Characteristics of dropouts, remainers, and refusers at a psychosocial rehabilitation program for the chronically mentally disabled

Thirty-eight chronically mentally disabled patients who were invited to join a newly established, vocationally oriented, day treatment program in Raleigh, North Carolina, served as subjects. We attempted to determine whether demographic and psychosocial characteristics significantly differed among groups of clients who dropped out of, remained in, or refused membership in this community-support program. A variety of demographic, expectancy, psychological, and psychosocial measures were administered to each subject. Most significant was the finding that the subjects' perceived level of help and support from friends was a significant determinant of the level of program participation. Those subjects who refused to participate (refusers) perceived themselves as receiving proportionately less support than did members of the other two groups (dropouts and remainers).     

An infrared system for the detection of a pigeon''s pecks at alphanumeric characters on a TV screen: the dependency of letter detection on the predictability of one letter by another.

Three pigeons pecked at letters of the alphabet and at the symbol "?" displayed on a computer-driven cathode ray screen. A 4 by 4 matrix of infrared emitting and detecting diodes and associated circuitry identified the location of a pigeon''s responses to the screen. Responses at the target letter T were probabilistically reinforced with food whenever T appeared in a string of three letters in the middle of the screen. Responses at the symbol "?" appearing below this string were probabilistically reinforced whenever T did not appear. The letter F anywhere in the three-character string either strongly predicted the occurrence of the target letter T, in two conditions, or predicted its nonoccurrence, in a third. This manipulation of the frequency with which the familiar letter F predicted T was shown to change the function relating probability of a correct peck at the symbol "?" to the number of Fs in the string. This effect may be interpreted as an instance of the phenomenon where an organism''s acquired knowledge changes what it sees.     

Discriminated interresponse times: role of autoshaped responses.

When discriminated interresponse-time (IRT) procedures have been used to assess preference relations among temporally extended operants, deviations from matching have been obtained. Using a yoked-control procedure, the present study found that key pecking in a discriminated IRT procedure has two sources of strength--that arising from the response-reinforcer contingency that is explicitly arranged, and that arising from a stimulus-reinforcer contingency that is a by-product of the explicitly arranged contingency. The key pecking of all lead birds, and that of 3 of the 4 birds exposed to a yoked autoshaping procedure, was controlled by the keylight that signaled the lead birds' criterion IRTs. Because stimulus control of key pecking by the keylight, whether autoshaped or discriminative, fosters deviations from matching, the discriminated IRT procedure does not provide an appropriate basis for conclusions about preference relations among IRTs.     

Alternation behavior, spatial discrimination, and reversal disturbances following 6-hydroxydopamine lesions in the nucleus accumbens of the rat

The effects of dopaminergic depletion of the nucleus accumbens was tested in various behavioral tasks such as alternation, spatial discrimination, and reversal learning, and in an extinction paradigm in a T maze. Animals with lesions showed impairment of spontaneous alternation behavior, disturbances in the acquisition of spatial discrimination, and great difficulty in reversing previously learned habits. In the extinction phase, experimental animals are unable to adjust their behavior, and continue to choose the previously reinforced arm of the T maze. It is suggested that the nucleus accumbens plays an important role in the transition of motivation into action, and that dopamine has a facilitatory influence on the mediation of these processes.     

Aggressive behavior inhibition by serotonin and quipazine injected into the amygdala in the rat

The effects on aggressive behavior, open-field activity, and pain threshold of bilateral microinjections of serotonin (20 micrograms) and quipazine (20 micrograms), the direct serotonergic receptor agonist, into the cortico-medial amygdala were investigated in Wistar rats. Both drugs significantly prolonged the attack latency in isolated killer rats (predatory aggression model), and suppressed the incidence of aggressive postures/attacks in shock-induced fighting test (affective aggression). The only difference in the open-field behavior was the lower number of central square entries in drug-treated compared to saline-injected rats. None of the substances produced any significant change in jump threshold. It is concluded that stimulation of serotonin receptors within the amygdala produces inhibition of affective and muricidal behavior in isolated rats. The effect does not seem to be dependent on changes in general activity and pain sensitivity.     

