Soft commitment: self-control achieved by response persistence.

With reinforcement contingent on a single peck on either of two available keys (concurrent continuous reinforcement schedules) 4 pigeons, at 80% of free-feeding weights, preferred a smaller-sooner reinforcer (2.5 s of mixed grain preceded by a 0.5-s delay) to a larger-later reinforcer (4.5 s of mixed grain preceded by a 3.5-s delay). However, when the smaller-sooner and larger-later reinforcers were contingent on a concurrent fixed-ratio 31 schedule (the first 30 pecks distributed in any way on the two keys), all pigeons obtained the larger-later reinforcer much more often than they did when only a single peck was required. This "self-control" was achieved by beginning to peck the key leading to the larger-later reinforcer and persisting on that key until reinforcement occurred. We call this persistence "soft commitment" to distinguish it from strict commitment, in which self-control is achieved by preventing changeovers. Soft commitment also effectively achieved self-control when a brief (1-s) signal was inserted between the 30th and 31st response of the ratio and with concurrent fixed-interval 30-s schedules (rather than ratio schedules) of reinforcement. In a second experiment with the same subjects, the fixed ratio was interrupted by darkening both keys and lighting a third (center) key on which pecking was required for various fractions of the fixed-ratio count. The interruption significantly reduced self-control. When interruption was complete (30 responses on the center key followed by a single choice response), pigeons chose the smaller-sooner reinforcer as frequently as they did when only a single choice response was required.     

EVIDENCE FOR SUPERIOR ORTHOGRAPHIC SKILLS IN DYSLEXICS

Abstract— The purpose of this study was to assess the development of both phonological and orthographic skills in normally achieving and dyslexic readers The subjects were 257 dyslexic and 342 normally achieving readers, matched at eight reading levels They were administered the Woodcock (1987) Word Attack Subtest, a measure of phonological skills requiring the designed to measure awareness of the properties of English words and the probable sequences and positions of letters within words The dyslexics had significantly higher scores than the normally achieving readers on the orthographic awareness task However, the normally achieving readers had significantly higher scores on the Word Attack Subtest Therefore, the difficulties with phonological processing and the increased orthographic awareness of the dyslexics may indicate a reading strategy that relies more on the visual than the phonological.     

Adolescent AIDS Prevention in Context: The Impact of Peer Educator Qualities and Classroom Environments on Intervention Efficacy

Peer-led, school-based interventions show promise for preventing AIDS among adolescents, but little is known about the processes underlying effective peer education or the conditions that promote its efficacy. This study examined the implementation in one school of an effective, peer-led AIDS prevention program for inner-city 7th-grade participants (n = 123) and identified the qualities of peer educators (n = 15) and classroom environments (n = 5) that contributed to improvement in participants' postintervention AIDS-related attitudes. The Peer Educator Rating Scale was developed to assess two dimensions of participants' perceptions of peer educators: positive regard and perceived similarity. Participants reported greater positive regard for more highly individuated and less shy peer educators, and participants' positive regard for peer educators in turn was associated with lowered AIDS risk as measured by perceptions of peer norms regarding sexual activity and self-efficacy for peer communication regarding sexual topics and condoms. Participants' perceived similarity was not associated with any postintervention improvements in AIDS-related knowledge and attitudes. Participants' classroom membership was associated with improvements in all 5 knowledge and attitude scales, and exploratory classroom-level findings indicated that classroom intervention environments perceived as more organized by participants showed slightly greater overall improvements across AIDS-related knowledge and attitudes scales. Consistent with individual-level findings regarding participants' positive regard for peer educators, the two classrooms with the greatest positive regard for their peer educator teams showed the most student improvement. Implications for further research and the design of future prevention and promotion programs for adolescents are discussed.     

Relativism,truth, and incoherence

Conclusion There are many contemporary sources and defenders of epistemological relativism which have not been considered thus far. I have, for example, barely touched on the voluminous literature regarding frameworks, conceptual schemes, and Wittgensteinian forms of life. Davidson's challenge to the scheme/content distinction and thereby to conceptual relativism, Rorty's acceptance of the Davidsonian argument and his use of it to defend a relativistic position, Winchian and other sociological and anthropological arguments for relativism, recent work in the sociology of science, and Goodman's novel articulation of a relativism of worlds and of worldmaking, to mention just some of the contemporary loci of debate, all need to be addressed. So also do the plethora of relativistic arguments spawned by Kuhn and related literature in recent philosophy of science. Therefore, it cannot be said that there is no more to be said on behalf of epistemological relativism. Moreover, the positive task of delineating a defensible version of absolutism remains to be accomplished.Nevertheless, the defenses of relativism considered above do seem to have been successfully undercut. More specifically, the arguments for the incoherence of relativism are as compelling as ever, and have manifestly not been laid to rest by contemporary relativists. The basic Socratic insight that relativism is self-refuting, and so incoherent, remains a fundamental difficulty for those who would resuscitate and defend the ancient Protagorean doctrine or a modern variant of it.     

Adolescents' concepts of depression among their peers

The purpose of this study was to quantify the behavioral cues adolescents use to identify their peers as depressed in order to gain a more accurate understanding of the factors associated with adolescent depressive symptomatology. Because of limited information about depression in adolescents, a questionnaire was constructed to explore the concept in this age group. Ninety-nine middle and high school students, 12 to 18 years old, completed the questionnaire which included open-ended and forced choice questions. The results indicated that social isolation was an important component of adolescents' concepts of depression among their peers. Subjects felt that there was a higher frequency of alcohol and marijuana use among depressed as compared to non-depressed peers. Eighty-six percent of the subjects believed that most depressed adolescents had suicidal thoughts, but only 35% believed that most depressed adolescents had attempted suicide. Factor analyses of the subjects' responses to the open-ended questions delineated several underlying dimensions of depressive symptomatology which adolescents appear to use in identifying their peers as depressed.     

Evidence from rats that morphine tolerance is a learned response.

It is proposed that the direct analgesic effect of morphine becomes attenuated over the course of successive administrations of the narcotic by a conditioned, compensatory, hyperalgesic response elicited by the administration procedure, the net result being analgesic tolerance. Using the "hot plate" analgesia assessment situation with rats, this conditioning view of tolerance is supported by several findings: (a) It is necessary to have reliable environmental cues predicting the systemic effects of morphine if tolerance is to be observed, (b) a hyperalgesic conditioned response may be observed in morphine-tolerant subjects when drug administration cues are followed by a placebo, and (c) merely by repeatedly presenting environmental cues previously associated with morphine (but now presented with a placebo), morphine tolerance can be extinguished.     

Iconic memory: A reply to Professor Holding

Professor Holding has argued that the partial report superiority normally taken as evidence for the existence of iconic memory might instead be due to cue anticipation or output interference. I have suggested that both of these alternative explanations are inconsistent with the finding that the partial report superiority diminishes rapidly with increasing cue delay. In addition, Sperling’s original partial report experiment was designed in such a way that cue anticipation could not have occurred; and both his results with selection by letter vs number and Averbach and Coriell’s bar-marker results indicate that output interference effects are absent or negligible in tachistoscopic experiments. Consequently, I have concluded that the partial report superiority, and especially its decline with increasing delay, remains as strong evidence in favor of the conventional view of iconic memory. Furthermore, if this view were wrong, there would remain no way of giving a satisfactory account of (a) Averbach and Coriell’s results, (b) “direct” investigations of visual persistence, or (c) integration and interruption effects in backward visual masking.