A scoping, narrative roadmap of SSVEP applications organized into three primary domains is provided, highlighting the versatility of SSVEPs in investigating neural mechanisms, supporting diagnosis and treatment of neurological and psychiatric conditions, and advancing brain-computer interface technology.
Abstract
The steady-state visual evoked potential (SSVEP), the brain's oscillatory response to repetitive visual stimulation (RVS), has emerged as a powerful tool in neuroscience with wide-ranging applications in multiple disciplines. This review provides a scoping, narrative roadmap of SSVEP applications organized into three primary domains: fundamental research in vision and cognition, clinical neuroscience, and neural engineering. Although these fields differ in focus, they often converge in their use of similar research questions, stimulation paradigms, analysis techniques, and application scenarios. At the same time, specialization may have created knowledge silos that limit cross-disciplinary transfer of methods and insights. By bridging findings from seemingly disparate domains, this review highlights the versatility of SSVEPs in investigating neural mechanisms, supporting diagnosis and treatment of neurological and psychiatric conditions, and advancing brain-computer interface technology. We conclude with cross-field insights on how stimulus and analysis choices affect interpretation and usability, and we outline directions for improving the comparability and transferability of SSVEP research and applications.
Gamma-band oscillations centered around 40 Hz play an important role in cortical communication, and their disruption has been documented as a neurophysiological feature of several neurodegenerative and neuropsychiatric disorders. This narrative review synthesizes preclinical and early-phase clinical evidence for 40 Hz non-invasive brain stimulation across five delivery modalities: (1) auditory stimulation, which leverages the 40 Hz auditory steady-state response (ASSR) to probe parvalbumin-positive (PV+) interneuron circuits and serves as a validated neurophysiological biomarker in schizophrenia; (2) visual stimulation, using luminance or invisible spectral flicker to induce steady-state visually evoked potentials (SSVEPs) and, in animal models, to activate microglial phagocytosis; (3) transcranial alternating current stimulation (tACS), which delivers sinusoidal sub-threshold membrane polarization at gamma frequency, with preliminary case-series evidence suggesting tau burden reduction and EEG-based biomarker changes in Alzheimer’s disease; (4) repetitive transcranial magnetic stimulation (rTMS), offering focal cortical entrainment that, when combined with tACS in phase-synchronized protocols, produces sustained gamma enhancement in the dorsolateral prefrontal cortex; and (5) multisensory combined stimulation, which engages multiple convergent pathways and currently represents the approach with the most promising early translational signal, including cognitive stabilization and hippocampal volume preservation in small AD trials. While single-session entrainment does not reliably yield cognitive gains, multi-week applications have shown neurophysiological and preliminary biomarker-level changes in selected populations. It should be emphasized, however, that the human evidence base remains early-phase and largely derived from small, often uncontrolled studies; 40 Hz stimulation should accordingly be regarded as a biologically plausible and well-tolerated investigational approach rather than an established therapeutic intervention. Adequately powered, randomized, sham-controlled trials are required before clinical conclusions can be drawn.
Parkinson's disease (PD) can disrupt retinal, early cortical, oscillatory, and distributed visuoperceptual processing. This structured integrative review synthesized human evidence from pattern electroretinography (PERG), electroretinography (ERG), optical coherence tomography (OCT)-linked and conventional visual evoked potentials (VEPs), visual event-related potentials (ERPs), electroencephalography (EEG), steady-state visual evoked potentials (ssVEPs), and occipital transcranial magnetic stimulation-electroencephalography (TMS-EEG), with searches verified up to 18 July 2026. Findings were organized into four domains: 1) Retinal and retinocortical contributions: retinal dysfunction can delay or attenuate afferent input, yet concurrent retinal physiology is rarely measured; therefore VEP abnormalities cannot generally be assigned specifically to cortex. 2) Early visual encoding: prolonged pattern-reversal P100 latency is the most reproducible finding, including a pooled 6.04-ms delay across 20 case-control studies, whereas amplitude findings are inconsistent. 3) Oscillatory dynamics: PD-specific ssVEP evidence suggests altered contextual gain, but it derives from one small unreplicated study; gamma-band and task-EEG findings remain sparse and confound-sensitive. 4) Higher-order and network-level processing: visual ERPs, resting microstates, and occipital TMS-EEG indicate possible associations with hallucinations, cognition, and network connectivity, but current studies are cross-sectional or unreplicated. Overall, PD is characterized by multilevel visual-pathway dysfunction rather than a single cortex-specific biomarker. Ophthalmic status, retinal physiology, medication state, cognition, mood, sleep, and recording quality should be controlled before electrophysiological measures are used for localization, stratification, or prognosis.
Emilia Samit, Karina dos Santos Machado· Neurophysiologie clinique· 0 citations
The study stresses the necessity of embedding relational autonomy and neural rights into BCI development, tying technological trajectories to governance demands in order to shape responsible paths for future neurotechnologies.
