Strain, sex, and environment effects on appetitively and aversively motivated learning tasks

✍ Scribed by Dr. Betty Jo Freeman; Oakley S. Ray

• Publisher: John Wiley and Sons
• Year: 1972
• Tongue: English
• Weight: 522 KB
• Volume: 5
• Category: Article
• ISSN: 0012-1630
• DOI: 10.1002/dev.420050203

✦ Synopsis

Two strains of rats were reared in either an enriched or isolated environment for 60 days (experiment I) or 27 days (experiment 11). At maturity, independent groups of subjects were tested on both appetitively and aversively motivated learning tasks. The results indicated that the effects of early rearing conditions on later behavior were both task and strain specific. Passive avoidance and appetitively motivated tasks were more sensitive to the early experience variable whereas active avoidance tasks were more sensitive to the genetic variable.

A number of variables have been shown to affect both the brain and the problem solving ability of the rat. Differences in brain chemistry and anatomy have consistently been found between rats reared in environments of differential complexity (Bennett, Diamond, Krech, & Rosenzweig, 1964). have reported that animals reared in an enriched environment (i-e., one containing many different objects and stimuli) for 30 days after weaning not only showed an increase in cortical weights when compared with animals reared in isolation,