Temporal control by signals of interval duration within variable-interval schedules

Rats' lever pressing produced sucrose reinforcers on a variable-interval schedule where, in different conditions, the duration of a stimulus presented immediately after reinforcement was either correlated or uncorrelated with the duration of the current interreinforcement interval. Under the baseline schedule, in which no stimulus was presented, the minimum interreinforcement interval was 8 s and the mean postreinforcement pause of each subject approximated this value. Response rates increased slowly over the first 10 to 15 s and then remained roughly constant throughout the remainder of the interval. In both the correlated and uncorrelated conditions, the added stimulus resulted in the postreinforcement pauses lengthening to values in excess of the duration of the preceding stimulus. This resulted in a poststimulus pause which was, in most cases, roughly constant irrespective of the duration of the preceding stimulus, or of the reinforcement contingencies prevailing immediately after stimulus offset. Local response-rate patterns in the uncorrelated conditions were similar to those obtained under the baseline schedule in which no stimulus was presented. However, in the correlated condition local response rates increased across the remainder of the interreinforcer interval. Further, the rate of acceleration was inversely related to the duration of the preceding stimulus. These results show that a correlation between stimulus duration and the ensuing time to reinforcement can control behavior—a type of temporal control not previously reported.     

Midi-level measurement of social anxiety in psychiatric and non-psychiatric samples

This paper reports the development and assessment of midi-level behavioral measures of social anxiety in the context of two experiments, one studying an analog student sample, the other a psychiatric sample. Judgments on nine categories of clinically practical midi-level behaviors (e.g. Facial Expression, Orienting, Sense of Timing), based on a review of the literature on human ethology and on pilot research, were compared to global judgments of social anxiety and social skill and to physiological arousal. Intraclass correlations exceeded 0.80 for judgments of the global and midi-level behavioral ratings on both samples. Results of correlational analyses indicated that while there were several significant predictors of global skill and anxiety among the midis, the magnitude of the relationship between midis and globals was stronger for the patient than the student sample. Further analyses based on S's heart rate (HR) reactivity suggested that while global ratings did not significantly predict H R in a high social anxiety situation, one midi-level behavioral rating (self-manipulations) did. The clinical utility of the newly developed measures is discussed with particular attention to their practicality for behavior therapy.     

Generalization of treatment effects in training public speakers

Three studies compared the efficacy of various treatments for public-speaking incompetence. These effects were evaluated for the target behavior as well as for generalization effects across situations (conversations), settings (different sizes and types of audiences) and time (6-month follow-up). The first study showed that Self-instructional Training, either alone or in combination with other procedures, produced little or no benefits. The second study demonstrated the superiority of a Skills Training program over flooding therapy, while the final study failed to detect any enhancement of treatment benefits for the addition of home-practice to the Skills Training. In the first two studies generalization occurred across the three dimensions (settings, situations and time), while in the final study it was shown that the program was effective for a clinical population as well as recruited volunteers.     

Coping behavior in depression: report on a new scale

The Coping Strategies Scales (COSTS) were developed to provide a means of measuring how depressed persons cope with depression and to identify the behavior which they find to be most or least helpful. Items were rated by eight psychologists, psychiatrists and social workers. Those items achieving 75% level of agreement on scale assignments were included. The COSTS was then administered to 100 depressed outpatients and inpatients currently in psychotherapy. A replication study of 64 patients was also completed. Nine of the 10 scales had acceptable internal reliability, ranging from 0.70 to 0.86. An initial factor analysis of the 10 scale scores showed there to be three primary factors. Internal reliability coefficients for these three factorially-derived scales ranged from 0.86 to 0.91.     

Time course of visual information utilization during fixations in reading

College students read short texts from a cathode-ray tube as their eye movements were being monitored. During selected fixations, the text was briefly masked and then it reappeared with one word changed. Subjects often were unaware that the word had changed. Sometimes they reported seeing the first presented word, sometimes the second presented word, and sometimes both. When only one word was reported, two factors were found to determine which one it was: the length of time a word was present during the fixation and the predictability of a word in its context. The results suggested that visual information is utilized for reading at a crucial period during the fixation and that this crucial period can occur at different times on different fixations. The pattern of responses suggested that the first letter of a word is not utilized before other letters and that letters are not scanned from left to right during a fixation.     

Factors influencing readability of rapidly presented text segments

Experiment 1 compared paragraph comprehension for texts shown either as normal pages on a computer terminal screen or as rapid serial visual presentations (RSVPs) of small text segments to a common location. Over several days of practice, reading comprehension was equivalent in the normal presentation mode and the RSVP format. When successive RSVP segments contained some information in common, to mimic the experience of successive parafoveal and foveal views of words in normal reading, comprehension was somewhat worse than when successive segments contained no overlapping information. Experiment 2 used a variety of segment size and segment duration combinations to investigate the optimal means of presenting text in the RSVP format. Across a variety of presentation rates and text difficulties, comprehension was maximal for segments averaging about 12 character spaces in length. In Experiment 3, texts were divided into short idea units or into random segments of equal average length. Comprehension was shown to be greater in the structured condition than in the random condition. An optimal means of presenting text in the RSVP format could be superior to normal presentation methods for reading and other text-processing tasks.     

Comprehension of directly and indirectly stated main ideas and details in discourse by brain-damaged and non-brain-damaged listeners

Aphasic, right-hemisphere-damaged, and non-brain-damaged subjects heard short narrative paragraphs. Each paragraph contained four main ideas and one or more details related to each main idea. After each paragraph was presented, subjects' comprehension and retention of main ideas and details from the paragraph were tested. Some of the test items directly restated information from paragraphs and others paraphrased information from paragraphs. All groups of subjects remembered main ideas better than they remembered details, and no group of subjects was significantly affected by whether test items directly or indirectly stated information from paragraphs. Disfluent aphasic and right-hemisphere-damaged subjects' overall paragraphs comprehension scores were not significantly poorer than those of non-brain-damaged subjects. Fluent and mixed aphasic subjects' overall paragraph comprehension scores were significantly worse than those of non-brain-damaged and right-hemisphere-damaged subjects. Token Test and Boston Diagnostic Aphasia Examination auditory comprehension scores did not predict aphasic subjects' paragraph comprehension scores. right-hemisphere-damaged subjects' overall paragraph comprehension scores were not significantly those of non-brain-damaged and right-hemisphere-damaged subjects. Token Test and Boston Diagnostic Aphasia Examination auditory comprehension scores did not predict aphasic subjects' paragraph comprehension scores.