Lawrence Wheeler

An application of discriminant functions to the problem of predicting brain damage using behavioral variables.

Discriminant functions were applied to 24 behavioral indices from each of 140 individuals tested in the Neuropsychology Laboratory, Indiana University Medical Center. The scores came from 11 Wechsler subtests, 11 Halstead subtests, and 2 Trail Making tests. Comparisons were made between 61 non-brain-damaged control Ss and 79 Ss showing any of several kinds of cerebral damage on the basis of criteria resulting from independent neurological examination. These 79 were subdivided and compared with the controls as follows: (a) 25 Ss with damage of the left cerebral hemisphere, (b) 31 Ss with damage of the right hemisphere, (c) 23 Ss with diffuse, bilateral involvement. Also the 25 left-damaged and the 31 right-damaged Ss were compared. The discriminant function in each comparison produced a single weighted score per S, an optimum, least-squares type of separation between the two groups. The resulting distributions of summed, weighted scores in each comparison were inspected for the point of minimum overlap. An individuals weighted score, falling above or below this point, categorized him as belonging to one group or the other. These assignments, when compared with the criterion assignments of Ss to groups, were expressed as percentages of correct predictions: controls versus all categories of cerebral damage, 90.7%; controls versus left damage, 93.0%; controls versus right damage, 92.4%; controls versus diffuse damage, 98.8%, and right versus left damage, 92.9%. Several other indices were examined for percentages of correct prediction, but the discriminant function was superior in all comparisons. A cross-validation study is now in press (6).

PRESENCE AND LATERALITY OF BRAIN DAMAGE PREDICTED FROM RESPONSES TO A SHORT APHASIA SCREENING TEST

A brief test for aphasia and certain perceprual functions that yields 26 scores per S was administered to a sample of 262 Ss. Without, at present, going into the fine structure of the response patrerns, we wish to be able to state how well this test allows us to predict cerebral damage in any single instance and whether the damage, if any, is diffuse (or bilateral) or principally involves one or the other of the cerebral hemispheres.

Discriminant Functions Applied to the Problem of Predicting Cerebral Damage from Behavioral Tests: A Cross-Validation Study

Linear discriminant functions were applied to 23 behavioral test scores from each of 304 patients who were divided into control, left cerebral damage, right damage, and diffuse or bilateral damage groups. Random-half and temporal-half (early versus late test period) cross-validations were performed by generating weights from the scores of each of the foregoing halves and applying them to the appropriate counter-halves. The reduction in accuracy of criterion prediction attributable to cross-validating, i.e., the “noise” in the system, varied between 10% and 20% of the uncrossed accuracy. Validated accuracy was about 80% for comparisons between controls and (a) all the damaged groups together, (b) diffuse or bilateral damage groups, (c) left damage groups, (d) right damage groups, and (e) between left and right damage groups; it was about 70% between the left damage and diffuse or bilateral damage groups; about 60–65% (essentially no better than chance) between the right damage and diffuse or bilateral damage groups. It was concluded that when greater validated accuracies of correct prediction are obtained, for situations like those of this study, they must rest at least partially upon the basis of nonlinear relationships that exist in the data. The obtained accuracies (except for lateralized damage versus non-lateralized damage groups) were considered to be high enough to indicate that the discriminant function has practical value.

Evaluation of Computer-based Diet Education in Persons with Diabetes Mellitus and Limited Educational Background

A study was conducted to determine whether computer-based techniques for meal planning and diet education could be an effective supplement to diabetes diet counseling in a group of inner-city subjects with limited educational background. Sixteen individuals with diabetes mellitus who were newly referred to an inner-city outpatient diet clinic and who demonstrated ninth-grade reading ability were given computer-based nutritional education. They received meal planning information through use of individualized computer-planned menus and education about the diabetes diet by computer-assisted instruction (CAI) combined with an interactive videodisc system (VIDEO). Total contact time was 180 min of CAI/VIDEO, 50 min of dietitian/patient education, and 20 min of dietitian/patient computer time (the last function could have been performed by a clerk). At the end of 4 wk, the group performance was improved in Exchange Lists knowledge (P < 0.001), recognition of foods containing concentrated carbohydrate (P < 0.05), and reduction of reported fat intake (P < 0.05). In addition, average group weight declined by 4.6 lb (P < 0.005). No improvement was found in food-measuring skills or in calorie-consumption compliance during a standardized buffet lunch. It appears that computer-based techniques are an acceptable supplement to traditional methods of education in this patient group and can improve the effectiveness of diabetes education programs without a significant increase in dietitian time.

