scholarly journals Auditory Target Detection Enhances Visual Processing and Hippocampal Functional Connectivity

2020 ◽  
Author(s):  
Roy Moyal ◽  
Hamid B. Turker ◽  
Wen-Ming Luh ◽  
Khena M. Swallow
Keyword(s):  
Visual Cortex ◽  
Functional Connectivity ◽  
Locus Coeruleus ◽  
Target Detection ◽  
Visual Processing ◽  
Target Tone ◽  
Auditory Target ◽  
Parahippocampal Gyrus ◽  
Subcortical Regions ◽  
Selection Of

AbstractThough dividing one’s attention between two input streams typically impairs performance, detecting a behaviorally relevant stimulus can sometimes enhance the encoding of task-irrelevant information presented at the same time. Previous research has shown that temporal selection of this kind boosts visual cortical activity and incidental memory. An important and yet unanswered question is whether such effects are reflected in processing quality and functional connectivity in visual regions and the hippocampus. In this fMRI study, participants were asked to memorize a stream of images and press a button when they heard an auditory tone of a prespecified pitch. Images could be presented with a target tone, with a distractor tone, or without a tone. Auditory target detection increased activity throughout the ventral visual cortex but lowered it in the hippocampus. These effects were accompanied by a widespread enhancement in functional connectivity between the ventral visual cortex and the hippocampus. Image category classification accuracy was higher on target tone trials than on distractor and no tone trials in the fusiform gyrus and the parahippocampal gyrus. This effect was stronger in clusters whose activity was more correlated with the hippocampus on target tone than on distractor tone trials. In agreement with accounts suggesting that subcortical noradrenergic influences play a role in temporal selection, auditory target detection also caused an increase in locus coeruleus activity and phasic pupil responses. These findings outline a network of cortical and subcortical regions that are involved in the selection and processing of information presented at behaviorally relevant moments.Significance StatementAttention influences the degree to which we remember everyday experiences. This study examines the neural mechanisms involved in committing important events to memory. It links the selection of important information in time (temporal selection) to enhanced functional connectivity between brain regions involved in perception and encoding. It also suggests the involvement of a small brainstem structure, the locus coeruleus (LC), whose degeneration is increasingly associated with cognitive decline in aging. The process of encoding behaviorally relevant events into episodic memory thus involves large-scale, coordinated activation spanning cortical and subcortical regions.

scholarly journals Structural and Functional Connectivity of Visual Cortex in Schizophrenia and Bipolar Disorder: A Graph-Theoretic Analysis

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Eric A Reavis ◽  
Junghee Lee ◽  
Lori L Altshuler ◽  
Mark S Cohen ◽  
Stephen A Engel ◽  
...  
Keyword(s):  
Bipolar Disorder ◽  
Visual Cortex ◽  
Functional Connectivity ◽  
Visual System ◽  
Visual Processing ◽  
Functional Outcomes ◽  
Brain Atlas ◽  
Imaging Data ◽  
Significant Group ◽  
Graph Theoretic

Abstract Visual processing abnormalities in schizophrenia (SZ) are poorly understood, yet predict functional outcomes in the disorder. Bipolar disorder (BD) may involve similar visual processing deficits. Converging evidence suggests that visual processing may be relatively normal at early stages of visual processing such as early visual cortex (EVC), but that processing abnormalities may become more pronounced by mid-level visual areas such as lateral occipital cortex (LO). However, little is known about the connectivity of the visual system in SZ and BD. If the flow of information to, from, or within the visual system is disrupted by reduced connectivity, this could help to explain perceptual deficits. In the present study, we performed a targeted analysis of the structural and functional connectivity of the visual system using graph-theoretic metrics in a sample of 48 SZ, 46 BD, and 47 control participants. Specifically, we calculated parallel measures of local efficiency for EVC and LO from both diffusion weighted imaging data (structural) and resting-state (functional) imaging data. We found no structural connectivity differences between the groups. However, there was a significant group difference in functional connectivity and a significant group-by-region interaction driven by reduced LO connectivity in SZ relative to HC, whereas BD was approximately intermediate to the other 2 groups. We replicated this pattern of results using a different brain atlas. These findings support and extend theoretical models of perceptual dysfunction in SZ, providing a framework for further investigation of visual deficits linked to functional outcomes in SZ and related disorders.

Selection of events in time enhances activity throughout early visual cortex

2012 ◽  
Vol 108 (12) ◽  
pp. 3239-3252 ◽  
Author(s):  
Khena M. Swallow ◽  
Tal Makovski ◽  
Yuhong V. Jiang
Keyword(s):  
Visual Cortex ◽  
Contextual Information ◽  
Brain Regions ◽  
Target Tone ◽  
Other Information ◽  
Early Visual Cortex ◽  
Cortical Regions ◽  
Visual Cortical ◽  
System Selection ◽  
Selection Of

Temporal selection poses unique challenges to the perceptual system. Selection is needed to protect goal-relevant stimuli from interference from new sensory input. In addition, contextual information that occurs at the same time as goal-relevant stimuli may be critical for learning. Using fMRI, we characterized how visual cortical regions respond to the temporal selection of auditory and visual stimuli. Critically, we focused on brain regions that are not involved in processing the target itself. Participants pressed a button when they heard a prespecified target tone and did not respond to other tones. Although more attention was directed to auditory input when the target tone was selected, activity in primary visual cortex increased more after target tones than after distractor tones. In contrast to spatial attention, this effect was larger in V1 than in V2 and V3. It was present in regions not typically involved in representing the target stimulus. Additional experiments demonstrated that these effects were not due to multimodal processing, rare targets, or motor responses to the targets. Thus temporal selection of behaviorally relevant stimuli enhances, rather than reduces, activity in perceptual regions involved in processing other information.

