The effects of working memory load and working memory capacity on online spoken word recognition: evidence from eye movements
Difficulties in speech perception, especially in adverse noisy conditions, are highly prevalent among older adults. However, the degree of the deficit is highly variable across older listeners. Previous research in our lab suggests that this variability could be related to individual differences in cognitive capacity (Hadar et al., 2016, Front. Neurosci. 10:221; Nitsan et al., 2019, Tr. Hear. 23:2331216519839624). Using the eye-tracking ‘visual world’ paradigm, listeners were asked to follow spoken instructions, while retaining either a low load (single-digit) or high (four-digits) load for later recall. In critical trials, instructions (e.g., “point at the candle”) directed listeners’ gaze to pictures of objects whose names shared either onset or offset sounds with the name of a competitor that was displayed on the screen at the same time (e.g., candy or sandal). We reported that for young listeners, high-load delayed real-time spoken word recognition both in quiet and in noise. Importantly, the interference effect of a concurrent memory load was greater for individuals with a smaller memory span than for those with a larger one. In an ongoing study, we administrated the paradigm with a group of 30 older listeners with clinically normal hearing. We examine whether older adults are similarly affected by a working memory load as younger adults, and how individual differences in older adults’ working memory capacity affect the timeline for spoken-word recognition. Preliminary data pointing to age-related similarities and differences in these effects will be discussed.