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Head Start children were matched into two groups on the basis of disruptive behavior during rest periods. Attempts were made to modify their behavior using either instructions or token reinforcement procedures. Results suggest that a combination of reinforcement together with instructions is much more effective than either of these alone. (Author)

Head Start children were matched into two groups on the basis of rates of disruptive behavior during rest periods. Attempts were made to modify their behavior using either individual or group token reinforcement procedures. While the reinforcement procedures reduced inappropriate behavior somewhat, the addition of instructions to the reinforcement reduced the inappropriate behavior to near zero for both groups. Instructions alone, however, were ineffective in controlling behavior. Type of reinforcement (group or individual) did not produce differential effects. While experimental control over the target behavior was demonstrated, there was little carryover from the experimental room to the regular classroom. Even when treatment was introduced into the regular class, follow-up results showed that with time the target behavior approximated pretreatment levels. The results suggest that (a) the combination of instructions and reinforcement is much more effective than either one of these alone, (b) behavior change is specific to the environmental contingencies, and (c) the group reinforcement technique, which is much more easily implemented, was at least as effective as individual reinforcement in the present study.

The effect of antral acidification on the antral and cephalic phases of gastric secretion has been studied. Cross-transfusions were carried out between pairs of dogs in which blood from the portal vein of one dog was administered to another dog with a denervated fundic pouch. Transfusion of blood collected during acidification of the antrum resulted in a diminution of Heidenhain pouch acid secretion in response to food and to topical acetylcholine of 64% and 83%, respectively. The effect of antral acidification on gastric secretion stimulated by insulin hypoglycemia was studied in dogs prepared with Pavlov and isolated antral pouches (innervated and denervated). Irrigation of the antral pouch with .1 n hydrochloric acid resulted in a 92% decrease in Pavlov pouch acid output.

A different type of stripe-geometry laser is demonstrated in which current confinement is achieved by selective diffusion of the n-type substrate prior to growth of the GaAs/GaAlAs heterostructure layers. This structure exhibits low room-temperature threshold currents resulting from the small lateral-current spreading from the edges of the stripe. Lowest order transverse-mode operation is achieved for stripe widths of 10μm.

Head Start children were matched into two groups on the basis of rates of disruptive behavior during rest periods. Attempts were made to modify their behavior using either individual or group token reinforcement procedures. While the reinforcement procedures reduced inappropriate behavior somewhat, the addition of instructions to the reinforcement reduced the inappropriate behavior to near zero for both groups. Instructions alone, however, were ineffective in controlling behavior. Type of reinforcement (group or individual) did not produce differential effects. While experimental control over the target behavior was demonstrated, there was little carryover from the experimental room to the regular classroom. Even when treatment was introduced into the regular class, follow-up results showed that with time the target behavior approximated pretreatment levels. The results suggest that (a) the combination of instructions and reinforcement is much more effective than either one of these alone, (b) behavior change is specific to the environmental contingencies, and (c) the group reinforcement technique, which is much more easily implemented, was at least as effective as individual reinforcement in the present study.