Pulvino-cortical interaction: an integrative role in the control of attention

2019 ◽  
Author(s):  
Alexia Bourgeois ◽  
Carole Guedj ◽  
Emmanuel Carrera ◽  
Patrik Vuilleumier
Keyword(s):  
Executive Control ◽  
Sensory Information ◽  
Relevant Information ◽  
Cortical Circuits ◽  
Attention And Executive Control ◽  
Neural Communication ◽  
Subcortical Regions ◽  
Theoretical Proposal ◽  
Selection Of

Selective attention is a fundamental cognitive function that guides behavior by selecting and prioritizing salient or relevant sensory information of our environment. Despite early evidence and theoretical proposal pointing to an implication of thalamic control in attention, most studies in the past two decades focused on cortical substrates, largely ignoring the contribution of subcortical regions as well as cortico-subcortical interactions. Here, we suggest a key role of the pulvinar in the selection of salient and relevant information via its involvement in priority maps computation. Prioritization may be achieved through a pulvinar- mediated generation of alpha oscillations, which may then modulate neuronal gain in thalamo-cortical circuits. Such mechanism might orchestrate the synchrony of cortico-cortical interaction, by rendering neural communication more effective, precise and selective. We propose that this theoretical framework will support a timely shift from the prevailing cortico- centric view of cognition to a more integrative perspective of thalamic contributions to attention and executive control processes.

scholarly journals Alzheimer’s Disease Progressively Reduces Visual Functional Network Connectivity

2021 ◽  
pp. 1-14
Author(s):  
Jie Huang ◽  
Paul Beach ◽  
Andrea Bozoki ◽  
David C. Zhu
Keyword(s):  
Visual Cortex ◽  
Lower Order ◽  
Resting State ◽  
Visual Processing ◽  
Network Connectivity ◽  
Higher Order ◽  
Functional Network ◽  
Functional Networks ◽  
The Face ◽  
Processing Network

Background: Postmortem studies of brains with Alzheimer’s disease (AD) not only find amyloid-beta (Aβ) and neurofibrillary tangles (NFT) in the visual cortex, but also reveal temporally sequential changes in AD pathology from higher-order association areas to lower-order areas and then primary visual area (V1) with disease progression. Objective: This study investigated the effect of AD severity on visual functional network. Methods: Eight severe AD (SAD) patients, 11 mild/moderate AD (MAD), and 26 healthy senior (HS) controls undertook a resting-state fMRI (rs-fMRI) and a task fMRI of viewing face photos. A resting-state visual functional connectivity (FC) network and a face-evoked visual-processing network were identified for each group. Results: For the HS, the identified group-mean face-evoked visual-processing network in the ventral pathway started from V1 and ended within the fusiform gyrus. In contrast, the resting-state visual FC network was mainly confined within the visual cortex. AD disrupted these two functional networks in a similar severity dependent manner: the more severe the cognitive impairment, the greater reduction in network connectivity. For the face-evoked visual-processing network, MAD disrupted and reduced activation mainly in the higher-order visual association areas, with SAD further disrupting and reducing activation in the lower-order areas. Conclusion: These findings provide a functional corollary to the canonical view of the temporally sequential advancement of AD pathology through visual cortical areas. The association of the disruption of functional networks, especially the face-evoked visual-processing network, with AD severity suggests a potential predictor or biomarker of AD progression.

fMRI-Guided TMS on Cortical Eye Fields: The Frontal But Not Intraparietal Eye Fields Regulate the Coupling Between Visuospatial Attention and Eye Movements

2009 ◽  
Vol 102 (6) ◽  
pp. 3469-3480 ◽  
Author(s):  
H. M. Van Ettinger-Veenstra ◽  
W. Huijbers ◽  
T. P. Gutteling ◽  
M. Vink ◽  
J. L. Kenemans ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Eye Movements ◽  
Visual Processing ◽  
Discrimination Performance ◽  
Visual Image ◽  
Single Pulse ◽  
Visuospatial Attention ◽  
Movement Direction ◽  
Key Factor ◽  
And Shifts

It is well known that parts of a visual scene are prioritized for visual processing, depending on the current situation. How the CNS moves this focus of attention across the visual image is largely unknown, although there is substantial evidence that preparation of an action is a key factor. Our results support the view that direct corticocortical feedback connections from frontal oculomotor areas to the visual cortex are responsible for the coupling between eye movements and shifts of visuospatial attention. Functional magnetic resonance imaging (fMRI)–guided transcranial magnetic stimulation (TMS) was applied to the frontal eye fields (FEFs) and intraparietal sulcus (IPS). A single pulse was delivered 60, 30, or 0 ms before a discrimination target was presented at, or next to, the target of a saccade in preparation. Results showed that the known enhancement of discrimination performance specific to locations to which eye movements are being prepared was enhanced by early TMS on the FEF contralateral to eye movement direction, whereas TMS on the IPS resulted in a general performance increase. The current findings indicate that the FEF affects selective visual processing within the visual cortex itself through direct feedback projections.

