Are There Any Connections between Language Deficits and Cognitive Slowing in Alzheimer's Disease?

BACKGROUND: Speech disorders already occur in the early phases of Alzheimer's disease (AD). As a possible cause, problems of executive processes are discussed. Cognitive slowing is also repeatedly addressed. AIMS: Are there any connections between cognitive slowing and speech disorders in AD? And is there a relationship between cognitive slowing and executive processes? METHODS: The data of 72 healthy controls and 52 AD patients were examined with regard to their language performance and their response times in a computerized Stroop paradigm. RESULTS: The AD patients showed significantly worse results in all language tests as well as much longer reaction times in all Stroop conditions, especially in the interference condition (Stroop 3). Speech errors and response times correlated with severity (MMSE), and the speech errors correlated with the reaction times in Stroop 3 (interference condition, which reflects the processing time of executive processes). CONCLUSION: The most interesting question now is: How are language processing and executive processing time (Stroop 3) related?