ON THE DETECTION OF AUDITORY DEVIATIONS - A PRE-ATTENTIVE ACTIVATION MODEL

The conscious perception of infrequent deviant sounds occurring in a s eries of frequent standard sounds may in part be based on the output o f an obligatorily operating deviance detection system. This system enc odes invariances inherent to the recent auditory stimulation into shor t-lived representations of auditory sensory memory and compares each a ctual input with these representations. The underlying processes may b e regarded as preattentive in the sense that they do not rely on the e xplicit intention of a person to detect deviants and that they may be active even in the absence of attention (although they may be prone to attentional modulations). The output of this feature-specific preatte ntive deviance detection system fuses into an integrated mismatch sign al that in turn may activate subsequent processes that result in the t riggering of a motor response.