The aim of this study was to examine brightness effect, which is the perceptual property of visual stimuli, on brain responses obtained during visual processing of these stimuli. For this purpose, brain responses of the brain to changes in brightness were explored comparatively using different emotional images (pleasant, unpleasant and neutral) with different luminance levels. In the study, electroencephalography recordings from 12 different electrode sites of 31 healthy participants were used. The power spectra obtained from the analysis of the recordings using short time Fourier transform were analyzed, and a statistical analysis was performed on features extracted from these power spectra. Statistical findings were compared with those obtained from behavioral data. The results showed that the brightness of visual stimuli affected the power of brain responses depending on frequency, time and location. According to the statistically verified findings, the increase in the brightness of pleasant and neutral images increased the average power of responses in the parietal and occipital regions whereas the increase in the brightness of unpleasant images decreased the average power of responses in these regions. Moreover, the statistical results obtained for unpleasant images were found to be in accordance with the behavioral data. The results revealed that the brightness of visual stimuli could be represented by changing the activity power of the brain cortex. The findings emphasized that the brightness of visual stimuli should be viewed as an important parameter in studies using emotional image techniques such as image classification, emotion evaluation and neuro-marketing.

中文翻译：

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视觉刺激亮度对脑电信号的影响。

这项研究的目的是检查亮度影响，即视觉刺激的感知特性，对这些视觉刺激过程中获得的大脑反应的影响。为此目的，使用具有不同亮度水平的不同情感图像（令人愉悦，不愉悦和中立）来比较探索大脑对亮度变化的大脑反应。在这项研究中，使用了来自31位健康参与者的12个不​​同电极部位的脑电图记录。分析了使用短时傅立叶变换对记录进行分析获得的功率谱，并对从这些功率谱中提取的特征进行了统计分析。将统计结果与从行为数据获得的结果进行比较。结果表明，视觉刺激的亮度会根据频率，时间和位置影响大脑反应的能力。根据经过统计验证的发现，令人愉悦的图像和中性图像的亮度增加会增加顶叶和枕骨区域的平均响应能力，而令人不快的图像的亮度增加会降低这些区域的平均响应能力。此外，发现针对不愉快的图像获得的统计结果与行为数据一致。结果表明，视觉刺激的亮度可以通过改变大脑皮层的活动能力来表示。