Saturday, January 26, 2008

Hippocampus, theta waves and movement VII

Vanderwolf wanted to sort out what would happen with direct brain stimulation as opposed to merely observing slow wave in conjunction with spontaneous behaviors.

Vanderwolf (p. 33) is careful to point out that:
"..the fact hippocampal rhythmical slow waves occur in close correlation with certain patterns of movement does not necessarily mean that hippocampal activity has a role in causing the movement. It is well recognized that correlation does not prove causation."
He goes on to say,
"It is apparent that some motor patterns, including the various forms of locomotion, head movements, spontaneous changes in posture, and manipulating objects with the forelimbs, are invariably accompanied by hippocampal rhythmical slow wave activity, while other motor patterns, including alert immobility, licking, biting, chewing, face-washing, and such gross motor patterns as the startle response and the writhing-stretching movements of giving birth, are generally accompanied by an irregular pattern of hippocampal activity. These hippocampo-behavior relations occur during both spontaneous behavior and the behavior elicited by hypothalamic stimulation. The two different classes of behavior cannot be distinguished on the basis of extent of muscular activity, degree of arousal, stress, or excitement and have no particular relation to the often stressed polarity of learning and instinct. How should all of this be interpreted and what should these classes of behavior be called?"

To me this is the crux of the matter, and why I'm busy reading this book. To continue:
"Animal behaviorists, following a proposal by Wallace Craig in 1918, often distinguish appetitive from consummatory behavior. Walking toward food is an appetitive behavior; eating the food, a consummatory behavior. Prior to Craig's suggestion, Charles Sherrington (1906) had suggested a distinction betwen precurrent reactions (similar to Craig's appetitive behavior) and consummatory reactions, stressing the dependence of the first type on distance receptors (vision, audition, olfaction) and of the second type on contact receptors (touch, taste). However, John Hughlings Jackson, an English neurologist writing well before either Sherrington or Craig, had suggested a continuum in the basis of motor control ranging from most voluntary to most automatic or reflexive... Consequently, I began to refer to behaviors consistently accompanied by hippocampal rhythmical slow wave as "voluntary" and behaviors not consistently accompanied by this wave form as "automatic." However, the attempt to apply Jacksonian terminology to hippocampal-behavioral relations was not welcomed."

Instead he categorized behaviors into Type I and Type II.
Here is the list:

Type I (slow wave hippocampal activity always present):
walking, running, swimming, rearing, jumping, digging, manipulating objects with forelimbs, isolated movements of head or of one limb, shifts of posture.
Related terms: voluntary, appetitive, instrumental, purposive, operant, or "theta" behavior.

Type II (irregular wave activity):
alert immobility in any posture, licking, chewing, chattering teeth, sneezing, startle response, vocalization, shivering, tremor, face-washing, scratching fur, pelvic thrusting, ejaculation, defecation, urination, piloerection.
Related terms: autonomic, reflexive, consummatory, respondent, "non-theta" behavior.

So, after all this investigating of this interesting material I don't think I'm any closer to knowing where ideomotor movement might fit, but at least I know more about hippocampal wave associated movement than I used to.

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