Intensity mismatch asymmetry in tinnitus: in which direction should participants pay attention?

Abstract

The effects attention has on intensity deviant Mismatch Negativity responses is an unknown factor in basic sensory neuroscience. It would be useful to understand how attention would affect responses to intensity deviants compared to each other (upward vs downward), and compared to other sensory dimensions such as frequency. Overall, previous research indicates that attention may modulate neuronal gain in healthy participants and change the amplitudes of evoked responses, and may mainly affect the responses to regularly repeating (standard) stimuli rather than deviants. Gain may respond differently in participants with tinnitus and/or hyperacusis under the same conditions compared to controls. Overall, results of the passive task condition were consistent with previous research. Auditory attention magnified MMN in response to upward deviants, while visual attention attenuated it in both control and tinnitus groups. However, auditory attention selectively enhanced downward deviant MMN in the tinnitus group (compared to passive attention). Using the auditory attention paradigm may be advantageous in MMN studies on tinnitus/hyperacusis because the observed differences would be particularly large.