Mood shapes the impact of reward on perceived fatigue from listening

Abstract

Knowledge of the underlying mechanisms of effortful listening could help to reduce cases of social withdrawal and mitigate fatigue, especially in older adults. However, the relationship between transient effort and longer term fatigue is likely to be more complex than originally thought. Here, we manipulated the presence/absence of monetary reward to examine the role of motivation and mood state in governing changes in perceived effort and fatigue from listening. In an online study, 185 participants were randomly assigned to either a "reward" (n = 91) or "no-reward" (n = 94) group and completed a dichotic listening task along with a series of questionnaires assessing changes over time in perceived effort, mood, and fatigue. Effort ratings were higher overall in the reward group, yet fatigue ratings in that group showed a shallower linear increase over time. Mediation analysis revealed an indirect effect of reward on fatigue ratings via perceived mood state; reward induced a more positive mood state which was associated with reduced fatigue. These results suggest that: (1) listening conditions rated as more "effortful" may be less fatiguing if the effort is deemed worthwhile, and (2) alterations to one's mood state represent a potential mechanism by which fatigue may be elicited during unrewarding listening situations.

Keywords: Listening-related fatigue; auditory attention; dichotic listening; effortful listening; motivation; reward; speech perception.

Figure 1.

Hypothetical data supporting either a transient (left panel) or sustained (right panel) effect of group (i.e., reward) on perceived fatigue from listening. Block “0” represents baseline fatigue rating. The divergent fatigue scores at Time-point 1 in the “Transient” panel reflect the hypothesised time frame in which fatigue might show a relative (transient) reduction in the “Reward” group before re-converging with the “No-reward” group at Time-point 2.

Figure 2.

Schematic representation of the variables entered into the mediation analysis. Group (no-reward, reward) was entered as the categorical predictor variable, mood rating (BMIS score) as the mediator variable, and fatigue rating (BFI score) as the dependent variable.

Figure 3.

Schematic outline of the study procedure with time estimates for each component. Rating scales included questionnaires measuring perceived effort, mood, and fatigue. Each dichotic listening task block comprised 60 trials.

Figure 4.

Mean proportion correct (left panel) and RT (right panel) with ±SE bars on the dichotic listening task as a function of block (1–3) and group (no-reward, reward). Overlaid solid lines illustrate the GLMM (accuracy) and LMM (RT) model fits to the data.

Figure 5.

Mean ratings for perceived effort (left panel), mood (middle panel), and fatigue (right panel) with ±SE bars as a function of block and group. Block “0” represents the mean baseline rating score provided immediately after the practice trials. Overlaid solid lines illustrate the LMM model fits to the data. NASA effort ratings range from 0 to 100, with higher scores reflecting increased perceived effort. BMIS ratings range from 16 to 64, with higher scores reflecting a more pleasant perceived mood state. Finally, BFI ratings range from 0 to 10, with higher scores reflecting increased perceived fatigue.MIS:: Brief Mood Introspection Scale.FI:: Brief Fatigue Inventory; LMM: Linear Mixed-effects Model.