Javascript verkar inte påslaget? - Vissa delar av Lunds universitets webbplats fungerar inte optimalt utan javascript, kontrollera din webbläsares inställningar.
Du är här

On the Relation of Mean Reaction Time and Intraindividual Reaction Time Variability

  • Florian Schmiedek
  • Martin Lövdén
  • Ulman Lindenberger
Publiceringsår: 2009
Språk: Engelska
Sidor: 841-857
Publikation/Tidskrift/Serie: Psychology and Aging
Volym: 24
Nummer: 4
Dokumenttyp: Artikel i tidskrift
Förlag: American Psychological Association (APA)


Researchers often statistically control for means when examining individual or age-associated differences in variances, assuming that the relation between the 2 is linear and invariant within and across individuals and age groups. We tested this assumption in the domain of working memory by applying variance-heterogeneity multilevel models to reaction times in the n-back task. Data are from the COGITO study, which comprises 101 younger and 103 older adults assessed in over 100 daily sessions. We found that relations between means and variances vary reliably across age groups and individuals, thereby contradicting the invariant linearity assumption. We argue that statistical control approaches need to be replaced by theoretical models that simultaneously estimate central tendency and dispersion of latencies and accuracies and illustrate this claim by applying the diffusion model to the same data. Finally, we note that differences in reliability between estimates for means and variances need to be considered when comparing their unique contributions to developmental outcomes.


  • Psychology
  • reliability
  • variance heterogeneity models
  • multilevel models
  • working memory
  • intraindividual variability


  • ISSN: 0882-7974

Box 117, 221 00 LUND
Telefon 046-222 00 00 (växel)
Telefax 046-222 47 20
lu [at] lu [dot] se

Fakturaadress: Box 188, 221 00 LUND
Organisationsnummer: 202100-3211
Om webbplatsen