Reinforcement magnitude effects in first- and second-order conditioning of directed action

Three experiments investigated the effects of reinforcement magnitude on conditioned key pecking in pigeons. Experiment 1, which included between-groups and within-subject designs, yielded significant effects of unconditioned stimulus (US) magnitude on the within-conditioned stimulus (CS) distribution of key pecks and on choice behavior, but no effect on the overall rate of key pecking. Experiment 2 employed a larger US-magnitude difference in a within-subject design. This manipulation resulted in differential rates of key pecking as well as a significant choice effect and differential within-CS key-peck distributions. A second-order conditioning procedure was used in Experiment 3, in which diffuse, visual stimuli (S1's) served as Pavlovian reinforcers for two key-light S2's. The S1 previously paired with a large US was more effective in conditioning second-order key-peck behavior to an S2 than was the S1 paired with a small US. The results of these experiments demonstrate that the associative effects of US magnitude can be expressed in the strength of CS-directed motor responding. The distinctive within-CS key-peck distributions in first-order conditioning suggests an interaction between CS- and US-directed responses.     

Blocking of inhibitory conditioning within a serial conditioned stimulus-conditioned inhibitor compound: Maintenance of acquired behavior without an unconditioned stimulus

Well-trained classically conditioned stimuli, presented unreinforced, were protected from extinction when they were followed by a signal of the omission of the reinforcer (conditioned inhibitor Konorskian type) in eight cats. An aversive classical conditioning paradigm with shock as the reinforcer was used. Of several behavioral (leg flexion, vocalization) and organismic arousal (heart rate, respiration rate, respiration amplitude) measures of conditioned responses, the respiration amplitude changes were found to be most informative for the continuous assessment of elicited arousal of low and medium intensity. In all subjects conditioned stimuli presented during extinction in serial compound with the conditioned inhibitor elicited larger responses than did conditioned stimuli presented alone during extinction. The mechanism of protection from extinction in a paradigm in which the elicitor of learned behavior occurs prior to the conditioned inhibitor provides the organism with the mechanism for the maintenance of learned behavior in the absence of a reinforcer.     

Loudness and reaction time: I

It is widely assumed, based on Chocholle’s (1940) research, that stimuli that appear equal in loudness will generate the same reaction times. In Experiment 1, we first obtained equal-loudness functions for five stimulus frequencies at four different intensity levels. It was found that equal loudness produced equal RT at 80 phons and 60 phons, but not at 40 phons and 20 phons. It is likely that Chocholle obtained equivalence between loudness and RT at all intensity levels because of relay-click transients in his RT signals. One main conclusion drawn from Experiment 1 is that signal detection (in reaction time) and stimulus discrimination (in loudness estimation) require different perceptual processes. In the second phase of this investigation, the RT-intensity functions from six different experiments were used to generate scales of auditory intensity. Our analyses indicate that when the nonsensory or “residual” component is removed from auditory RT measures, the remaining sensory-detection component is inversely related to sound pressure according to a power function whose exponent is about — 3. The absolute value of this exponent is the same as the .3 exponent for loudness when interval-scaling procedures are used, and is one-half the size of the .6 exponent which is commonly assumed for loudness scaling.     

Unions as Justice-Promoting Organizations: The Interactive Effect of Ethnicity,Gender, and Perceived Union Effectiveness

This study explored the interactive effect ofmembers' ethnicity, gender, and perceived unioneffectiveness in promoting fairness on formal unionparticipation. Research on union participation suggests that formal participation is lowest amongethnic minority and women members. It was predicted andfound that the relationship between perceived unioneffectiveness and formal participation is jointlymoderated by ethnicity and gender. The nature of thetriple interaction was such that the relationshipbetween perceived effectiveness and formal participationwas strongest for ethnic minority women (n = 102), next strongest for nonethnic minority women (n =300) and nonethnic minority men (n = 734), and weakestfor ethnic minority men (n = 82).     

The need for teaching philosophy in medical education

The dearth of philosophical contributions to medicine has recently been discussed in a series of articles in this journal. The present article focuses on physicians' lack of training in philosophy as a part of the explanation of the scarcity of works in philosophy of medicine. In section I I outline two philosophy courses which would be reasonable additions to the medical school curriculum required of all medical students. In section II I suggest two other philosophy courses as electives in a medical education. All four courses are in the fields of epistemology and metaphysics, and so will help others see the relevance to medicine of philosophical fields other than ethics.     

Forensic neuropsychology: A reply to the method skeptics

Various critics or method skeptics have contended that clinical neuropsychology is not sufficiently developed as a science to be offered as evidence in legal or trial proceedings. The present article attempts to balance the extreme position of the method skeptics with an overview of legal and research data that support forensic applications of neuropsychology. It is suggested that clinical evidence can usefully inform legal decision making and that the modern trend has been for courts to be increasingly open to such expert testimony. The relevance of studies of clinical judgment, experience, and actuarial prediction is discussed, and neuropsychological assessment validity is specifically addressed. It is concluded that the arguments of the method skeptics should guide future research and caution forensic neuropsychologists, but that a retreat from the courtroom is unwarranted.     

Measurement of Health Care Attitudes In Cystic Fibrosis Patients and Their Parents

Previous research indicates that attitudes about information acquisition, and attitudes about behavioral involvement, moderate important health behaviors. These attitudes may play an important role in the management of cystic fibrosis (CF) because of the crucial role that patient knowledge and self-involvement play in maintaining adequate functioning. However, due to the young age of CF onset, and the necessary involvement of parents in CF patients' care, two preliminary questions require attention. First, can health care attitudes be measured reliably in young samples? Second, are parents' attitudes related to their children's attitudes? In this study we examined the measurement of health care attitudes in CF patients and their parents by administering the Health Opinion Survey. Results indicated that health care attitudes could be measured reliably in parents and teens, but that for younger patients (ages 8 to 12 years), reliability was reduced. Results also indicated that parents' attitudes and patients' attitudes were largely unrelated, suggesting that patients do not automatically adopt the health care attitudes of their parents. By implication, educational interventions targeted at parents may have limited effectiveness for their children.     

Intergroup Interaction and Self-Disclosure1

Two studies were designed to test hypotheses concerning self-disclosure during initial interactions with ingroup or outgroup strangers. Based on intergroup anxiety theory it was predicted that ingroup members would disclose less to outgroup strangers than to ingroup strangers. One study involved interaction with handicapped and nonhandicapped confederates and one involved interaction with Caucasian and Black confederates. It was found that on some dimensions there was less self-disclosure to outgroup than ingroup strangers during initial interactions. Additional data suggested that high levels of public self-awareness and perceived dissimilarity also reduced some aspects of self-disclosure.