scholarly journals Antero-posterior versus lateral vestibular input processing in human visual cortex

2019 ◽  
Author(s):  
Felipe Aedo-Jury ◽  
Benoit R. Cottereau ◽  
Simona Celebrini ◽  
Alexandra Séverac Cauquil
Keyword(s):  
Optic Flow ◽  
Insular Cortex ◽  
Vestibular Stimulation ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Vestibular Input ◽  
Middle Temporal ◽  
Input Processing ◽  
Psychophysiological Interaction ◽  
Functional Areas

AbstractVisuo-vestibular integration is crucial for locomotion, yet cortical mechanisms involved remain poorly understood. We combined binaural monopolar galvanic vestibular stimulation (GVS) and functional magnetic resonance imaging (fMRI) to characterize the cortical networks activated during antero-posterior and lateral stimulations in humans. We focused on functional areas that selectively respond to egomotion-consistent optic flow patterns: the human middle temporal complex (hMT+), V6, the ventral intraparietal (VIP) area, the cingulate sulcus visual (CSv) area and the posterior insular cortex (PIC). Areas hMT+, CSv, and PIC were equivalently responsive during lateral and antero-posterior GVS while areas VIP and V6 were highly activated during antero-posterior GVS but remained silent during lateral GVS. Using psychophysiological interaction (PPI) analyses, we confirmed that a cortical network including areas V6 and VIP is engaged during antero-posterior GVS. Our results suggest that V6 and VIP play a specific role in processing multisensory signals specific to locomotion during navigation.

The cerebral representation of scratching-induced pleasantness

2014 ◽  
Vol 111 (3) ◽  
pp. 488-498 ◽  
Author(s):  
Hideki Mochizuki ◽  
Satoshi Tanaka ◽  
Tomoyo Morita ◽  
Toshiaki Wasaka ◽  
Norihiro Sadato ◽  
...  
Keyword(s):  
Supplementary Motor Area ◽  
Premotor Cortex ◽  
Imaging Study ◽  
Insular Cortex ◽  
Reward System ◽  
Magnetic Resonance Imaging Study ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Significant Activation ◽  
Cerebral Mechanisms

Itch is an unpleasant sensation with the desire to scratch. Although it is well known that scratching itchy skin is pleasurable, the cerebral mechanisms underlying this phenomenon are poorly understood. We hypothesized that the reward system is associated with scratching-induced pleasantness. To investigate this hypothesis, a functional magnetic resonance imaging study was performed in 16 healthy subjects. Pleasantness was evoked by scratching the wrists where itch stimuli were applied, while scratching the dorsal forearms, far from itch stimuli, did not evoke pleasantness. Interestingly, pleasantness evoked by scratching activated not only the reward system (i.e., the striatum and midbrain) but also key regions of perception (i.e., the primary somatosensory cortex) and awareness of subjective feelings (i.e., the insular cortex), indicating that a broad network is involved in scratching-induced pleasantness. Moreover, although itch was suppressed by scratching, motor-related regions such as the supplementary motor area, premotor cortex, and cerebellum showed significant activation when pleasantness was evoked. This activation could explain why scratching-induced pleasantness potentially reinforces scratching behaviors. This study is the first to identify networks activated by scratching-induced pleasantness. The results of the present study provide important information on the cerebral mechanisms underlying why scratching itchy skin evokes pleasurable feelings that reinforce scratching behaviors.

Vestibular and visual responses in human posterior insular cortex

2014 ◽  
Vol 112 (10) ◽  
pp. 2481-2491 ◽  
Author(s):  
Sebastian M. Frank ◽  
Oliver Baumann ◽  
Jason B. Mattingley ◽  
Mark W. Greenlee
Keyword(s):  
Visual Motion ◽  
Insular Cortex ◽  
Vestibular Stimulation ◽  
Visual Responses ◽  
Functional Magnetic Resonance ◽  
Vestibular Information ◽  
Perception Of Self ◽  
Self Motion ◽  
Similar Location ◽  
Trial Participants

