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K J Saunders

Publications and source records attributed to K J Saunders.

14 recordsLinked to original sources
PubMed1992

Comparison between near retinoscopy and cycloplegic retinoscopy in the refraction of infants and children.

We investigated the validity of replacing cycloplegic retinoscopy with a noncycloplegic, "near" retinoscopy technique. We refracted a group of 31 infants (less than 2 years) and 43 children (greater than 2 years) with both techniques, grading our level of confidence in the result. Near retinoscopy gave on average a less hypermetropic result than cycloplegic retinoscopy by 0.39 D. The difference was significant in infants and for low levels of examiner confidence. However, a repeatability study showed that much of the variability in the infant group could be attributed to the poor repeatability of either retinoscopy technique. Agreement between the two techniques is improved by changing the suggested adjustment factor from 1.25 to 1.00 D for children and to 0.75 D for infants.

Adolescent↗
PubMed1990

Conditional discrimination in mentally retarded adults: the development of generalized skills.

The development of generalized conditional discrimination skills was examined in adults with retardation. Two subjects with histories of failure to acquire arbitrary matching under trial-and-error procedures were successful under procedures that trained one or more prerequisite skills. The successive discrimination between the sample stimuli was established by training the subjects to name the stimuli. The simultaneous discrimination between the comparison stimuli was established using either (a) standard simple discrimination training with reversals or (b) a procedure in which each of the two sample-comparison relations in the conditional discrimination was presented in blocks of trials, with the size of the blocks decreasing gradually until sample presentation was randomized. The amount of prerequisite training required varied across subjects and across successive conditional discriminations. After acquiring either two or three conditional discriminations with component training, both subjects learned new conditional discriminations under trial-and-error procedures. In general, each successive conditional discrimination was acquired more rapidly. Tests showed that conditional responding had become a generalized skill. Symmetry was shown for almost all trained relations. Symmetry trial samples were ultimately named the same as the stimuli to which they were related in training.

Adult↗
PubMed1990

Long-term stability of equivalence relations in the absence of training or practice.

An adult male with mild mental retardation, whose laboratory history included training in a match-to-sample task on 16 arbitrary relations among 16 visual stimuli and 2 auditory stimuli, had performances that showed the development of 112 additional arbitrary relations that had never been reinforced. In the presented study on 2-year and 3-year follow-up tests for these derived relations, his performances remained stable despite the absence of opportunities to practice these relations between the tests and the absence of explicit feedback during the tests. The similarity to the long-term stability of language was discussed.

Adult↗
PubMed1989

Naming in conditional discrimination and stimulus equivalence.

Using a matching-to-sample procedure, McIntire, Cleary, and Thompson (1987) taught monkeys the conditional relations A1-R1-A1-R1, A2-R2-A2-R2, A1-R1-B1-R1, A2-R2-B2-R2, B1-R1-C1-R1, and B2-R2-C2-R2, where the first and third terms in each relation refer to the sample and comparison stimuli, respectively, and the second and last terms refer to the emission of a distinctive pattern of responding. The subjects were then tested for the emergent relations A-C, C-A, B-A, C-B, and B-B, with the differential response produced by a given stimulus during training also emitted on test trials (e.g., A1-R1-C1-R1). The performances of both subjects were as accurate on the tested relations as they had been on the trained relations. The new relations were characterized as demonstrations of stimulus equivalence. However, the conditional discrimination literature shows that such training procedures generate control of comparison selection by the differential response patterns. Therefore, no emergent relations were demonstrated because all of the trained response-stimulus relations were preserved on test trials. This paper suggests that these procedures do not provide an appropriate analogy for the kind of emergent stimulus-stimulus relations exhibited by human subjects in equivalence studies and outlines a paradigm for assessing the relative influence of stimulus-stimulus and response-stimulus relations.

Animals↗
PubMed1989

Conditional discrimination in mentally retarded adults: the effect of training the component simple discriminations.

