Speed and Capacity of Language Processing Test: Normative Data From an Older American Community-Dwelling Sample

Abstract

This study presents normative data for the Speed and Capacity of Language Processing (SCOLP) test from an older American sample. The SCOLP comprises 2 subtests: Spot-the-Word, a lexical decision task, providing an estimate of premorbid intelligence, and Speed of Comprehension, providing a measure of information processing speed. Slowed performance may result from normal aging, brain damage (e.g., head injury), or dementing disorders or may represent the intact performance of someone who always performed at the low end of normal. The SCOLP enables the clinician to differentiate between these possibilities. Adequate age-appropriate norms to differentiate dementia from normal aging do not exist. We present data from 424 older community-dwelling Americans (75-94 years old). The results confirm that information processing speed slows with increasing age. By contrast, increasing age has little effect on lexical decision. Thus, our data suggest that the SCOLP shows promise as a tool to help distinguish between normal aging and the early stages of dementia.