Can the occipital alpha‐phase speed up visual detection through a real‐time EEG‐based brain–computer interface (BCI)?

Abstract

Electrical brain oscillations reflect fluctuations in neural excitability. Fluctuations in the alpha band (α,(8)(9)(10)(11)(12) in the occipito-parietal cortex are thought to regulate sensory responses, leading to cyclic variations in visual perception. Inspired by this theory, some past and recent studies have addressed the relationship between α-phase from extra-cranial EEG and behavioural responses to visual stimuli in humans. The latest studies have used offline approaches to confirm α-gated cyclic patterns.However, a particularly relevant implication is the possibility to use this principle online for realtime neurotechnology, whereby stimuli are time-locked to specific α-phases leading to predictable outcomes in performance. Here we aimed at providing a proof-of-concept for such real-time neurotechnology. Participants performed a speeded response task to visual targets that were presented upon a real-time estimation of the α-phase via an EEG closed-loop brain-computer interface (BCI). We predicted, according to the theory, a modulation of reaction times (RTs) along the α-cycle. Our BCI system achieved reliable trial-to-trial phase-locking of stimuli to the phase of individual occipito-parietal α-oscillations. Yet, the behavioural results did not support a consistent relation between RTs and the phase of the α-cycle neither at group nor single participant levels. We must conclude that although the α-phase might play a role in perceptual decisions from a theoretical perspective, its impact on EEG-based BCI application appears negligible.

Effect of Tempo on Temporal Expectation Driven by Rhythms in Dual-Task Performance

“…These effects might be associated with entrainment, in which low-frequency neural oscillations in connection with fluctuations between periods of high and low neural sensitivity to the input and become phase-aligned to the external rhythmic stream such that periods of high sensitivity coincide with on-beat times of rhythmic stimuli ( Jones, 1976 ; Large and Jones, 1999 ; Barnes and Jones, 2000 ; Schroeder and Lakatos, 2009 ; Breska and Deouell, 2016 ). A handful of studies failed to find the rhythmic behavioral benefits ( Benwell et al, 2017 ; Ruzzoli et al, 2019 ; Vigué-Guix et al, 2020 ; Lin et al, 2021 ).…”

Rhythms in cognition: The evidence revisited

“…For instance, the exact sampling frequencies implicated in cognitive functions often differ between studies and have been shown to depend on the task and/or stimulus characteristics (Chen et al, 2020;Ho et al, 2017;Merholz et al, 2022;Ronconi et al, 2017; also see table in Ruzzoli et al, 2019), which is difficult to reconcile with any simple model of fixed, discrete temporal 'frames' (White, 2018). Additionally, the effect sizes in studies showing periodicity in behavioural or neural measures tend to be small, hence not in line with clear, all-or-nothing frame boundaries (Milton & Pleydell-Pearce, 2016;White, 2018) or utility for real-life applications (Vigué-Guix et al, 2020). Furthermore, the literature suffers from a lack of direct replications, preregistered studies, data, and code sharing (Garrett-Ruffin et al, 2021;Niso et al, 2021;Pavlov et al, 2021), as well as low statistical power (Button et al, 2013).…”

No behavioural evidence for rhythmic facilitation of perceptual discrimination

“…This entrainment proposal rests on the key idea that neural oscillations reflect alternating excitability states (excitation/inhibition) of neuronal ensembles (Başar et al, 2013;Bishop, 1932). While there is some evidence that the phase of ongoing oscillations at the time of sensory stimulation impacts the neural response to that stimulus, as well as subsequent behavioural performance (e.g., Busch et al, 2009;Mathewson et al, 2009;Ten Oever & Sack, 2019; for a review see VanRullen, 2016), this evidence is far from conclusive as several studies have reported null results (e.g., Benwell et al, 2017;O'Hare, 1954;Ruzzoli et al, 2019;Vigué-Guix et al, 2020;Walsh, 1952).…”