The role of reward and task demand in value-based strategic allocation of auditory comprehension effort

Listeners who fail to optimize their allocation of effort during auditory comprehension tasks can experience from compromised performance, fatigue and stress, which might result in reduced engagement in social communication activities. Strategically allocating effort based on costs and perceived benefits are commonly observed in the research of effortful physical and visual behaviors. Whether people manage their effort in a similar manner in audition remains unclear. As the listening performance of people with normal hearing often serves as the goal of auditory rehabilitation for people with hearing loss, this study evaluated how strategy-induced effort allocation, challenged by reward and task demand, interactively impacted auditory comprehension in normal hearing adults.

A value-based strategic effort allocation paradigm was evaluated in 40 normal-hearing young adults. The paradigm included five levels of reward (motivation) and five levels of task demand (speech rate) that were independently manipulated. Effects of reward and task demand on performance accuracy and pupil dilation (a measure of auditory comprehension effort) were examined.

There was a significant interaction effect of reward and task demand on both pupil dilation and comprehension accuracy. At the response stage of speech comprehension processing, pupil dilation significantly decreased as the task demand increased at high reward levels. In contrast, pupil dilation did not vary significantly as a function of task demand at low reward levels. Reward significantly improved performance accuracy at fast and extremely fast rate conditions, but not at the slower rates.

Consistent with previous studies on effort regulation, reward and task demand appear to be associated with auditory comprehension effort allocation in an interactive manner when strategic effort control was required to achieve a reward goal. The young normal-hearing listeners in this study prioritized their effort to relatively easy task items over difficult ones at high levels of reward, suggesting a cost-effective value-based strategic effort allocation. Reward significantly improved task performance in terms of accuracy at difficult listening conditions. These findings support the incorporation of affective factors (e.g., reward) and the utility of the value-based strategic effort allocation paradigm in the experimental setting to understand how clinically relevant factors (such as hearing loss and age) might change strategic auditory comprehension behavior.