The Effect of Prior Caffeine Consumption on Neuropsychological Test Performance: A Placebo-Controlled Study.

Background: The aim of this study was to investigate whether the prior consumption of 200 mg of pure caffeine affected neuropsychological test scores in a group of elderly participants aged over 60 years.

Method: Using a double-blind placebo versus caffeine design, participants were randomly assigned to receive 200 mg of caffeine or placebo. A neuropsychological assessment testing the domains of general cognitive function, processing speed, semantic memory, episodic memory, executive function, working memory and short-term memory was carried out.

Time of day and caffeine influence some neuropsychological tests in the elderly.

We report that performance on neuropsychological tests used in the diagnosis of dementia can be influenced by external factors such as time of day (TOD) and caffeine. This study investigates TOD effects on cognitive performance in the elderly. The optimal TOD at which an individual is at his or her maximal arousal alters with age, and in the elderly, typically occurs in the morning.

The effect of recent consumption of caffeine-containing foodstuffs on neuropsychological tests in the elderly.

We investigated the effect of recent intake of caffeine-containing foodstuffs (CCFS) on a group of elderly participants (age range 67-95 years) on a series of neuropsychological tests. There was no significant effect of CCFS intake on performance in any of the tests in the battery used. However, a significant interaction effect was found between age and CCFS consumption on scores of some neuropsychological tests.

Testing graceful degradation in a patient with aphasia.

We report an investigation of phonological priming of a picture naming task in an anomic aphasic, PB, using caffeine as a pharmacological manipulation. We compare her results to controls on a similar paradigm testing the hypothesis that qualitative results in controls would carry over to the damaged brain demonstrating a "graceful degradation" in performance. When primed with words phonologically related to a target, PB made more word retrieval failures on caffeine as a function of related primes (controls make fewer) and fewer word retrieval failures as a function of unrelated primes (controls make more).

Caffeine, priming, and tip of the tongue: evidence for plasticity in the phonological system.

A study was performed involving phonological priming and tip-of-the-tongue states (TOTs) in which participants took either 200 mg of caffeine or placebo. Results show a clear positive priming effect produced for the caffeine group when primed with phonologically related words. When primed with unrelated words, the caffeine subgroup produced a significant increase in the number of TOTs.