CNTM-03. Functional connectivity networks in patients with brain tumors and vascular lesions in the occipital cortex

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi224-vi225
Author(s):  
Katharina Rosengarth ◽  
Katharina Hense ◽  
Tina Plank ◽  
Mark Greenlee ◽  
Christina Wendl ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Brain Tumors ◽  
Visual Processing ◽  
Network Connectivity ◽  
Occipital Cortex ◽  
Brain Lesions ◽  
Vascular Lesions ◽  
Surrounding Tissue ◽  
Tumor Patients ◽  
Default Mode

Abstract OBJECTIVE Space-occupying brain lesions as brain tumors in the occipital lobe have only been sparsely investigated so far, as this localization is extremely rare with only 1% of cases. It is still unclear how this affects the overall organization of the visual system. We investigated functional connectivity of functional networks associated with higher visual processing between patients with occipital space-occupying lesion in the occipital cortex and healthy controls. METHODS 12 patients with brain tumors, 7 patients with vascular lesions in the occipital cortex and 19 healthy subjects matched for age and sex were included. During functional MRI patients and subjects performed a visual excentricity mapping task. Data analysis was done using CONN toolbox based on Matlab. See-to-ROI connectivities of 23 Regions of Interest (ROIs) implemented in the CONN toolbox which were assigned to the Default Mode, Visual, Salience, Dorsal Attention, and Frontoparietal network were assessed. For each subject, connectivity was calculated using Fischer transformed pairwise correlations. These correlations were first considered separately for each group in one-sample analyses and then compared between the groups. RESULTS Main results show, that compared to control subjects and vascular patients, tumor patients showed weaker intra-network connectivity of components of all networks except the default-network. Tumor patients showed even stronger between-network connectivity in the default-mode network compared to the other groups. Weaker connectivity was observed within the salience network in both patient groups compared to controls. CONCLUSION The results indicate that in the course of the disease, compensatory countermeasures take place in the brain against a brain tumor or a space-occupying brain lesion with the aim of maintaining the performance level and cognitive processes for as long as possible. However, more research is needed in this area to understand the mechanisms and effects of brain tumors and space-consuming brain lesions on surrounding tissue.

Clinical correlates of hypothalamic functional changes in migraine patients

Cephalalgia ◽  
2021 ◽  
pp. 033310242110466
Author(s):  
Roberta Messina ◽  
Maria A Rocca ◽  
Paola Valsasina ◽  
Paolo Misci ◽  
Massimo Filippi
Keyword(s):  
Functional Connectivity ◽  
Resting State ◽  
Visual Processing ◽  
Episodic Migraine ◽  
Resting State Functional Connectivity ◽  
Functional Interaction ◽  
Functional Changes ◽  
Lingual Gyrus ◽  
Headache Impact

Objective To elucidate the hypothalamic involvement in episodic migraine and investigate the association between hypothalamic resting state functional connectivity changes and migraine patients’ clinical characteristics and disease progression over the years. Methods Ninety-one patients with episodic migraine and 73 controls underwent interictal resting state functional magnetic resonance imaging. Twenty-three patients and controls were re-examined after a median of 4.5 years. Hypothalamic resting state functional connectivity changes were investigated using a seed-based correlation approach. Results At baseline, a decreased functional interaction between the hypothalamus and the parahippocampus, cerebellum, temporal, lingual and orbitofrontal gyrus was found in migraine patients versus controls. Increased resting state functional connectivity between the hypothalamus and bilateral orbitofrontal gyrus was demonstrated in migraine patients at follow-up versus baseline. Migraine patients also experienced decreased right hypothalamic resting state functional connectivity with ipsilateral lingual gyrus. A higher migraine attack frequency was associated with decreased hypothalamic-lingual gyrus resting state functional connectivity at baseline, while greater headache impact at follow-up correlated with decreased hypothalamic-orbitofrontal gyrus resting state functional connectivity at baseline. At follow-up, a lower frequency of migraine attacks was associated with higher hypothalamic-orbitofrontal gyrus resting state functional connectivity. Conclusions During the interictal phase, the hypothalamus modulates the activity of pain and visual processing areas in episodic migraine patients. The hypothalamic-cortical interplay changes dynamically over time according to patients’ clinical features.

scholarly journals Altered functional connectivity of primary visual cortex in late blindness

2018 ◽  
Vol Volume 14 ◽  
pp. 3317-3327 ◽  
Author(s):  
Zhi Wen ◽  
Fu-Qing Zhou ◽  
Xin Huang ◽  
Han Dong Dan ◽  
Bao-Jun Xie ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Functional Connectivity ◽  
Primary Visual Cortex
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