Prenatal stress and learned helplessness

Abstract

Prenatally stressed rats (n = 18) and non-stressed controls (n = 18) were given prior avoidance experience in a Skinner box before being trained in a two-way shuttlebox avoidance task within a standard triadic learned helplessness paradigm. Results indicated that there was no effect of prenatal stress on the acquisition of a lever press in a Skinner box, but that prenatal stress had significant adverse effects on the acquisition of a more difficult two-way shuttlebox avoidance response. The phenomenon of learned helplessness was demonstrated for non-stressed but not for prenatally stressed subjects. The failure to observe the learned helplessness effect in the prenatally stressed subjects appears to have been due to the performance of the prenatally stressed, unshocked control group which displayed slower learning similar to that of the groups exposed to uncontrollable shock.