Improving digit span assessment of short-term verbal memory

Abstract

We measured digit span (DS) in two experiments that used computerized presentation of randomized auditory digits with performance-adapted list length adjustment. A new mean span (MS) metric of DS was developed that showed reduced variance, improved test-retest reliability, and higher correlations with the results of other neuropsychological test results when compared to traditional DS measures. The MS metric also enhanced the sensitivity of forward versus backward span comparisons, enabled the development of normative performance criteria with sub-digit precision, and elucidated changes in DS performance with age- and education level. Computerized stimulus delivery and improved scoring metrics significantly enhance the precision of DS assessments of short-term verbal memory.

Repetitive Transcranial Magnetic Stimulation Improved Symptoms of Obsessive-Compulsive Disorder, but Also Cognitive Performance: Results from a Randomized Clinical Trial with a Cross-Over Design and Sham Condition

“…Second, to test short-term memory, a short-term verbal memory test was applied [20] . Lists of 3 digits with the list length increasing following a 1: 2 staircase were presented, and patients had to repeat the digits; a single correct response increased the length of the subsequent list by 1 digit.…”

Acute tryptophan depletion reduces kynurenine levels: implications for treatment of impaired visuospatial memory performance in irritable bowel syndrome

“…Tests of working memory capacity have been shown to engage the left PFC, right inferior frontal gyrus and regions of the occipital visual cortex (Groeger et al 1999;Sun et al 2005;Woods et al 2010). The outcome measures assessed at each testing session for forward and reverse SSP were span length and total errors.…”

Impulsivity, working memory, and impaired control over alcohol: A latent variable analysis.

“…The task is analogous to the digit span task found in the Wechsler Memory Scale (Wechsler, 1997) and was adapted from an auditory version of the task described by Woods et al (2011). The task involves the forward and backward recall of lists of digits.…”

“…Digits are presented one at a time on a computer screen (for one second each), and at the end of each list participants are asked to recall the digits in forward or backward order by using the number pad on the keyboard. All subjects are first presented a list of 3 digits; the list length then increases adaptively (as described in Woods et al, 2011) such that correct responses result in a one digit increase in list length on the next trial, while two consecutive incorrect responses result in a one digit reduction in list length on the next trial. The task consists of 14 trials of forward recall (i.e., in order of presentation) followed by 14 trials of backward recall (i.e., in reverse order of presentation).…”

“…We derived three related but distinct indices from the digit span task to serve as indicators of working memory performance: the mean span index, which represents the list length at which 50% of the trials are expected to be correct; the two-error total, which is the total number of trials before two consecutive errors at the same list length (Woods et al, 2011); and median response time across trials. The total response time for a given trial (i.e., the time between the offset of the list presentation and the completion of list recall) is a function of the list length as well as pauses before initiating a response and pauses between digits.…”