title: Computerized analysis of error patterns in digit span recall.
abstract: We analyzed error patterns during digit span (DS) testing in four experiments. In Experiment 1, error patterns analyzed from a community sample of 427 subjects revealed strong primacy and recency effects. Subjects with shorter DSs showed an increased incidence of transposition errors in comparison with other error types and a greater incidence of multiple errors on incorrect trials. Experiment 2 investigated 46 young subjects in three test sessions. The results replicated those of Experiment 1 and demonstrated that error patterns of individual subjects were consistent across repeated test administrations. Experiment 3 investigated 40 subjects from Experiment 2 who feigned symptoms of traumatic brain injury (TBI) with 80% of malingering subjects producing digit spans in the abnormal range. A digit span malingering index (DSMI) was developed to detect atypical error patterns in malingering subjects. Overall, 59% of malingering subjects with abnormal digit spans showed DSMIs in the abnormal range and DSMI values correlated significantly with the magnitude of malingering. Experiment 4 compared 29 patients with TBI with a new group of 38 control subjects. The TBI group showed significant reductions in digit span. Overall, 32% of the TBI patients showed DS abnormalities and 11% showed abnormal DSMIs. Computerized error-pattern analysis improves the sensitivity of DS assessment and can assist in the detection of malingering.
authors.affiliation: Human Cognitive Neurophysiology Laboratory, Veterans Affairs Northern California Health Care System, Martinez, CA, USA. dlwoods@ucdavis.edu
authors.forename: David L
authors.initials: DL
authors.lastname: Woods
authors.forename: T J
authors.initials: TJ
authors.lastname: Herron
authors.forename: E W
authors.initials: EW
authors.lastname: Yund
authors.forename: R F
authors.initials: RF
authors.lastname: Hink
authors.forename: M M
authors.initials: MM
authors.lastname: Kishiyama
authors.forename: Bruce
authors.initials: B
authors.lastname: Reed
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D004522:Educational Status; D005260:Female; D006801:Humans; D008297:Male; D008306:Malingering / Q000175:diagnosis; D008433:Mathematics; D008569:Memory Disorders / Q000175:diagnosis*; D011939:Mental Recall / Q000502:physiology*; D008875:Middle Aged; D009483:Neuropsychological Tests; D009716:Numerical Analysis, Computer-Assisted; D011340:Problem Solving; D011601:Psychophysics; D012691:Serial Learning; D012737:Sex Factors; D055815:Young Adult