The two-factor theory of avoidance learning predicted that turning on the fear-inducing tone in the shuttlebox would generate fear and accelerate jumping. Twenty-four hours later the dogs were placed in a shuttlebox and were supposed to learn to escape shock by jumping a short barrier between the two chambers. To find out they restrained dogs in a hammock and the dogs got 64 mild-moderate electric shocks to their back paws, each shock heralded by a tone.
In the early 1960s, Richard Solomon and his students at the University of Pennsylvania wanted to know how prior Pavlovian fear conditioning would influence later instrumental learning.
FARAWAY PUZZLE ESCAPE QUOTE HOW TO
We speculate that default passivity and the compensating detection and expectation of control may have substantial implications for how to treat depression. In addition, alterations of the ventromedial prefrontal cortex-dorsal raphe pathway can come to subserve the expectation of control. So animals learn that they can control aversive events, but the passive failure to learn to escape is an unlearned reaction to prolonged aversive stimulation. This passivity can be overcome by learning control, with the activity of the medial prefrontal cortex, which subserves the detection of control leading to the automatic inhibition of the dorsal raphe nucleus. It is the default, unlearned response to prolonged aversive events and it is mediated by the serotonergic activity of the dorsal raphe nucleus, which in turn inhibits escape. Passivity in response to shock is not learned. The mechanism of learned helplessness is now very well-charted biologically and the original theory got it backwards. Seligman and Maier (1967) theorized that animals learned that outcomes were independent of their responses-that nothing they did mattered – and that this learning undermined trying to escape. Learned helplessness, the failure to escape shock induced by uncontrollable aversive events, was discovered half a century ago.
0 kommentar(er)
