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Auditory processing in a patient with a unilateral lesion of the inferior colliculus
Author(s) -
Champoux F.,
Paiement P.,
Mercier C.,
Lepore F.,
Lassonde M.,
Gagné J.P.
Publication year - 2007
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1111/j.1460-9568.2006.05260.x
Subject(s) - inferior colliculus , dichotic listening , binaural recording , sound localization , audiology , stimulus (psychology) , inferior colliculi , psychology , lesion , auditory system , neuroscience , medicine , cognitive psychology , nucleus , psychiatry
The role of the inferior colliculus (IC) in human auditory processing is still poorly understood. We report here the results obtained with a 12‐year‐old boy (FX) who suffered a very circumscribed lesion of the right IC without additional neurological damage. The child underwent an extensive battery of psychophysical hearing tests. Results revealed normal peripheral auditory functioning, bilaterally. Furthermore, masking‐level differences and frequency‐pattern recognition were normal for each ear. When the right ear was stimulated, behavioural tests assessing central auditory processing yielded normal results. However, when the left ear was stimulated, speech recognition in the presence of a competing ipsilateral signal and duration‐pattern recognition were impaired. Similarly, performance on two dichotic speech recognition tests was poor when the target stimulus was presented in the left and the competing signal in the right ear. Finally, sound‐source localization in space was deficient for speakers located on the side contralateral to the lesion. The pattern of results suggests that auditory functions such as recognition of low‐redundancy speech presented monaurally, recognition of tone duration patterns, binaural separation and integration, as well as sound‐source localization in space, depend on the integrity of the bilateral auditory pathways at the IC level.