Mismatch negativity indices of enhanced preattentive automatic processing in panic disorder as measured by a multi-feature paradigm

• Preattentive automatic information processing of PD patients was measured by MMN.
• PD patients showed a significantly increased MMN of sound intensity and location.
• Anomalous preattentive automatic information processing was found in PD patients.
• Our findings provide new evidence for three-stage model of anxiety disorders.

Panic disorder (PD) is a mental disorder characterized by recurrent panic attacks and worrying about having subsequent attacks. Mismatch negativity (MMN) has been established as a correlate of preattentive automatic processing. The aim of the present study is to investigate the preattentive automatic information processing in PD patients as measured by MMN. Subjects included 15 medication-free patients with a DSM-IV diagnosis of PD and 15 age-matched healthy volunteers. MMN was investigated using event-related potentials. The protocol used a multi-feature paradigm. Mean amplitudes and peak latencies were subjected to repeated-measures ANOVAs. PD patients showed a significantly increased MMN of sound intensity and location compared with healthy participants. The correlation between the amplitudes of intensity-MMN and disease severity was also significant. These data provide evidence of anomalous preattentive automatic information processing in PD patients. In particular, the abnormality may be specific for PD.