Within-Individual Variation in Cognitive Performance Is Not Noise: Why and How Cognitive Assessments Should Examine Within-Person Performance.

Despite evidence that it exists, short-term within-individual variability in cognitive performance has largely been ignored as a meaningful component of human cognitive ability. In this article, we build a case for why this within-individual variability should not be viewed as mere measurement error and why it should be construed as a meaningful component of an individual's cognitive abilities. We argue that in a demanding and rapidly changing modern world, between-individual analysis of single-occasion cognitive test scores does not account for the full range of within-individual cognitive performance variation that is implicated in successful typical cognitive performance.

Challenges for an interdisciplinary consideration of cognitive training.

Whether fluid cognitive functions are malleable has been a topic of ongoing debate for at least the past 100 years. Ever-evolving technology has led to new and diverse fields of investigation entering this debate. There are significant advantages to be gained by integrating different scientific paradigms, but there are also significant challenges.