Time-frequency analysis of brain activity in response to directional and non-directional visual stimuli: an event related spectral perturbations (ERSP) study

Abstract

Objective: A large part of the cerebral cortex is dedicated to the processing of visual stimuli and there is still much to understand about such processing modalities and hierarchies. The main aim of the present study is to investigate the differences between Directional (DS) and non-Directional (n-DS) visual stimuli processing by time-frequency analysis of brain EEG activity during a visuo-motor task. EEG data were divided into 4 Regions of Interest (ROIs) (Frontal, Central, Parietal, Occipital). Approach: The analysis of the visual stimuli processing was based on the combination of electroencephalographic recordings and Time-frequency analysis. Event Related Spectral Perturbations (ERSPs) were computed with spectrum analysis that allow to obtain the average time course of relative changes induced by the stimulus presentation in spontaneous EEG amplitude spectrum. Main results: Visual stimuli processing enhanced the same pattern of spectral modulation in all investigated ROIs with differences in amplitudes and timing. Additionally, statistically significant differences in Occipital ROI between the DS and n-DS visual stimuli processing in theta, alpha and beta bands were found. Significance: These evidences suggest that ERSPs could be a useful tool to investigate the encoding of visual information in different brain regions. Because of their simplicity and their capability in the representation of brain activity, the ERSPs might be used as biomarkers of functional recovery for example in the rehabilitation of visual dysfunction and motor impairment following a stroke, as well as diagnostic tool of anomalies in brain functions in neurological diseases tailored to personalized treatments in clinical environment.

Mnemonic-trained brain tuning to a regular odd-even pattern subserves digit memory in children

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The Effects of Directional and Non-Directional Stimuli during a Visuomotor Task and Their Correlation with Reaction Time: An ERP Study

“…The monitor of the computer was located at a distance of around 60 cm. A typical trial was characterized by the sequence of visual stimuli shown in Figure 1 [ 33 , 34 ]: (1) a central white cross (diameter of 0.5°) in the background; (2) a cue stimulus as a square (size about 0.8°) with an “arrow” or a smaller “square” appearing inside, on the centre of the monitor for 2000 ms; (3) a go stimulus “green square” (size about 0.8°) lasting until subject response or until 2000 ms after its appearance; (4) the sequence restarting from point (1) for 2000 ms.…”

Concurrent behavioral modelling and multimodal neuroimaging reveals how feedback affects the performance of decision making in internet gaming disorder

“…The Morlet wavelet transform is generally used to generate EEG spectral components as it strikes a favorable balance between temporal and frequency resolution. More specifically, Morlet wavelet transform demonstrates its exceptional efficiency when applied to non-stationary signals, making it an excellent candidate to analyze the present data (Vecchio et al, 2022). Statistical analysis of EROs was performed with a non-parametric procedure based on permutations (1000 times) and cluster-level statistics ( p = 0.001, cluster-level p = 0.01).…”