Biomedical subjects

S S Glenn

Publications and source records attributed to S S Glenn.

3 recordsLinked to original sources

PubMed2001

A general account of selection: biology, immunology, and behavior.

Authors frequently refer to gene-based selection in biological evolution, the reaction of the immune system to antigens, and operant learning as exemplifying selection processes in the same sense of this term. However, as obvious as this claim may seem on the surface, setting out an account of "selection" that is general enough to incorporate all three of these processes without becoming so general as to be vacuous is far from easy. In this target article, we set out such a general account of selection to see how well it accommodates these very different sorts of selection. The three fundamental elements of this account are replication, variation, and environmental interaction. For selection to occur, these three processes must be related in a very specific way. In particular, replication must alternate with environmental interaction so that any changes that occur in replication are passed on differentially because of environmental interaction. One of the main differences among the three sorts of selection that we investigate concerns the role of organisms. In traditional biological evolution, organisms play a central role with respect to environmental interaction. Although environmental interaction can occur at other levels of the organizational hierarchy, organisms are the primary focus of environmental interaction. In the functioning of the immune system, organisms function as containers. The interactions that result in selection of antibodies during a lifetime are between entities (antibodies and antigens) contained within the organism. Resulting changes in the immune system of one organism are not passed on to later organisms. Nor are changes in operant behavior resulting from behavioral selection passed on to later organisms. But operant behavior is not contained in the organism because most of the interactions that lead to differential replication include parts of the world outside the organism. Changes in the organism's nervous system are the effects of those interactions. The role of genes also varies in these three systems. Biological evolution is gene-based (i.e., genes are the primary replicators). Genes play very different roles in operant behavior and the immune system. However, in all three systems, iteration is central. All three selection processes are also incredibly wasteful and inefficient. They can generate complexity and novelty primarily because they are so wasteful and inefficient.

Behaviorism↗

PubMed1991

Effects of self-management training and reinforcement on the transfer of improved conduct in the absence of supervision.

The instruction, maintenance, and transfer of training of social skills of 3 seriously emotionally disturbed adolescents were accomplished by a self-management training and reinforcement package. During baseline sessions these students, who were covertly filmed in their classroom, averaged over 90% off-task or socially inappropriate behavior while their teacher was out of the room. They showed similar behaviors when walking between classes, unattended by their teacher. Treatment was introduced in the classroom and consisted of social skills and self-management training and reinforcement. Treatment procedures included instruction, modeling, and role playing of social skills, as well as self-assessment, self-recording, and self-reinforcement for correct approximations of these skills. After 5 weeks of training, all subjects demonstrated substantial improvements in the classroom during the teacher's absence and when distracted by other students; however, transfer of social skills did not occur to the between-class setting until students were given explicit instruction to initiate self-managing procedures in this setting.

Adolescent↗

PubMed1978

Imaginal response events in systematic desensitization: a pilot study.

The primary focus of systematic desensitization (SD) is physiological responsivity in the presence of a conditioned aversive stimulus. However, SD also effects changes in motorapproach behavior and self-report. This study explores the possibility that SD directly affects the motor response system by way of conditioning covert approach responses in the presence of the imaginal aversive stimulus. Two independent variables were investigated: the content of instructions and actual covert motor responses during SD. Twenty-four subjects were classified as high- or low-responders on the basis of electromyographic responsiveness to instructions to imagine movement. Half the high- and half the low-responders were given a series of instructions to imagine-motor-approach behavior toward snakes. The remaining subjects received instructions to imagine only the snakes themselves with no reference to motor response. Imaginal scenes of 30-sec duration were alternated with relaxation periods of the same length. A significant difference was found between the posttreatment scores of high- and low-responders on performance measures, the high-responders performing better. The difference between the two instruction groups was not statistically significant. Self-report data suggested some subjects given instructions to imagine only snakes actually imagined themselves approaching snakes. Therefore, data were re-analyzed after instruction groups were reconstructed accordingly. A statistically significant difference was found on both factors. Continued investigation may further support imagery as covert behavior, open to empirical study.

Behavior Therapy↗