Influence of Spatial Frequency on Human Subconscious and Related Neural Activity Using the Implicit Association Test

Spatial frequency is the most basic element among all visual constructs and can be quantified as a frequency characteristic. However, it is a parameter that lacks clearly identifiable emotional information. Therefore, this study introduced the Implicit Association Test to assess the potential implicit link between spatial frequency and cognitive functions. To estimate the influence of spatial frequency, we used a dummy target in the form of a square or a rhomboid and placed a spatial frequency of image as the target’s background. The reaction time and the Implicit Association Test scores were measured for a comprehensive overview of how they affect the observer’s subconscious mental processing, based on the spatial frequency of the background. We also used electroencephalogram to measure the neural activity. The association between behavioral indexes-reaction time and the Implicit Association Test score-and neural responses-theta/gamma oscillation-showed that spatial frequency of images placed against the background influenced implicit biases.