PMID-4888623[0] Electrical stimulation of the brain in behavioral context.
- Excellent review.
- Focal stimulation of macaques can induce insect-grabbing responses, after which they will carefully examine their hands to see what was caught!
- Same thing has been observed in humans -- the patient reported that he wanted to catch 'that butterfly'.
- Such complicated action must be the effect of downstream / upstream targets of the stimulated site, as the actual stimulation carries no information other than it's spatial locality within the brain.
- Stimulation of the rostral thalamus in the language hemisphere can elicit phrases: "Now one goes home", "Thank you", "I see something".
- These are muttered involuntarily and without recollection of having been spoken.
- Doty stimulated macaques at 20ua for 500us as a CS in postcentral gyrus (S1?) for a lever press CR, which should (he says)only activate a few dozen neurons.
- Can elicit mating behaviors in oposums with electrical stimulation of the hypothalamus, but only if another opossum or furry object is present.
- Stimulation of the caudate nucleus in humans causes an arrest reaction: they may speak, smile, or laught inappropriately, but appropriate voluntary responses are brought to a halt.
- Stimulation of the basolateral amygdala can cause:
- Hungry cats to immediately stop eating
- Stop stalking prey
- Non-hunting animals to stalk prey, and indeed will solve problems to gain access to rats which can be attacked.
- Prolonged stimulation of almost every place in the brain of a cat at 3-8Hz can put it to sleep, though since lab cats normally sleep 17/24hours, this result may not be significant.
- Stimulation at most sites in the limbic system has the still mysterious ability to organize motor activity in any fashion required to produce more of the activity or to avoid it, as the case may be.
- Rats that are stimulated in the periaqueductal gray will self-administer stimulation, but will squeal and otherwise indicate pain and fright during the stimulation. Increasing the duration of stimulation from 0.5 to 1 second makes self-administration of this apparently fearful stimulation stop in both rats and cats.
- Certain patterns of activity within systems responsible for fearful or aggressive behavior, rather than being aversive are perversely gratifying. This is clearly recognized in the sociology of man...
- Rats will self-stimulate with the same stimulus trains that will cause them to eat and drink, and under some conditions the self-stimulation occurs only if food or water is available.
- On the other hand, rats will choose self-stimulation of the lateral hypothalamus instead of food, even when they are starving.
- Electrically induced hunger is its own reward.
- The work of Loucks (124, 125) forms the major point of origin for the concept that motivation is essential to learning. with careful and thorough training, Loucks was unable to form CRs to an auditory CS using stimulation of the motor cortex as the US. With this paradigm, the limb movements elicited by the US never appeared to the CS alone; but movements were readily established when each CS-US combination was immediately followed by the presentation of food.
- However: Kupalov independently proved that stimulation of the motor cortex could be used as the US, at the same time using stimulation at other loci as the CS.
- Why the difference? Attention -- failures are commonly obtained with animals that consistenly fidget or fight restraint, as most of them do.
- Cortical stimulation itself is not rewarding or aversive; animals neither seek nor avoid stimulation of most neocortical areas.
- On classical conditioning: [Bures and colleagues (20, 65) bibtex:Bures-1968 bibtex:Gerbrandt-1968] found that if an anticedent stimulus, which might or might not effect a neuron, were consistently followed by effective intracellular electrical stimulation of that individual neuron, in roughly 10 percent of the cells of the neocortex, hippocampus, thalamus, or mesencephalic reticular formation a change in the response of that cell to the antecedent stimulus could be observed.
- With an apparent exception of the cerebellum it is possible to electrical excitation any place in the brain as a CS in chickens, rats, rabbits ...
- Stimulation of group 1 proprioceptive muscle-afferent fibers in cats is ineffective as a CS.
- Muscle spindles lack clear access to the systems subserving conditioned reflexes. (These instead go to the cerebellum)
- Macaques can also discriminate between two stimulation sites 1-3 mm apart apparently over the entirety of the cortex, at frequencies between 2 and 100Hz, and over a 4-10fold range of currents.
- In human cases where electrical stimulation or the cortex elicits specific memories, extirpation of the stimulated area does not effect recall of this memory (156) {973}.
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[0] Doty RW, Electrical stimulation of the brain in behavioral context.Annu Rev Psychol 20no Issue
289-320 (1969) |
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