The Mirror System (MS) subserves imitation and may facilitate emotional processing. We explored the possibility that this system is dysfunctional in schizophrenia. Schizophrenic patients and controls completed an imitation task to test basic MS function, and an affective startle paradigm to investigate the MS for emotional processing.

Imitation task: reaction time to initiate finger movement in response to (1) observation of finger movement and (2) a numerical cue was recorded (Brass et al, 2001).

participants viewed pictures that were divided into emotionally positive, neutral and negative categories. Pictures were preceded by emotionally congruent primes: half the primes consisted of a videoclip showing hand-object interaction and half consisted of a control sequence showing static images of the interaction. Acoustic startle probes were presented during picture viewing and startle eyeblink amplitude was recorded.

There were no differences between groups on either task.

Imitation task: observation of biological motion facilitated motor responses compared to a numerical cue.

Affective startle: startle amplitude was inhibited during positive picture viewing and potentiated during negative picture viewing when pictures were primed with moving videoclips compared to static controls.

Our results suggest that the MS functions normally in schizophrenia. Both patients and controls exhibited comparable facilitation of movement responses when observing biological motion, reflecting recruitment of the basic motor MS during imitation. Furthermore, both groups showed enhanced startle reactivity to pictures primed with moving videoclips designed to recruit the MS, reflecting involvement of the MS in emotional processing.