Ictal and interictal brain activation in episodic migraine: Neural basis for extent of allodynia

In some patients, migraine attacks are associated with symptoms of allodynia which can be localized (cephalic) or generalized (extracephalic). Using functional neuroimaging and cutaneous thermal stimulation, we aimed to investigate the differences in brain activation of patients with episodic migraine (n = 19) based on their allodynic status defined by changes between ictal and interictal pain tolerance threshold for each subject at the time of imaging. In this prospective imaging study, differences were found in brain activity between the ictal and interictal visits in the brainstem/pons, thalamus, insula, cerebellum and cingulate cortex. Significant differences were also observed in the pattern of activation along the trigeminal pathway to noxious heat stimuli in no allodynia vs. generalized allodynia in the thalamus and the trigeminal nucleus but there were no activation differences in the trigeminal ganglion. The functional magnetic resonance imaging (fMRI) findings provide direct evidence for the view that in migraine patients who are allodynic during the ictal phase of their attacks, the spinal trigeminal nucleus and posterior thalamus become hyper-responsive (sensitized)–to the extent that they mediate cephalic and extracephalic allodynia, respectively. In addition, descending analgesic systems seem as “switched off” in generalized allodynia.

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The Neural Basis of Successful Word Reading in Aphasia

Journal of Cognitive Neuroscience ◽

10.1162/jocn_a_01214 ◽

2018 ◽

Vol 30 (4) ◽

pp. 514-525 ◽

Cited By ~ 2

Author(s):

Sara B. Pillay ◽

William L. Gross ◽

William W. Graves ◽

Colin Humphries ◽

Diane S. Book ◽

...

Keyword(s):

Word Reading ◽

Functional Neuroimaging ◽

Semantic Network ◽

Brain Activity ◽

Brain Regions ◽

Anterior Cingulate ◽

Angular Gyrus ◽

Bold Signal ◽

Neural Basis ◽

Successful Performance

Understanding the neural basis of recovery from stroke is a major research goal. Many functional neuroimaging studies have identified changes in brain activity in people with aphasia, but it is unclear whether these changes truly support successful performance or merely reflect increased task difficulty. We addressed this problem by examining differences in brain activity associated with correct and incorrect responses on an overt reading task. On the basis of previous proposals that semantic retrieval can assist pronunciation of written words, we hypothesized that recruitment of semantic areas would be greater on successful trials. Participants were 21 patients with left-hemisphere stroke with phonologic retrieval deficits. They read words aloud during an event-related fMRI paradigm. BOLD signals obtained during correct and incorrect trials were contrasted to highlight brain activity specific to successful trials. Successful word reading was associated with higher BOLD signal in the left angular gyrus. In contrast, BOLD signal in bilateral posterior inferior frontal cortex, SMA, and anterior cingulate cortex was greater on incorrect trials. These data show for the first time the brain regions where neural activity is correlated specifically with successful performance in people with aphasia. The angular gyrus is a key node in the semantic network, consistent with the hypothesis that additional recruitment of the semantic system contributes to successful word production when phonologic retrieval is impaired. Higher activity in other brain regions during incorrect trials likely reflects secondary engagement of attention, working memory, and error monitoring processes when phonologic retrieval is unsuccessful.

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Naturalistic hyperscanning with wearable magnetoencephalography

10.1101/2021.09.07.459124 ◽

2021 ◽

Author(s):

Niall Holmes ◽

Molly Rea ◽

Ryan M Hill ◽

Elena Boto ◽

Andrew Stuart ◽

...

