Self-report measures of interpretation have been criticized on methodological grounds. An approach is g introduced in this article that enables the assessment of interpretive bias with a greater degree of methodological rigor than previously has been the case. Psychophysiological researchers have established that the magnitude of the human blink reflex is augmented A hen elicited during negative rather than neutral imagery. The 1st experiment demonstrates that the blink reflex is sensitive to the emotional valence of Imagery evoked by interpretations Imposed on ambiguous stimuli. In the 2nd experiment, this measure is used to assess interpretations imposed on ambiguous stimuli by individuals who differ in depression levels. The findings are consistent with the hypothesis that depression is associated with a negative interpretive bias.