The validity of d prime as a working memory index: Results from the “Bergen n-back task”

Abstract

The n-back task is frequently used as an experimental paradigm in imaging studies of working memory. This study aimed to investigate whether the Bergen 2-back task is suitable for use in desktop assessment of patients with schizophrenia. Looking at the psychometric properties of the task, including the newly added measure of discriminability, d prime (d ′), our analyses confirmed that the 2-back d ′ is the preferred measure of working memory dysfunction in desktop assessment compared to the Digit Span Backward and the Letter–Number Sequencing subtests from the Wechsler Adult Intelligence Scale–Third Edition (WAIS–III). d ′ has the advantage of capturing executive skills needed to perform mental operations in patients with schizophrenia, without being influenced by demographic variables or IQ.

Keywords:

• n-back
• Psychometric properties
• d prime
• Working memory
• Schizophrenia