Biomedical subjects

F R Hoogeveen

Publications and source records attributed to F R Hoogeveen.

5 recordsLinked to original sources

PubMed1990

Time-delay discrimination training: replication with different stimuli and different populations.

Two time-delay conditions for teaching complex visual discriminations to normal preschoolers and children with mild and moderate intellectual handicaps were compared. One condition involved spatially separating the distinctive components from the redundant parts of both stimuli (multiple dynamic distinctive-feature prompts). The other condition involved adding a colored field to the correct stimulus (single static nondistinctive-feature prompt). The effect of the latter condition was assessed with unlearned and learned tasks. The study consisted of four experiments. In one experiment, children were also required to use the prompts for self-monitoring responses given before prompting had occurred. The results indicated that for all populations and stimuli (a) time delay of multiple dynamic distinctive-feature prompts consistently produced learning, and (b) time delay of the single static nondistinctive-feature prompt almost never produced learning and frequently led to a complete loss of discriminative performance on previously learned tasks. The resistance to disruption was a function of the training history (i.e., with or without time delay) and IQ level. Self-monitoring increased the efficacy of time delay when multiple dynamic distinctive-feature prompts were used but not when the single static nondistinctive-feature prompt was used.

Adolescent↗

PubMed1989

Teaching moderately mentally retarded children basic reading skills.

The present study assessed the efficacy of a program for teaching moderately mentally retarded children basic reading skills. Central to the program were the use of a phonemic alphabet as well as the application of pictorial cueing and stimulus manipulation techniques. The program consisted of six phases. It started with the training of graphemes for vowels (Phase 1) and ended with the training of two-syllable words (Phase 6). Four moderately mentally retarded students participated. Given time constraints, not all subjects completed all phases of the program. The training ended with the reading of one-syllable three letter words for one subject, one-syllable four letter words for two subjects, and two-syllable words for one subject. Subsequent generalization tests revealed that all subjects were capable of reading untrained words of the same complexity as those previously trained; and to read and, to a lesser extent, understand simple sentences. The execution of the program required an average training time of 35 hours per subject. Aspects pertaining to the validity of the program, the efficacy of the procedures, and the relevance of the learned skills are discussed.

Adolescent↗

PubMed1989

Establishing sound blending in moderately mentally retarded children: implications of verbal instruction and pictorial prompting.

The present study evaluated a program for establishing blending of consonants (C) and vowel-consonant (VC) syllables in moderately mentally retarded children. The study consisted of two experiments. Experiment 1 assessed whether the subjects' failure to blend was due to the task requirements per se, or to the inadequacy of the instructional terminology ("Say together"). Experiment 2 evaluated the implications of using pictorial prompts in the acquisition and generalization of C-VC blending. The data revealed that (a) adequate verbal instruction had a modest but significant effect on the subjects' blending performance (Experiment 1), and (b) training without pictorial prompts resulted in better blending of trained and untrained C-VC items than training with pictorial prompts (Experiment 2).

Adolescent↗

PubMed1984

Effects of different stimulus manipulations of the acquisition of word recognition in trainable mentally retarded children.

The present study was designed to assess the efficacy of different procedures for establishing transfer of stimulus control from pictorial representations to printed words in trainable mentally retarded school children. The study consisted of two experiments. In experiment 1, four training conditions were used, i.e. two conditions (stimulus shaping and stimulus connected prompt fading) in which the subjects' attention was guided to the training stimuli, and two conditions (stimulus disconnected prompt fading and no fading) in which the subjects were allowed to respond only to the prompts. The results showed that stimulus shaping and stimulus connected prompt fading were far more effective than either one of the other procedures. Subsequent analyses revealed that 1 the stimulus control of the trained words was restricted to one or two letters, and 2 in case it was restricted to one letter, this was frequently a letter other than the one used for training. Furthermore, it was noted that the learned discriminations deteriorated as time or training progressed. Experiment 2 was designed to replicate some of the findings of experiment 1, and to control for one of the variables contributing to the superior efficiency of stimulus shaping over stimulus connected prompt fading. In general, the results of this experiment confirmed those obtained in experiment 1.

Adolescent↗

PubMed1984

Using stimulus shaping and fading to establish stimulus control in normal and retarded children.

The present study was an effort to investigate whether, in addition to his IQ level, the child's ability to identify all relevant stimulus components would affect the frequency of overselective responding. Children of different IQ levels (i.e. normal, educably retarded, and trainable retarded children) participated. Subjects were trained to learn the meanings of four sets of fictitious words, i.e. two sets containing words printed in Roman letters (Roman words), and two sets containing words printed in Hebrew letters (Hebrew words). All subjects could identify the words of each set. The normal and educably retarded subjects could read aloud the Roman words, whereas the trainable retarded subjects could not. None of the subjects could read the Hebrew words. Two training procedures were used, one requiring transfer of stimulus control (fading), and one which did not (stimulus shaping). The results indicated that, firstly, the discrimination learning of the normal and educably retarded subjects covaried with the IQ level and their ability to read the words. The learning rate was not affected by the training procedures. Secondly, the trainable retarded subjects learned much better through stimulus shaping than through fading. Their acquisition rates were slow and not affected by the types of letters. Thirdly, the training procedures had no effect on the breadth of stimulus control. Instead, it covaried as a function of the IQ level (all groups) and of the child's ability to read the words (normal and educably retarded subjects). Fourthly, the training procedures had, however, considerable effect on which letters controlled the discriminations. When overselective selective responding was evident, the letters that had been associated with the prompts were more often functional than the other letters, but only for the words trained through stimulus shaping.

Child↗