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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

Time series of EEG.Mean EEG amplitude time series for three levels of spatial frequency (λ), for leftmost plot waviness (μ) = 100 (waviest lines) through to rightmost plot waviness (μ) = inf (straight lines). Top row = O1, bottom row O2.
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pone.0139400.g003: Time series of EEG.Mean EEG amplitude time series for three levels of spatial frequency (λ), for leftmost plot waviness (μ) = 100 (waviest lines) through to rightmost plot waviness (μ) = inf (straight lines). Top row = O1, bottom row O2.

Mentions: The grand average EEG response for the electrodes O1 and O2 are plotted in Fig 3. This shows the EEG response averaged over valid trials, and then averaged over observers. As O1 and O2 were similar, results for O1 are reported. Fig 3 shows that signals returned to baseline before the end of the 500 ms epoch. The peak amplitude P100 response for each observer was calculated as the maximum amplitude of the positive response within the time frame 90–110ms (calculated from the baseline). This is plotted on the right hand side of Fig 2. There was a significant main effect of spatial frequency (λ) on amplitude of the P100 component. There was no effect of waviness (μ). The interaction between waviness (μ) and spatial frequency (λ) was significant. Post-hoc tests showed a similar pattern to the discomfort judgements for spatial frequency. Averaged over waviness, responses to high spatial frequency stimuli were lower on average than responses to low spatial frequency stimuli, and midrange spatial frequency stimuli. There was no difference between low and midrange spatial frequency stimuli. Although the right hand side of Fig 2 shows a different pattern for the waviest lines (μ = 100) compared to the other two, there are no significant differences between the three levels of line waviness. Overall, the highest spatial frequency stripes have lower P100 amplitude compared to the lower spatial frequencies. Statistics can be seen in Table 1.


VEP Responses to Op-Art Stimuli.

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

Time series of EEG.Mean EEG amplitude time series for three levels of spatial frequency (λ), for leftmost plot waviness (μ) = 100 (waviest lines) through to rightmost plot waviness (μ) = inf (straight lines). Top row = O1, bottom row O2.
© Copyright Policy
Related In: Results  -  Collection

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

pone.0139400.g003: Time series of EEG.Mean EEG amplitude time series for three levels of spatial frequency (λ), for leftmost plot waviness (μ) = 100 (waviest lines) through to rightmost plot waviness (μ) = inf (straight lines). Top row = O1, bottom row O2.
Mentions: The grand average EEG response for the electrodes O1 and O2 are plotted in Fig 3. This shows the EEG response averaged over valid trials, and then averaged over observers. As O1 and O2 were similar, results for O1 are reported. Fig 3 shows that signals returned to baseline before the end of the 500 ms epoch. The peak amplitude P100 response for each observer was calculated as the maximum amplitude of the positive response within the time frame 90–110ms (calculated from the baseline). This is plotted on the right hand side of Fig 2. There was a significant main effect of spatial frequency (λ) on amplitude of the P100 component. There was no effect of waviness (μ). The interaction between waviness (μ) and spatial frequency (λ) was significant. Post-hoc tests showed a similar pattern to the discomfort judgements for spatial frequency. Averaged over waviness, responses to high spatial frequency stimuli were lower on average than responses to low spatial frequency stimuli, and midrange spatial frequency stimuli. There was no difference between low and midrange spatial frequency stimuli. Although the right hand side of Fig 2 shows a different pattern for the waviest lines (μ = 100) compared to the other two, there are no significant differences between the three levels of line waviness. Overall, the highest spatial frequency stripes have lower P100 amplitude compared to the lower spatial frequencies. Statistics can be seen in Table 1.

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