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Gender differnces in visual habit formation in 3‐month‐old rhesus monkeys 1
Author(s) -
Bachevalier Jocelyne,
Hagger Corinne,
Bercu Barry B.
Publication year - 1989
Publication title -
developmental psychobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.055
H-Index - 93
eISSN - 1098-2302
pISSN - 0012-1630
DOI - 10.1002/dev.420220605
Subject(s) - testosterone (patch) , habit , psychology , correlation , developmental psychology , positive correlation , physiology , gonadal hormones , negative correlation , hormone , endocrinology , medicine , castration , biology , social psychology , geometry , mathematics
The rate of learning concurrent visual discriminations with 24‐hr intertrial intervals, a measure of habit formation, was assessed in infant monkeys of both sexes and compared with the rate of learning in adults. In two separate series of animals, 3‐month‐old male monkeys learned an initial set of discriminations (but not later sets) more slowly than 3‐month‐old females. This gender difference was absent in 6‐month‐old monkeys and in adults, both of which learned the initial set at the same rate. Determination of plasma gonadal hormone levels at the time of testing revealed a significant correlation ( r s = 0.95) between testosterone levels and learning scores on the initial set in the 3‐month‐old male monkeys (i.e., the higher the level the poorer the score). No such correlation was found in the 3‐month‐old female monkeys or in the 6‐month‐olds of either sex. These results suggest that high testosterone levels found perinatally in male monkeys temporarily slows maturation of the neutral system underlying visual habit formation.