Errorless and errorful learning in people with aphasia across novel-object pairing and word retrieval tasks

While linguistic deficits are key to diagnosing and treating aphasia, there is growing interest in the cognitive processes important for rehabilitation outcomes, particularly the role of learning. Of relevance to the current study, research has manipulated instructional methods (errorless vs. errorful) to assess their effects on outcomes. However, it is still unclear whether individualized profiles of errorless and errorful learning exist in aphasia and whether they might be meaningful for clinical practice.

The current study aimed to examine learning in people with aphasia, manipulating instruction method (errorless, errorful) and linguistic demands of learning.

Nine people with stroke-induced aphasia participated in this preliminary study. Participants engaged in errorless and errorful novel object pairing and word retrieval tasks. Learning outcomes were assessed on the same day, next day, and after one week. Participants also completed cognitive-linguistic assessments to investigate the contribution of memory, language, and executive functioning abilities to learning outcomes.

At the group level, participants performed significantly better following errorful training for novel object pairing (p = 0.001) relative to errorless training. An errorful advantage was observed at the individual level in 7 participants during same day testing, with the highest overall performers on the task showing the most persistent errorful learning benefits. In the word retrieval practice task, group and individual-level differences in scores following errorless and errorful practice were minimal. Scores in errorful novel object pair learning correlated with verbal short-term memory and nonverbal long-term memory assessments, while no other correlations were found between learning scores and cognitive-linguistic variables.

Findings are consistent with prior research that suggests that successful effortful retrieval may pose an advantage over errorless learning when acquiring novel information and the potential contributions of verbal short-term memory and nonverbal long term memory on learning. Results from the word retrieval practice task draw attention to differences between practicing lexical access and novel learning. The lack of an errorful advantage in word retrieval may alternatively be due to task design and merits further research. Results support the hypothesis that people with aphasia display variable learning profiles that may stem from differences in underlying cognitive-linguistic abilities. Continuing research is needed to characterize learning in aphasia to consider its potential influence on rehabilitation outcomes and support speech-language pathologists in considering and accounting for different learning and cognitive-linguistic abilities when individualizing treatment decisions.