The voice of emotional memory: content-filtered speech in panic disorder, social phobia, and major depressive disorder

We asked patients with either panic disorder, social phobia, or major depressive disorder and healthy control participants to describe their most frightening experience and to describe an emotionally neutral experience. Both fear and neutral autobiographical memories were audiotaped and processed through a low-pass filter that eliminated frequencies above 400 Hz, thereby abolishing semantic content but leaving paralinguistic aspects like rate, pitch, and loudness intact, and these convey emotional cues. Raters blind to content and diagnosis rated the content-filtered speech clips on emotional dimensions. The results revealed that content-filtered fear memories received significantly higher ratings on anxious, aroused, and dominant (but not sad or negative) scales than did content-filtered neutral memories, irrespective of the diagnostic status of the speaker. Content-filtered speech appears promising as an on-line probe of emotional processing during accessing of autobiographical memories.