Two subjects with retardation who exhibited generalized identity matching, but who had extensive histories of failure to acquire arbitrary matching, were exposed to a series of conditions designed to train separately the components of a two-choice conditional discrimination. First, the successive discrimination between the sample stimuli was established by programming a different schedule of reinforcement in the presence of each sample stimulus. Schedule performance was acquired and maintained by both subjects, but neither acquired arbitrary matching. To train the simultaneous discrimination between the comparison stimuli, 1 subject was then exposed to a series of simple discrimination reversals and subsequently failed to acquire arbitrary matching. Both subjects acquired arbitrary matching under a procedure that maintained both the sample and the comparison discrimination by first presenting entire sessions composed of one sample-comparison relation and then gradually reducing the number of consecutive trials with the same sample until sample presentation was randomized (schedule performance was maintained). Removal of the schedule requirement had no effect on arbitrary matching accuracy. Both subjects subsequently demonstrated control by relations symmetric to the trained relations.

Adult↗
PubMed1988

The merger and development of equivalence classes by unreinforced conditional selection of comparison stimuli.

Three experiments assessed the likelihood that subjects with histories of equivalence class development would respond conditionally on new discriminations in the absence of differential consequences for responses. In the first two experiments, two groups of subjects with different experimental histories, but whose performances showed four equivalence classes, responded on trials without explicit reinforcement involving samples from two of the classes and comparisons from the other two classes, in a two-choice matching-to-sample format. Subjects consistently selected a particular comparison in the presence of a particular sample. Subsequent tests showed the emergence of equivalence relations between stimuli from classes linked by the unreinforced conditional selections. Subsequently, in Experiment II, the subjects' responses in the conditional selection trials were reinforced if the selection was reversed from that made previously. Although reversed selection was maintained, 2 of the 3 subjects continued to perform on equivalence relation trials according to their original unreinforced selections. In the third experiment, these 2 subjects responded on a series of conditional discriminations involving three new pairs of sample stimuli and one new pair of comparison stimuli. No explicit reinforcement followed responses on any trial in this experiment. Subsequent tests for equivalence between sample stimuli revealed the development of two equivalence classes.

Adolescent↗
PubMed1987

A personal sampling method for the determination of styrene exposure.

A diffusive sampler, which is suitable for the determination of time-weighted average personal and static exposures to styrene, is described. The sampler is based on a commercially available tube design that is amenable to fully-automated thermal desorption. The performance of the sampler has been evaluated using a protocol, developed by the U.K. Health and Safety Executive, involving both laboratory and field experiments. The sampler has been shown to give results that are similar both in magnitude and precision to those obtained using conventional sorbent tube and pump methods. The diffusive method is preferred because of its simplicity and convenience.

Adsorption↗
PubMed1986

Increased proficiency of search in breast self-examination.

Two experiments were conducted to assess the relative thoroughness of three search patterns for breast self-examination (BSE). Experiment 1 compared the commonly taught concentric circles (CC) pattern to a new pattern composed of vertical strips (VS). Experiment 2 compared a radial spoke (RS) pattern to the VS pattern. Twenty-eight female subjects participated in each experiment. Each learned BSE and was post-tested using the two patterns under investigation; order of presentation was counterbalanced. BSE thoroughness was measured with the aid of a numbered grid projected on the subject's chest allowing an observer to mark each square of the grid palpated on a congruently gridded scoresheet. The percentage of the cone of the breast and of the totality of the breast tissue examined was calculated for each exam. Experiment 1 showed that the VS pattern engendered more thorough coverage of the total breast area (64.4% vs. 38.9%) and of the cone (64.1% vs. 48.7%). The results of Experiment 2 were similar: the VS pattern produced more thorough coverage of the total area (67.9% vs. 44.7%) and of the cone (70.3% vs. 57.2%). All differences were statistically reliable. Of 112 intrasubject comparisons involving the VS pattern, it produced more thorough coverage in all but nine. These results indicate that the VS pattern is the pattern of choice for maximally effective BSE.

Adolescent↗
PubMed1978

Automated measurement of patient activity on a hospital rehabilitation ward.

Change in patient activity is frequently an important clinical variable, yet these changes are difficult to monitor and document empirically. Patients on a rehabilitation ward in a Veterans Administration hospital during a three-month period participated in a direct measure of their daily motion by wearing digital pedometers. The resulting data suggest that changes in patient activity can be easily quantified without disrupting ward routine and that the data can serve to strengthen clinical estimates of change which can assist staff in their analysis and interpretation of patient progress.

Activities of Daily Living↗