Try harder! The influence of evaluative feedback on the pupil dilation response, saliva-cortisol, and saliva alpha-amylase levels during listening
The pupil dilation response is sensitive to listening effort, but is also sensitive to emotions such as those evoked by the social and emotional significance of a task. Standard listening tests that ask listeners to repeat auditory stimuli usually do not take social aspects such as feedback and (threat of) evaluation by others into account. As a result, it is currently unclear to what extent evaluative feedback may influence listening effort as assessed by the pupil dilation response. We aimed to assess this effect using an adapted speech reception threshold (SRT) task. Besides the pupil dilation response, we acquired two physiological biomarkers sensitive to stress: cortisol and alpha-amylase levels as determined in saliva samples.
We included 34 participants with normal hearing (mean age = 52 years, age range 25-67 years) and 29 age-matched participants with mild-to-moderate hearing loss (mean age = 52 years, age range 23-64 years). Half of the participants performed a standard SRT test without feedback, and the other half performed an SRT test in which 1) written feedback was provided after each trial, 2) a performance indicator showed the actual performance level and an unrealistically high target performance level, and 3) the experimenter provided relatively cold, evaluative feedback twice during the test. The SRT conditions targeted 50% and 71% correct reception of the sentences. Pupil size was recorded during listening and saliva samples were obtained before, during and after the test.
As expected, the participants with hearing loss performed poorer on the SRT test than listeners with normal hearing, and lower (better) SRTs were obtained for the 50% as compared to the 71% intelligibility condition. The participants receiving feedback had lower (better) SRTs in the 71% intelligibility condition and higher peak pupil dilation in both intelligibility conditions as compared to the participants who performed the standard SRT test. No effect of hearing status on the pupil dilation response was observed. We will furthermore present the influence of feedback on the subjective ratings, and the cortisol and alpha-amylase levels. We will discuss our findings that indicate that social evaluation can influence listening performance and several physiological measures.