Jt. Coull et al., A FRONTOPARIETAL NETWORK FOR RAPID VISUAL INFORMATION-PROCESSING - A PET STUDY OF SUSTAINED ATTENTION AND WORKING-MEMORY, Neuropsychologia, 34(11), 1996, pp. 1085-1095
The rapid visual information processing (RVIP) task, a lest of sustain
ed attention which also requires working memory for its successful exe
cution, has been used in a number of human psychopharmacological studi
es. Single digits are presented in quick succession (100 or 200 digits
/min) on a computer screen, and target sequences of numbers must be de
tected with a button press. Although previous neuroimaging studies hav
e implicated the frontal and parietal cortices in performance of simpl
e sustained attention tasks, the neuroanatomical substrates of RVIP pe
rformance are not yet known. This information would prove invaluable i
n the interpretation of drug effects on this task, possibly delineatin
g a neuron;al network for neurotransmitter action. Therefore, this stu
dy investigated the functional anatomy of the RVIP task using positron
emission tomography (PET) derived measures of regional cerebral blood
flow (rCBF) in eight healthy volunteers. Subjects were required to pe
rform variants of the RVIP task which manipulated both the level of wo
rking memory load and the speed of stimulus presentation. Compared wit
h a rest condition (eyes closed), the RVIP task increased rCBF bilater
ally in the inferior frontal gyri, parietal cortex and fusiform gyrus,
and also in the right frontal superior gyrus rostrally. In comparison
with a simple sustained attention control condition, the aforemention
ed right frontal activations were no longer apparent. We suggest that
these data are consistent with the existence of a right fronto-parieta
l network for sustained, and possibly selective: attention, and a left
fronto-parietal network for the phonological loop component of workin
g memory. Copyright (C) 1996 Elsevier Science Ltd.