Assessment of planning performance in clinical samples: Reliability and validity of the Tower of London task (TOL-F)

Lena Köstering; Charlotte S M Schmidt; Karl Egger; Florian Amtage; Jessica Peter; Stefan Klöppel; Lena-A Beume; Markus Hoeren; Cornelius Weiller; Christoph P Kaller

doi:10.1016/j.neuropsychologia.2015.07.017

Assessment of planning performance in clinical samples: Reliability and validity of the Tower of London task (TOL-F)

Neuropsychologia. 2015 Aug:75:646-55. doi: 10.1016/j.neuropsychologia.2015.07.017. Epub 2015 Jul 18.

Authors

Affiliations

¹ Department of Neurology, University Medical Center, University of Freiburg, Germany; Freiburg Brain Imaging, University of Freiburg, Germany; Biological and Personality Psychology, Department of Psychology, University of Freiburg, Germany; BrainLinks-BrainTools Cluster of Excellence, University of Freiburg, Germany. Electronic address: lena.koestering@uniklinik-freiburg.de.
² Department of Neurology, University Medical Center, University of Freiburg, Germany; Freiburg Brain Imaging, University of Freiburg, Germany; Biological and Personality Psychology, Department of Psychology, University of Freiburg, Germany; BrainLinks-BrainTools Cluster of Excellence, University of Freiburg, Germany.
³ Freiburg Brain Imaging, University of Freiburg, Germany; Department of Neuroradiology, University Medical Center, University of Freiburg, Germany.
⁴ Department of Neurology, University Medical Center, University of Freiburg, Germany; Freiburg Brain Imaging, University of Freiburg, Germany.
⁵ Freiburg Brain Imaging, University of Freiburg, Germany; Department of Psychiatry and Psychotherapy, University Medical Center, University of Freiburg, Germany.
⁶ Department of Neurology, University Medical Center, University of Freiburg, Germany; Freiburg Brain Imaging, University of Freiburg, Germany; Department of Psychiatry and Psychotherapy, University Medical Center, University of Freiburg, Germany.
⁷ Department of Neurology, University Medical Center, University of Freiburg, Germany; Freiburg Brain Imaging, University of Freiburg, Germany; BrainLinks-BrainTools Cluster of Excellence, University of Freiburg, Germany.

PMID: 26197091
DOI: 10.1016/j.neuropsychologia.2015.07.017

Abstract

Objective: Executive deficits are frequent sequelae of neurological and psychiatric disorders, but their adequate neuropsychological assessment is still a matter of contention, given that executive tasks draw on a multitude of cognitive processes that are often not sufficiently specified. In line with this, results on psychometric properties of the Tower of London, a task measuring planning ability as a prototypical executive function, are equivocal and furthermore lacking completely for adult clinical populations.

Methods: We used a structurally balanced item set implemented in the Tower of London (Freiburg version, TOL-F) that accounts for major determinants of problem difficulty beyond the commonly used minimum number of moves to solution. Split-half reliability, internal consistency, and criterion-related concurrent validity of TOL-F accuracy were assessed in patients with stroke (N = 60), Parkinson syndrome (N = 51), and mild cognitive impairment (N = 29), and healthy adults (N = 155).

Results: Across samples, mean split-half and lower-bound indices of reliability of accuracy scores were adequate (r ≥ .7) or higher. Compared to a subset of healthy controls matched for age, sex, and education levels, deficits in planning accuracy emerged for all three clinical samples.

Conclusions: Based on consistently adequate reliability and a good criterion-related validity of accuracy scores, the TOL-F demonstrates its utility for testing planning ability in clinical samples and healthy adults. Using item sets systematically accounting for several determinants of task difficulty can thus significantly enhance the contended reliability of executive tasks and provide an opportunity to resolve the underspecification of cognitive processes contributing to executive functioning in health and disease.

Keywords: Executive function; Mild cognitive impairment; Neuropsychological tests; Parkinson disease; Psychometrics; Stroke.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Aged
Cognitive Dysfunction / diagnosis
Cognitive Dysfunction / psychology
Executive Function*
Female
Humans
Male
Middle Aged
Neuropsychological Tests* / statistics & numerical data
Parkinsonian Disorders / diagnosis
Parkinsonian Disorders / psychology
Problem Solving*
Psychometrics
Reproducibility of Results
Stroke / diagnosis
Stroke / psychology