Event-related potentials during mental imagery of animal sounds.

To investigate the neural correlates of imagined animal sounds, event-related potentials (ERPs) were recorded while subjects were presented with (1) animal pictures without any imagery instruction (control) or (2) animal pictures with instructions to imagine the corresponding sounds (imagery). The results revealed imagery effects starting with an enhancement of the P2, possibly indexing the top-down allocation of attention to the imagery task, and continuing into a more positive-going deflection in the time window of 350-600 ms poststimulus, probably reflecting the formation of auditory imagery. A centro-parietally distributed late positive complex (LPC) was identified in the difference waveform (imagery minus control) and might reflect two subprocesses of imagery formation: sound retrieval from stored information and representation in working memory.