Selection of neuropsychological tasks from a language test battery that optimally related to the function of each cortical area: Toward making a cognitive cortical map.

Yasuhiro Suzuki

doi:10.1016/j.nicl.2019.101799

Abstract

We developed a cortical language map from performance data on a language test battery in patients with brain lesions. The research problem was how to select the subtest that was most related to the function of each cortical area from the battery. When studied by voxel-based lesion-symptom mapping (VLSM), patients were divided into two groups: those with and without a lesion at each particular region. We considered the task that optimally discriminated between the two groups to be the task most related to the function of a given region. One hundred and fifty left-lesioned patients were examined using the Japanese Standard Language Test of Aphasia (SLTA), which is composed of 26 subtests. Using logistic discriminant analysis, we selected the subtest that optimally discriminated the lesioned and non-lesioned groups for each cortical region. Patients with left middle frontal gyrus (area 46) lesions were optimally discriminated from patients without lesions in that area by the speech sound–kana letter choice matching subtest. Patients with lesions in the inferior postcentral gyrus were optimally distinguished by the disturbance of word repetition. Patients with lesions in the anterior cingulate gyrus were characterized by impaired performance on the category fluency subtest. Voxel-based discriminant analysis can thus select the subtest that can be regarded as most related to the function of each cortical area.

Highlights

Research on higher brain function has enabled the discovery of many roles of cortical areas in cognitive functions, and more than one cognitive function is sometimes associated with a particular cortical region
In functional images such as functional magnetic resonance imaging, the signal intensity elicited by a task can be an indicator of task-region association, allowing for comparison of the association strength
We controlled for the severity of aphasia in each patient

Summary

Introduction

Research on higher brain function has enabled the discovery of many roles of cortical areas in cognitive functions, and more than one cognitive function is sometimes associated with a particular cortical region. Our focus in this paper was on developing a method of identifying functions with the strongest relationship to cortical areas. In functional images such as functional magnetic resonance imaging (fMRI), the signal intensity elicited by a task can be an indicator of task-region association, allowing for comparison of the association strength. The present research problem was to determine which of the candidate cognitive tasks was most associated with function in a given cortical region in the study of patients with lesions. VLSM was proposed as a method for judging significant statistical differences in cognitive performance between patients with and without a lesion in a specific voxel. The task with the greatest difference in performance between patients with and without lesions is considered to be the task that is most related to a local function of the voxel

Methods

Results

Conclusion