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Abstract:
Abstract: Studies performed with a ten minute and five minute
inter-stimulus interval (ISI) show a complete reduction in
habituation for olfactory event-related potentials (OERPs).The
present study attempted to maintain the reduced effects of
habituation using a three minute ISI. The olfactory stimulus, amyl
acetate, was presented by an olfactometer which has been previously
described (Murphy, et al., Chemical Senses, 19, 1994). Airflow,
temperature, and humidity were kept constant. Velopharyngeal
closure was employed to maintain a consistent airflow inside the
nose. OERPs were recorded monopolarly at the Fz, Cz, and Pz
electrode sites in ten subjects (five males, five females), for
three trials. Brain potentials were amplified and digitized, and a
grand average was created for all subjects at each trial. Component
amplitudes were selected by choosing the largest positive or
negative peak during corresponding latency windows (n1= 300-500,
p2=450-700, n2=600-900, p3=750-1100msec). Repeated measures ANOVAs
demonstrated no significant reduction in component amplitudes
across trials and no significant difference in latencies over
trials, indicating no habituation effect at this ISI. These results
indicate that with a three minute ISI, a substantial reduction in
habituation is achieved which adds to its desirable characteristics
for clinical use. Supported by NIH grant # DC 02064 to CM.
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