executive network (CEN), and the dorsal and ventral attention networks (DAN and VAN). Twenty-eight undergraduate participants completed the Five-Facet Mindfulness Questionnaire (FFMQ), a self-report measure of trait mindfulness which also provides scores on five of its sub-categories (Observing, Describing, Acting with Awareness, Non-judging of Inner Experience, and Non-reactivity to Inner Experience). Participants then underwent a structural MRI scan and a 7-min resting state functional MRI scan. Resting-state data were analyzed using independent-component analyses. An analysis of covariance (ANCOVA) was performed to determine the relationship between each resting state network and each FFMQ score. These analyses indicated that: (1) trait mindfulness and its facets showed increased functional connectivity with neural regions related to attentional control, interoception, and executive function; and (2) trait mindfulness and its facets showed decreased functional connectivity with neural regions related to self-referential processing and mind wandering. These patterns of functional connectivity are consistent with some of the benefits of mindfulness—enhanced attention, self-regulation, and focus on present experience. This study provides support for the notion that non-judgmental attention to the present moment facilitates the integration of regions in neural networks that are related to cognition, attention, and sensation

The role of somatosensory cortex in pain processing

Peer reviewed: YesNRC publication: Ye

Emotion-dependent responses in spinal cord neurons: a spinal fMRI study

Previous research has demonstrated that emotional stimuli receive preferential processing in the brain. In the current study, functional magnetic resonance imaging was utilized to determine if emotion-specific responses are detectable in the cervical spinal cord. During the passive (i.e., non-motoric) perception of images, activity was detected in the left dorsal and right ventral spinal cord in response to negative emotional stimuli; however, this pattern was reversed in response to neutral and positive stimuli. Critically, during active motoric responses to images, there was greater activity in the ventral cervical spinal cord in response to negative emotional stimuli than to neutral stimuli. These results demonstrate preferential motor responses to negative emotional images by the spinal cord, likely indicating an enhancement of activity in response to threat.Peer reviewed: YesNRC publication: Ye

Altered Neural Activity Associated with Mindfulness during Nociception: A Systematic Review of Functional MRI

Objective: To assess the neural activity associated with mindfulness-based alterations of pain perception. Methods: The Cochrane Central, EMBASE, Ovid Medline, PsycINFO, Scopus, and Web of Science databases were searched on 2 February 2016. Titles, abstracts, and full-text articles were independently screened by two reviewers. Data were independently extracted from records that included topics of functional neuroimaging, pain, and mindfulness interventions. Results: The literature search produced 946 total records, of which five met the inclusion criteria. Records reported pain in terms of anticipation (n = 2), unpleasantness (n = 5), and intensity (n = 5), and how mindfulness conditions altered the neural activity during noxious stimulation accordingly. Conclusions: Although the studies were inconsistent in relating pain components to neural activity, in general, mindfulness was able to reduce pain anticipation and unpleasantness ratings, as well as alter the corresponding neural activity. The major neural underpinnings of mindfulness-based pain reduction consisted of altered activity in the anterior cingulate cortex, insula, and dorsolateral prefrontal cortex

A neural correlate of visceral emotional responses: evidence from fMRI of the thoracic spinal cord. Soc Cogn Affect Neurosci

Functional magnetic resonance imaging (fMRI) of thoracic spinal cord neurons was used to examine the neural correlates of visceral emotional responses. Participants completed four spinal fMRI runs involving passive viewing (i.e. no movement) and motoric responses to negative or neutral images. Negative images, particularly in the movement condition, elicited robust activity in motoric nuclei, indicating action preparedness. These images also enhanced activity in autonomic and sensory nuclei, thus providing a clear neural representation of visceral responses to emotional stimuli. Keywords: magnetic resonance imaging; functional MRI; spinal cord; thoracic spinal cord; emotion A core feature of emotional experience is a subjective visceral response to a stimulus or event. These responses imbue events with a vividness that enhances perception Quantifying neural activity related to such phenomenologically complex experiences poses significant methodological challenges. Paramount among these is the difficulty in separating neural activity related to the bodily responses from activity associated with the cognitive interpretation of these responses. Previous research has successfully identified key structures related to the latter. Activation of the right insula has been consistently linked with interoception One such region is the spinal cord, which has different sensory, motoric and autonomic functions but is not directly related to any cognitive process. The spinal cord is divided into four different regionscervical, thoracic, lumbar and sacraleach of which is composed of a number of individual segments projecting to and receiving information from different regions of the body. Each of these segments consists of dorsal and ventral aspects, which correspond to sensory and motoric activity and, in the thoracic segments, a lateral aspect that corresponds to autonomic activity. Although often thought to be a simple structure, the patterns of activity in the spinal cord reflect a number of potentially interacting systems. Numerous separate descending pathways from the brain modulate motoric regions of the spinal cord, and similarly, multiple separate ascending pathways bring different types of somatosensory information back to the brain. In addition to these brain-spinal cord interactions, the spinal cord houses interneurons that project both intra-segmentally and intersegmentally and that are involved in a number of reflexive responses that occur independent of the brain. Therefore, studies examining the excitability of a single descending pathway from the brain (e.g. the corticospinal tract) are measuring only a fraction of the activity occurring in the spinal cord. Examining activity at the level of the spinal cord itself will provide researchers with unique information about nervous system activity that cannot be identified using traditional brain fMRI (functional magnetic resonance imaging). In previous studies, we have used fMRI of the spinal cord ('spinal fMRI'; Stroman, 2005) to examine whether the spinal cord activity can be modulated by emotional stimuli. In the first study to examine spinal cord responses to emotions, we measured activity in the cervical spinal cord, which innervates the upper limbs including the hands (Smith and Kornelsen, 2011). We found that negative emotional stimuli elicited greater levels of activity in ventral (motoric) regions of several spinal cord segments, particularly those related to hand responses. This activity was more pronounced when participants made a movement (pressed a button on a response pad) than when they passively viewed the emotional images. Because of this very specific pattern of activity, we suggested that spinal cord neurons show evidence of emotion-dependent 'action preparedness'. However, emotional responses are obviously not limited to rapid gestural responses, as shown by measurements of the cervical spinal cord. Instead, emotional responses generally involve muscle tension in the chest and abdomen as well as autonomic nervous system activity. Neuroanatomical studies suggest that these responses should be linked with activity in a different region of the spinal cord, the thoracic cord. Spinal nerves emanating from the thoracic spinal cord innervate muscles in the trunk and abdomen, stimulating muscle contraction of these regions. Afferent somatosensory projections from the peripheral nervous system synapse with this region as well. These responses are likely linked to the subjective awareness of our emotionally aroused state. Additionally, the thoracic spinal cord is critical for a number of autonomic nervous system responses ranging from pupil dilation and cardiopulmonary responses (segments T1-T4) to the secretion of norepinephrine and epinephrine by the adrenal medulla (T10-T12; see Shields, 1993, for a detailed review). Therefore, measuring activit

