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Physiology of Equilibrium
Published in John C Watkinson, Raymond W Clarke, Christopher P Aldren, Doris-Eva Bamiou, Raymond W Clarke, Richard M Irving, Haytham Kubba, Shakeel R Saeed, Paediatrics, The Ear, Skull Base, 2018
Floris L. Wuyts, Leen K. Maes, An Boudewyns
The insular cortex is a part of the cerebral cortex folded deep within the lateral sulcus and is believed to have a main role in the processing of vestibular signals.48,49 Moreover, a predominant role of the right hemisphere in the cortical processing of vestibular afferents has also been proven in the meta-analysis by zu Eulenburg et al. 47 More specifically, zu Eulenburg et al. suggest that operculum parietale 2, a histological defined part of the human parietal operculum in the right hemisphere, is the core region of the human vestibular cortex and possibly processes only vestibular information instead of multisensory input. Recently, changes in the vestibular cortex have been shown in an astronaut returning from space.50 Space is a unique lab to investigate the effect of unusual physiological stimuli on the human body such as weightlessness. These preliminary findings corroborate the concept of neuroplasticity and may guide further research to find possible causes in the brain of vestibular disorders such as visual vestibular mismatch among others. Until recently, many vestibular dysfunctions were traditionally attributed to peripheral vestibular lesions, but the brain will become more and more important in vestibular physiology.
The cortical processing of pain
Published in Camille Chatelle, Steven Laureys, Assessing Pain and Communication in Disorders of Consciousness, 2015
Several studies have recorded local field potentials (LFPs) elicited by transient nociceptive stimuli within different areas of the brain of awake humans, using surgically implanted intracranial electrodes or subdural electrode grids (Peyron et al., 2002). These studies have demonstrated that brief thermal stimuli above the thermal activation threshold of A-delta and C fibres elicit responses in the left and right suprasylvian opercular region (Frot & Mauguiere, 1999, 2003; Frot, Rambaud, Guenot, & Mauguiere, 1999). The latency of the response coincides with the latency of the N1 and N2 waves of nociceptive ERPs. Interestingly, researchers observed a delay of approximately 15 ms between the responses elicited in the ipsilateral and contralateral hemispheres. Furthermore, the studies showed that thermal stimuli probably elicit two temporally distinct responses within the suprasylvian region: an early response originating from the parietal operculum, followed by a later response originating from the insula.
Functional Magnetic Resonance Imaging of the Human Motor Cortex
Published in Alexa Riehle, Eilon Vaadia, Motor Cortex in Voluntary Movements, 2004
Andreas Kleinschmidt, Ivan Toni
So far, one of the few studies using on-line EMG recordings during fMRI of motor imagery was that of Hanakawa et al.,116 and they did not find significant M1 activation. However, they used an interesting analytical approach. Instead of qualitatively mapping activation under different conditions with a somewhat arbitrary threshold, the authors addressed the quantitative relation of activation effects under imagery and execution of movement. They determined areas with movement-predominant activity, imagery-predominant activity, and activity common to both movement and imagery modes of performance (movement-and-imagery activity). The movement-predominant activity included the primary sensory and motor areas, the parietal operculum, and the anterior cerebellum, which had little imagery-related activity (-0.1~0.1%), and the caudal premotor areas and Brodmann area 5, which
Seizure and cognitive outcomes of posterior quadrantic disconnection: a series of 12 pediatric patients
Published in British Journal of Neurosurgery, 2020
Yao Wang, Chao Zhang, Xiu Wang, Lin Sang, Feng Zhou, Jian-Guo Zhang, Wen-Han Hu, Kai Zhang
Similar to the description of Daniel et al.,2 the surgeries in our centre included the following procedures:(1) Stage I: Periinsular window: After a ‘barn-door’ incision on the scalp, the bone flap was cut and the dura was cut open. The superior temporal gyrus (T1) was coagulated approximately 5–8 mm from the sylvian fissure. Then, the full length of the T1 was cut open and removed. The full length of the inferior limiting sulcus was exposed. Along the inferior limiting sulcus, the temporal stem was disconnected towards the temporal horn of the lateral ventricle. Towards the posterior part of the temporal horn, the atrium was exposed. In this region, it was easy to locate the cortex of the parietal operculum and posterior superior limiting sulcus. After disconnection of the posterior corona radiata through the posterior superior limiting sulcus, the body of the lateral ventricle was exposed.
