Sentence comprehension by Broca's aphasics: Effects of some suprasegmental variables

Three subtests of comprehension (one of varying sentential stress, one of shifting juncture, and one of applying emphatic stress to functors) were administered to eight Broca's aphasics and eight controls to determine the effects of stress and juncture on disambiguation of these sentences. Data indicated that the aphasic group performed significantly worse than the normals on all three subtests of comprehension. In addition, there was a strong positive correlation between severity of aphasia and error scores for all three tests. Results are discussed in relation to intact-vs.-disordered comprehension.     

Spatial ability and handedness

The relationship between preferred handedness and spatial visualization was examined for 124 female and 229 male undergraduate students. Handedness and spatial ability were used in the design as continuous variables. Other variables examined were sex of subject and family history of sinistrality. Spatial ability was found to be systematically related to measured handedness, familial left-handedness, and sex of subject. Males outperformed females at all levels of handedness. The lowest performance was obtained by subjects who were either extremely left-handed or extremely right-handed. The highest scores were obtained by individuals with left-handed relatives and whose handedness scores were in the range considered mixed or slightly right-handed. The results suggest that decreased hemispheric specialization is associated with increased spatial ability.     

A multifunctional on-line brain stimulation system

A flexible on-line electrical brain stimulation system designed for brain stimulation reward (BSR) research is described. A Cromemco Z-2D microcomputer is interfaced with a constant-current stimulator and a standard operant chamber. The system programs, written substantially in BASIC, calculate BSR threshold by two rate-independent methods, measure rate of operant responding, and determine resistance of the brain. Other software programs are used for training rats on complex schedules of reinforcement, for system hardware calibration, and for sophisticated statistical data analyses.     

Memory scanning of shapes,colors, and compounds: A comparison of retarded and nonretarded adults

Three experiments were performed to assess memory scanning of shapes, colors, and shape-color compounds by retarded and nonretarded people. Attributes comprising compounds provided either redundant or nonredundant information. Large retarded-nonretarded differences in reaction time were obtained. In contrast to previous reports of slow scanning of digits and nonsense shapes by retarded people, scan rates for shapes and colors did not differ between groups. Retarded subjects were not characterized by a deficient scan rate. Although compound stimuli required twice as many attributes in their repersentation as did simple stimuli, they were not scanned more slowly, indicating that per item scan rate is not determined by the number of attributes required to define each item. Both groups were able to exploit redundant relevant information to achieve faster processing than in simple conditions. Decision rules for rejecting compound stimuli comprised one, two, or more binary tests. Groups did not differ in speed of performing elementary binary test(s).     

Negatively reinforced key pecking

A reinforcement-switching procedure was used to produce negatively reinforced key pecking in pigeons. First, key pecking on a chain schedule (fixed-interval 10-sec variable-interval 60-sec) was conditioned using grain reinforcement. Second, intermittent shock in the initial link was introduced at a low intensity and gradually increased. Third, food reinforcement in the terminal link was eliminated. With shock at 90 V occurring on the average every 3 sec, initial-link pecking was maintained with no terminal-link food. Three of four pigeons responded consistently at shock intensities of 90, 70, and 50 V but not at 30 V. A fourth pigeon responded at but not below 90 V. Rate of response was directly related to shock frequency. Eliminating food deprivation did not affect the negatively reinforced performance.     

THE PREDICTION OF OCCUPATIONAL SUCCESS AND PROFICIENCY

Neither standardized test data nor grades made in required courses in high school contribute significantly to the prediction of occupational success or proficiency. The General Aptitude Test Battery makes practically no contribution to the prediction of success although the instrument is widely used to predict trainability. Intelligence test scores are of little value in predicting success in the labor market. It may be that efforts to predict occupational success and proficiency are in reality exercises in futility since workers tend to be successful regardless of test results. Apparently workers find places where they are considered successful. Possibly new research designs will be required before success can be predicted. Success should not be considered an entity, however, because it does not lend itself to exact measurement.