Multilevel auditory and cognitive processing in post-stroke aphasia: associations with language performance using ABR, LLR, and P300: a cross-sectional observational study.

BACKGROUND

Aphasia following stroke is primarily characterized by language impairment; however, accumulating evidence suggests that deficits in auditory and cognitive processing may also contribute to impaired language function. Auditory evoked potentials provide objective markers of neural processing across subcortical, cortical, and cognitive levels and may help clarify the neurophysiological mechanisms underlying post-stroke aphasia.

OBJECTIVES

To investigate multilevel auditory processing and its relationship with language performance in individuals with post-stroke aphasia using Auditory Brainstem Responses (ABR), Late Latency Responses (LLR), and P300 potentials.

DESIGN AND

SETTING

Cross-sectional observational study conducted at a university hospital in Türkiye.

METHODS

Twenty-nine individuals with post-stroke aphasia and 33 age-matched healthy controls were included. Language performance was assessed using the Aphasia Language Assessment Test and a standardized naming task. Auditory processing was evaluated using ABR, LLR (P1, N1, P2, N2), and P300 potentials recorded according to standard electrophysiological protocols. Group comparisons were performed for latency and amplitude measures, and correlation analyses were conducted to examine associations between electrophysiological parameters and language performance.

RESULTS

Compared with healthy controls, individuals with aphasia demonstrated significantly prolonged latencies in ABR waves and interpeak intervals, as well as in all LLR and P300 components (p < 0.05). No significant group differences were observed in amplitude measures. Naming performance was significantly lower in the aphasia group. Although correlations between language performance and electrophysiological measures did not reach statistical significance, moderate negative trends were observed between naming scores and N2 and P300 latencies.

CONCLUSION

Post-stroke aphasia is associated with delayed auditory processing across subcortical, cortical, and cognitive levels, reflecting generalized slowing rather than reduced neural recruitment. Latency-based auditory evoked potential measures may complement behavioral language assessments and support a multilevel auditory-cognitive framework for aphasia evaluation and rehabilitation.