scholarly journals Dynamic reorganization of human resting-state networks during visuospatial attention

2015 ◽  
Vol 112 (26) ◽  
pp. 8112-8117 ◽  
Author(s):  
Sara Spadone ◽  
Stefania Della Penna ◽  
Carlo Sestieri ◽  
Viviana Betti ◽  
Annalisa Tosoni ◽  
...  

Fundamental problems in neuroscience today are understanding how patterns of ongoing spontaneous activity are modified by task performance and whether/how these intrinsic patterns influence task-evoked activation and behavior. We examined these questions by comparing instantaneous functional connectivity (IFC) and directed functional connectivity (DFC) changes in two networks that are strongly correlated and segregated at rest: the visual (VIS) network and the dorsal attention network (DAN). We measured how IFC and DFC during a visuospatial attention task, which requires dynamic selective rerouting of visual information across hemispheres, changed with respect to rest. During the attention task, the two networks remained relatively segregated, and their general pattern of within-network correlation was maintained. However, attention induced a decrease of correlation in the VIS network and an increase of the DAN→VIS IFC and DFC, especially in a top-down direction. In contrast, within the DAN, IFC was not modified by attention, whereas DFC was enhanced. Importantly, IFC modulations were behaviorally relevant. We conclude that a stable backbone of within-network functional connectivity topography remains in place when transitioning between resting wakefulness and attention selection. However, relative decrease of correlation of ongoing “idling” activity in visual cortex and synchronization between frontoparietal and visual cortex were behaviorally relevant, indicating that modulations of resting activity patterns are important for task performance. Higher order resting connectivity in the DAN was relatively unaffected during attention, potentially indicating a role for simultaneous ongoing activity as a “prior” for attention selection.

2021 ◽  
Author(s):  
Elizabeth Musz ◽  
Rita Loiotile ◽  
Janice Chen ◽  
Marina Bedny

AbstractOccipital cortices of different sighted people contain analogous maps of visual information (e.g., foveal vs. peripheral space). In congenital blindness, “visual” cortices enhance responses to nonvisual stimuli. Do deafferented visual cortices of different blind people represent common informational maps? We leverage a naturalistic stimulus paradigm and inter-subject pattern similarity analysis to address this question. Blindfolded sighted (S, n=22) and congenitally blind (CB, n=22) participants listened to three auditory excerpts from movies; a naturalistic spoken narrative; and matched degraded auditory stimuli (i.e., shuffled sentences and backwards speech) while undergoing fMRI scanning. In a parcel-based whole brain analysis, we measured the spatial activity patterns evoked by each unique, ten-second segment of each auditory clip. We then compared each subject’s spatial pattern to that of all other subjects in the same group (CB or S) within and across segments. In both blind and sighted groups, segments of meaningful auditory stimuli produced distinctive patterns of activity that were shared across individuals. Crucially, only in the CB group, this segment-specific, cross-subject pattern similarity effect emerged in visual cortex, but only for meaningful naturalistic stimuli and not backwards speech. These results suggest that spatial activity patterns within deafferented visual cortices encode meaningful, segment-level information contained in naturalistic auditory stimuli, and that these representations are spatially organized in a similar fashion across blind individuals.Significance StatementRecent neuroimaging studies show that the so-called “visual” cortices activate during non-visual tasks in people who are born blind. Do the visual cortices of people who are born blind develop similar representational maps? While congenitally blind individuals listened to naturalistic auditory stimuli (i.e., sound clips from movies), distinct timepoints within each stimulus elicited unique spatial activity patterns in visual cortex, and these patterns were shared across different people. These findings suggest that in blindness, the visual cortices encode meaningful information embedded in naturalistic auditory signals in a spatially distributed manner, and that a common representational map can emerge in visual cortex independent of visual experience.


2020 ◽  
Vol 11 ◽  
pp. 204201882096029
Author(s):  
Yao Yu ◽  
Dong-Yi Lan ◽  
Li-Ying Tang ◽  
Ting Su ◽  
Biao Li ◽  
...  

