Record Display for the EPA National Library Catalog


Main Title Evidence for an Involvement of Associative Conditioning in Reflex Modification of the Acoustic Startle Response with Gaps in Background Noise.
Author Crofton, K. M. ; Dean, K. F. ; Sheets, L. P. ; Peele, D. B. ;
CORP Author Health Effects Research Lab., Research Triangle Park, NC. Neurotoxicology Div. ;Northrop Services, Inc., Research Triangle Park, NC.
Publisher c1990
Year Published 1990
Report Number EPA/600/J-90/349;
Stock Number PB91-163634
Additional Subjects Startle reaction ; Acoustic reflex ; Rats ; Acoustic stimulation ; Background noise ; Reprints ; Psychobiology ; Associative conditioning
Library Call Number Additional Info Location Last
NTIS  PB91-163634 Some EPA libraries have a fiche copy filed under the call number shown. 07/26/2022
Collation 10p
The experiments reported here were designed to determine the role of associative conditioning in reflex modification of the acoustic startle response using gaps in background noise. Experiments were conducted with independent, naive groups of adult Long Evans hooded rats tested using 20-msec gaps in white noise (ON 80dB/OFF 35dB) as the prestimulus (S1, ISI = 190 msec) and a 120-dB, 40-msec 13-kHz pure tone as the eliciting stimulus (S2). The first experiment characterized the effects of repeated testing for 9 days. The second experiment was a test of associative conditioning. Three groups of rats were tested daily for 6 days under one of the following conditions: S1 and S2 paired in a contingent manner, S2 only, or S1 only. All groups then received the contingent pairing of S1 and S2 for an additional 9 days of testing. In the third experiment, a separate group of rats was tested using either contingent or non-contingent presentation of stimuli in a contingent fashion. Results indicate that the amount of inhibition increases with repeated, daily testing, and achieve asymptotic levels of inhibition 5-6 daily sessions.