The central hub of the cortical vestibular network in humans is likely localized in the region of posterior lateral sulcus. An area characterized by responsiveness to visual motion has previously been described at a similar location and named posterior insular cortex (PIC). Currently it is not known whether PIC processes vestibular information as well. We localized PIC using visual motion stimulation in functional magnetic resonance imaging (fMRI) and investigated whether PIC also responds to vestibular stimuli. To this end, we designed an MRI-compatible caloric stimulation device that allowed us to stimulate bithermally with hot temperature in one ear and simultaneously cold temperature in the other or with warm temperatures in both ears for baseline. During each trial, participants indicated the presence or absence of self-motion sensations. We found activation in PIC during periods of self motion when vestibular stimulation was carried out with minimal visual input. In combined visual-vestibular stimulation area PIC was activated in a similar fashion during congruent and incongruent stimulation conditions. Our results show that PIC not only responds to visual motion but also to vestibular stimuli related to the sensation of self motion. We suggest that PIC is part of the cortical vestibular network and plays a role in the integration of visual and vestibular stimuli for the perception of self motion.

scholarly journals Neural correlates of syntax production in schizophrenia

2005 ◽  
Vol 186 (3) ◽  
pp. 209-214 ◽  
Author(s):  
Tilo T. J. Kircher ◽  
Tomasina M. Oh ◽  
Michael J. Brammer ◽  
Philip K. McGuire
Keyword(s):  
Magnetic Resonance Imaging ◽  
Neural Correlates ◽  
Control Group ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Posterior Portion ◽  
Middle Temporal ◽  
Complex Sentences ◽  
The Right ◽  
Superior Frontal Cortex

BackgroundThe production of grammatically complex sentences is impaired in schizophrenia. It has been suggested that impaired syntax processing reflects a risk for the disorder.AimsTo examine the neural correlates of syntax production in people with schizophrenia using functional magnetic resonance imaging (fMRI).MethodSix patients with schizophrenia and six healthy volunteers spoke about seven Rorschach inkblots for 3 min each while correlates of brain activation were measured with fMRI. Participants produced varying amounts of syntactically simple and complex sentences during each 3 min run. The number of simple and complex sentences was correlated separately with the BOLD contrast.ResultsIn the comparison between the control group and the patient group, the number of complex sentences produced was correlated with activation in the posterior portion of the right middle temporal (Brodmann area 21) and left superior frontal (BA 10) gyri in the control group but not in the patients.ConclusionsThe absence of activation in the right posterior temporal and left superior frontal cortex in patients with schizophrenia might contribute to the articulation of grammatically more simple speech in people with this disorder.

scholarly journals Cannabis affects people differently: inter-subject variation in the psychotogenic effects of Δ9-tetrahydrocannabinol: a functional magnetic resonance imaging study with healthy volunteers

2012 ◽  
Vol 43 (6) ◽  
pp. 1255-1267 ◽  
Author(s):  
Z. Atakan ◽  
S. Bhattacharyya ◽  
P. Allen ◽  
R. Martín-Santos ◽  
J. A. Crippa ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Healthy Volunteers ◽  
Temporal Cortex ◽  
Psychotic Symptoms ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Middle Temporal ◽  
The Right

BackgroundCannabis can induce transient psychotic symptoms, but not all users experience these adverse effects. We compared the neural response to Δ9-tetrahydrocannabinol (THC) in healthy volunteers in whom the drug did or did not induce acute psychotic symptoms.MethodIn a double-blind, placebo-controlled, pseudorandomized design, 21 healthy men with minimal experience of cannabis were given either 10 mg THC or placebo, orally. Behavioural and functional magnetic resonance imaging measures were then recorded whilst they performed a go/no-go task.ResultsThe sample was subdivided on the basis of the Positive and Negative Syndrome Scale positive score following administration of THC into transiently psychotic (TP; n = 11) and non-psychotic (NP; n = 10) groups. During the THC condition, TP subjects made more frequent inhibition errors than the NP group and showed differential activation relative to the NP group in the left parahippocampal gyrus, the left and right middle temporal gyri and in the right cerebellum. In these regions, THC had opposite effects on activation relative to placebo in the two groups. The TP group also showed less activation than the NP group in the right middle temporal gyrus and cerebellum, independent of the effects of THC.ConclusionsIn this first demonstration of inter-subject variability in sensitivity to the psychotogenic effects of THC, we found that the presence of acute psychotic symptoms was associated with a differential effect of THC on activation in the ventral and medial temporal cortex and cerebellum, suggesting that these regions mediate the effects of the drug on psychotic symptoms.

