Relationships between facial electromyography and subjective experience during affective imagery

Sixty subjects were exposed for 40 s each to 48 imagery situations designed to reflect happy, sad, angry and fearful conditions. Facial electromyographic (EMG) activity from zygomatic, corrugator, masseter and lateral frontalis muscle regions was recorded, and experienced emotion was measured on a scale tapping these four emotions. Results showed that: (1) zygomatic activity reliably differentiated happy imagery, corrugator activity reliably differentiated sad imagery, but masseter activity did not differentiate angry imagery and lateral frontalis activity did not differentiate fearful imagery; (2) different intensities of specific emotional imagery situations evoked the expected differential patterns of self-report and EMG; (3) higher correlations between self-report and EMG for 'present', rather than 'future' ratings of experienced emotion emerged for positive affect only; and (4) the use of a standardized imagery scale, rather than the self-generated, personally-relevant affective situations used in previous studies, allowed for more sensitive measurement of the relationship between facial muscle activity and subjective experience of emotion during affective imagery.