ABSTRACT
OBJECTIVES@#To analyze the Nogo-P3 component of event-related potential (ERP) in the process of visual acuity processing, to provide electrophysiological evidence for objective evaluation of visual acuity.@*METHODS@#Twenty-six subjects with no other ocular diseases except for ametropia were recruited, and all subjects had uncorrected visual acuity both eyes 1/10 (evaluated using Monoyer chart). Block letter E with different visual angles and directions were used as graphic stimuli. The Go/Nogo paradigm was used for ERP studies. The visual angle of Go stimulation angle was 1°15', Nogo stimuli were 1°15', 55', 24' and 15'. The visual acuity test was performed on each of the two naked eyes separately in all subjects, and the characteristics of the Nogo-P3 component were analyzed.@*RESULTS@#The latency of Nogo-P3 showed no difference between the stimuli of 1°15' and 55', and between Nogo stimulation angle 24' and 15'. There was significant difference between Nogo stimulation angle 1°15' and 24', and between Nogo stimulation angle 1°15' and 15' (P<0.05). There was significant difference between Nogo stimulation angle 55' and 24', and between Nogo stimulation angle 55' and 15' (P<0.05). No significant differences were observed in the Nogo-P3 amplitude among Nogo stimulation.@*CONCLUSIONS@#In the Go/Nogo paradigm, Nogo-P3 can reflect the cognitive response of subjects to Nogo stimulation, which can be used for objective evaluation of visual acuity.
Subject(s)
Humans , Electroencephalography , Evoked Potentials/physiology , Photic Stimulation , Reaction Time/physiology , Refractive Errors , Visual AcuityABSTRACT
Objective The tests of three types of auditory evoked potentials （AEPs） were performed on normal young adults, to understand the frequency characteristics of different testing methods and the relationship between response threshold and pure tone audiometry threshold of different methods, and to discuss the forensic value of 3 types of AEPs to evaluate hearing function. Methods Twenty normal young adults were selected, their standard pure tone audiometry threshold, short-term pure tone audiometry threshold and the response threshold of 3 types of AEPs （tone burst-auditory brainstem response, 40 Hz auditory event-related potential and slow vertex response） at 0.5 kHz, 1.0 kHz, 2.0 kHz and 4.0 kHz were recorded. The relationship between the response threshold and standard pure tone audiometry threshold, short-term pure tone audiometry threshold of 3 types of AEPs at different frequencies as well as the differences between different types of AEPs were analyzed. Results The short-term pure tone audiometry threshold was higher than the standard pure tone audiometry threshold at each frequency. The response threshold and standard pure tone audiometry threshold of the 3 types of AEPs all had a certain correlation, and the response threshold of the 3 types of AEPs was higher than short-term pure tone audiometry threshold and standard pure tone audiometry threshold at each frequency. The differences in the differences between the response threshold and standard pure tone audiometry threshold of the 3 types of AEPs at different frequencies had statistical significance. Linear regression mathematical models were established to infer the standard pure tone audiometry threshold （hearing level） from response threshold （sound pressure level） of 3 types of AEPs of normal young adults. Conclusion When using response threshold of different types of AEPs to estimate pure tone audiometry threshold, conversion and correction are needed. Combined use of different types of AEPs could improve the accuracy of hearing function evaluation.
Subject(s)
Humans , Young Adult , Audiometry, Evoked Response , Audiometry, Pure-Tone , Auditory Threshold , Evoked Potentials, Auditory , Evoked Potentials, Auditory, Brain Stem , HearingABSTRACT
In this study,we aimed to study the pattern visual evoked potentials (P-VEPs) in two eyes with varying visual acuity in one eye and to provide an objective estimation of visual acuity by comparing P-VEPs in one and two eyes.Thirty subjects were chosen,who had one eye with an acuity of 5.0,4.85,4.6,4.0,or scieropia and obstructed vision and the other eye with an acuity of 5.0,respectively.P-VEPs were detected under the large grating stimuli at 3×4 spatial frequency,moderate grating stimuli (12× 16 spatial frequency) and small grating stimuli (48×64 spatial frequency).Under large grating stimuli,there was no significant difference in P100 peak latency between the groups,nor was there a significant difference between the amplitude of two eyes and the amplitude of one normal-vision eye.Under moderate and small grating stimuli,there was a significant difference in P100 peak latency between the group with both eyes having an acuity of 5.0 and the group with visual acuity below 4.0 in one eye.There was a significant difference in P100 amplitude between the group with visual acuity of 5.0 in both eyes and the group with one normal-vision eye.There was no significant difference in the amplitude of two eyes and the amplitude of one normal-vision eye between any other two groups.In forensic identification,characteristics and variability of P-VEPs in one and two eyes can be used to identify malingering or decline in visual acuity.
ABSTRACT
In this study,we aimed to study the pattern visual evoked potentials (P-VEPs) in two eyes with varying visual acuity in one eye and to provide an objective estimation of visual acuity by comparing P-VEPs in one and two eyes.Thirty subjects were chosen,who had one eye with an acuity of 5.0,4.85,4.6,4.0,or scieropia and obstructed vision and the other eye with an acuity of 5.0,respectively.P-VEPs were detected under the large grating stimuli at 3×4 spatial frequency,moderate grating stimuli (12× 16 spatial frequency) and small grating stimuli (48×64 spatial frequency).Under large grating stimuli,there was no significant difference in P100 peak latency between the groups,nor was there a significant difference between the amplitude of two eyes and the amplitude of one normal-vision eye.Under moderate and small grating stimuli,there was a significant difference in P100 peak latency between the group with both eyes having an acuity of 5.0 and the group with visual acuity below 4.0 in one eye.There was a significant difference in P100 amplitude between the group with visual acuity of 5.0 in both eyes and the group with one normal-vision eye.There was no significant difference in the amplitude of two eyes and the amplitude of one normal-vision eye between any other two groups.In forensic identification,characteristics and variability of P-VEPs in one and two eyes can be used to identify malingering or decline in visual acuity.