Nm. Ward et Vj. Brown, DEFICITS IN RESPONSE INITIATION, BUT NOT ATTENTION, FOLLOWING EXCITOTOXIC LESIONS OF POSTERIOR PARIETAL CORTEX IN THE RAT, Brain research, 775(1-2), 1997, pp. 81-90
Damage to posterior parietal cortex in humans is known to cause hemine
glect, and specifically difficulty in disengaging attention in tests o
f covert orienting. Aspirative lesions of a region of cortex in rats w
hich is thought to be homologous to primate posterior parietal cortex
has also been reported to cause what appears to be multimodal neglect.
In order to make an assessment of the nature of this disorder, a vari
ety of tests were employed: (1) a test of somatosensory neglect after
Schallert et al. (Pharmacol. Biochem. Behav., 16 (1982) 455-462); (2)
a skilled paw-reaching test after Whishaw et al. (Brain 109 (1986) 805
-843); (3) a visual reaction time task with peripheral cues analogous
to Posner's test of covert orienting (Q. J. Exp. Psychol., 32 (1980) 3
-25). Following the posterior parietal lesion there was a global incre
ase in reaction time of responses made contralateral to the lesion in
the reaction time task, but there was no evidence of a deficit in cove
rt orienting. There was also no evidence of somatosensory neglect. The
re was a decrease in the number of attempted reaches with the contrala
teral paw and a tendency to spend a smaller proportion of time in the
contralateral half of the reaching cage. (C) 1997 Elsevier Science B.V
.