Compensation through Increased Functional Connectivity: Neural Correlates of Inhibition in Old and Young

With increasing age, people experience more difficulties with suppressing irrelevant information, which may have a major impact on cognitive functioning. The extent of decline of inhibitory functions with age is highly variable between individuals. In this study, we used ERPs and phase locking analyses to investigate neural correlates of this variability in inhibition between individuals. Older and younger participants performed a selective attention task in which relevant and irrelevant information was presented simultaneously. The participants were split into high and low performers based on their level of inhibition inefficiency, that is, the slowing of RTs induced by information that participants were instructed to ignore. P1 peak amplitudes were larger in low performers than in high performers, indicating that low performers were less able to suppress the processing of irrelevant stimuli. Phase locking analyses were used as a measure of functional connectivity. Efficient inhibition in both age groups was related to the increased functional connectivity in the alpha band between frontal and occipito-parietal ROIs in the prestimulus interval. In addition, increased power in the alpha band in occipito-parietal ROIs was related to better inhibition both before and after stimulus onset. Phase locking in the upper beta band before and during stimulus presentation between frontal and occipito-parietal ROIs was related to a better performance in older participants only, suggesting that this is an active compensation mechanism employed to maintain adequate performance. In addition, increased top–down modulation and increased power in the alpha band appears to be a general mechanism facilitating inhibition in both age groups.

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No changes in parieto-occipital alpha during neural phase locking to visual quasi-periodic theta-, alpha-, and beta-band stimulation

10.1101/219766 ◽

2017 ◽

Cited By ~ 2

Author(s):

Christian Keitel ◽

Christopher SY Benwell ◽

Gregor Thut ◽

Joachim Gross

Keyword(s):

Alpha Rhythm ◽

Visual Stimulation ◽

Phase Locking ◽

Stimulation Frequency ◽

Alpha Band ◽

Human Visual Perception ◽

Beta Band ◽

Frequency Bands ◽

Low Intensity ◽

Increased Sensitivity

ABSTRACTRecent studies have probed the role of the parieto-occipital alpha rhythm (8 – 12 Hz) in human visual perception through attempts to drive its neural generators. To that end, paradigms have used high-intensity strictly-periodic visual stimulation that created strong predictions about future stimulus occurrences and repeatedly demonstrated perceptual consequences in line with an entrainment of parieto-occipital alpha. Our study, in turn, examined the case of alpha entrainment by non-predictive low-intensity quasi-periodic visual stimulation within theta-(4 – 7 Hz), alpha-(8 – 13 Hz) and beta (14 – 20 Hz) frequency bands, i.e. a class of stimuli that resemble the temporal characteristics of naturally occurring visual input more closely. We have previously reported substantial neural phase-locking in EEG recording during all three stimulation conditions. Here, we studied to what extent this phase-locking reflected an entrainment of intrinsic alpha rhythms in the same dataset. Specifically, we tested whether quasi-periodic visual stimulation affected several properties of parieto-occipital alpha generators. Speaking against an entrainment of intrinsic alpha rhythms by non-predictive low-intensity quasi-periodic visual stimulation, we found none of these properties to show differences between stimulation frequency bands. In particular, alpha band generators did not show increased sensitivity to alpha band stimulation and Bayesian inference corroborated evidence against an influence of stimulation frequency. Our results set boundary conditions for when and how to expect effects of entrainment of alpha generators and suggest that the parieto-occipital alpha rhythm may be more inert to external influences than previously thought.

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Distinct oscillatory frequencies underlie excitability of human occipital and parietal cortex

10.1101/082693 ◽

2016 ◽

Cited By ~ 3

Author(s):

Jason Samaha ◽

Olivia Gosseries ◽

Bradley R. Postle

Keyword(s):

