scholarly journals Finger representations in primary somatosensory cortex are modulated during vibrotactile working memory

2021 ◽  
Author(s):  
Finn Rabe ◽  
Sanne Kikkert ◽  
Nicole Wenderoth
Keyword(s):  
Working Memory ◽  
Somatosensory Cortex ◽  
Pattern Analysis ◽  
Blood Oxygen Level Dependent ◽  
Brain Regions ◽  
Delay Period ◽  
Blood Oxygen Level ◽  
Secondary Somatosensory Cortex ◽  
Analysis Technique ◽  
Hand Area

It is well-established that vibrotactile stimulations elicit Blood-oxygen-level-dependent (BOLD) responses in somatotopically organized brain regions. Whether these somatotopic maps are modulated by working memory (WM) is still unknown. In our WM experiment, participants had to compare frequencies that were separated by a delay period. Vibrotactile stimuli were sequentially applied to either their right index or little finger. Using functional MRI, we investigated whether vibrotactile WM modulated neural activity in primary somatosensory (S1), an area that is known to contain individual finger representations. Our mass-univariate results revealed the well-described network of brain regions involved in WM. Interestingly, our mass-univariate results did not demonstrate S1 to be part of this network. However, when we parametrically modulated the time-binned regressors in our GLM we found that the delay activity in S1 and secondary somatosensory cortex (S2) was reflected in a U-shaped manner. Using multi-voxel pattern analysis (MVPA), an analysis technique that is more sensitive to subtle activity differences, we found finger-specific patterns of activation in the S1 hand area during the WM delay period. These results indicate that processes underlying WM modulate finger-specific representations during our discrimination task.

scholarly journals Brain reactivity using fMRI to insomnia stimuli in insomnia patients with discrepancy between subjective and objective sleep

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Young-Bo Kim ◽  
Nambeom Kim ◽  
Jae Jun Lee ◽  
Seo-Eun Cho ◽  
Kyoung-Sae Na ◽  
...  
Keyword(s):  
Brain Activity ◽  
Blood Oxygen Level Dependent ◽  
Brain Regions ◽  
Cognitive Distortion ◽  
Sleep Diary ◽  
Bold Signal ◽  
Blood Oxygen Level ◽  
General Anxiety ◽  
Sleep Deficit ◽  
Perception Of Sleep

AbstractSubjective–objective discrepancy of sleep (SODS) might be related to the distorted perception of sleep deficit and hypersensitivity to insomnia-related stimuli. We investigated differences in brain activation to insomnia-related stimuli among insomnia patients with SODS (SODS group), insomnia patients without SODS (NOSODS group), and healthy controls (HC). Participants were evaluated for subjective and objective sleep using sleep diary and polysomnography. Functional magnetic resonance imaging was conducted during the presentation of insomnia-related (Ins), general anxiety-inducing (Gen), and neutral (Neu) stimuli. Brain reactivity to the contrast of Ins vs. Neu and Gen vs. Neu was compared among the SODS (n = 13), NOSODS (n = 15), and HC (n = 16) groups. In the SODS group compared to other groups, brain areas including the left fusiform, bilateral precuneus, right superior frontal gyrus, genu of corpus callosum, and bilateral anterior corona radiata showed significantly increased blood oxygen level dependent (BOLD) signal in the contrast of Ins vs. Neu. There was no brain region with significantly increased BOLD signal in the Gen vs. Neu contrast in the group comparisons. Increased brain activity to insomnia-related stimuli in several brain regions of the SODS group is likely due to these individuals being more sensitive to sleep-related threat and negative cognitive distortion toward insomnia.

scholarly journals BOLD and Perfusion Response to Finger-Thumb Apposition after Acetazolamide Administration: Differential Relationship to Global Perfusion

2003 ◽  
Vol 23 (7) ◽  
pp. 829-837 ◽  
Author(s):  
Gregory G. Brown ◽  
Lisa T. Eyler Zorrilla ◽  
Bassem Georgy ◽  
Sandra S. Kindermann ◽  
Eric C. Wong ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Blood Oxygen Level Dependent ◽  
Bold Response ◽  
Blood Oxygen Level ◽  
Individual Subject ◽  
Cerebrovascular Reserve ◽  
Global Cerebral Blood Flow ◽  
Hand Area ◽  
Cortical Perfusion

The authors studied the effects of altering global cerebral blood flow on both blood oxygen level–dependent (BOLD) response and perfusion response to finger-thumb apposition. A PICORE/QUIPSS II protocol was used to collect interleaved BOLD-weighted and perfusion-weighted images on eight finger-thumb apposition trials. Subjects were studied on a drug-free day and on a day when acetazolamide was administered between the second and third trials. After acetazolamide administration, resting cortical perfusion increased an average of 20% from preadministration levels, whereas the BOLD response to finger-thumb apposition decreased by an average of 35% in the S1M1 hand area. Contrary to predictions from the exhausted cerebrovascular reserve hypothesis and the oxygen limitation model, an effect of acetazolamide on cerebral blood flow response in the S1M1 hand area was not observed. Across the acetazolamide trials, BOLD response was inversely correlated with resting cortical perfusion for individual subject data. These results suggest that resting perfusion affects the magnitude of the BOLD response and is thus an important confounding factor in fMRI studies, and that the physiologic systems that increase cerebral blood flow in response to acetazolamide administration and systems that increase cerebral blood flow in response to altered neural activity appear to have additive effects.

