Cognition Methodology

Question 1

Why did you choose to use an oculomotor task to measure EF?

Answer 1

I chose to use an oculomotor task to measure EF because it provides a hands- and language-free assessment tool that is highly sensitive to executive function deficits. Unlike traditional EF tasks, which can be confounded by non-EF components such as language processing, perception-based shape identification, and numerical processing, antisaccades offer a direct measure of EF. Antisaccades demand high-level inhibitory control and cognitive flexibility and are useful for detecting subtle EF deficits that might not be captured by traditional measures (Kaufman et al., 2012; Peltsch et al., 2014).

Question 2

Why did you choose to measure the inhibitory aspect of EF?

Answer 2

• The inhibitory aspect of EF was chosen because it essential for goal-directed behavior and involves suppressing automatic responses in favor of task-specific ones, critical for effective cognitive functioning (Diamond, 2013; MacLeod, 1992). Concussions, particularly sports-related concussions (SRC), often impair inhibitory control, a major component of EF. Measuring this aspect provides direct insights into the cognitive deficits caused by SRC (Howell et al., 2013; Rabinowitz & Levin, 2014; Webb et al., 2018). SRC-related EF deficits, including inhibitory control, persist from the early (<24 hours) to later stages (>2 months) of recovery (Gallo et al., 2020). Webb et al. (2018) found that SRC patients exhibited longer antisaccade reaction times and more errors both shortly after injury and during follow-up. The antisaccade task effectively measures inhibitory control by requiring goal-directed eye movements opposite to a visual stimulus. This task results in longer reaction times and more errors, making it a reliable measure of inhibitory control deficits (Hallett, 1978; Dafoe et al., 2007; Gillen & Heath, 2014). Research shows that SRC patients have increased antisaccade reaction times and errors even after medical clearance, indicating persistent cognitive deficits (Johnson et al., 2015a, 2015b; Webb et al., 2018). Thus, measuring inhibitory control with the antisaccade task provides a precise and sensitive assessment of EF impairments, particularly relevant to concussion.

Question 3

Why not use a more comprehensive cognitive battery (e.g., CANTAB) to measure several aspects of EF?

Answer 3

• While comprehensive cognitive batteries like CANTAB provide a broad assessment of various cognitive domains, they also introduce complexities related to language, perception, and numerical processing. These non-EF components can confound the results, making it difficult to isolate specific EF deficits. By using a targeted oculomotor task such as the antisaccade, we can specifically measure inhibitory control without these confounding factors, providing a more precise assessment of EF. Additionally, oculomotor tasks are less time-consuming and can be administered more efficiently, which is beneficial in both research and clinical settings (Kaufman et al., 2012; Peltsch et al., 2014).