Cortical Network Activity Associated With Different Types of Word Recognition Errors by Older Adults

Word recognition scores are useful general metrics of speech understanding but provide limited insight about why listeners exhibit difficulties with word recognition tasks. For example, older adults can have the same word recognition score but make different types of errors. Different types of misperceptions for audible speech, such as misunderstanding the final consonant or a whole word, suggest that word recognition errors reflect distinct neural failures in speech processing. Patterns of activity in central auditory and attention-related cortical networks were hypothesized to predict different types of word recognition errors. Trial-level error analyses were performed with data from two neuroimaging experiments where older adults performed word recognition in noise tasks (Data Set 1: N = 45, mean age = 64.71 years; Data Set 2: N = 40, mean age = 68.97 years). Group-level independent component analysis of fMRI data collected during these tasks identified distinct patterns of activity in auditory and cingulo-opercular networks that were associated with initial or final consonant substitution errors. In addition, complete word omission errors occurred with relatively low activity in the auditory network and elevated activity in cingulo-opercular and/or default mode networks. These findings suggest that some errors occur with more cingulo-opercular-related performance monitoring, whereas other errors occur with insufficient signal in auditory cortex and/or task disengagement that has been associated with default-mode network function. Thus, patterns of cortical activity reflect the type of word recognition error and may inform reason(s) for those errors that may not be evident in an overall word recognition score.