Subjective Cognitive Impairment (SCI) is a self-perceived worsening of cognitive decline, carrying an increased risk of developing Mild Cognitive Impairment (MCI) and Alzheimer's Disease (AD). Due to the self-report nature of SCI, an understanding of the biological mechanisms that contribute to an increased dementia risk is needed. This study aims to assess the differences in resting state electroencephalography (EEG) (eyes-open, eyes-closed; EO, EC) between older adults with SCI and healthy controls (HCs) utilising frequency principal components analysis (fPCA), a novel data driven approach.
View Article and Find Full Text PDFMindfulness meditation is linked to a broad range of psychological and physical health benefits, potentially mediated by changes in neural oscillations. This study explored changes in neural oscillations associated with both immediate and regular mindfulness meditation practice. Electroencephalographic (EEG) data were collected from 40 healthy young adults (M = 20.
View Article and Find Full Text PDFDetailed studies of the equiprobable auditory Go/NoGo task have allowed for the development of a sequential-processing model of the perceptual and cognitive processes involved. These processes are reflected in various components differentiating the Go and NoGo event-related potentials (ERPs). It has long been established that electroencephalography (EEG) changes through normal lifespan development.
View Article and Find Full Text PDFMind-wandering is characterised as the emergence of thought and emotions which shift attention away from a primary task. It is thought to consume up to 50 % of our waking lives and has several negative implications. Breath-counting is one task that has been utilised in conjunction with electroencephalography (EEG) to examine the brain states associated with mind-wandering.
View Article and Find Full Text PDFSokolov described both phasic and tonic aspects of the Orienting Reflex (OR), but subsequent research and theory development has focussed primarily on the phasic OR at the expense of the tonic OR. The present study used prestimulus skin conductance level (SCL) during a dishabituation paradigm to model the tonic OR, examining its amplitude patterning over repeated standard stimulus presentations and a change stimulus. We expected sensitisation (increased amplitude) following the initial and change trials, and habituation (decrement) over the intervening trials.
View Article and Find Full Text PDFAlzheimers Dement (N Y)
October 2023
Although the P300 event-related potential (ERP) is the most likely central measure of Sokolov's Orienting Reflex (OR), there are few systematic comparisons with the skin conductance response (SCR), the "gold standard" electrodermal OR measure. We examine habituation, stimulus significance, and inter-stimulus interval (ISI) effects in SCRs and components of the P300 from single-trial ERPs in an auditory dishabituation paradigm. Single trial ERP components were separated by temporal principal components analysis, and five components of the P300 were examined as potential phasic OR measures: P3a, P3b, Novelty P3, and two Slow Waves (SW1, SW2).
View Article and Find Full Text PDFObjective: Endometriosis is associated with neuroplastic changes in cognitive control and pain processing networks. This was the first study to assess eyes-closed resting electroencephalogram (EEG) oscillatory amplitudes in women with endometriosis compared to healthy controls, and explore the relationship with chronic pelvic pain.
Methods: Women with endometriosis-related chronic pelvic pain and individually age-matched pain-free controls (N = 20 per group) documented pelvic pain for 28 days before having continuous EEG recorded during a 2 min eyes closed resting state.
The effects of transcranial direct current stimulation (tDCS) for improving attention and working memory have been generally mixed and small, potentially due to variability between studies with montages, stimulus parameters and outcome measures. The tDCS montage is an important parameter which determines the degree and intensity of stimulation in targeted brain regions. This study aimed to examine the effects of using three different montages for modulating attention and working memory performance: Bi-frontal, Broad-frontal and Broad-parietal.
View Article and Find Full Text PDFThe resting-state paradigm is frequently applied to study spontaneous activity of the brain in normal and clinical conditions. However, the relationship between the ongoing experience of mind wandering and the individual biological signal is still unclear. We aim to estimate associations between subjective experiences measured with the Amsterdam Resting-State Questionnaire and data-driven components of an electroencephalogram extracted by frequency principal component analysis (f-PCA).
View Article and Find Full Text PDFOur previous studies of the equiprobable auditory Go/NoGo task have been used to substantiate a perceptual/cognitive Processing Schema in young and older adults, and in children. The processes in the Schema are linked to PCA components derived separately from Go and NoGo ERPs. Here we investigated sex differences in the child Schema.
View Article and Find Full Text PDFAuditory stimulus intensity of innocuous tones is generally thought to have a direct effect on the amplitude of ERP components, but these effects have rarely been explored across a wide component range, or in multiple paradigms. Here we investigate component sensitivity to stimulus intensity differences in two studies. Study 1 (N = 36) employed a between-participants paradigm in which repeated trains of standard stimuli were presented as 50 or 80 dB SPL 1000 Hz tones.
View Article and Find Full Text PDFFollowing investigations into the benefits of meditation on psychological health and well-being, research is now seeking to understand the mechanisms underlying these outcomes. This study aimed to identify natural alpha and theta frequency components during eyes-closed resting and concentrative meditation states and examined their differences within and between two testing sessions. Novice meditators had their EEG recorded during eyes-closed resting and concentrative meditation conditions, before and after engaging in a brief daily concentrative meditation practice for approximately one-month.
