Stimulus discriminability in free-operant and discrete-trial detection procedures.

Six pigeons were trained to discriminate different light intensities in four experimental procedures. Experiment 1 compared stimulus discriminability in a yes-no signal-detection task with discriminability measures obtained from two free-operant procedures. Discriminability estimates were significantly lower in the detection procedure. Experiment 2 showed this lowered discriminability to be a function of the delay between stimulus presentation and the availability of the choice-response keys in the standard detection task. In addition, reinforcement sensitivity was lowest when correct choice responses were intermittently, rather than continuously, reinforced.     

Perceived depth vs. structural relevance in the object-superiority effect

When subjects must identify a barely visible line in a briefly flashed display, their accuracy depends on the configuration of the context in which the target line appears. Weisstein and Harris (1974) found that accuracy is highest when the target is part of a pattern that resembles a unified, three-dimensional object, and lowest in a flat-looking pattern composed of disconnected lines; they labeled this phenomenon the object-superiority effect. In the three experiments reported here, identification accuracy was found to correlate highly and significantly (r =.78) with the judged depth of the patterns. Judged structural relevance of the target line to the pattern (McClelland & Miller, 1979) was uncorrelated with accuracy (r=?.28). Even when the target line appeared as an isolated fragment within the context pattern, a pattern perceived as three-dimensional yielded higher identification accuracy than one perceived as flat.     

Facial and vocal cues of deception and honesty

Facial expressions and vocal cues (filtered speech) of honest and deceptive messages were examined in posed and spontaneous situations. The question of interest was the degree to which nonverbal cues transmit information about deception. Results indicated that (a) for both the facial and vocal channels, posing (as compared to spontaneous behavior) produced a higher level of communication accuracy; (b) facial expressions of deceptive (as compared to honest) messages were rated as less pleasant, while vocal expressions of deception were rated as less honest, less assertive, and less dominant, particularly in the posed condition; (c) the sender's ability to convey honesty was negatively correlated with his/her ability to convey deception, suggesting the existence of a demeanor bias—individual senders tend to appear and sound consistently honest (or dishonest) regardless of whether they deliver an honest or a deceptive message; (d) in the posing condition, the sender's abilities to convey honesty/deception via facial and vocal cues were positively and significantly correlated, whereas in the spontaneous condition they were not; and (e) senders whose full (unfiltered) speech indicated more involvement with their responses were judged as more honest from both their vocal (filtered speech) and facial cues, in both the honest and deceptive conditions.     

Increasing engagement in activity of residents in old people's homes by providing recreational materials

This project investigated whether the level of engagement in two special Homes for the elderly could be increased by providing a regular recreational session, where the residents had the opportunity to use various extra recreational materials and to interact with the organiser of the session. The residents' level of engagement during the sessions was consistently higher than under baseline conditions. This indicates that the low engagement of the residents is at least partly due to lack of opportunity to engage, rather than to the specific disabilities of the residents. The methodological approach used in this study is suggested as a useful, objective way of evaluating the effects of, and preferences for, various types of recreational activities that might be offered to elderly people in residential care.     

TEACHING COIN EQUIVALENCE TO THE MENTALLY RETARDED1

A program was designed to teach coin equivalence to mentally retarded adolescents. Coin equivalence was defined as choosing several different combinations of coins to equal specified target values. A pretest-posttest matched-groups design was employed with an experimental group receiving the monetary training, and a no-training control group. A multiple baseline across coin-counting responses was also incorporated in the experimental group. Training was divided into six stages, each teaching one specific method of combining coins to equal 10 target values from 5¢ through 50¢. A three-component response chain was used, requiring (a) naming, (b) selecting and counting, and (c) depositing target monetary values into a coin machine. Experimental subjects improved significantly in coin equivalence performance and maintained their skill on follow up tests; control subjects did not.     

An illusion of auditory saltation similar to the cutaneous "rabbit"

Trains of brief clicks produced successively at 3 points in a horizontal array were not localized accurately. Observers reported clicks occurring in succession across the spaces between sources as well as at the sources themselves. The illusion is functionally related to interstimulus interval, number of clicks per speaker, and regularity of pulsing. It appears similar to Geldard and Sherrick's cutaneous "rabbit" illusion.     

What do you do after you say hello? Observing,coding, and analyzing parent-infant interactions

Procedures for observing, coding, and analyzing parent-infant interactions are described. Sample data are presented to illustrate the outcome of these procedures and the manner in which developmental issues can be addressed using the hardware and software systems described.     

Pastoral psychotherapy and the symbolic

The author points out and illustrates the interrelatedness of the capacity to think symbolically and a sense of self. Through a case study he describes the disclosure of hidden and unresolved personal concerns by symbolic references and the correspondence between personal myth and emotional concerns. A perspective of therapy is suggested—that it is a process of clarifying and demythologizing self-perceptions, conscious and unconscious, so that a person can move on to other representations of self and be liberated from restrictions imposed by undisclosed myths. Finally, the author examines what is pastoral or religious about a psychotherapeutic process and offers questions for further study.