Physical Pain as Pleasure: A Theoretical Perspective
Published in The Journal of Sex Research, 2020
Cara R. Dunkley, Craig D. Henshaw, Saira K. Henshaw, Lori A. Brotto
One study compared masochists to nonmasochists in their brain responses (with functional magnetic resonance imaging [fMRI]) after they viewed painful stimuli paired with masochistic visual stimuli (Kamping et al., 2016). Emotionally neutral, positive, and negative pictures paired with and without painful stimuli were used as a control. Self-identified masochists reported lower pain intensity and pain unpleasantness ratings when painful stimuli was induced within a masochistic context, with the reduction in pain perception comparable to that of opioids (Furlan, Sandoval, Mailis-Gagnon, & Tunks, 2006). No difference in pain ratings between masochists and nonmasochistic controls emerged when other positive, negative, or neutral emotional context was present, indicating that differential pain ratings were exclusive to the masochistic context. Neurologically, the brain activation patterns of masochists observed when painful stimuli was paired with a visual masochistic context showed increased activity in the parietal operculum, which is involved in pain processing, as well as somatosensory and visual integration. Further, the parietal operculum is associated with Pavlovian nociceptive conditioning and emotional memories, suggesting that the neural patterns observed may be acquired, emerging as a result of emotional memories involving positive masochistic experiences (Sacco & Sacchetti, 2010). The parietal operculum also showed attenuated functional connectivity with the left and right insulae, the central operculum, and the supramarginal gyrus—brain regions involved in the affective-motivational aspects of pain processing. These findings demonstrate that the operculum serves as a key relay station for conveying somatosensory input to the limbic system, influencing the emotional-motivational aspects of pain in masochists.
Hypnotic Automaticity in the Brain at Rest: An Arterial Spin Labelling Study
Published in International Journal of Clinical and Experimental Hypnosis, 2019
Pierre Rainville, Anouk Streff, Jen-I Chen, Bérengère Houzé, Carolane Desmarteaux, Mathieu Piché
Importantly, the coactivation analysis further supports the notion that changes in PO activity relate to a brain network involving the mid and anterior cingulate cortices and the inferior frontal cortex (Table 3). These areas are part of the executive network of the brain broadly construed. Interestingly, coactivation of the anterior cingulate cortex and the inferior parietal cortex has also been reported at very similar locations during hypnosis-induced limb paralysis, with unsuccessful efforts to move the paralyzed arm associated with increased activity in the anterior cingulate cortex and adjacent supplementary motor area (see Tables 2a and 3b in Deeley et al., 2013; also see ACC activation in Burgmer et al., 2013). Using a lesion mapping method, a recent report showed that the dorsal anterior cingulate region constitutes a core of functional networks including the parietal operculum and underlying the experience of volition (Darby et al., 2018). Lesions to the dorsal anterior cingulate area produce deficits in self-generated goal-directed actions (Cohen, Kaplan, Moser, Jenkins, & Wilkinson, 1999), while electrical stimulation of this area during neurosurgical procedures may produce subjective experiences of urges to act or persevere (Parvizi, Rangarajan, Shirer, Desai, & Greicius, 2013). Theoretical accounts of the function of the dorsal ACC have suggested a key role in conflict monitoring, evaluative processes, and cognitive control (e.g., Carter, Botvinick, & Cohen, 1999; Shackman et al., 2011). Recent models further integrate a motivational perspective, suggesting that the ACC regulates control processes based on the cost-benefit analysis (i.e. value) of allocating executive resources (Shenhav, Cohen, & Botvinick, 2016). Interestingly, this value-based process of executive engagement is also suggested to translate into a subjective experience of mental effort (Shenhav et al., 2017), another experiential dimension relevant to hypnosis phenomenology (Polito et al., 2013). These findings have direct implication for the current models of hypnosis and reinforce the proposition that hypnosis is a relevant experimental model to study and test neuro-cognitive/phenomenological theories of consciousness and brain function (Rainville & Price, 2003; Raz & Shapiro, 2002; Terhune, Cleeremans, Raz, & Lynn, 2017).