Commissurotomy subjects show lateralized difference between manual and oral responding.
This study investigates the influence of the mode of response on the right ear advantage in verbal dichotic testing. Four complete commissurotomy subjects were tested on an ascending digits tape with oral response and manual response by the dominant hand with the volume equal and raised in each ear. Oral response elicited right ear report in all tests under all conditions at all levels of task difficulty. Pointing and writing responses elicited left ear report when the volume was raised in the left ear and the number of digits to report was small. Right ear performance increased and left ear performance decreased as the number of digits to process increased. Results indicate that response modes differ significantly in the degree to which they engage the left hemisphere or to which they suppress the ipsilateral pathways within the left hemisphere. Use of an oral response may obscure the lateralized contribution of the cognitive activity under investigation.
California Institute of Technology.
P H
PH
Pechstedt
D000328:Adult; D001921:Brain / Q000601:surgery*; D004007:Dichotic Listening Tests; D005260:Female; D007839:Functional Laterality; D006236:Handwriting; D006801:Humans; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D013060:Speech / Q000502:physiology*