Binaural brainstem responses are disrupted by large electrode place mismatches

Evidence

It has been suggested that physiological measures of binaural interactions (e.g., evoked potentials) will likely be required to accomplish best-matched interaural electrode pairs (Pelizzone et al. 1990 ). More recently, the binaural interaction component (BIC) of the electrically evoked auditory brainstem responses (eABRs) have been obtained in both animals (Smith and Delgutte 2007 ) and humans (He et al. 2010 ; Gordon et al. 2012 ). Smith and Delgutte ( 2007 ) proposed a potential way by using evoked potentials to match interaural electrode pairs for bilaterally implanted cats. Their study shows that the interaural electrode pairings that produced the best aligned IC activation patterns were also those that yielded the maximum BIC amplitude. More recently, He et al. ( 2010 ) observed some evidence of a BIC/electrode-offset interaction at low current levels. In another follow up study, they used the same electroencephalography (EEG) procedure to examine whether the BIC amplitude evoked from different electrode pairings correlated with an interaural pitch comparison task (He et al. 2012 ). Their results show that there is no significant correlation between results of BIC measures and interaural pitch comparisons on either the individual or group levels. Gordon et al. ( 2012 ) demonstrated that binaural processing in the brainstem of children using bilateral CI occurs regardless of bilateral or unilateral deafness; it is disrupted by a large but not by a small mismatch in place of stimulation. — Dijk, Pim van, Physiology, Psychoacoustics and…, 1452

Categorization

• XREF: Fits the stated reading goal on binaural cue processing physiology in normal-hearing and implanted listeners.
• QUESTION: Worth chasing: why does BIC fail to correlate with pitch comparison yet track electrode offset in some paradigms? What does that say about what BIC actually measures?