Stimulus variables in the block design task.

Abstract

Block-design construction tasks reliably assess cognitive deficits due to brain injury. We examined the important aspects of this task with four experiments using normal subjects. Two problem-solving strategies are identified: an analytic strategy in which subjects mentally segment each block in the design to be constructed and a synthetic strategy, which involves wholistic pattern matching. Three experiments found a predominate analytic strategy. The time to place a single test block in a display decreased the greater the number of interior edges for that block in the design. Also, two-colored blocks requiring an orientation judgment were placed slower than solid blocks. The fourth experiment predicted overall construction times for a design from the number of solid blocks and interior edges of its blocks. These studies suggest refinements in the blockdesign test for investigating constructional disability in brain-damaged patients. We recommend such analyses of other neuropsychological tests.

The role of the oblique effect in the block-design selection process

“…Among these, the "block-selection" operation pertains to the time required for selecting a surface from the alternatives presented by the block faces so that it matches a given mentally recoded stimulus unit (a perceived portion of the stimulus pattern that has been reprocessed into units like those of the various block faces). Experimental manipulations of relevant task parameters have shown that when attempting to find such a match, subjects take longer to select a correctly oriented two-color surface than a correctly oriented solid-color surface (Royer, 1977;Schorr, Bower, & Kiernan, 1982).…”

“…partially responsible for the longer selection times (Schorr et al, 1982). That is, with two-color surfaces, one does not simply have more alternatives from which to choose, one must select the correct orientation of the block face.…”

“…Among these, the "block-selection" operation pertains to the time required for selecting a surface from the alternatives presented by the block faces so that it matches a given mentally recoded stimulus unit (a perceived portion of the stimulus pattern that has been reprocessed into units like those of the various block faces). Experimental manipulations of relevant task parameters have shown that when attempting to find such a match, subjects take longer to select a correctly oriented two-color surface than a correctly oriented solid-color surface (Royer, 1977;Schorr, Bower, & Kiernan, 1982).Since there are four possible two-color surfaces from which to choose (two bits of uncertainty), and only two solid-color surfaces (one bit), and since response time increases directly with the amount of uncertainty, slower latencies for selecting two-color surfaces may be entirely attributable to this factor (Royer, 1977). It has also been suggested that the orientation judgment required to correctly match a two-color stimulus unit may in itself be Copyright 1990 Psychonomic Society, Inc. 412 partially responsible for the longer selection times (Schorr et al, 1982).…”

“…Experimental manipulations of relevant task parameters have shown that when attempting to find such a match, subjects take longer to select a correctly oriented two-color surface than a correctly oriented solid-color surface (Royer, 1977;Schorr, Bower, & Kiernan, 1982).…”

“…It has also been suggested that the orientation judgment required to correctly match a two-color stimulus unit may in itself be Copyright 1990 Psychonomic Society, Inc. 412 partially responsible for the longer selection times (Schorr et al, 1982). That is, with two-color surfaces, one does not simply have more alternatives from which to choose, one must select the correct orientation of the block face.…”