General methodological considerations for the assessment of nutritional influences on human cognitive functions

The premise that cognitive functioning can be influenced through dietary means has gained widespread interest. The assessment of cognitive functioning is a key method to scientifically substantiate such nutritional effects on cognition. The current paper provides a basic overview of the main concepts, issues and pitfalls of human cognitive research. General methods of cognitive assessment, selection of appropriate tests, factors that may mediate task performance and issues pertaining to the interpretation of the results are discussed.