Lake Forest CollegeIn line with current efforts to achieve a general view of living systems the degree of coupling is considered using specific examples at the levels of cell and organ, organism and group, organization and society. Loose coupling among systems, similar to Ashby's concept of independence, contributes to stability by allowing persistent behavior of the system in the face of certain inputs. It can be achieved either actively, by having a more tightly coupled subsystem which compensates for a given category of input by negative feedback, or passively, by an arrangement which allows certain variables only limited access to the system. The evolution of adaptive and maladaptive degrees of coupling in different systems is discussed. r+a XTELLECTUAL endeavor has always in-

No abstract

No abstract

Rats with ablated frontal sensorimotor cortex and one with ablated sensorimotor connections to forebrain showed more vacuous chewing movements following 6-week chronic administration of a neuroleptic than did occipitally damaged rats or normal controls who were treated in the same way. The effect was still present 1 month after withdrawal. It was not clearly enhanced by subsequent treatments. Other behaviors (e.g., walking, rearing, or grooming) were not similarly affected by drug withdrawal. Additional results of terminal probes with amphetamine, apormorphine, and haloperidol are described, including movements labeled 'sham eating', observed only in frontal rats given apomorphine (AP). The results are interpreted in terms of a Jacksonina model of levels of brain organization; such a model may be applicable to tardive dyskinesia, seen in many schizophrenic patients who are maintained on neuroleptics for long periods.

No abstract