Mw. Geisler et C. Murphy, Event-related brain potentials to attended and ignored olfactory and trigeminal stimuli, INT J PSYCP, 37(3), 2000, pp. 309-315
Event-related brain potentials (ERPs) were recorded from 26 young adults, w
ith equal numbers of male and female subjects, using attended and ignored,
olfactory and trigeminal stimuli. The amplitudes and latencies of the N1, P
2, and P3 components were recorded using a single-stimulus paradigm, with a
n inter-stimulus interval of 60 s, employing amyl acetate as the olfactory
stimulus and ammonia as the trigeminal stimulus. Subjects estimated stimulu
s intensity in the attend condition or continued with a visual tracking tas
k in the ignore condition. Results indicate that olfactory information is p
rocessed 30-70 ms faster than trigeminal information for the N1 and P2 pote
ntial and 100 ms faster for the P3 ERP component. N1/P2 interpeak amplitude
was greater for the trigeminal than the olfactory stimuli, and greater in
the attended than ignored condition. P3 amplitude was greater in the attend
than ignore condition for olfactory information processing and equivalent
for trigeminal information processing. These findings suggest that neuronal
resource allocation is greatest for attended stimuli and that a painful st
imulus demands neuronal resources even when ignored. (C) 2000 Elsevier Scie
nce B.V. All rights reserved.