Keyword(s):

Functional Neuroimaging ◽

Brain Activity ◽

Poor Performance ◽

Neural Substrates ◽

High Fidelity ◽

Neural Basis ◽

Temporal Precision ◽

Naturalistic Setting ◽

New Generation ◽

Subject Motion

The evolution of human cognitive function is reliant on complex social interactions which form the behavioural foundation of who we are. These social capacities are subject to dramatic change in disease and injury; yet their supporting neural substrates remain poorly understood. Hyperscanning employs functional neuroimaging to simultaneously assess brain activity in two individuals and offers the best means to understand the neural basis of social interaction. However, present technologies are limited, either by poor performance (low spatial/temporal precision) or unnatural scanning environment (claustrophobic scanners, with interactions via video). Here, we solve this problem by developing a new form of hyperscanning using wearable magnetoencephalography (MEG). This approach exploits quantum sensors for MEG signal detection, in combination with high-fidelity magnetic field control – afforded by a novel "matrix coil" system – to enable simultaneous scanning of two freely moving participants. We demonstrate our approach in a somatosensory task and an interactive ball game. Despite large and unpredictable subject motion, sensorimotor brain activity was delineated clearly in space and time, and correlation of the envelope of neuronal oscillations between people was demonstrated. In sum, unlike existing modalities, wearable-MEG combines high fidelity data acquisition and a naturalistic setting, which will facilitate a new generation of hyperscanning.

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Utility of SPECT Functional Neuroimaging of Pain

Frontiers in Psychiatry ◽

10.3389/fpsyt.2021.705242 ◽

2021 ◽

Vol 12 ◽

Author(s):

Mohammed Bermo ◽

Mohammed Saqr ◽

Hunter Hoffman ◽

David Patterson ◽

Sam Sharar ◽

...

Keyword(s):

Brain Imaging ◽

Functional Neuroimaging ◽

Brain Activity ◽

Photon Emission ◽

Brain Activation ◽

Brain Perfusion ◽

Functional Brain Imaging ◽

Functional Brain ◽

Clinical Scenarios ◽

The Brain

Functional neuroimaging modalities vary in spatial and temporal resolution. One major limitation of most functional neuroimaging modalities is that only neural activation taking place inside the scanner can be imaged. This limitation makes functional neuroimaging in many clinical scenarios extremely difficult or impossible. The most commonly used radiopharmaceutical in Single Photon Emission Tomography (SPECT) functional brain imaging is Technetium 99 m-labeled Ethyl Cysteinate Dimer (ECD). ECD is a lipophilic compound with unique pharmacodynamics. It crosses the blood brain barrier and has high first pass extraction by the neurons proportional to regional brain perfusion at the time of injection. It reaches peak activity in the brain 1 min after injection and is then slowly cleared from the brain following a biexponential mode. This allows for a practical imaging window of 1 or 2 h after injection. In other words, it freezes a snapshot of brain perfusion at the time of injection that is kept and can be imaged later. This unique feature allows for designing functional brain imaging studies that do not require the patient to be inside the scanner at the time of brain activation. Functional brain imaging during severe burn wound care is an example that has been extensively studied using this technique. Not only does SPECT allow for imaging of brain activity under extreme pain conditions in clinical settings, but it also allows for imaging of brain activity modulation in response to analgesic maneuvers whether pharmacologic or non-traditional such as using virtual reality analgesia. Together with its utility in extreme situations, SPECTS is also helpful in investigating brain activation under typical pain conditions such as experimental controlled pain and chronic pain syndromes.

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Neurogenetics of Resilience

The Oxford Handbook of Positive Psychology, 3rd Edition ◽

10.1093/oxfordhb/9780199396511.013.58 ◽

2020 ◽

Author(s):

Adam Anderson ◽

Hans Melo

Keyword(s):

