Anticipation of affective image modulates visual evoked magnetic fields (VEF).

We investigated the interaction between anticipation of positive and negative affective images and visual evoked magnetic fields (VEF). Participants (n = 13) were presented emotionally positive or negative images under different anticipatory conditions, and their subsequent brain responses were recorded by magnetoencephalography (MEG). In the Affective Cue conditions, the cue stimulus indicated the emotional valence of the image, which followed 2 s later. In the Null Cue conditions, the cue stimulus did not include any information about the valence of the image. In the No Cue conditions, the affective image was suddenly presented, without a cue stimulus. The VEF amplitude for the negative image in the Affective Cue condition was smaller than that of the positive image in the Affective Cue condition and that of the negative image in the Null Cue condition. This result suggests that anticipation of the valence of affective images modulates the processes of the visual cortex.