The negative priming effect: Inhibitory priming by ignored objects

A priming paradigm was employed to investigate the processing of an ignored object during selection of an attended object. Two issues were investigated: the level of internal representation achieved for the ignored object, and the subsequent fate of this representation. In Experiment 1 a prime display containing two superimposed objects was briefly presented. One second later a probe display was presented containing an object to be named. If the ignored object in the prime display was the same as the subsequent probe, naming latencies were impaired. This effect is termed negative priming. It suggests that internal representations of the ignored object may become associated with inhibition during selection. Thus, selection of a subsequent probe object requiring these inhibited representations is delayed. Experiment 2 replicated the negative priming effect with a shorter inter-stimulus interval. Experiment 3 examined the priming effects of both the ignored and the selected objects. The effect of both identity repetition and a categorical relationship between prime and probe stimuli were investigated. The data showed that for a stimulus selected from the prime display, naming of the same object in the probe display was facilitated. When the same stimulus was ignored in the prime display, however, naming of it in the probe display was again impaired (negative priming). That negative priming was also demonstrated with categorically related objects suggests that ignored objects achieve categorical levels of representation, and that the inhibition may be at this level.     

Selective attention and priming: Inhibitory and facilitatory effects of ignored primes

The priming effects of ignored information have been studied in Stroop displays (Neill, 1977) and with spatially superimposed drawings (Tipper, in this issue); naming of probes related to ignored primes is delayed in these experiments (“negative priming”). This negative priming effect is confirmed in a list reading task in Experiment 1, which used partially superimposed letters, and Experiment 2, which used spatially separated letters. Furthermore, Lowe (1979) using Stroop colour words observed that changing the nature of the probe such that it did not require selection from a competing word reversed the priming effects of the ignored word from inhibition to facilitation. Experiment 3 confirmed this observation when subjects selected a red letter from a green letter. Two models are suggested to account for this result. In the first, negative priming is a product of the ignored prime and subsequent probe being encoded both as a stimulus to be ignored and one to be named (Allport, Tipper and Chmiel, in press; Lowe, in press). This dual encoding is ambiguous, requiring further processing before response can be output. The other model suggests that negative priming reflects inhibition of response to ignored information, slowing naming latencies to probe stimuli that require the same response. Experiment 4 attempts to differentiate between the models, and the latter inhibition view is preferred.     

The pathological left-handedness syndrome

A clinical syndrome of pathological left-handedness (PLH) is proposed to identify the pattern of correlative changes in lateral development associated with early brain injury in some manifest left-handers. This syndrome is believed to be caused by a hemispheric lesion that is predominantly left-sided (or bilateral asymmetric), which onsets before Age 6, and which encroaches upon the critical speech zones of the frontotemporal/frontoparietal cortex. The pattern of changes may include any or all of the following features: shifts in manual dominance, trophic changes in the extremities, transfer of hemispheric speech, and/or intrahemispheric reorganization of visuospatial cognitive functions. Although some of these correlates of PLH have long been known, they have not been recognized as an interrelated pattern of traits that constitute a clinical syndrome. Identification of these individuals, all manifest left-handers, will be shown to have implications for diagnosis/remediation and for models of recovery of function.     

Seeking urgent pediatric treatment: factors contributing to frequency, delay, and appropriateness

The present study explored the factors that contribute to mothers' decisions to seek urgent medical attention for their children when symptoms are not of a traumatic nature. One hundred mothers seeking treatment for their children at a prepaid clinic completed a questionnaire eliciting their expectations regarding the course of their children's problems, seriousness of the problems, perceived responsibility for the symptoms, and extent to which a variety of factors contributed to their decisions to seek treatment. Demographic data and information about each child's symptoms and medical history were also obtained. Four major "reasons for seeking treatment" factors were identified: family history of the presenting complaint, worry regarding the symptoms, situational variables, and the extent of the child's illness behavior. The appropriateness of the visit, delay in seeking treatment, and frequency of mothers' use of the pediatric clinic were predicted by the nature of the presenting symptoms (particularly the presence of fever), the ages of the mother and child, and two of the reasons for seeking treatment factors (i.e., family history and child's illness behavior). The present study suggests that mothers pay more attention to presenting symptoms and to the children's behavior than to psychosocial stressors in deciding to seek urgent care.