scholarly journals Anterior insular cortex plays a critical role in interoceptive attention

2018 ◽  
Author(s):  
Xingchao Wang ◽  
Qiong Wu ◽  
Laura Egan ◽  
Xiaosi Gu ◽  
Pinan Liu ◽  
...  
Keyword(s):  
Critical Role ◽  
Insular Cortex ◽  
The Body ◽  
Physiological Signals ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Discrimination Accuracy ◽  
Anterior Insular Cortex ◽  
Interoceptive Accuracy ◽  
Healthy Participants

AbstractAlthough accumulating evidence indicates that the anterior insular cortex (AIC) mediates interoceptive attention, which refers the attention towards physiological signals arising from the body, the necessity of the AIC in this process has not been demonstrated. Using a novel task that directs attention toward breathing rhythm, we assessed the involvement of the AIC in interoceptive attention in healthy participants using functional magnetic resonance imaging and examined the necessity of the AIC in interoceptive attention in patients with AIC lesions. We found that interoceptive attention was associated with greater AIC activation, as well as enhanced coupling between the AIC and somatosensory area along with reduced coupling between AIC and visual sensory areas. AIC activation and connectivity were predictive of individual differences in interoceptive accuracy. Importantly, AIC lesion patients showed disrupted interoceptive discrimination accuracy and sensitivity. Together, these results provide compelling evidence that AIC plays a critical role in interoceptive attention.

Monitoring of Motor Nerve Function Rehabilitation in Patients with Upper Extremity Hemiplegia Based on Functional Magnetic Resonance Imaging

2021 ◽  
Vol 11 (6) ◽  
pp. 1761-1770
Author(s):  
Ding Zhang ◽  
Gang Liu ◽  
Liemi Huang ◽  
Lun Zhang ◽  
Xinghua Gui ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Data Collection ◽  
Functional Magnetic Resonance Imaging ◽  
Motor Function ◽  
Motor Nerve ◽  
Fmri Data ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Functional Areas

Through functional magnetic resonance imaging (fMRI) technology, it is planned to use complex brain network technology to track brain functional imaging tracking treatment of stroke hemiplegia with scalp acupuncture. Functional magnetic resonance imaging (fMRI) can continuously monitor the rehabilitation process of motor nerve function in patients with stroke and upper limb hemiplegia, and explore the mechanism of brain plasticity changes at different levels of neural function cortex, motor function neural circuit, and behavior level. First, the fMRI test uses a block design, and the subjects complete the movement of the thumb and index finger. After completing the dysfunction assessment, fMRI data collection was performed on the patient before the CIMT treatment using a magnetic resonance apparatus, and a second fMRI data collection was performed 2 weeks after the CIMT treatment; only one fMRI data collection was performed on the volunteers. The functional magnetic resonance data was processed using the AFNI software package, and the functional scores of subjects were calculated using SPSS software. Second, studying the remodeling of residual brain tissue and functional compensation pathways can help to further clarify the recovery mechanism of motor function after stroke hemiplegia. Finally, compulsory exercise therapy can effectively improve upper limb motor dysfunction in stroke patients. The forced use of upper extremities during treatment induces the reorganization and compensation of cerebral cortical functional areas. This change in brain functional areas is consistent with the increase of upper extremity movement and improvement of motor function, fMRI can provide neuronal reorganization after exercise therapy evidence with compensation.

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