Distinct Neural Correlates for Volitional Generation and Inhibition of Saccades

2010 ◽  
Vol 22 (4) ◽  
pp. 728-738 ◽  
Author(s):  
Benedikt Reuter ◽  
Christian Kaufmann ◽  
Julia Bender ◽  
Thomas Pinkpank ◽  
Norbert Kathmann
Keyword(s):  
Neural Correlates ◽  
Blood Oxygen Level Dependent ◽  
Blood Oxygen Level ◽  
Clinical Neuroscience ◽  
Fmri Study ◽  
Dependent Signal ◽  
Supplementary Eye Fields ◽  
Reflexive Saccades ◽  
Saccade Generation

The antisaccade task has proven highly useful in basic and clinical neuroscience, and the neural structures involved are well documented. However, the cognitive and neural mechanisms that mediate task performance are not yet understood. An event-related fMRI study was designed to dissociate the neural correlates of two putative key functions, volitional saccade generation and inhibition of reflexive saccades, and to investigate their interaction. Nineteen healthy volunteers performed a task that required (a) to initiate saccades volitionally, either with or without a simultaneous demand to inhibit a reflexive saccade; and (b) to inhibit a reflexive saccade, either with or without a simultaneous demand to initiate a saccade volitionally. Analysis of blood oxygen level-dependent signal changes confirmed a major role of the frontal eye fields and the supplementary eye fields in volitional saccade generation. Inhibition-related activation of a specific fronto-parietal network was highly consistent with previous evidence involved in inhibitory processes. Unexpectedly, there was little evidence of specific brain activation during combined generation and inhibition demands, suggesting that the neural processing of generation and inhibition in antisaccades is independent to a large extent.

The Relationship of Three Cortical Regions to an Information-Processing Model

2004 ◽  
Vol 16 (4) ◽  
pp. 637-653 ◽  
Author(s):  
John R. Anderson ◽  
Yulin Qin ◽  
V. Andrew Stenger ◽  
Cameron S. Carter
Keyword(s):  
Region Of Interest ◽  
Blood Oxygen Level Dependent ◽  
Blood Oxygen Level ◽  
Information Processing Model ◽  
Response Hand ◽  
Equation Solving ◽  
Fmri Study ◽  
Cortical Regions ◽  
Relationship Of

This research tests a model of the computational role of three cortical regions in tasks like algebra equation solving. The model assumes that there is a left parietal region-of-interest (ROI) where the problem expression is represented and transformed, a left prefrontal ROI where information for solving the task is retrieved, and a motor ROI where hand movements to produce the answer are programmed. A functional magnetic resonance imaging (fMRI) study of an abstract symbolmanipulation task was performed to articulate the roles of these three regions. Participants learned to associate words with instructions for transforming strings of letters. The study manipulated the need to retrieve these instructions, the need to transform the strings, and whether there was a delay between calculation of the answer and the output of the answer. As predicted, the left parietal ROI mainly reflected the need for a transformation and the left prefrontal ROI the need for retrieval. Homologous right ROIs showed similar but weaker responses. Neither the prefrontal nor the parietal ROIs responded to delay, but the motor ROI did respond to delay, implying motor rehearsal over the delay. Except for the motor ROI, these patterns of activity did not vary with response hand. In an ACT-R model, it was shown that the activity of an imaginal buffer predicted the blood oxygen level-dependent (BOLD) response of the parietal ROI, the activity of a retrieval buffer predicted the response of the prefrontal ROI, and the activity of a manual buffer predicted the response of the motor ROI.

scholarly journals Effects of Age on Prestimulus Neural Activity Predictive of Successful Memory Encoding: An fMRI Study

2020 ◽  
Author(s):  
E Song Liu ◽  
Joshua D Koen ◽  
Michael D Rugg
Keyword(s):  
Neural Activity ◽  
Memory Performance ◽  
Blood Oxygen Level Dependent ◽  
Angular Gyrus ◽  
Blood Oxygen Level ◽  
Age Related ◽  
Fmri Study ◽  
Left Hippocampus ◽  
Dependent Signal ◽  
Left Angular Gyrus

