The Relative utility of implicit memory tasks and a forced-choice memory test for the detection of simulated brain injury deficits
Date
2017-06-15
Authors
Fisher, Kimberly Gail
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Clinical neuropsychologists are often called upon to make
decisions on the genuineness of cognitive deficits following
a head injury. This is a difficult task, particularly when
deficits are subtle, as there are few reliable tools to aid
the clinician in his or her decision making process. In the
present study, normal participants instructed to feign brain
injury (M) , traumatically brain-injured individuals (BI) , and
normal controls (C), completed a series of computer-administered
implicit memory (IM) tasks. Results were
compared to those for the Victoria Symptom Validity Test
(VSVT; Slick, Hopp, Strauss, & Pinch, 1994; Slick, Hopp,
Strauss, & Thompson, 1997), a commercially available forced-choice
recognition task. All IM tasks included items which
had been previously presented once, twice or four times, as
well as foils (items not previously presented). Previous
exposure to test items was expected to be associated with
increased accuracy (Hits) and decreased Response Latency.
Participants in the BI and C groups were expected to perform
equally well and better than the M group participants with
respect to Hits. Response Latency on incorrect items
(Misses) was also expected to discriminate M participants
from BI and C participants because the conscious decision to
provide an incorrect response was expected to increase
decision making time. Results with respect to overall Hits were confirmed (M=127.87, M=129.72, and M=107.10 for the BI, C, and M groups, respectively) . Increased accuracy with
repetition of items in the priming phase was not confirmed,
likely because both BI and C participants performed close to
ceiling levels. Discriminant function analysis based on
total Hit rates, resulted in correct classification of 85
percent (46 out of 54) of the participants. This was
comparable to the results for Hard items combined on the
VSVT. Response Latency measures did not effectively
discriminate among groups, while results did indicate a main
effect of Presentation Level (priming) on Response Latency
with participants, independent of Group Membership, tending
to respond most quickly (Hits only) to items presented 4
times during the priming phase and least quickly to items
presented only once. Overall, results suggest that further
investigation of IM tasks for the detection of conscious
malingering is warranted as these tasks appear to tap the
dimensions on which the general population hold
misconceptions about the effects of brain injury, i.e.,
overall ability/performance and response latency.
Description
Keywords
Brain damage, Central nervous system