Electroencephalographic Indicators in Default Mode, Habituation, and Visual-motor Association in Female College Students.

BACKGROUND: Oscillations, action, and postsynaptic potentials in glial-neuronal ensembles integrate the spectral power (SP) of electroencephalographic (EEG). Our objective is to propose SP indicators of healthy brains (control groups) based on the default mode and their modifications by habituation and visual-motor association (VM-asso), to support diagnostic and rehabilitation processes. However, important differences seem to exist between men and women. Therefore, we aim to analyze EEG characteristics in a female sample. SUBJECTS AND METHODS: In the current study, EEG was recorded at rest with closed eyes before and during repeated photostimulations (RPh) and before (pre) and during association of RPh with switch pressing (VM-asso) in 70 female adults. EEG was analyzed using UAM/INR software, which removes artifacts, identifies corresponding signals, selects 20 samples (2-s) from each condition, applies Welch's periodogram to calculate and average the absolute power (AP; AAPs) of áµ¹, θ, α, and ß, before and during learning, and emits data to a spreadsheet. Differences in each condition were evaluated using non-parametric tests. RESULTS: The AAPs were different; in habituation, áµ¹ and θ increased significantly in fronto-frontal (FF) and frontocentral and decreased in the other leads. During association, they increased in FF and decreased in the other three regions. α AAP decreased in all leads except in FF during habituation, and the decrement was lower in the association. ß AAP increased in all leads during both learning conditions. CONCLUSION: The SP and the topographic distribution are descriptive parameters of habituation and VM-asso; we propose them as EEG indicators.

Attentional impairment in Parkinson's disease is modulated by side of onset: Neurophysiological evidence.

OBJECTIVE: Neurophysiological studies exploring involuntary attention have reported that electroencephalographic (EEG) measures can indicate impaired neural processing from initial stages of Parkinson's disease (PD). Since involuntary attention is regulated by right hemisphere networks and PD generally initiates its motor symptomatology unilaterally, whether involuntary attention is impaired depending on the onset side of PD remains unknown. METHODS: We compared the neurophysiological correlates of involuntary attention among a PD group with left-side onset (L-PD), a PD group with right-side onset (R-PD) symptomatology, and a healthy control group (HC). All participants performed an auditory involuntary attention task while a digital EEG was recorded. RESULTS: Our main finding was a reduction both in the P3a amplitude and evoked delta-theta phase alignment in the L-PD group compared to the HC. Further, there was a significant correlation between P3a amplitude and disease duration in the R-PD, but not in the L-PD group. Behaviorally, both clinical groups, and in particular L-PD, showed reduced orientation towards novel stimuli, and no reduction of distraction effects during the experiment. CONCLUSIONS: Our results indicate that involuntary attention is differentially impaired in patients with left side onset of symptoms. Involuntary attention impairment might be present from initial stages of left onset PD and become progressively compromised in patients with right onset PD. SIGNIFICANCE: The onset side of symptomatology should be considered for attentional impairment in PD.