Abstract Prestimulus subsequent memory effects (SMEs)—differences in neural activity preceding the onset of study items that are predictive of later memory performance—have consistently been reported in young adults. The present functional magnetic resonance imaging experiment investigated potential age-related differences in prestimulus SMEs. During study, healthy young and older participants made one of two semantic judgments on images, with the judgment signaled by a preceding cue. In test phase, participants first made an item recognition judgment and, for each item judged old, a source memory judgment. Age-invariant prestimulus SMEs were observed in left dorsomedial prefrontal cortex, left hippocampus, and right subgenual cortex. In each case, the effects reflected lower blood oxygen level dependent signal for later recognized items, regardless of source accuracy, than for unrecognized items. A similar age-invariant pattern was observed in left orbitofrontal cortex, but this effect was specific to items attracting a correct source response compared to unrecognized items. In contrast, the left angular gyrus and fusiform cortex demonstrated negative prestimulus SMEs that were exclusive to young participants. The findings indicate that age differences in prestimulus SMEs are regionally specific and suggest that prestimulus SMEs reflect multiple cognitive processes, only some of which are vulnerable to advancing age.

Motor and Limbic System Contribution to Emotional Laughter across the Lifespan

2019 ◽  
Vol 30 (5) ◽  
pp. 3381-3391
Author(s):  
Francesca Talami ◽  
Anna Elisabetta Vaudano ◽  
Stefano Meletti
Keyword(s):  
Real Life ◽  
Neural Correlates ◽  
Blood Oxygen Level Dependent ◽  
Anterior Cingulate ◽  
Blood Oxygen Level ◽  
Close Link ◽  
Reward Circuitry ◽  
Frontal Operculum ◽  
Neuroimaging Techniques

Abstract Laughter is a universal human behavior generated by the cooperation of different systems toward the construction of an expressive vocal pattern. Given the sensitivity of neuroimaging techniques to movements, the neural mechanisms underlying laughter expression remain unclear. Herein, we characterized the neural correlates of emotional laughter using the onsets and the duration of laughter bursts to inform functional magnetic resonance imaging. Laughter-related blood oxygen level-dependent (BOLD) increases involved both the motor (motor cortex, supplementary motor area, frontal operculum) and the emotional/limbic (anterior cingulate cortex, amygdala, n. accumbens, hippocampus) systems, as well as modulatory circuitries encompassing the basal ganglia, thalamus, and cerebellum. BOLD changes related to the 2 s preceding the laughter outbreak were selectively observed at the temporo-occipital junction and the periaqueductal gray matter, supporting the role of the former in the detection of incongruity and the gating role of the latter in the initiation of spontaneous laughter. Moreover, developmental changes were identified in laughter processing, consisting in a greater engagement of the reward circuitry in younger subjects; conversely, the default mode network appears more activated in older participants. Our findings contribute valuable information about the processing of real-life humorous materials and suggest a close link between laughter-related motor, affective, and cognitive elements, confirming its complex and multi-faceted nature.

scholarly journals Neural representations of own-voice in the human auditory cortex

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Taishi Hosaka ◽  
Marino Kimura ◽  
Yuko Yotsumoto
Keyword(s):  
Auditory Cortex ◽  
Superior Temporal Gyrus ◽  
Neural Correlates ◽  
Blood Oxygen Level Dependent ◽  
Blood Oxygen ◽  
Oxygen Level ◽  
Blood Oxygen Level ◽  
Neural Representations ◽  
Human Auditory Cortex ◽  
The Voice

AbstractWe have a keen sensitivity when it comes to the perception of our own voices. We can detect not only the differences between ourselves and others, but also slight modifications of our own voices. Here, we examined the neural correlates underlying such sensitive perception of one’s own voice. In the experiments, we modified the subjects’ own voices by using five types of filters. The subjects rated the similarity of the presented voices to their own. We compared BOLD (Blood Oxygen Level Dependent) signals between the voices that subjects rated as least similar to their own voice and those they rated as most similar. The contrast revealed that the bilateral superior temporal gyrus exhibited greater activities while listening to the voice least similar to their own voice and lesser activation while listening to the voice most similar to their own. Our results suggest that the superior temporal gyrus is involved in neural sharpening for the own-voice. The lesser degree of activations observed by the voices that were similar to the own-voice indicates that these areas not only respond to the differences between self and others, but also respond to the finer details of own-voices.

