Is Happy Facial Expression Identified by the Left or Right Hemisphere?

摘要

A critical difference between the right hemisphere hypothesis and valence hypothesis of emotion processing is whether the processing of happy facial expressions is lateralized to the right or left hemisphere. In this study participants from a Chinese sample were asked to classify happy or neutral facial expressions presented either bilaterally in both visual fields or unilaterally in the left visual field (LVF) or right visual field (RVF) . They were required to make the speeded responses using either the left or right hand. It was found that for both left and right hand responses, happy (and neutral) expressions presented in the LVF were identified faster than happy (and neutral) expressions presented in the RVF. Bilateral presentation showed no further advantage over LVF presentation.Moreover, left hand responses were generally faster than right hand responses, although this effect was more pronounced for neutral expression. These findings were interpreted as supporting the right hemisphere hypothesis, with happy expression being identified initially by the right hemisphere.