COMPLEX BEHAVIORAL INDICES WEIGHTED BY LINEAR DISCRIMINANT FUNCTIONS FOR THE PREDICTION OF CEREBRAL DAMAGE.

Linear discriminant functions were applied to seven dichotomized measures from each of 224 patients who were divided into control, left cerebral damage, right cerebral damage, and diffuse or bilateral damage groups. The measures were: Wechsler Verbal Weighted Score, Wechsler Performance Weighted Score, Halstead Impairment Index, Trail Making Test A, Trail Making Test B, Aphasia 4-rule Prediction, and age of patient. Four comparisons were made, one for each criterion group vs all remaining groups. The discriminant function in each comparison produced a single weighted score per S, and an optimum, least-squares type of separation between the two sets of scores. The resulting distributions of summed, weighted scores in each comparison were inspected for the point of minimum overlap, and an individuals weighted score, falling above or below this point, categorized him as belonging either in the single criterion group or in any one of the remaining three groups. These assignments, when compared with the actual criterion classes of the patients, were expressed as percentages of correct prediction: control vs non-control, 83.0%; left damage vs non-left, 87.5%; right damage vs non-right, 85.7%; diffuse (or bilateral) damage vs non-diffuse, 84.4%. Each measure was examined individually for percentages of correct prediction, but the discriminant function was superior in all instances, being approached only by the Halstead Impairment Index (one comparison) and by the Aphasia 4-rule Prediction (two comparisons). The seven-variable discriminant function was approximately as efficient as either of two previous functions that included more than 20 variables each.

Use of cai/video in diabetes patient nutritional education

An innovative approach to patient education has been developed using a combination of computer assisted instruction (CAI) and video techniques, CAI/VIDEO. Several hours of nutritional education material for diabetics have been prepared. The CAI/VIDEO material is presented on a microcomputer which is electronically connected to a videodisk player. A clinical evaluation of the effectiveness of CAI/VIDEO in patient education is currently being performed.

Betakid--lessons learned while developing a microcomputer pediatric case simulation.

An arcade-style game, Betakid, was developed to provide diabetic children an opportunity to practice and evaluate skills in food and insulin dose selection. The user participates in the events through displays of text and graphics, occasionally accompanied by music. Choices are made concerning insulin dose, diet, and exercise. A displayed score indicates the appropriateness of the users actions. Remediation is available after each decision. During the design and initial evaluation of Betakid, a number of lessons were learned about the application of computer-based simluations to diabetes education and care. The approach that was followed in developing Betakid, a summary of the characteristics of the simulation, and a list of suggestions for efficiently developing this type of project are presented.

Review of Microcomputer Nutrient Analysis and Menu Planning Programs

Physicians and patients are becoming more conscious of the importance of good nutrition, but analyzing nutritional intake and evaluating its appropriateness is a time-consuming process. Microcomputer programs are now available to help. They analyze the patient’s past food intake, plan diets that satisfy requirements, and even fit the patient’s favorite recipes into meal plans.

The regenstrief clinical laboratory system

The Regenstrief Clinical Laboratory System (RCLS) has been operational since 1975 at Wishard Memorial Hospital in Indianapolis, Indiana (a 580 bed facility). The clinician support, user interfaces, and use of a true data base management system distinguish this system from many commercially avaiIabIe laboratory systems. Physician reports include laboratory, clinic, pharmacy and radiology data in a single, compact flow sheet. The system can search patient medical records for conditions that may require corrective action and inform physicians of the reasons these actions should be considered. The site-specific modifications required to transport this system do not require re-programming. The system allows multiple specimen numbering sequences; identification of terms by name or number; unlimited amounts of free text; reports that can be tailored by non-programmer personnel; CAP accounting statistics; on-line instrument interfaces; and extensive on-line instructional facilities. The Regenstrief Clinical Laboratory System (RCLS) accomplishes most of the data capture, reporting and management functions expected of such systems, but it has a number of distinguishing features. These include: 1) its focus on usage by the clinician; 2) its accomodating user interface; 3) its roots in a true data base management system.