Parietal Cortex ◽

Posterior Parietal Cortex ◽

Cortical Excitability ◽

Neural Correlates ◽

Cortical Inhibition ◽

Alpha Band ◽

Beta Band ◽

Time Frequency ◽

Posterior Parietal ◽

Near Threshold

AbstractMagnetic stimulation (TMS) of human occipital and posterior parietal cortex can give rise to visual sensations called phosphenes, but neural correlates of phosphene perception preceding and succeeding stimulation of both areas are unknown. Using near-threshold TMS with concurrent electroencephalography (EEG) recordings, we uncover oscillatory brain dynamics that covary, on single trials, with the perception of phosphenes following occipital and parietal TMS. Prestimulus power and phase predominantly in the alpha-band (8-13 Hz) predicted occipital TMS phosphenes, whereas higher frequency beta-band (13-20 Hz) power (but not phase) predicted parietal TMS phosphenes. TMS evoked responses related to phosphene perception were similar across stimulation sites and were characterized by an early (200 ms) posterior negativity and a later (>300 ms) parietal positivity in the time domain and an increase in low-frequency (~5-7 Hz) power followed by a broadband decrease in alpha/beta power in the time-frequency domain. These correlates of phosphene perception closely resemble known electrophysiological correlates of conscious perception using near-threshold visual stimuli and speak to the possible early onset of visual consciousness. The differential pattern of prestimulus predictors of phosphene perception suggest that distinct frequencies reflect cortical excitability within different cortical regions, and that the alpha-band rhythm, long thought of as a general index of cortical inhibition, may not reflect excitability of posterior parietal cortex.Significance statementAlpha-band oscillations are thought to reflect cortical excitability and are therefor suggested to play an important role in gating information transmission across cortex. We directly probe cortical excitability in human occipital and parietal cortex and observed that whereas alpha-band dynamics indeed reflect excitability of occipital areas, beta-band activity was most predictive of parietal cortex excitability. Differences in the state of cortical excitability predicted perceptual outcomes, which were manifest in both early and late patterns of evoked activity, shedding light on the neural correlates of consciousness. Our findings prompt revision of the notion that alpha activity reflects inhibition across all of cortex and suggests instead that excitability in different regions is reflected in distinct frequency bands.

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Resistance-induced brain activity changes during cycle ergometer exercises

BMC Sports Science Medicine and Rehabilitation ◽

10.1186/s13102-021-00252-w ◽

2021 ◽

Vol 13 (1) ◽

Author(s):

Ming-An Lin ◽

Ling-Fu Meng ◽

Yuan Ouyang ◽

Hsiao-Lung Chan ◽

Ya-Ju Chang ◽

...

Keyword(s):

Resistance Exercise ◽

High Resistance ◽

Exercise Intensity ◽

Spectral Power ◽

Brain Activity ◽

Phase Locking ◽

Cycle Ergometer ◽

Cortical Activation ◽

Alpha Band ◽

Beta Band

Abstract Background EEGs are frequently employed to measure cerebral activations during physical exercise or in response to specific physical tasks. However, few studies have attempted to understand how exercise-state brain activity is modulated by exercise intensity. Methods Ten healthy subjects were recruited for sustained cycle ergometer exercises at low and high resistance, performed on two separate days a week apart. Exercise-state EEG spectral power and phase-locking values (PLV) are analyzed to assess brain activity modulated by exercise intensity. Results The high-resistance exercise produced significant changes in beta-band PLV from early to late pedal stages for electrode pairs F3-Cz, P3-Pz, and P3-P4, and in alpha-band PLV for P3-P4, as well as the significant change rate in alpha-band power for electrodes C3 and P3. On the contrary, the evidence for changes in brain activity during the low-resistance exercise was not found. Conclusion These results show that the cortical activation and cortico-cortical coupling are enhanced to take on more workload, maintaining high-resistance pedaling at the required speed, during the late stage of the exercise period.

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Age differences in ventromedial prefrontal cortex functional connectivity during socioemotional content processing

Social Behavior and Personality An International Journal ◽

10.2224/sbp.9380 ◽

2020 ◽

Vol 48 (7) ◽

pp. 1-19

Author(s):

Ryan T. Daley ◽

Holly J. Bowen ◽

Eric C. Fields ◽

Angela Gutchess ◽

Elizabeth A. Kensinger

Keyword(s):

