Computer-Based Assessment: Dual-Task Outperforms Large-Screen Cancellation Task in Detecting Contralesional Omissions

Abstract

Objective: Traditionally, asymmetric spatial processing (i.e., hemispatial neglect) has been assessed with paper-and-pencil tasks, but growing evidence indicates that computer-based methods are a more sensitive assessment modality. It is not known, however, whether simply converting well-established paper-and-pencil methods into a digital format is the best option. The aim of the present study was to compare sensitivity in detecting contralesional omissions of two different computer-based methods: a "digitally converted" cancellation task was compared with a computer-based Visual and Auditory dual-tasking approach, which has already proved to be very sensitive. Methods: Participants included 40 patients with chronic unilateral stroke in either the right hemisphere (RH patients, N = 20) or the left hemisphere (LH patients, N = 20) and 20 age-matched healthy controls. The cancellation task was implemented on a very large format (173 cm × 277 cm) or in a smaller (A4) paper-and-pencil version. The computer-based dual-tasks were implemented on a 15'' monitor and required the detection of unilateral and bilateral briefly presented lateralized targets. Results: Neither version of the cancellation task was able to show spatial bias in RH patients. In contrast, in the Visual dual-task RH patients missed significantly more left-sided targets than controls in both unilateral and bilateral trials. They also missed significantly more left-sided than right-sided targets only in the bilateral trials of the Auditory dual-task. Conclusion: The dual-task setting outperforms the cancellation task approach even when the latter is implemented on a (large) screen. Attentionally demanding methods are useful for revealing mild forms of contralesional visuospatial deficits.

Keywords: computer-based methods; dual-task; extinction; hemispatial neglect; neuropsychological evaluation; neuropsychology; paper-and-pencil tasks; stroke.

FIGURE 1

The large-screen Twinkle Task: demonstrations of empty task sheet (left), and correctly selected targets (right).

FIGURE 2

The large-screen Twinkle Task: visualization of the scanning pattern and the selected targets in a representative patient.

FIGURE 3

A representative trial of the Visual dual-task (image not in scale). A left target (alternative positions possible: right or bilateral) is briefly presented (50 ms) concurrently with a central letter and an auditory digit. Correct responses for the Visual dual-task would have been “a” (central letter) and “left” (target position), while for the Auditory dual-task they would have been “four, six” (count in steps of two from the auditorily presented “two”) and “left.” (Adapted from Bonato, 2015).

FIGURE 4

The Visual dual-task: average percentages of missed targets within each group in unilateral (top panel) and bilateral (bottom panel) trials. RH patients missed significantly more left-sided targets than controls in both the unilateral and bilateral trials. Asterisks represent effect size (***large effect; **medium effect).

FIGURE 5

The Auditory dual-task: average percentages of missed targets within each group in unilateral (top panel) and bilateral (bottom panel) trials. RH patients missed significantly more left-sided than right-sided targets in bilateral trials. Asterisks represent effect size (***large effect).