Invited talk 2

Crossing the desert: challenges in measuring individual differences in cognitive abilities

Craig Hedge

It is increasingly common for experimental psychologists to relate individual differences in cognition to real-world outcomes and neuroimaging measures. However, such efforts are often unfruitful, even with the most well-established tasks. In this talk I will offer some explanations for failures in the application of robust cognitive paradigms to the study of individual differences, drawing on examples from response inhibition, attention, and vision. One explanation is that experimental effects become well established – and thus those tasks become popular – when between-subject variability is low. However, low between-subject variability causes low reliability for individual differences, destroying replicable correlations with other factors and potentially undermining published conclusions drawn from correlational relationships. A second explanation is that we typically attribute experimental effects at the group level to a single mechanism (e.g. the cause of the Stroop effect is conflict in the stimulus), but individual differences in the size of the effect can often be multifaceted. I will consider some recommendations for how we can design and analyse tasks to mitigate these concerns.