Yuzhang Wu· Theoretical and Natural Scie...· 0 citations
Unlike the pattern-reversal visual evoked potential, the flash visual evoked potential (FVEP) has had limited clinical use because of lower reproducibility and higher inter- and intra-individual variability. One potential explanation involves the time-locked nature of FVEP recordings, where activity such as unintentional suppression of eyes-closed alpha can lead to overlapping potentials that might obscure the FVEP-P2. The present investigation evaluated the reliability of the FVEP-P2 in young healthy controls across five sessions after applying narrow-band filtering (1-7 Hz) and additional notch filtering to remove alpha and beta activity. It was hypothesized that spectral entrainment would occur within the alpha and that correction for this entrainment would significantly improve the reliability of FVEP-P2. 27 younger, healthy participants aged 18-39 years (M = 24.48, SD = 5.26; 17 females) took part in the study, all reporting no history of photosensitivity or seizures, neurological disorders, or color deficiency. Each participant experienced five sessions of 100 strobe flashes with their eyes closed. The FVEP-P2 associated with each trial was identified using an automated algorithm. Narrow-band filtering (1-7 Hz) significantly improved FVEP-P2 latency reliability compared to the uncorrected condition. Notch filters targeting alpha and beta separately did not produce significant improvements, suggesting additive or overlapping contributions. FVEP-P2 amplitude reliability also improved with filtering, primarily because of attenuating alpha-band interference. Narrow-band and notch filtering mitigated alpha- and beta-band interference, enhancing the test-retest reliability of the FVEP-P2. These findings establish a clearer physiological basis for FVEP unreliability and demonstrate that spectral correction can elevate the FVEP-P2 to clinically acceptable reliability levels, supporting the continued clinical utility of the FVEP, particularly in patients for whom pattern-reversal stimuli are unsuitable (e.g., infants, comatose, or uncooperative individuals) and as a candidate biomarker in mild cognitive impairment and Alzheimer's disease (Arruda et al., 2020; Fix et al., 2014).
J. Arruda, Neil M. Dundon, Angelique Jefferson et al.· Applied Psychophysiology and...· 0 citations
Non-invasive brain stimulation (NIBS) allows to investigate the causal relationship between the activity of a target brain region and the performance in a specific task. Regarding visual perception tasks and NIBS of the visual cortex, previous attempts reported mixed results, possibly because of (1) the use of different NIBS protocols, and (2) the lacking consideration that visual perception can be modulated by visuomotor activity. It is therefore still unclear whether the combination of visuomotor activity with which specific NIBS protocol can best influence visual perception. To fill this gap, we measured visual performance (detection) before and after three visuomotor-coupled, excitatory, high-definition NIBS [transcranial direct current stimulation (tDCS), oscilatory tDCS (otDCS), transcranial random noise stimulation (tRNS)] and a sham condition, all delivered to the visual cortex in the human brain. Eighty-four neurotypical participants divided in four groups (tDCS, otDCS, tRNS, Sham) took part in the study. The online visuomotor activity was a virtual reality game where participants had to hit different targets (mosquitoes), repeated for four days. Detection accuracy of visual stimuli was measured on each day. Results showed that otDCS was associated with significantly higher visual detection performance, compared to sham, tDCS, and tRNS, with effects emerging after the first session and becoming more pronounced across subsequent sessions. These effects depended on stimulus eccentricity, with the largest effects observed in the peripheral visual field. These findings suggest that visuomotor-coupled otDCS is a promising approach to enhance visual detection, particularly in the peripheral visual field.
S. Giannoni-Luza, S. Osimo, Silvio Ionta· NeuroImage· 0 citations
Non-invasive brain stimulation techniques, such as transcranial electric stimulation (tES), are increasingly promoted as methods to enhance attention. However, their efficacy and optimal stimulation targets remain uncertain. We conducted a preregistered meta-analysis of randomized controlled trials in healthy adults (58 trials, 295 outcomes) examining the effects of tES on attentional functions (PROSPERO: CRD42023487035), complemented by a performance-electric field correlation (PEC) analysis to identify brain regions most strongly linked to tES-induced behavioral improvements. In general, tES produced a small but significant improvement in attentional functions compared to control conditions (standardized mean difference [SMD] = 0.24, 95% confidence interval [CI] = 0.12-0.36, I2 = 61%). Small but consistent benefits were observed in trials assessing attentional functions after stimulation (40 trials, SMD = 0.23, 95% CI = 0.12-0.33, I2 = 39%) and in trials applying anodal transcranial direct current stimulation (tDCS) targeting prefrontal regions (vs sham; 31 trials, SMD = 0.26, 95% CI = 0.12-0.39, I2 = 46%) with no evidence of publication bias or serious imprecision. The PEC analysis further revealed that tDCS-induced electric fields in the ventral subregion of the left dorsolateral prefrontal cortex (left vDLPFC) were most strongly associated with improvements in attentional functions following tDCS. Taken together, these findings suggest that tES may enhance attentional functions and the left vDLPFC may be a potential target for future tES studies aiming to improve attention.
Toru Takahashi, Ikko Kimura, S. Vafaei et al.· Biological Psychology· 0 citations