Prefrontal Cortex ◽

Functional Connectivity ◽

Inferior Frontal Gyrus ◽

Age Groups ◽

Emotional Content ◽

Ventromedial Prefrontal Cortex ◽

Anterior Cingulate ◽

Supramarginal Gyrus ◽

Age Related ◽

Content Processing

Self-relevance effects are often confounded by the presence of emotional content, rendering it difficult to determine how brain networks functionally connected to the ventromedial prefrontal cortex (vmPFC) are affected by the independent contributions of self-relevance and emotion. This difficulty is complicated by age-related changes in functional connectivity between the vmPFC and other default mode network regions, and regions typically associated with externally oriented networks. We asked groups of younger and older adults to imagine placing emotional and neutral objects in their home or a stranger's home. An age-invariant vmPFC cluster showed increased activation for self-relevant and emotional content processing. Functional connectivity analyses revealed age × self-relevance interactions in vmPFC connectivity with the anterior cingulate cortex. There were also age × emotion interactions in vmPFC functional connectivity with the anterior insula, orbitofrontal gyrus, inferior frontal gyrus, and supramarginal gyrus. Interactions occurred in regions with the greatest differences between the age groups, as revealed by conjunction analyses. Implications of the findings are discussed.

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Odour Memory and Odour Hedonics in Children

Perception ◽

10.1068/p180391 ◽

1989 ◽

Vol 18 (3) ◽

pp. 391-396 ◽

Cited By ~ 24

Author(s):

Loredana Hvastja ◽

Lucia Zanuttini

Keyword(s):

Recognition Test ◽

Age Groups ◽

Stimulus Presentation ◽

Emotional Memory ◽

Point Scale ◽

Olfactory Memory ◽

Rapid Decay ◽

Memory Decay ◽

Olfactory Stimuli

The characteristics of olfactory memory during development were investigated and the hypothesis that the pleasantness of smells may be affected by previous associations with pleasant or unpleasant objects or events was tested. This type of emotional memory was compared in the immediate and long-term recognition of olfactory stimuli. Children from three different age groups (mean ages: 6 years 6 months; 8 years 9 months; and 10 years 5 months) were subdivided into two groups. One group was presented with six different odours, each with a slide depicting a pleasant picture. The other group was presented with the odours accompanied by unpleasant pictures. Immediately after stimulus presentation the subjects underwent a recognition test. One month later the subjects underwent a second recognition test, at the end of which they were required to give an evaluation of the pleasantness of each odour on a nine-point scale. At no age level did the pictures matched to the odours affect the recognition score. Olfactory memory varied with age, chiefly because memory decay increased with age, perhaps because of greater proactive interference. With increasing age more rapid decay was set against better immediate recognition. The hypothesis that the hedonic characteristics of odours are partially learned and are affected by events experienced in other modalities was supported.

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Brain Structure and Functional Connectivity Correlate with Psychosocial Development in Contemplative Practitioners and Controls

Brain Sciences ◽

10.3390/brainsci11060728 ◽

2021 ◽

Vol 11 (6) ◽

pp. 728

Author(s):

Omar Singleton ◽

Max Newlon ◽

Andres Fossas ◽

Beena Sharma ◽

Susanne R. Cook-Greuter ◽

...

Keyword(s):

Functional Connectivity ◽

Cortical Thickness ◽

Adult Development ◽

Psychosocial Development ◽

Neural Correlates ◽

Control Group ◽

Contemplative Practice ◽

Temporoparietal Junction ◽

Posterior Cingulate

Jane Loevinger’s theory of adult development, termed ego development (1966) and more recently maturity development, provides a useful framework for understanding the development of the self throughout the lifespan. However, few studies have investigated its neural correlates. In the present study, we use structural and functional magnetic resonance imaging (MRI) to investigate the neural correlates of maturity development in contemplative practitioners and controls. Since traits possessed by individuals with higher levels of maturity development are similar to those attributed to individuals at advanced stages of contemplative practice, we chose to investigate levels of maturity development in meditation practitioners as well as matched controls. We used the Maturity Assessment Profile (MAP) to measure maturity development in a mixed sample of participants composed of 14 long-term meditators, 16 long-term yoga practitioners, and 16 demographically matched controls. We investigated the relationship between contemplative practice and maturity development with behavioral, seed-based resting state functional connectivity, and cortical thickness analyses. The results of this study indicate that contemplative practitioners possess higher maturity development compared to a matched control group, and in addition, maturity development correlates with cortical thickness in the posterior cingulate. Furthermore, we identify a brain network implicated in theory of mind, narrative, and self-referential processing, comprising the posterior cingulate cortex, dorsomedial prefrontal cortex, temporoparietal junction, and inferior frontal cortex, as a primary neural correlate.

