Auditory serial position effects in story retelling for non-brain-injured participants and persons with aphasia

Using story retelling as an index of language ability, it is difficult to disambiguate comprehension and memory deficits. Collecting data on the serial position effect (SPE), however, illuminates the memory component. This study examined the SPE of the percentage of information units (%IU) produced in the connected speech samples of adults with aphasia and age-matched, non-brain-injured (NBI) participants. The NBI participants produced significantly more direct and alternate IUs than participants with aphasia. Significant age and gender differences were found in subsamples of the NBI controls, with younger and female participants generating significantly more direct IUs than male and older NBI participants. Alternate IU productions did not generate an SPE from any group. There was a significant linear increase from the initial (primacy) to the final (recency) portion of the recalled alternate IUs for both the NBI group and the group of participants with aphasia. Results provide evidence that individuals with aphasia recall discourse length information using similar memory functions as the nonimpaired population, though at a reduced level of efficiency or quantity. A quadratic model is suggested for the recall of information directly recalled from discourse-length language material.