Motor network recovery in patients with chronic spinal cord compression: a longitudinal study following decompression surgery

2018 ◽  
Vol 28 (4) ◽  
pp. 379-388 ◽  
Author(s):  
Kayla Ryan ◽  
Sandy Goncalves ◽  
Robert Bartha ◽  
Neil Duggal
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Compression ◽  
Surgical Intervention ◽  
Blood Oxygen Level Dependent ◽  
Cord Compression ◽  
Decompression Surgery ◽  
Blood Oxygen Level ◽  
Motor Network ◽  
Dependent Signal

OBJECTIVEThe authors used functional MRI to assess cortical reorganization of the motor network after chronic spinal cord compression and to characterize the plasticity that occurs following surgical intervention.METHODSA 3-T MRI scanner was used to acquire functional images of the brain in 22 patients with reversible cervical spinal cord compression and 10 control subjects. Controls performed a finger-tapping task on 3 different occasions (baseline, 6-week follow-up, and 6-month follow-up), whereas patients performed the identical task before surgery and again 6 weeks and 6 months after spinal decompression surgery.RESULTSAfter surgical intervention, an increased percentage blood oxygen level–dependent signal and volume of activation was observed within the contralateral and ipsilateral motor network. The volume of activation of the contralateral primary motor cortex was associated with functional measures both at baseline (r = 0.55, p < 0.01) and 6 months after surgery (r = 0.55, p < 0.01). The percentage blood oxygen level–dependent signal of the ipsilateral supplementary motor area 6 months after surgery was associated with increased function 6 months after surgery (r = 0.48, p < 0.01).CONCLUSIONSPlasticity of the contralateral and ipsilateral motor network plays complementary roles in maintaining neurological function in patients with spinal cord compression and may be critical in the recovery phase following surgery.

scholarly journals Aberrant blood-oxygen-level-dependent signal oscillations across frequency bands characterize the alcoholic brain

2017 ◽  
Vol 23 (2) ◽  
pp. 824-835 ◽  
Author(s):  
Jui-Yang Hong ◽  
Eva M. Müller-Oehring ◽  
Adolf Pfefferbaum ◽  
Edith V. Sullivan ◽  
Dongjin Kwon ◽  
...  
Keyword(s):  
Blood Oxygen Level Dependent ◽  
Blood Oxygen ◽  
Oxygen Level ◽  
Blood Oxygen Level ◽  
Frequency Bands ◽  
Dependent Signal

scholarly journals fMRI of the rod scotoma elucidates cortical rod pathways and implications for lesion measurements

2015 ◽  
Vol 112 (16) ◽  
pp. 5201-5206 ◽  
Author(s):  
Brian Barton ◽  
Alyssa A. Brewer
Keyword(s):  
Blood Oxygen Level Dependent ◽  
Cortical Reorganization ◽  
Blood Oxygen Level ◽  
Short Term ◽  
Traumatic Lesion ◽  
Electrophysiological Studies ◽  
Short Term Adaptation ◽  
Early Visual Cortex ◽  
Dependent Signal

Are silencing, ectopic shifts, and receptive field (RF) scaling in cortical scotoma projection zones (SPZs) the result of long-term reorganization (plasticity) or short-term adaptation? Electrophysiological studies of SPZs after retinal lesions in animal models remain controversial, because they are unable to conclusively answer this question because of limitations of the methodology. Here, we used functional MRI (fMRI) visual field mapping through population RF (pRF) modeling with moving bar stimuli under photopic and scotopic conditions to measure the effects of the rod scotoma in human early visual cortex. As a naturally occurring central scotoma, it has a large cortical representation, is free of traumatic lesion complications, is completely reversible, and has not reorganized under normal conditions (but can as seen in rod monochromats). We found that the pRFs overlapping the SPZ in V1, V2, V3, hV4, and VO-1 generally (i) reduced their blood oxygen level-dependent signal coherence and (ii) shifted their pRFs more eccentric but (iii) scaled their pRF sizes in variable ways. Thus, silencing, ectopic shifts, and pRF scaling in SPZs are not unique identifiers of cortical reorganization; rather, they can be the expected result of short-term adaptation. However, are there differences between rod and cone signals in V1, V2, V3, hV4, and VO-1? We did not find differences for all five maps in more peripheral eccentricities outside of rod scotoma influence in coherence, eccentricity representation, or pRF size. Thus, rod and cone signals seem to be processed similarly in cortex.

scholarly journals Role of blood oxygen level-dependent MRI in differentiation of acute renal allograft dysfunction

2018 ◽  
Vol 28 (6) ◽  
pp. 441
Author(s):  
Hira Lal ◽  
Ezaz Mohamed ◽  
Neelam Soni ◽  
Priyank Yadav ◽  
Manoj Jain ◽  
...  
Keyword(s):  
Renal Allograft ◽  
Blood Oxygen Level Dependent ◽  
Blood Oxygen ◽  
Oxygen Level ◽  
Blood Oxygen Level ◽  
Allograft Dysfunction
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