Cerebral mechanisms underlying orienting of attention towards auditory frequency changes

Brain mechanisms underlying detection of auditory frequency changes were st udied with event-related potentials (ERPs) in 14 human subjects discriminat ing visual stimuli. Scalp-current density mapping revealed bilateral compon ents of mismatch negativity (MMN) in frontal and auditory cortices. Devianc e-related activations in frontal and temporal cortex began to be significan t at 94 ms and 154 ms in the right hemisphere, and at 128 ms and 132 ms in the left hemisphere. The magnitude of MMN-neuroelectric currents from the l eft temporal cortex correlated significantly (r = -0.56, p < 0.05) with dis traction caused by MMN-eliciting deviant tones. These results suggest a com plex cerebral circuitry involved in frequency change detection and strongly support the role of this circuitry in driving attention involuntarily towa rds potentially relevant frequency changes in the acoustic environment. Neu roReport 12:2583-2587 (C) 2001 Lippincott Williams & Wilkins.