Habituation of distraction to a tone in the absence of neocortex in rats

Expected and actual behavioural capacity after diffuse reduction in cerebral cortex: A review and suggestions for rehabilitative techniques with the mentally handicapped and head injured

“…Such responses might include those used to operate a teaching machine, and the use of such equipment by the retarded has been considered (see Beasley, 1974). This approach might possibly be applied to the attentional remediation of the traumatically head injured (Oakley, 1983~).…”

“…Where it has been possible to differentiate between cortical and subcortical damage it has been shown that, in particular, subcortical structures are capable of mediating what we call association learning (Pavlovian conditioning, instrumental learning and habituation) and its memory. Thus it would appear that this 'primitive' form of learning (in terms of its location of mediation in the neuraxis) is particularly robust, in contrast to more cognitive learning systems, which appear increasingly sensitive to cortical insult (Oakley, 1983~).…”

“…When moving or illuminated levers (which the animal may contact or press) serve as conditional stimuli predictive of food reinforcement there is a clearer differentiation in responding to the predictive and non-predictive levers in the lesioned animals (Oakley et al, 1981). Some impairments have been found in association GO-NOGO performance (Oakley, 1 9 7 9~; Oakley & Russell, 1979), although conditioned inhibition of non-directed responses appears to be independent of neocortex (Moore et al, 1980), as does the ability to habituate to a distracting tone stimulus (Ye0 & Oakley, 1983).…”

Habituation of heart rate in functionally decorticate rats.

“…However, "there are no direct observations of habituation in adequately controlled situations in either decorticate or 'striatal' preparations" (Buchwald & Brown, 1973, p. 106). To our knowledge, only one habituation study in surgically decorticate animals has been published during the last 10 years (Yeo & Oakley, 1983): Decorticate rats showed STH and LTH of distraction to a tone.…”

“…In evaluating relevant experiments and observations, Lynn (1966, p. 46) and Sokolov (1965) concluded that the cortex plays an important role in habituation because “decortication abolishes or severely impairs habituation.” Sokolov (1969, p. 695) also suggested “that the formation of a neural model of the stimulus … may take place on the cortical level and not in the reticular system of the brain.” However, “there are no direct observations of habituation in adequately controlled situations in either decorticate or ‘striatal’ preparations” (Buchwald & Brown, 1973, p. 106). To our knowledge, only one habituation study in surgically decorticate animals has been published during the last 10 years (Yeo & Oakley, 1983): Decorticate rats showed STH and LTH of distraction to a tone.…”