Functional Neuroimaging ◽

Brain Activity ◽

Activity Patterns ◽

Poor Mental Health ◽

Imaging Genetics ◽

Synthetic Approach ◽

Neural Basis ◽

Fine Grained ◽

Optimal Functioning ◽

Methodological Considerations

Our ability to recover from a negative experiences has profound implications not only for mental disorder but also for healthy living; while some individuals are deeply affected by life stressors and develop poor mental health, others seem to overcome even major traumatic events quickly and effortlessly. Critically, individual differences in resilience reflect underlying differences in the neural and genetic mechanisms implemented by different individuals to cope with hardship. Recent advances in functional neuroimaging and molecular genetics have given rise to a synthetic approach referred to as Imaging Genetics with great potential to develop a more fine-grained neurobiological characterization of optimal human functioning. The goal of imaging genetics is to identify mid-level phenotypes, or endophenotypes, in the form of brain activity patterns that reveal genetic influences on specific cognitive and emotional neural processes in the path from genes to behavior, and disorder. Recent years have seen increasing interest in understanding the genetic and neural basis of resilience. In this context, optimal functioning is not defined as the absence of disease but rather as the characteristics and conditions that allow a person to live well, thrive, and flourish. In this chapter we introduce the imaging genetics approach by providing methodological considerations, and discussing relevant studies and future directions as they may relate to resilience and the field of positive psychology in general.

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Maladaptive Plasticity in Aphasia: Brain Activation Maps Underlying Verb Retrieval Errors

Neural Plasticity ◽

10.1155/2016/4806492 ◽

2016 ◽

Vol 2016 ◽

pp. 1-11 ◽

Cited By ~ 1

Author(s):

Kerstin Spielmann ◽

Edith Durand ◽

Karine Marcotte ◽

Ana Inés Ansaldo

Keyword(s):

Language Impairment ◽

Functional Neuroimaging ◽

Brain Activation ◽

Naming Task ◽

Adaptive Plasticity ◽

Neural Basis ◽

Activation Patterns ◽

Maladaptive Plasticity ◽

Partial View ◽

Network Approaches

Anomia, or impaired word retrieval, is the most widespread symptom of aphasia, an acquired language impairment secondary to brain damage. In the last decades, functional neuroimaging techniques have enabled studying the neural basis underlying anomia and its recovery. The present study aimed to explore maladaptive plasticity in persistent verb anomia, in three male participants with chronic nonfluent aphasia. Brain activation maps associated with semantic verb paraphasia occurring within an oral picture-naming task were identified with an event-related fMRI paradigm. These maps were compared with those obtained in our previous study examining adaptive plasticity (i.e., successful verb naming) in the same participants. The results show that activation patterns related to semantic verb paraphasia and successful verb naming comprise a number of common areas, contributing to both maladaptive and adaptive neuroplasticity mechanisms. This finding suggests that the segregation of brain areas provides only a partial view of the neural basis of verb anomia and successful verb naming. Therefore, it indicates the importance of network approaches which may better capture the complexity of maladaptive and adaptive neuroplasticity mechanisms in anomia recovery.

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Attentional Bias Modification is associated with fMRI Response towards Negative Stimuli in Residual Depression: A Randomized Controlled Trial

10.1101/322842 ◽

2018 ◽

Cited By ~ 1

Author(s):

E. Hilland ◽

N.I. Landrø ◽

C. J. Harmer ◽

M. Browning ◽

L. A. Maglanoc ◽

...

Keyword(s):

Emotion Regulation ◽

Brain Activity ◽

Controlled Trial ◽

Brain Activation ◽

Anterior Cingulate ◽

Attentional Biases ◽

Depression Symptoms ◽

Affective States ◽

Neural Basis ◽

Attentional Bias Modification

AbstractBackgroundModification of attentional biases (ABM) may lead to more adaptive emotion perception and emotion regulation. Understanding the neural basis of these effects may lead to greater precision for future treatment development. Task-related fMRI following ABM training has so far not been investigated in depression. The main aim of the RCT was to explore differences in brain activity after ABM training in response to emotional stimuli.MethodsA total of 134 previously depressed individuals were randomized into 14 days of ABM- or a placebo training followed by an fMRI emotion regulation task. Depression symptoms and subjective ratings of perceived negativity during fMRI was examined between the training groups. Brain activation was explored within predefined areas (SVC) and across the whole brain. Activation in areas associated with changes in attentional biases (AB) and degree of depression was explored.ResultsThe ABM group showed reduced activation within the amygdala and within the anterior cingulate cortex (ACC) when passively viewing negative images compared to the placebo group. No group differences were found within predefined SVC’s associated with emotion regulation strategies. Response within the temporal cortices was associated with degree of change in AB and with degree of depressive symptoms in ABM versus placebo.LimitationsThe findings should be replicated in other samples of depressed patients and in studies using designs that allow analyses of within-group variability from baseline to follow-up.ConclusionsABM training has an effect on brain function within circuitry associated with emotional appraisal and the generation of affective states.Clinicaltrials.gov identifier: NCT02931487

