Sensory Affective Gating - A New Design, an Old Phenomenon, Examined by Way of Magnetoencephalography

Abstract

The present study explored sensory gating for affective stimuli in the visual modality. The original double-click paradigm was changed into a double-affective-flash paradigm. Seventeen subjects (7 male) attended to 300 pairs of identical pictures (high arousing pleasant, high arousing unpleasant and low arousing neutral), presented for 100 ms with 500 ms SOA, while the magnetoencephalogram was recorded. Gating, defined as ratio of the event related field responses at 50 70 ms latency (ERF to the second divided by ERF to the first stimulus), was analyzed for each picture category. Ratios were significantly smaller for pleasant and unpleasant relative to neutral pictures, but did not differ between pleasant and unpleasant stimuli. Source analysis indicated affective sensory gating origin in the limbic system. Results indicate sensory gating for visual affective stimuli, suggesting an affective sensory filter system in the brain, which guides and determines human behavior.