Steady-state evoked potentials

Abstract

The advantages of steady-state EP recording include (1) speed in assessing sensory function in normal and sick infants (e.g., in amblyopia) and in sick adults (e.g., in multiple sclerosis); (2) monitoring certain activities of sensory pathways that do not intrude into conscious perception; (3) rapidly assessing sensory function when a large number of subjects must be tested (e.g., in refraction); (4) objective measurement at very high suprathreshold levels where psychophysical methods are difficult or ineffective; (5) rapidly assessing sensory function in normal subjects when EP variability and nonstationarity preculde lengthy experiments; and (6) proving a speedy objective equivalent to behavioral test in animals.

Steady-State Visual Evoked Potentials: Distributed Local Sources and Wave-Like Dynamics Are Sensitive to Flicker Frequency

“…Early human studies using EEG electrodes positioned over occipital cortex (Sperkeijse et al, 1977;Regan, 1977;Tyler et al, 1978;Regan, 1989), and local field potentials recorded within monkey visual cortex (Nakayama and Mackeben, 1982) demonstrated that steady-state responses recorded over visual cortex depend on the temporal frequency of visual input. The dependence of the magnitude of the steady-state response on the input frequency is characterized by local maxima in the response amplitude at the stimulation frequency in at least three different "resonance" bands.…”

Human Sensitivity to High Frequency Sine Wave and Pulsed Light Stimulation as Measured by the Steady State Cortical Evoked Response

“…If such speculation can be ccnfirmed, it would mean that the brain contains units which are tuned to this type of stimulation at these particular frequencies. Further, this tuning is specific to stimuli that produce gradual intensity changes, since it is neither found with stroboscopic stimulation nor with alternating checkerboard patterns (Regan, 1977).…”

“…It is well established that an occipital lead is appropriate for studying basic functioning of the visual system and for investigating and detecting certain pathological states (Regan, 1977). The expanding range of possible applications for th;is technique raises other questions concerning appropriate sites of electrode placement.…”

V-5 : Les POTENTIELS ÉVOQUÉS VISUELS corticaux (PEV)

“…Le temps de culmination n'a pas de signification. L'amplitude varie avec la fréquence temporelle de stimulation et présente successivement trois maximums, le premier autour de 10 Hz, puis le deuxième 10% moins ample autour de 18 Hz, enfin le troisième 60% moins ample, autour de 50 Hz (Regan, 1977) (figure V-5-13). Ce résultat correspond probablement à la séparation progressive des vitesses de conduction des signaux le long des différentes voies visuelles -P voie lente et M voie rapide -en relation avec les différents diamètres de leurs axones (Hammett & Smith, 1992), (Milner et al 1972), (Baseler & Sutter, 1997).…”