Age effects on block design: Qualitative performance features and extended-time effects (original) (raw)

Qualitative performance features and extended-time effects on the Block Design subtest of the WAIS-R were examined in 145 healthy Ss ages 50-95. Raw scores were calculated at standard and extended time limits; error types and starting points were recorded for a subgroup of Ss. In Ss age 60 and older, there was a consistent decline with age in overall scores at both time limits. Extra time allotments resulted in modest but significant increases in scores. Older and younger Ss benefited equally from the extra time, indicating that the age-related decline on this task cannot be accounted for by general age-related psychomotor slowing. Single-and multiblock rotation errors were relatively common, whereas stimulus boundedness and broken configurations were rare. Despite some potential limitations in generalizability, the results suggest that the incorporation of qualitative scoring procedures in the assessment of visuoconstructional skills may enhance understanding of normal and abnormal brain-behavior relationships. Age-associated declines in a variety of cognitive abilities are well established (e.g., Albert, Duffy, & Naeser, 1987; Manton, Siegler, & Woodbury, 1986). These declines do not pervade all areas of intellectual functioning; some functions remain intact or even improve with age. One commonly observed pattern of cognitive changes is the stability of many verbal abilities and a notable decrement in visuospatial and constructional abilities (e.g., as measured by some of the performance subtests of the Wechsler scales; Doppelt & Wallace, 1955; Wechsler, 1981). One possible explanation for relatively greater visuospatial decrements relates to the general slowing of information processing that occurs with age. Because many visuospatial tasks are timed and require motor responses, whereas most verbal tasks are untimed and require oral responses, relative declines on visuospatial tasks could possibly be explained by age-related reductions in psychomotor speed (e.g., Hertzog, 1989). There is some evidence, however, that a higher cognitive component is also involved in declining performance on these tasks (Birren, Woods, & Williams, 1980; Salthouse, 1985; Welford, 1984). For example, some researchers have found that when time constraints on cognitive tests are extended or eliminated, older subjects tend to benefit more than younger subjects, but the extra time does not appear to eliminate age differences (Doppelt & Wallace, 1955; Schaie, 1990). Additional support is derived from studies demon