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VEP Responses to Op-Art Stimuli.

O'Hare L, Clarke AD, Pollux PM - PLoS ONE (2015)

Bottom Line: Previous research using op-art-based stimuli has demonstrated that spurious eye movement signals can cause the experience of illusory motion, or shimmering effects, which might be perceived as uncomfortable.Whilst the shimmering effects are one cause of discomfort, another possible contributor to discomfort is excessive neural responses: As striped patterns do not have the statistical redundancy typical of natural images, they are perhaps unable to be encoded efficiently.This study found that stimuli that were judged to be most comfortable were also those with the lowest EEG amplitude.

View Article: PubMed Central - PubMed

Affiliation: School of Psychology, University of Lincoln, Lincoln, United Kingdom.

ABSTRACT
Several types of striped patterns have been reported to cause adverse sensations described as visual discomfort. Previous research using op-art-based stimuli has demonstrated that spurious eye movement signals can cause the experience of illusory motion, or shimmering effects, which might be perceived as uncomfortable. Whilst the shimmering effects are one cause of discomfort, another possible contributor to discomfort is excessive neural responses: As striped patterns do not have the statistical redundancy typical of natural images, they are perhaps unable to be encoded efficiently. If this is the case, then this should be seen in the amplitude of the EEG response. This study found that stimuli that were judged to be most comfortable were also those with the lowest EEG amplitude. This provides some support for the idea that excessive neural responses might also contribute to discomfort judgements in normal populations, in stimuli controlled for perceived contrast.

No MeSH data available.


Related in: MedlinePlus

Eye movements.Mean amplitude for aggregate eye channel against spatial frequency (λ), for three levels of waviness (μ). (μ) = inf are straight lines. Error bars are one standard error.
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pone.0139400.g004: Eye movements.Mean amplitude for aggregate eye channel against spatial frequency (λ), for three levels of waviness (μ). (μ) = inf are straight lines. Error bars are one standard error.

Mentions: Eye movements were analysed by taking the average of the three ocular (EOG) channels, and FP1, to form something similar to the ‘radial EOG’ of Keren et al., [68]. The aim was to see if there is any systematic variation in the magnitude of gross eye movements between stimuli. Pre-processing was minimal—the sampling rate of raw EEG was reduced to 256Hz and the EEG data was re-referenced to the average of all electrodes. The raw EEG was split into 500ms epochs. A measure was needed to see if there was any systematic variation between the nine stimuli for the overall amplitude of the eye movements. In order to characterise potential eye movements, the absolute value of the amplitude over each epoch was taken. The whole time series was integrated, to obtain one value for each repetition. The integral of each time series was then averaged over repetitions. Results of a 3 x 3 repeated measures ANOVA show no main effect of spatial frequency (λ), or waviness (μ), and no interaction on gross eye movements (see Table 1 for statistics). The results can be seen in Fig 4. It must be highlighted that this analysis will only demonstrate effects of gross eye movements, not any transient effects.


VEP Responses to Op-Art Stimuli.

O'Hare L, Clarke AD, Pollux PM - PLoS ONE (2015)

Eye movements.Mean amplitude for aggregate eye channel against spatial frequency (λ), for three levels of waviness (μ). (μ) = inf are straight lines. Error bars are one standard error.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4589386&req=5

pone.0139400.g004: Eye movements.Mean amplitude for aggregate eye channel against spatial frequency (λ), for three levels of waviness (μ). (μ) = inf are straight lines. Error bars are one standard error.
Mentions: Eye movements were analysed by taking the average of the three ocular (EOG) channels, and FP1, to form something similar to the ‘radial EOG’ of Keren et al., [68]. The aim was to see if there is any systematic variation in the magnitude of gross eye movements between stimuli. Pre-processing was minimal—the sampling rate of raw EEG was reduced to 256Hz and the EEG data was re-referenced to the average of all electrodes. The raw EEG was split into 500ms epochs. A measure was needed to see if there was any systematic variation between the nine stimuli for the overall amplitude of the eye movements. In order to characterise potential eye movements, the absolute value of the amplitude over each epoch was taken. The whole time series was integrated, to obtain one value for each repetition. The integral of each time series was then averaged over repetitions. Results of a 3 x 3 repeated measures ANOVA show no main effect of spatial frequency (λ), or waviness (μ), and no interaction on gross eye movements (see Table 1 for statistics). The results can be seen in Fig 4. It must be highlighted that this analysis will only demonstrate effects of gross eye movements, not any transient effects.

Bottom Line: Previous research using op-art-based stimuli has demonstrated that spurious eye movement signals can cause the experience of illusory motion, or shimmering effects, which might be perceived as uncomfortable.Whilst the shimmering effects are one cause of discomfort, another possible contributor to discomfort is excessive neural responses: As striped patterns do not have the statistical redundancy typical of natural images, they are perhaps unable to be encoded efficiently.This study found that stimuli that were judged to be most comfortable were also those with the lowest EEG amplitude.

View Article: PubMed Central - PubMed

Affiliation: School of Psychology, University of Lincoln, Lincoln, United Kingdom.

ABSTRACT
Several types of striped patterns have been reported to cause adverse sensations described as visual discomfort. Previous research using op-art-based stimuli has demonstrated that spurious eye movement signals can cause the experience of illusory motion, or shimmering effects, which might be perceived as uncomfortable. Whilst the shimmering effects are one cause of discomfort, another possible contributor to discomfort is excessive neural responses: As striped patterns do not have the statistical redundancy typical of natural images, they are perhaps unable to be encoded efficiently. If this is the case, then this should be seen in the amplitude of the EEG response. This study found that stimuli that were judged to be most comfortable were also those with the lowest EEG amplitude. This provides some support for the idea that excessive neural responses might also contribute to discomfort judgements in normal populations, in stimuli controlled for perceived contrast.

No MeSH data available.


Related in: MedlinePlus