View Article and Find Full Text PDFInt J Psychophysiol
January 2022
Since the equiprobable Go/NoGo task lacks the dominant Go imperative of the usual Go/NoGo (with more Go than NoGo stimuli), it is generally regarded as involving little inhibition. However, children have relative difficulty with this task, and have a large frontal NoGo N2. We previously found that this 'child N2' does play an inhibitory role, with larger frontal N2b associated with fewer commission errors.
View Article and Find Full Text PDFThe power spectrum of the human electroencephalogram (EEG) as a function of frequency is a mix of brain oscillations (Osc) (e.g. alpha activity around 10 Hz) and non-Osc or noise of uncertain origin.
View Article and Find Full Text PDFEndometriosis is a debilitating women's health condition and is the most common cause of chronic pelvic pain. Impaired cognitive control is common in chronic pain conditions, however, it has not yet been investigated in endometriosis. The aim of this study was to explore the neuronal correlates of cognitive control in women with endometriosis.
View Article and Find Full Text PDFJ Caffeine Adenosine Res
June 2020
We used caffeine as a tool to explore the active cognitive-processing stages in a simple Go/NoGo task, in terms of the event-related potential (ERP) components elicited by the Go and NoGo stimuli. Two hundred and fifty milligrams of caffeine was administered to adult participants ( = 24) in a randomized double-blind placebo-controlled repeated-measures crossover study. Two blocks of an equiprobable auditory Go/NoGo task were completed, each with a random mix of 75 tones at 1000 Hz and 75 at 1500 Hz, all 60 dB sound pressure level (SPL).
View Article and Find Full Text PDFInt J Psychophysiol
September 2020
The immediately-prestimulus electroencephalographic (EEG) brain state influences subsequent event-related processing, dynamically impacting event-related potential (ERP) and behavioural outcomes. Both EEG and ERPs are known to undergo age-related change, yet few have investigated the consistency in their dynamic interrelations in the context of ageing. The present investigation assessed the impact of prestimulus alpha and beta brain states in 20 young (18-26 years) and 20 gender-matched healthy older (59-75 years) adults who completed an equiprobable auditory Go/NoGo paradigm.
View Article and Find Full Text PDFSome 40 years ago, Erol Başar began an interesting line of brain dynamics research on the phase of oscillatory EEG activity. Stimuli presented at a fixed interstimulus interval (ISI) were reported to produce a "preferred phase angle" at stimulus onset in the ongoing EEG oscillations, so that cortical negativity occurred more often than expected. Our previous work has confirmed this phenomenon in young adults, and linked it to enhancements in stimulus-elicited ERP components and behaviour.
View Article and Find Full Text PDFNon-invasive transcranial direct current stimulation (tDCS) has been reported to facilitate working memory in normal adults. There is some evidence in people with Traumatic Brain Injury (TBI) but overall evidence is mixed. This study aimed to address shortcomings of prior study designs in TBI to examine whether a single dose of tDCS would lead to benefits in working memory.
View Article and Find Full Text PDFObjective: Global EEG alpha activity is negatively correlated with skin conductance level (SCL), supporting alpha as an inverse marker of arousal. Frequency Principal Components Analysis (f-PCA) of resting EEG amplitude spectra has demonstrated natural components in the alpha band of healthy persons. This is a preliminary exploration of whether such components differ with arousal, possibly underpinning the anomalous ADHD hypoarousal link to reduced alpha.
View Article and Find Full Text PDFBrain dynamics research has highlighted the contributions of the ongoing EEG to ERP and behavioural responses. This study examined the effects of state-related EEG changes, from rest to the task and within the task, on stimulus-response efforts in a visual Continuous Performance Test (CPT). EEG was recorded from fifty-six adults at rest with eyes-closed (EC) then eyes-open (EO), and during the CPT.
View Article and Find Full Text PDFThe ratio between frontal resting-state electroencephalography (EEG) theta and beta frequency power (theta/beta ratio, TBR) is negatively related to cognitive control. It is unknown which psychological processes during resting state account for this. Increased theta and reduced beta power are observed during mind wandering (MW), and MW is related to decreased connectivity in the executive control network (ECN) and increased connectivity in the default mode network (DMN).
View Article and Find Full Text PDFCogn Affect Behav Neurosci
October 2019
The reflexive orienting response triggered by nonpredictive gaze cues is thought to be driven by a dedicated social neural network responsible for directing attention toward socially salient information. However, atypical processing of eye gaze using concomitant perceptual features has been proposed to underlie attentional orienting in groups with impairments in social cognition. Here, we examined the neurophysiological indices of visuospatial attention during a spatial cueing task, considering individual variability in social cognition in typically developing individuals, and the relative salience of social gaze and perceptual motion cues.
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