Categorization in Context for Young and Older Adults Abstract This investigation explored effects of linguistic context on category structure in young and typical older adults. In a timed computer-based contextual categorization task, participants

This investigation explored effects of linguistic context on category structure in young and typical older adults. In a timed computer-based contextual categorization task, participants were provided with 150 stimulus sentences containing a superordinate category label. Participants were required to make a semantic decision relative to determining if a specific exemplar was the best example of the target category concept in the sentence using context. Response accuracy and reaction time results revealed that use of linguistic context for categorization was vulnerable to the aging process, as older adults were slower and less accurate for all response types except out-of-set examplars. Individuals organize information by grouping items into categories sharing characteristics (Barsalou, 1983; 1987; Hough 2007b; Kiran & Thompson, 2003; Pennequin et al., 2006; Sachs et al., 2008; Sebastian & Kiran, 2007; Smith & Medin, 1981). Research indicates that older adults may organize concepts differently than young adults (Hough, 1989, 1993; 2007a; 2007b); however, findings are inconsistent. Linguistic context is influential in determining word meaning in language (Dagerman et al., 2006; Roth & Shoben, 1983; Smith et al., 1974). It is unclear whether aging influences individuals‟ ability to utilize linguistic context (Cohen & Faulkner, 1983; Meyer et al., 1975; Wingfield et al., 1994). Cohen and Faulkner (1983) theorized that increase in older adults‟ ability to use context was compensation for declines in processing of sensory information. Reduced ability interpreting information from sense organs may be balanced by more intact retrieval relative to utilizing context. However, Wingfield et al. (1994) suggested that although older adults utilize linguistic context to derive meaning, memory decline may make it more difficult for them to use vital contextual cues for clarification of ambiguous words. Memory impairment may adversely affect retrieval of words dependent upon context to resolve meaning. Thus, older adults may not utilize context as effectively as younger adults (Hough, 1989, 2007a), due to difficulty with retrieving contextually-based lexical referents of categories that are less typical relative to category graded structure (Barsalou, 1982; 1983; 1987; Hough, 1989; 2007a). Questions remain regarding whether older adults utilize linguistic context as effectively as young adults for retrieval of concepts. Reduced ability relative to utilizing context for categorization disrupts comprehension of linguistic information. Thus, the purpose of this study was to examine effect of linguistic context on category structure in young and older adults. Method Participants Participants were 40 typical adults: 20-35 (i.e., younger) and 65-80 (i.e., older). All participants had attained at least a high school diploma and were native speakers of American English, had hearing acuity within normal limits (Ventry, 1992), and adequate vision/reading proficiency. All passed a category-screening test with 80% accuracy (Table 1). Participants were administered the Peabody Picture Vocabulary Test-IV (PPVT-IV) (Dunn & Dunn, 2007), achieving standard scores within normal limits (>85). Materials