Abstract
A new method was developed to study the effects of drugs on learning. In this each subject served as his own control. Pigeons worked for food reinforcenment in a chamber containing three response keys; all three keys were illuminated at the same time by one of four colors. For each session the pigeon's task was to learn a new four-response sequence by pecking the correct key in the presence of each color. After learning (within-session error reduction) had stabilized (40-60 sessions), this base line of repeated acquisition was used to assess the effects of drugs. The dose-effect data indicated that overall accuracy was impaired by phenobarbital, chlordiazepoxide and d-amphetamine arid that the degree of impairment generally increased as a function of dose. In contrast, chlorpromazine did not affect overall accuracy across the dose range tested, although there was a slight error-increasinig effect at the largest doses during the first part of the session. All four drugs increased pausing as a function of dose. Within-session analyses of the effects of the largest doses of phenobarbital, chlondiazepoxide and d-amphetamine indicated that the rate at which errors decreased was less in the drug sessions than in the control sessions.
Footnotes
- Received April 20, 1972.
- Accepted October 3, 1972.
- © 1973 by The Williams & Wilkins Co.
JPET articles become freely available 12 months after publication, and remain freely available for 5 years.Non-open access articles that fall outside this five year window are available only to institutional subscribers and current ASPET members, or through the article purchase feature at the bottom of the page.
|