Purpose: In this study, we aimed to investigate the differences in the intrinsic functional connectivity (iFC) of the primary visual cortex (V1), based on resting-state functional magnetic resonance imaging (rs-fMRI), between patients with proliferative diabetic retinopathy (PDR) and healthy controls (HCs). Methods: In total, 26 patients (12 males, 14 females) with PDR and 26 HCs (12 males, 14 females), matched for sex, age, and education status, were enrolled in the study. All individuals underwent rs-fMRI scans. We acquired iFC maps and compared the differences between PDR patients and the HCs. Results: The PDR group had significantly increased FC between the left V1 and the right middle frontal gyrus (RMFG), and significantly reduced FC between the left V1 and the cuneus/calcarine/precuneus. In addition, the PDR patients had significantly increased FC between the right V1 and the right superior frontal gyrus (RSFG), and significantly reduced FC between the right V1 and the cuneus/calcarine/precuneus. The individual areas under the curve (AUCs) of FC values for the left V1 were as follows: RMFG (0.871, p < 0.001) and the cuneus/calcarine/precuneus (0.914, p < 0.001), while the AUCs of FC values for the right V1 were as follows: RSFG (0.895, p < 0.001) and the cuneus/calcarine/precuneus (0.918, p < 0.001). Conclusions: The results demonstrated that, in PDR patients, altered iFC in distinct brain regions, including regions related to visual information processing and cognition. Considering the rise in the diabetes mellitus incidence rate and the consequences of PDR, the results could provide promising clues for exploring the neural mechanisms related to PDR and possible approaches for the early identification of PDR.


2017 ◽  
Author(s):  
Muriel Lobier ◽  
J. Matias Palva ◽  
Satu Palva

Visuospatial attention prioritizes processing of attended visual stimuli. It is characterized by lateralized alpha-band (8-14 Hz) amplitude suppression in visual cortex and increased neuronal activity in a network of frontal and parietal areas. It has remained unknown what mechanisms coordinate neuronal processing among frontoparietal network and visual cortices and implement the attention-related modulations of alpha-band amplitudes and behavior. We investigated whether large-scale network synchronization could be such a mechanism. We recorded human cortical activity with magnetoencephalography (MEG) during a visuospatial attention task. We then identified the frequencies and anatomical networks of inter-areal phase synchronization from source localized MEG data. We found that visuospatial attention is associated with robust and sustained long-range synchronization of cortical oscillations exclusively in the high-alpha (10-14 Hz) frequency band. This synchronization connected frontal, parietal and visual regions and was observed concurrently with amplitude suppression of low-alpha (6-9 Hz) band oscillations in visual cortex. Furthermore, stronger high-alpha phase synchronization was associated with decreased reaction times to attended stimuli and larger suppression of alpha-band amplitudes. These results thus show that high-alpha band phase synchronization is functionally significant and could coordinate the neuronal communication underlying the implementation of visuospatial attention.


2019 ◽  
Author(s):  
DoHyun Kim ◽  
Tomer Livne ◽  
Nicholas V. Metcalf ◽  
Maurizio Corbetta ◽  
Gordon L. Shulman

AbstractThe function of spontaneous brain activity is an important issue in neuroscience. Here we test the hypothesis that patterns of spontaneous activity code representational patterns evoked by stimuli and tasks. We compared in human visual cortex multi-vertex patterns of spontaneous activity to patterns evoked by ecological visual stimuli (faces, bodies, scenes) and low-level visual features (e.g. phase-scrambled faces). Specifically, we identified regions that preferred particular stimulus categories during localizer scans (e.g. extra-striate body area for bodies), measured multi-vertex patterns for each category during event-related task scans, and then correlated over vertices these stimulus-evoked patterns to the pattern measured on each frame of resting-state scans. The mean correlation coefficient was essentially zero for all regions/stimulus categories, indicating that resting multi-vertex patterns were not biased toward particular stimulus-evoked patterns. However, the spread of correlation coefficients between stimulus-evoked and resting patterns, i.e. both positive and negative, was significantly greater for the preferred stimulus category of an ROI (e.g. body category in body-preferring ROIs). The relationship between spontaneous and stimulus-evoked multi-vertex patterns also governed the temporal correlation or functional connectivity of patterns of spontaneous activity between individual regions (pattern-based functional connectivity). Resting patterns related to an object category fluctuated preferentially between ROIs preferring the same category, and patterns related to different categories fluctuated independently within their respective preferred ROIs (e.g. body- and scene-related multi-vertex patterns within body- and scene-preferring ROIs). These results support the general proposal that spontaneous multi-vertex activity patterns are linked to stimulus-evoked patterns, consistent with a representational function for spontaneous activity.


