Age differences in symbol-digit substitution task performance

Abstract

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 group were interpreted as evidence for a change in a sensorimotor component and in two information‐processing operations: Symbol encoding and visual search.

Symbol–digit substitution and individual differences in visual search ability

“…As noted above, the ESS of a symbol has been shown to affect several informationprocessing components, including encoding speed and memory. The manipulation of this variable does affect substitution task performance (Gilmore, Royer, & Gruhn, 1983;Royer, 1971b;Royer, Gilmore, & Gruhn, 1981) but the independent contributions of feature composition and visual confusability to the dramatic influence of ESS have not been assessed. Indeed, in previous investigations by Royer et al the visual confusability and the ESS of the symbols have been confounded.…”

“…Royer et al have reported differences in symbol-digit substitution task performance between groups classified by gender (Royer, 1978), severity of schizophrenia (Royer & Janowitch, 1973), and age (Gilmore et al, 1983) that are similar in pattern to that reported here for the good and poor search groups. Those studies used multiform substitution tasks in which the symbols were varied across forms according to the ESS of the symbols.…”

Normative data stratified by age and sex for 12 neuropsychological tests

“…Stein (1962) found that there was no significant sex difference. However, the effect of age was noted in research that used a similar test, Symbol Digit from the WAIS (Gilmore, Royer, & Gruh, 1983). Such a general decline in psychomotor ability has been well documented by others (Bak & Greene, 1980;Bayley, 1968;Horn & Cattell, 1966).…”

Traumatic Brain Injury and Executive Functioning in an Incarcerated Sample

“…Some research has suggested that gender also has an impact (Jorm, Anstey, Christensen, & Rodgers, 2004), though other studies have found no difference (Gilmore, Royer, & Gruhn, 1983). Level of acculturation in an African American sample was found to affect scores on the written version (Kennepohl, Shore, & Nabors, 2004).…”