Biomedical subjects

J J Gruhn

Publications and source records attributed to J J Gruhn.

3 recordsLinked to original sources

PubMed1984

Stimulus parameters that produce age differences in block design performance.

Administered block designs that varied according to two parameters, Task Uncertainty and Perceptual Cohensiveness, to 83 persons 49 years of age or older. Performance was adjusted to remove motor speed differences. Performance changed significantly over the age span as a function of Task Uncertainty. From 49 years up, performance did not change as a function of Perceptual Cohesiveness. An analysis that included a group of 20 persons 30 years of age or younger yielded an interaction of Age and Perceptual Cohesiveness. From 49 years on, analytic or image segmentation processes do not seem to change, but other information processing becomes slower.

Adult↗

PubMed1983

Age differences in symbol-digit substitution task performance.

A decline in performance on the Digit Symbol Substitution test related to aging is well documented. There is no agreement on the reason for the decline, however. In part, the lack of consensus with regard to changes on the test may be attributed to the limitations imposed by comparing groups on a single performance measure. In the present study, three forms of a Symbol-Digit Substitution task that varied in difficulty level were administered to 125 persons between the ages of 30 and 92. On all forms there was a clear performance decline associated with age. The differences observed among the age groups were interpreted as evidence for a change in a sensorimotor component and in two information-processing operations: Symbol encoding and visual search.

Adult↗

PubMed1981

Normative data for the Symbol Digit Substitution Task.

Administered three forms of a Symbol-Digit Substitution task to normals, 16 to over 80 years of age, to schizophrenic and other hospitalized groups. Their data are presented for normative purposes. The three forms vary in difficulty and provide a measure of visual information processing ability, Clinical and research implications of the data are discussed.

Adolescent↗