Examining the effects of forward masking on emotion-related perceptual decision-making

Abstract

The low road hypothesis proposed the automaticity of threat-detection; accordingly, threat-related information is hypothesized to capture attention in a bottomup manner through the fast magnocellular pathway. This fast pathway prioritized the low spatial frequency stimuli. The current study aimed to study the role of fast pathway on threat detection in emotion-discrimination tasks under top-down factors (endogenous attention). To do so, we manipulated the visual environment and investigated participants’ performance while facing different spatial frequencies. Adopting an emotion-discrimination paradigm, the presence and duration of visual masking were controlled. Being instructed to attend to threat or non-threat-related stimuli, participants made decisions regarding the specific emotion of the presented faces (fearful or neutral) when there was not a forward mask or under five different mask durations. Accuracy rate, response time and signal detection theory measures were recorded. Results of the current study implied an interference (integration) effect of masks on emotion-related decision-making performance. An interaction between the forward mask duration and spatial frequencies of the stimuli was also supported, suggesting that participants may no longer rely on low spatial frequency in perceiving and detecting threat-related signals when endogenous attention is controlled, regardless of the presence of the forward mask. Also, low spatial frequency was more fragile to the interfering influence of the visual environment than other spatial frequencies. Our findings imply that threat-detection under endogenous attention is no longer prioritized through the magnocellular pathway.