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Exploring the relationship of phase and peak-frequency EEG alpha-band and beta-band activity to temporal judgments of stimulus duration

Cognitive Neuroscience ◽

10.1080/17588928.2017.1359524 ◽

2017 ◽

Vol 8 (4) ◽

pp. 193-205 ◽

Cited By ~ 3

Author(s):

Alex Milton ◽

Christopher Pleydell-Pearce

Keyword(s):

Stimulus Duration ◽

Peak Frequency ◽

Alpha Band ◽

Beta Band ◽

Eeg Alpha ◽

Relationship Of ◽

The Relationship ◽

Temporal Judgments ◽

Band Activity

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Quantitative electroencephalography as a tool for objective neurophysiological seizure diagnosis: A retrospective study

Indian Journal of Medical Sciences ◽

10.25259/ijms_160_2020 ◽

2020 ◽

Vol 0 ◽

pp. 1-6

Author(s):

Rajesh Kumar ◽

Tribhuwan Kumar ◽

Kamlesh Jha ◽

Yogesh Kumar

Keyword(s):

Energy Level ◽

Matched Control ◽

Age Groups ◽

Quantitative Electroencephalography ◽

Beta Band ◽

Significant Difference ◽

Males And Females ◽

The Mean ◽

The Difference ◽

Electrical Activities

Objectives: Seizure is the fourth most common neurological disorder in the world; it affects all age groups with equal possibility of occurrence in both males and females. Many antiepileptic drugs are available today, but its diagnosis is challenging. The present study attempted to see if seizure activities could be predicted by analyzing the pre-seizure electrical activities. The prediction may help in taking preventive measures appropriately beforehand in the individuals with seizure proneness. Material and Methods: We selected 11 generalized seizure patients and 19 control patients out of total 115 patients referred for electro-diagnostics for various reasons. EEG of the subjects recorded, segmented as per protocol, and analyzed using MATLAB and EEGLAB tools. Results: The mean energy level in alpha and beta band of the study subject was significantly lower (P = 0.04 and 0.004, respectively) as compared to the age matched control subjects. Theta and delta bands did not show any significant difference between the groups. The difference between the pre- and post-electrical seizure energy and entropy was statistically insignificant. Conclusion: The study shows that the energy level remains low in the seizure patients in the alpha and beta bands. This further goes down when electrophysiological seizure activities starts. The randomness or entropy does not alter significantly among the seizure subjects in comparison to non-seizure subjects.

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Attentional Fluctuations Influence the Neural Fidelity and Connectivity of Stimulus Representations

Journal of Cognitive Neuroscience ◽

10.1162/jocn_a_01306 ◽

2018 ◽

Vol 30 (9) ◽

pp. 1209-1228 ◽

Cited By ~ 6

Author(s):

David Rothlein ◽

Joseph DeGutis ◽

Michael Esterman

Keyword(s):

Functional Connectivity ◽

Large Scale ◽

Brain Networks ◽

Relevant Information ◽

Mental States ◽

Attention Task ◽

Default Mode ◽

Neural Representations ◽

Similarity Structure ◽

Similarity Matrices

Attention is thought to facilitate both the representation of task-relevant features and the communication of these representations across large-scale brain networks. However, attention is not “all or none,” but rather it fluctuates between stable/accurate (in-the-zone) and variable/error-prone (out-of-the-zone) states. Here we ask how different attentional states relate to the neural processing and transmission of task-relevant information. Specifically, during in-the-zone periods: (1) Do neural representations of task stimuli have greater fidelity? (2) Is there increased communication of this stimulus information across large-scale brain networks? Finally, (3) can the influence of performance-contingent reward be differentiated from zone-based fluctuations? To address these questions, we used fMRI and representational similarity analysis during a visual sustained attention task (the gradCPT). Participants ( n = 16) viewed a series of city or mountain scenes, responding to cities (90% of trials) and withholding to mountains (10%). Representational similarity matrices, reflecting the similarity structure of the city exemplars ( n = 10), were computed from visual, attentional, and default mode networks. Representational fidelity (RF) and representational connectivity (RC) were quantified as the interparticipant reliability of representational similarity matrices within (RF) and across (RC) brain networks. We found that being in the zone was characterized by increased RF in visual networks and increasing RC between visual and attentional networks. Conversely, reward only increased the RC between the attentional and default mode networks. These results diverge with analogous analyses using functional connectivity, suggesting that RC and functional connectivity in tandem better characterize how different mental states modulate the flow of information throughout the brain.

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