Learning from performance feedback is critical for effective cognitive performance. In neurotypical (NT) individuals, positive and negative feedback signal correct or incorrect responses, respectively, to shape learning (Dobryakova and Tricomi, 2013; Tricomi et al., 2006; Tricomi and Fiez, 2008). Rehabilitation settings employ behavioral interventions that treat cognitive impairments in people with multiple sclerosis (MS). Critically, these interventions often administer performance feedback to the participant throughout treatment (Dardiotis et al., 2018; Hart et al., 2019). Negative performance feedback provides constructive information towards rehabilitation, so it is imperative that participants recognize the value of this feedback.

Cognitive fatigue (CF) is a common symptom of MS, with prevalence estimates as high as 90% (Dobryakova et al., 2017; Manjalay et al., 2019). CF is characterized by difficulty, or the inability, to initiate or sustain mental effort (Chaudhuri and Behan, 2000). This form of fatigue differs from motor, or physical, fatigue, which is difficulty maintaining a certain level of physical output (e.g., during exercise; Chaudhuri and Behan, 2000). CF typically presents as one of two distinct forms – trait fatigue (the type under investigation in this study) and state fatigue. The former refers to stable, “baseline” levels of CF, while the latter refers to dynamic changes in CF in response to a cognitively effortful stimulus (Enoka et al., 2021; Genova et al., 2013; Spiteri et al., 2019). CF in MS is linked to reduced reward sensitivity (Heitmann et al., 2020; Pardini et al., 2012) and has been characterized as an imbalance between diminished perceived reward value of a stimulus and inflation of costs required to obtain it (Dobryakova et al., 2013). Findings from our group also indicate possible neural disruptions in reward network activity associated with CF during performance feedback processing in people with MS (Cagna et al., 2022). Thus, CF may impact subjective valuation of feedback, whereby people with MS may not be motivated to pursue feedback due to CF skewing its reward value. This could be problematic for cognitive interventions that require mental effort and volition from the participant (Whyte et al., 2019).

When deciding whether to pursue an outcome, if perceived costs outweigh perceived reward value, a net negative subjective value emerges, which reduces motivation to pursue the outcome (Kable and Glimcher, 2007; Peters and Büchel, 2010). “Willingness-to-pay” (WTP) paradigms quantify subjective value by presenting participants with decisions to engage with a stimulus in exchange for a cost (e.g., money; Peters and Büchel, 2010). Highly-valued stimuli elicit more decisions to pay for them. Given the importance of performance feedback for cognitive intervention efficacy, a critical, but lacking, research area is how CF in MS affects the perceived value of feedback information. Here, we investigated how trait CF influences subjective valuation of feedback, motivation to seek feedback, and cognitive performance in people with MS. MS and NT groups completed a WTP associative memory paradigm, which measured subjective valuation of feedback through participant decisions to purchase feedback. If trait CF reduces the value of feedback in the MS group, we would predict these participants to make fewer feedback purchase decisions, compared to NT participants. Alternatively, similar amounts of feedback purchases between groups would suggest the possibility that performance feedback valuation is robust to trait CF in people with MS.