2016 ◽  
Author(s):  
Sirawaj Itthipuripat ◽  
Kexin Cha ◽  
Anna Byers ◽  
John T. Serences

AbstractAttention supports the selection of relevant sensory information from competing irrelevant sensory information. This selective processing is thought to be supported via the attentional gain amplification of sensory responses evoked by attended compared to unattended stimuli. However, recent studies in highly trained subjects suggest that attentional gain plays a relatively modest role and that other types of neural modulations – such as a reduction in neural noise – better explain attention-related changes in behavior. We hypothesized that the amount of training may alter neural mechanisms that support attentional selection in visual cortex. To test this hypothesis, we investigated the influence of training on attentional modulations of stimulus-evoked visual responses by recording electroencephalography (EEG) from humans performing a selective visuospatial attention task over the course of one month. Early in training, visuospatial attention induced a robust attentional gain amplification of sensory-evoked responses in contralateral visual cortex that emerged within ~100ms after stimulus onset, and a quantitative model based on signal detection theory (SDT) successfully linked this attentional gain amplification to attention-related improvements in behavior. However, after training, this attentional gain amplification of visual responses was almost completely eliminated and modeling suggested that noise reduction was required to link the amplitude of visual responses with attentional modulations of behavior. These findings suggest that the neural mechanisms supporting selective attention can change as a function of training and expertise, and help to bridge different results from studies carried out in different model systems that require substantially different amount of training.


Author(s):  
Weiyu Zhang ◽  
Se-Hoon Jeong ◽  
Martin Fishbein†

This study investigates how multitasking interacts with levels of sexually explicit content to influence an individual’s ability to recognize TV content. A 2 (multitasking vs. nonmultitasking) by 3 (low, medium, and high sexual content) between-subjects experiment was conducted. The analyses revealed that multitasking not only impaired task performance, but also decreased TV recognition. An inverted-U relationship between degree of sexually explicit content and recognition of TV content was found, but only when subjects were multitasking. In addition, multitasking interfered with subjects’ ability to recognize audio information more than their ability to recognize visual information.


Author(s):  
Laura Broeker ◽  
Harald Ewolds ◽  
Rita F. de Oliveira ◽  
Stefan Künzell ◽  
Markus Raab

AbstractThe aim of this study was to examine the impact of predictability on dual-task performance by systematically manipulating predictability in either one of two tasks, as well as between tasks. According to capacity-sharing accounts of multitasking, assuming a general pool of resources two tasks can draw upon, predictability should reduce the need for resources and allow more resources to be used by the other task. However, it is currently not well understood what drives resource-allocation policy in dual tasks and which resource allocation policies participants pursue. We used a continuous tracking task together with an audiomotor task and manipulated advance visual information about the tracking path in the first experiment and a sound sequence in the second experiments (2a/b). Results show that performance predominantly improved in the predictable task but not in the unpredictable task, suggesting that participants did not invest more resources into the unpredictable task. One possible explanation was that the re-investment of resources into another task requires some relationship between the tasks. Therefore, in the third experiment, we covaried the two tasks by having sounds 250 ms before turning points in the tracking curve. This enabled participants to improve performance in both tasks, suggesting that resources were shared better between tasks.


2021 ◽  
pp. 216770262110302
Author(s):  
M. Justin Kim ◽  
Maxwell L. Elliott ◽  
Annchen R. Knodt ◽  
Ahmad R. Hariri

Past research on the brain correlates of trait anger has been limited by small sample sizes, a focus on relatively few regions of interest, and poor test–retest reliability of functional brain measures. To address these limitations, we conducted a data-driven analysis of variability in connectome-wide functional connectivity in a sample of 1,048 young adult volunteers. Multidimensional matrix regression analysis showed that self-reported trait anger maps onto variability in the whole-brain functional connectivity patterns of three brain regions that serve action-related functions: bilateral supplementary motor areas and the right lateral frontal pole. We then demonstrate that trait anger modulates the functional connectivity of these regions with canonical brain networks supporting somatomotor, affective, self-referential, and visual information processes. Our findings offer novel neuroimaging evidence for interpreting trait anger as a greater propensity to provoked action, which supports ongoing efforts to understand its utility as a potential transdiagnostic marker for disordered states characterized by aggressive behavior.


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