scholarly journals Interhemispheric Connectivity Supports Load-Dependent Working Memory Maintenance for Complex Visual Stimuli

2021 ◽  
Author(s):  
Chelsea Reichert Plaska ◽  
Jefferson Ortega ◽  
Bernard A. Gomes ◽  
Timothy M. Ellmore
Keyword(s):  
Working Memory ◽  
Phase Locking ◽  
Visual Stimuli ◽  
Load Condition ◽  
Brain Regions ◽  
Delay Period ◽  
Temporal Region ◽  
Verbal Rehearsal ◽  
Complex Stimuli ◽  
Low Load

AbstractAn open question in the working memory (WM) field is how information is kept online during the WM delay period. Maintenance of simple stimuli in WM is supported by connectivity between frontal and parietal brain regions. How does delay period activity and connectivity support WM of complex stimuli? Twenty-two participants completed a modified Sternberg WM task with complex stimuli and were told to remember either 2 (low-load) or 5 (high-load) scenes while 32- channel scalp EEG was recorded. During the 6-sec delay period 6 phase-scrambled scenes were presented, which served as interference. While increasing the WM load, particularly with complex stimuli, places a greater demand on attentional resources, interfering stimuli may hijack the available resources. This was confirmed in the examination of theta and alpha amplitude, as amplitude was reduced for the high WM load as compared with the low WM load across frontal, central, and parietal regions. Delay period connectivity was assessed with phase-locking value (PLV). We identified 3 supporting networks that facilitated performance for the low-load condition: 1) increased PLV between left frontal and right posterior temporal in the theta and alpha bands; 2) increased PLV between right anterior temporal and left central in the alpha and lower beta bands; and 3) increased PLV between left anterior temporal and left posterior temporal in theta, alpha, and lower beta bands for the low-load condition. These results suggest that these brain networks facilitated the low-load WM by filtering of interference and the use of verbal rehearsal during the delay period.Impact StatementAlthough, studies of working memory maintenance with simple stimuli have suggested a role of frontal-parietal networks in supporting maintenance, the current study suggests that maintenance of complex visual stimuli with interference present is supported by interhemispheric frontal-posterior temporal and intrahemispheric left temporal region connectivity. These networks support maintenance by filtering of the interfering stimuli, which facilitates the use of verbal rehearsal strategies during the delay period.

Effective Connectivity During an Avoidance-Based Pavlovian-to-Instrumental Transfer Task

2021 ◽  
Author(s):  
Daniel Petrie ◽  
Sy-Miin Chow ◽  
Charles Geier
Keyword(s):  
Effective Connectivity ◽  
A Priori ◽  
Transfer Task ◽  
Blood Oxygen Level Dependent ◽  
Brain Regions ◽  
Response Patterns ◽  
Multiple Model ◽  
Hemodynamic Response Function ◽  
Blood Oxygen Level ◽  
Psychological Phenomena

Pavlovian-to-instrumental transfer (PIT) refers to a phenomenon whereby a classically conditioned stimulus (CS) impacts the motivational salience of instrumental behavior. We examined behavioral response patterns and functional magnetic resonance imaging (fMRI) based effective connectivity during an avoidance-based PIT task. Eleven participants (8 females; Mage = 28.2, SD = 2.8, range = 25-32 years) completed the task. Effective connectivity between a priori brain regions engaged during the task was determined using hemodynamic response function group iterative multiple model estimation (HRF-GIMME). Behaviorally, participants exhibited specific PIT, a CS previously associated with a reinforcing outcome increased instrumental responding directed at the same outcome. We did not find evidence for general PIT; a CS did not significantly increase instrumental responding towards a different but related outcome. Using HRF-GIMME, we recovered effective connectivity maps among corticostriatal circuits engaged during the task. Group-level paths revealed directional effects from left putamen to right insula and from right putamen to right cingulate. Importantly, a direct effect of specific PIT stimuli on blood-oxygen-level-dependent (BOLD) activity in the left putamen was found. Results provide initial evidence of effective connectivity in key brain regions in an avoidance-based PIT task network. This study adds to the literature studying PIT effects in humans and employing GIMME models to understand how psychological phenomena are supported in the brain.

scholarly journals GENDER AND ADOLESCENT ALCOHOL USE DISORDERS ON BOLD (BLOOD OXYGEN LEVEL DEPENDENT) RESPONSE TO SPATIAL WORKING MEMORY

