Attentional shifting as a potential explanatory variable in aphasic anomia

In addition to the language impairments experienced by people with aphasia (PWA), such as lexical access deficits, aphasia is often also accompanied by impaired attention, working memory, and verbal short-term memory. Growing evidence also suggests that difficulties in lexical access may be related to impaired domain-general cognitive processes, such as attention switching and processing speed.

This study explored attentional shifting and processing speed in people with aphasia (n = 14) and age-matched controls (n = 18) using an Attentional Blink paradigm with both linguistic stimuli (letters) and nonlinguistic stimuli (shapes), along with tasks assessing overall processing speed.

Compared to controls, PWA showed impaired attentional blink performance in the linguistic condition (F _1,20 = 7.35, p = 0.01) and also impaired processing speed [χ ² (1) = 13.38, p < 0.05]. In addition, an exploratory mediation analysis revealed a potential association between severity of lexical access impairments and performance on the attentional blink task, when accounting for verbal short-term memory abilities. The nonlinguistic condition was found to be too difficult for the control participants to address the experimental questions, but identified issues to be addressed in future studies with this focus.

These findings suggest that attentional shifting may play a foundational role in aphasic language processing and impairment. Further investigation is needed to understand the role of processing speed and whether attention shifting impairments are language-specific or extend to non-linguistic attentional shifting, as well.