Table 2.

Key findings from literature review

Key Findings from Literature Review
Measures Measures of semantic content were widely used across studies, most often in some form of pre-defined content “units.” There was evidence of reduced content across multiple stages (pre-symptomatic, MCI, mild to severe AD).
Accruing evidence of simplification of syntax even in MCI, which refutes the common notion that syntax is preserved in early stages
Picture description measures accurately distinguish controls from adults with AD dementia, but show weak correlations with naming tasks and verbal fluency tasks, suggesting connected language may tap into additional cognitive processes
Limitations Studies had small sample sizes (mean n = 35), lacking in ethnic and cultural diversity Hearing status not reported in majority of studies Stages of disease were not always clearly defined Many studies of adults with AD dementia, few with MCI Few longitudinal studies Minimal cohesiveness in terms used to identify language constructs, thus limiting the ability to aggregate results across studies