A technique for rapid,reliable assessment of thermal-pain threshold in humans

A simple and reliable method of assessing pain threshold in humans may be useful in a number of research areas, such as in examining acute antinociceptive effects of drugs. We have developed a low-cost, computer-controlled method to reliably assess thermal-pain threshold using radiant heat focused from a slide projector and applied to a small area of skin. An electronic shutter is attached to the projector opening to provide precise onset and offset of heat. A computer keypad allows for subject response at the point of pain onset (i.e., threshold), with latency to threshold determined by computer timer. The details of the apparatus setup, subject preparation, and instructions to subjects are presented. The development of the method is described, and sources of unreliability are identified. Coefficients of variation (CVs) are calculated to provide a measure of variability within subjects across trial exposures and across sessions. Results indicate that the method is reliable for determining pain threshold, especially within sessions, and can be employed with relatively minimal expense and subject preparation.     

Processing of identity and position information in normal and disabled readers

Processing of identity and position information was investigated in normal and disabled readers at two grade levels (third/fourth grade and sixth grade). Two partial-report tasks were used. The identity task consisted of visual presentation of a five-letter array, followed by a probe letter. Subjects responded yes for a match and no for a mismatch (identity response). The identity + position task was identical except that an additional response was required on correct yes trials: subjects reported the position of the probe letter in the array (position response). Both grade level and reading ability differences were found on the identity response measure, but not on the position response measure. Results were inconsistent with the hypothesis that disabled readers have difficulties in processing order information. Reader ability differences in identity processing attenuated somewhat with age. Serial position functions for both identity and position responses suggested the presence of a left-to-right scanning operation in both age and ability groups. Reader ability differences in processing letter identities were discussed in the context of current theories of reading acquisition.     

Immediate reinforcement in delayed reward learning in pigeons

Pigeons were trained on simultaneous red-green discrimination procedures with delayed reward and sequences of stimuli during the delay. In Experiment 1, three stimuli appeared during the 60-second intervals between the correct responses and reward, and the incorrect responses and nonreward. The stimulus that immediately followed a correct response also preceded nonreward, and the stimulus that followed an incorrect response preceded reward. These stimuli were 10 or .33 second in duration for different groups. Stimuli during the remainder of the delay interval differed following correct and incorrect responses. Group 10 initially persisted in the nonrewarded choice, but shifted to a preponderance of rewarded responses after further training. Group .33 rapidly acquired the correct response. Similar results were obtained in Experiment 2 where delay intervals consisted of opposite sequences of two stimuli of equal duration and total delays were 6, 20, or 60 seconds. Early in training, generalization of differential conditioned-reinforcing properties from the conditions preceding reward and nonreward to postchoice conditions had a greater effect relative to backchaining than it did later. It was concluded that delayed-reward learning is best analyzed in terms of the conditioned-reinforcing value of the patterns of cues that follow immediately after rewarded and nonrewarded responses.     

The Toronto Word Pool: Norms for imagery,concreteness, orthographic variables,and grammatical usage for 1,080 words

Imagery and concreteness norms and percentage noun usage were obtained on the 1,080 verbal items from the Toronto Word Pool. Imagery was defined as the rated ease with which a word aroused a mental image, and concreteness was defined in relation to level of abstraction. The degree to which a word was functionally a noun was estimated in a sentence generation task. The mean and standard deviation of the imagery and concreteness ratings for each item are reported together with letter and printed frequency counts for the words and indications of sex differences in the ratings. Additional data in the norms include a grammatical function code derived from dictionary definitions, a percent noun judgment, indexes of statistical approximation to English, and an orthographic neighbor ratio. Validity estimates for the imagery and concreteness ratings are derived from comparisons with scale values drawn from the Paivio, Yuille, and Madigan (1968) noun pool and the Toglia and Battig (1978) norms.     

INCREASING HABILITATIVE SERVICES FOR PERSONS WITH PROFOUND HANDICAPS: AN APPLICATION OF STRUCTURAL ANALYSIS TO STAFF MANAGEMENT

We evaluated a structural analysis methodology for enhancing the utility of a staff management program. In Experiment 1, a structural analysis of direct-care staff behavior in a mental retardation facility revealed differences in work patterns over time. Specific times were identified when few basic care duties were necessary and staff engaged in nonwork activity. In Experiment 2, a management program was implemented to increase staff members' training activities during periods identified through the structural analysis. The program was accompanied by increases in training activities and decreases in nonwork behavior. The improvements were maintained during a 43-week period while the most labor-intensive component of the program was withdrawn. Staff acceptability measures indicated a positive response to the management intervention, although responses varied across components within the multifaceted program. The increased training was accompanied by beneficial changes among clients with profound handicaps. Results are discussed regarding practical considerations for improving staff performance and for adopting innovations resulting from applied research.     

Effects of response-produced stimuli upon conditional discrimination performance

In zero-delay matching procedures the performance of three groups of pigeons was examined when exteroceptive stimuli, response-produced stimuli associated with the completion of either of two fixed ratios, or a compound of exteroceptive and response-produced stimuli were available as samples. Exteroceptive samples were found to control a higher level of matching accuracy than response-produced samples, while compound samples controlled a higher level of accuracy than did exteroceptive samples alone. When all subjects were placed on a transfer procedure, during which the previously used red and green samples were replaced by horizontal and vertical lines, the availability of sample-specific fixed-ratios facilitated acquisition of the task.     

Relation of age at onset to duration of episode in unipolar depression

The purpose of this study was to test the hypothesis that the duration of episodes of unipolar depression increases with age at onset. On the basis of elevated scores on a self-report depression measure, 2,020 persons were selected from a larger community sample to be interviewed and diagnosed using the Schedule for Affective Disorders and Schizophrenia-Research Diagnostic Criteria procedures. Of the 2,020 persons, 865 had a history of one or more episodes of unipolar depression. The potential effects of the following variables (singly and in interaction) on duration of episode were assessed by means of multiway frequency table analysis and chi-square: age at onset, sex of subject, interval since occurrence of the episode, and type of disorder (major vs. minor depressive disorder). The hypothesis that duration of episodes of depression increases with age at onset was not supported. Women were more likely to have multiple episodes, but did not have longer lasting episodes.