Rxivist logo

A multi-modal approach to decomposing standard neuropsychological test performance: Symbol Search

By Nicolas Langer, Erica J. Ho, Andreas Pedroni, Lindsay M. Alexander, Enitan T. Marcelle, Kenneth Schuster, Michael P. Milham, Simon P. Kelly

Posted 11 Oct 2017
bioRxiv DOI: 10.1101/200998

Neuropsychological test batteries provide normed assessments of cognitive performance across multiple functional domains. Although each test emphasizes a certain component of cognition, a poor score can reflect many possible processing deficits. Here we explore the use of simultaneous eye tracking and EEG to decompose test performance into interpretable components of cognitive processing. We examine the specific case of Symbol Search, a processing speed subtest of the WISC, which involves searching for the presence of either of two target symbols among five search symbols. To characterise the signatures of effective performance of the test, we asked 26 healthy adults to perform a computerized version of it while recording continuous EEG and eye-tracking. We first established basic gaze-shifting patterns in the task, such as more frequent and prolonged fixation of each target than each search symbol, and longer search symbol fixations and overall trial duration for target-absent trials. We then entered multiple such metrics into a least absolute shrinkage and selection operator (LASSO) analysis, which revealed that short trial completion times were mainly predicted by longer initial fixations on the targets and fewer subsequent confirmatory saccades directed back to the targets. Further, the tendency to make confirmatory saccades was associated with stronger gamma-amplitude modulation by mid-frontal theta-phase in the EEG during initial target symbol encoding. Taken together, these findings indicate that efficient Symbol Search performance depends more on effective memory encoding than on general processing speed.

Download data

  • Downloaded 1,281 times
  • Download rankings, all-time:
    • Site-wide: 8,163 out of 94,912
    • In neuroscience: 1,246 out of 16,862
  • Year to date:
    • Site-wide: 6,895 out of 94,912
  • Since beginning of last month:
    • Site-wide: 9,514 out of 94,912

Altmetric data

Downloads over time

Distribution of downloads per paper, site-wide


Sign up for the Rxivist weekly newsletter! (Click here for more details.)