Abstract
BackgroundStandardized neuropsychological testing serves to quantify cognitive impairment in multiple sclerosis (MS) patients. However, the exact mechanism underlying the translation of cognitive dysfunction into difficulties in everyday tasks has remained unclear. To answer this question, we tested if MS patients with intact vs. impaired information processing speed measured by the Symbol Digit Modalities Test (SDMT) differ in their visual search behavior during ecologically valid tasks reflecting everyday activities.MethodsForty-three patients with relapsing-remitting MS enrolled in an eye-tracking experiment consisting of a visual search task with naturalistic images. Patients were grouped into “impaired” and “unimpaired” according to their SDMT performance. Reaction time, accuracy and eye-tracking parameters were measured.ResultsThe groups did not differ regarding age, gender, and visual acuity. Patients with impaired SDMT (cut-off SDMT-z-score < −1.5) performance needed more time to find and fixate the target (q = 0.006). They spent less time fixating the target (q = 0.042). Impaired patients had slower reaction times and were less accurate (both q = 0.0495) even after controlling for patients' upper extremity function. Exploratory analysis revealed that unimpaired patients had higher accuracy than impaired patients particularly when the announced target was in unexpected location (p = 0.037). Correlational analysis suggested that SDMT performance is inversely linked to the time to first fixation of the target only if the announced target was in its expected location (r = −0.498, p = 0.003 vs. r = −0.212, p = 0.229).ConclusionDysfunctional visual search behavior may be one of the mechanisms translating cognitive deficits into difficulties in everyday tasks in MS patients. Our results suggest that cognitively impaired patients search their visual environment less efficiently and this is particularly evident when top-down processes have to be employed.
Highlights
Cognitive deficits are associated with unemployment, fewer social contacts as well as problems with household activities, and have an essential impact on the daily lives of multiple sclerosis (MS) patients [1,2,3,4,5]
Studies using eyetracking while performing the Symbol Digit Modalities Test (SDMT) have already shown that MS patients differ from healthy individuals, among other measures, with an increased total number of fixations in the test area [9]
Neuropsychological Tests Using age- and education-normative data, SDMT raw scores were transformed to z-scores [6]
Summary
Cognitive deficits are associated with unemployment, fewer social contacts as well as problems with household activities, and have an essential impact on the daily lives of multiple sclerosis (MS) patients [1,2,3,4,5]. Studies using eyetracking while performing the SDMT have already shown that MS patients differ from healthy individuals, among other measures, with an increased total number of fixations in the test area [9] This suggests that MS patients may have uncertainties during their visual search behavior, possibly reflected by the fact that the target areas are checked multiple times for safety [9]. The exact mechanism underlying the translation of cognitive dysfunction into difficulties in everyday tasks has remained unclear To answer this question, we tested if MS patients with intact vs impaired information processing speed measured by the Symbol Digit Modalities Test (SDMT) differ in their visual search behavior during ecologically valid tasks reflecting everyday activities We tested if MS patients with intact vs. impaired information processing speed measured by the Symbol Digit Modalities Test (SDMT) differ in their visual search behavior during ecologically valid tasks reflecting everyday activities
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
