Negative priming refers to an inhibitory effect, in which responding i
s slower when an attended target is identical, or related to a previou
sly ignored distractor. It has been suggested that the processes under
lying this effect are important for maintaining attentional focus and
orientation. A version of this paradigm, in which subjects attended to
digits presented to the RVF, and ignored digits presented to the LVF
was employed with two split-brain subjects and seven normal controls.
The task was to categorize RVF digits as odd or even. Each of the spli
t-brain patients showed significant amounts of negative priming from i
gnored LVF distractors, as did the normal control subjects. It is conc
luded that even in the split-brain there are rich attentional interact
ions with respect to complex attributes encoded within each hemisphere
. It is suggested that these rely on interaction between cortical and
subcortical processing, and may play an important role in relation to
the unified and apparently well integrated behaviour of commissurotomy
patients in everyday settings.