2005 ◽  
Vol 40 (3) ◽  
pp. 194-200 ◽  
Author(s):  
LISA C. CALDWELL ◽  
ALECIA D. SCHWEINSBURG ◽  
BONNIE J. NAGEL ◽  
VALERIE C. BARLETT ◽  
SANDRA A. BROWN ◽  
...  
Keyword(s):  
Working Memory ◽  
Alcohol Use ◽  
Spatial Working Memory ◽  
Alcohol Use Disorders ◽  
Blood Oxygen Level Dependent ◽  
Blood Oxygen ◽  
Oxygen Level ◽  
Blood Oxygen Level ◽  
Adolescent Alcohol Use ◽  
Adolescent Alcohol

scholarly journals A Theoretical Investigation of the Relationship between Structural Equation Modeling and Partial Correlation in Functional MRI Effective Connectivity

2009 ◽  
Vol 2009 ◽  
pp. 1-9 ◽  
Author(s):  
Guillaume Marrelec ◽  
Habib Benali
Keyword(s):  
Structural Equation Modeling ◽  
Structural Equation ◽  
Partial Correlation ◽  
Effective Connectivity ◽  
Real Data ◽  
Blood Oxygen Level Dependent ◽  
Brain Regions ◽  
Equation Modeling ◽  
Blood Oxygen Level ◽  
Partial Correlations

An important field of blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI) is the investigation of effective connectivity, that is, the actions that a given set of regions exert on one another. We recently proposed a data-driven method based on the partial correlation matrix that could provide some insight regarding the pattern of functional interaction between brain regions as represented by structural equation modeling (SEM). So far, the efficiency of this approach was mostly based on empirical evidence. In this paper, we provide theoretical fundaments explaining why and in what measure structural equation modeling and partial correlations are related. This gives better insight regarding what parts of SEM can be retrieved by partial correlation analysis and what remains inaccessible. We illustrate the different results with real data.

scholarly journals fMRI: blood oxygen level–dependent activation during a working memory–selective attention task in children born extremely preterm

2013 ◽  
Vol 74 (2) ◽  
pp. 196-205 ◽  
Author(s):  
Silja Torvik Griffiths ◽  
Hilde Gundersen ◽  
Emanuel Neto ◽  
Irene Elgen ◽  
Trond Markestad ◽  
...  
Keyword(s):  
Working Memory ◽  
Selective Attention ◽  
Blood Oxygen Level Dependent ◽  
Blood Oxygen ◽  
Oxygen Level ◽  
Blood Oxygen Level ◽  
Attention Task ◽  
Extremely Preterm

scholarly journals Amphetamine modulates brain signal variability and working memory in younger and older adults

2015 ◽  
Vol 112 (24) ◽  
pp. 7593-7598 ◽  
Author(s):  
Douglas D. Garrett ◽  
Irene E. Nagel ◽  
Claudia Preuschhof ◽  
Agnieszka Z. Burzynska ◽  
Janina Marchner ◽  
...  
Keyword(s):  
Older Adults ◽  
Working Memory ◽  
Cognitive Aging ◽  
Memory Task ◽  
Blood Oxygen Level Dependent ◽  
Brain Dynamics ◽  
Blood Oxygen Level ◽  
Age Related ◽  
And Performance ◽  
Signal Variability

Better-performing younger adults typically express greater brain signal variability relative to older, poorer performers. Mechanisms for age and performance-graded differences in brain dynamics have, however, not yet been uncovered. Given the age-related decline of the dopamine (DA) system in normal cognitive aging, DA neuromodulation is one plausible mechanism. Hence, agents that boost systemic DA [such as d-amphetamine (AMPH)] may help to restore deficient signal variability levels. Furthermore, despite the standard practice of counterbalancing drug session order (AMPH first vs. placebo first), it remains understudied how AMPH may interact with practice effects, possibly influencing whether DA up-regulation is functional. We examined the effects of AMPH on functional-MRI–based blood oxygen level-dependent (BOLD) signal variability (SDBOLD) in younger and older adults during a working memory task (letter n-back). Older adults expressed lower brain signal variability at placebo, but met or exceeded young adult SDBOLD levels in the presence of AMPH. Drug session order greatly moderated change–change relations between AMPH-driven SDBOLD and reaction time means (RTmean) and SDs (RTSD). Older adults who received AMPH in the first session tended to improve in RTmean and RTSD when SDBOLD was boosted on AMPH, whereas younger and older adults who received AMPH in the second session showed either a performance improvement when SDBOLD decreased (for RTmean) or no effect at all (for RTSD). The present findings support the hypothesis that age differences in brain signal variability reflect aging-induced changes in dopaminergic neuromodulation. The observed interactions among AMPH, age, and session order highlight the state- and practice-dependent neurochemical basis of human brain dynamics.

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