Citation

Hienz RD, Weed MR, Zarcone TJ, Brady JV. Pharmacol. Biochem. Behav. 2003; 74(2): 287-296.

Affiliation

Division of Behavioral Biology, Department of Psychiatry and Behavioral Sciences, The Johns Hopkins University School of Medicine, Hopkins Bayview Medical Center, 5510 Nathan Shock Drive, Suite 3000, Baltimore, MD 21224, USA. bhienz@mail.jhmi.edu

Copyright

(Copyright © 2003, Elsevier Publishing)

DOI

unavailable

PMID

12479947

Abstract

The perceptual effects of cocaine were examined under conditions that required baboons to detect the presence of tones as well as to identify tones of different pitches, and the results compared to the results of prior studies on cocaine's effects on the detection of tones, the discrimination of different tone pitches, and the discrimination of different human vowel sounds of similar pitch. A reaction time procedure was employed in which baboons were trained to press a lever in the presence of a visual "ready" signal, and release the lever only when one tone pitch occurred, but not release the lever when a second, different tone pitch occurred. Changes in the percentage of correct detections and median reaction times for each tone were measured following intramuscular administration of cocaine (0.01-1.0 mg/kg). Cocaine impaired tone identification and shortened reaction times to the tones in all baboons. Cocaine's effects on accuracy, however, were primarily due to elevations in false alarm rates, as opposed to detection of the stimuli themselves. The results demonstrate that cocaine impairs the discriminability of tone pitches in baboons, and that such impairments can depend upon the type of stimuli employed (tones vs. speech sounds) and the type of procedure employed (discrimination vs. identification).

Language: en