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Behavior in the Brain

Journal of Psychophysiology ◽

10.1027/0269-8803/a000016 ◽

2010 ◽

Vol 24 (2) ◽

pp. 76-82 ◽

Cited By ~ 15

Author(s):

Martin M. Monti ◽

Adrian M. Owen

Keyword(s):

Motor Behavior ◽

Functional Neuroimaging ◽

Brain Activity ◽

Motor Output ◽

The Unconscious ◽

Ethical Implications ◽

Brain Responses ◽

Minimally Conscious ◽

Brain Insults ◽

Brain Behavior

Recent evidence has suggested that functional neuroimaging may play a crucial role in assessing residual cognition and awareness in brain injury survivors. In particular, brain insults that compromise the patient’s ability to produce motor output may render standard clinical testing ineffective. Indeed, if patients were aware but unable to signal so via motor behavior, they would be impossible to distinguish, at the bedside, from vegetative patients. Considering the alarming rate with which minimally conscious patients are misdiagnosed as vegetative, and the severe medical, legal, and ethical implications of such decisions, novel tools are urgently required to complement current clinical-assessment protocols. Functional neuroimaging may be particularly suited to this aim by providing a window on brain function without requiring patients to produce any motor output. Specifically, the possibility of detecting signs of willful behavior by directly observing brain activity (i.e., “brain behavior”), rather than motoric output, allows this approach to reach beyond what is observable at the bedside with standard clinical assessments. In addition, several neuroimaging studies have already highlighted neuroimaging protocols that can distinguish automatic brain responses from willful brain activity, making it possible to employ willful brain activations as an index of awareness. Certainly, neuroimaging in patient populations faces some theoretical and experimental difficulties, but willful, task-dependent, brain activation may be the only way to discriminate the conscious, but immobile, patient from the unconscious one.

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Emotional Reactivity to Visual Content as Revealed by ERP Component Clustering

Journal of Psychophysiology ◽

10.1027/0269-8803/a000145 ◽

2015 ◽

Vol 29 (4) ◽

pp. 135-146 ◽

Cited By ~ 3

Author(s):

Miroslaw Wyczesany ◽

Szczepan J. Grzybowski ◽

Jan Kaiser

Keyword(s):

Emotional Reactivity ◽

Brain Activity ◽

Affective State ◽

Occipital Lobe ◽

Stimulus Onset ◽

Emotional States ◽

Neural Basis ◽

Temporoparietal Junction ◽

The Right ◽

The Impact

Abstract. In the study, the neural basis of emotional reactivity was investigated. Reactivity was operationalized as the impact of emotional pictures on the self-reported ongoing affective state. It was used to divide the subjects into high- and low-responders groups. Independent sources of brain activity were identified, localized with the DIPFIT method, and clustered across subjects to analyse the visual evoked potentials to affective pictures. Four of the identified clusters revealed effects of reactivity. The earliest two started about 120 ms from the stimulus onset and were located in the occipital lobe and the right temporoparietal junction. Another two with a latency of 200 ms were found in the orbitofrontal and the right dorsolateral cortices. Additionally, differences in pre-stimulus alpha level over the visual cortex were observed between the groups. The attentional modulation of perceptual processes is proposed as an early source of emotional reactivity, which forms an automatic mechanism of affective control. The role of top-down processes in affective appraisal and, finally, the experience of ongoing emotional states is also discussed.

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