Mental ability and the discrimination of auditory frequency and duration change without focused attention: An analysis of mismatch negativity

Mismatch negativity (MMN), an event-related potential measure that probes an early, pre-attentive stage of the discrimination process, was used to examine the relation between mental ability and the detection of change in auditory frequency and duration.MMN waveforms were derived from auditory sequences presented to 83 participants who were instructed to ignore the stimuli. Higher mental ability (HA) was associated with larger MMN amplitude to infrequent (deviant) change in auditory frequency. There was no effect of mental ability on MMN to change in auditory stimulus duration. Although HA was associated with better frequency and duration discrimination, there was no relation between the discrimination thresholds and MMN measures, an observation that challenges the efficacy of MMN amplitude as an index of discrimination ability. The MNN amplitude effect for auditory frequency change is indicative of greater facility in accessing sensory memory for HA than LA, and notably, this advantage is accomplished automatically, without focused attention.