A functional magnetic resonance imaging investigation of the autonomous sensory meridian response

Background Autonomous Sensory Meridian Response (ASMR) is a sensory-emotional experience in which specific stimuli (ASMR “triggers”) elicit tingling sensations on the scalp, neck, and shoulders; these sensations are accompanied by a positive affective state. In the current research, functional magnetic resonance imaging (fMRI) was used in order to delineate the neural substrates of these responses. Methods A total of 17 individuals with ASMR and 17 age- and sex-matched control participants underwent fMRI scanning while watching six 4-minute videos. Three of the videos were designed to elicit ASMR tingling and three videos were not. Results The results demonstrated that ASMR videos have a distinct effect on the neural activity of individuals with ASMR. The contrast of ASMR participants’ responses to ASMR videos showed greater activity in the cingulate gyrus as well as in cortical regions related to audition, movement, and vision. This activity was not observed in control participants. The contrast of ASMR and control participants’ responses to ASMR-eliciting videos detected greater activity in right cingulate gyrus, right paracentral lobule, and bilateral thalamus in ASMR participants; control participants showed greater activity in the lingula and culmen of the cerebellum. Conclusions Together, these results highlight the fact that ASMR videos elicit activity in brain areas related to sensation, emotion, and attention in individuals with ASMR, but not in matched control participants

Assessing Nociception by Fmri of the Human Spinal Cord: A Systematic Review

Objective To assess the use of fMRI of the spinal cord in measuring noxious stimulation. Methods The Scopus, Medline, EMBASE, and Web of Science databases were searched, along with the reference lists of included articles. Two independent reviewers screened abstracts, full-text articles, and extracted data. Original research was included if fMRI of the human spinal cord was used to measure responses to noxious stimulation. Results Of the 192 abstracts screened, 19 met the search criteria and were divided according to their focus: investigating pain responses ( n = 6), methodology ( n = 6), spinal cord injury ( n = 2), or cognition–pain interactions ( n = 5). All but one study appear to have observed activity in ipsilateral and dorsal gray matter regions in response to noxious stimuli, although contralateral or ventral activity was also widely observed. Conclusions Although nociception can be investigated using spinal fMRI, establishing reliability, standardizing methodology, and reporting of results will greatly advance this field

Neural Responses to Consciously and Unconsciously Perceived Emotional Faces: A Spinal fMRI Study

Emotional stimuli modulate activity in brain areas related to attention, perception, and movement. Similar increases in neural activity have been detected in the spinal cord, suggesting that this understudied component of the central nervous system is an important part of our emotional responses. To date, previous studies of emotion-dependent spinal cord activity have utilized long presentations of complex emotional scenes. The current study differs from this research by (1) examining whether emotional faces will lead to enhanced spinal cord activity and (2) testing whether these stimuli require conscious perception to influence neural responses. Fifteen healthy undergraduate participants completed six spinal functional magnetic resonance imaging (fMRI) runs in which three one-minute blocks of fearful, angry, or neutral faces were interleaved with 40-s rest periods. In half of the runs, the faces were clearly visible while in the other half, the faces were displayed for only 17 ms. Spinal fMRI consisted of half-Fourier acquisition single-shot turbo spin-echo (HASTE) sequences targeting the cervical spinal cord. The results indicated that consciously perceived faces expressing anger elicited significantly more activity than fearful or neutral faces in ventral (motoric) regions of the cervical spinal cord. When stimuli were presented below the threshold of conscious awareness, neutral faces elicited significantly more activity than angry or fearful faces. Together, these data suggest that the emotional modulation of spinal cord activity is most impactful when the stimuli are consciously perceived and imply a potential threat toward the observer

Headache and Intrinsic Brain Network Improvement in Chronic Migraine Following Onabotulinumtoxin-A Treatment: a Resting-State-Functional-MRI Study

Here we report the effect of Onabotulinumtoxin-A (Onabot-A) in twelve patients with chronic migraine (CM=15 or more headaches/months), behaviourally, i.e. improvement in the headaches quantity/severity, and functionally, i.e. changes in brain functional connectivity (FC) patterns using resting-state-functional magnetic resonance imaging (rsfMRI)