Word form encoding is under attentional demand: evidence from dual-task interference in aphasia

ABSTRACT

Although speakers can go on producing utterances while doing concurrent tasks, language planning is affected in conditions of divided attention. It is however unclear whether a concurrent task impacts only lexical selection, or if post-lexical processing is also impacted. To elucidate this question, we reasoned that if an encoding process is under attentional control, this should be even more the case when the planning process is disrupted due to brain damage: increased error rates in left-hemisphere damaged participants under dual-task conditions should therefore shed light on which encoding processes need attentional resources. Twelve participants producing either predominantly lexical or phonological errors following left-hemisphere stroke and eleven matched healthy controls underwent a dual-task picture naming paradigm with a concurrent auditory verbal and non-verbal task. The results indicate an impact of active dual-tasks on word production in both controls and aphasic participants, but a magnified effect on errors in aphasic participants with an overall increase of phonological errors under dual-task conditions. These results suggest that post-lexical encoding processes are under attentional demand.

KEYWORDS:

• Aphasia
• attention
• dual-task interference
• language
• word production

Disclosure statement

No potential conflict of interest was reported by the authors.

Declaration of interest statement

The authors confirm the absence of any conflict of interest.

Notes

1 As most syllables are words in French, all the selected CV syllables are words or interjections.

2 These synonyms are variants used to name a specific concept, with different predominance according to age or to the linguistic community (ex. for “pillow” in French some people rather say “coussin” and other “oreiller”; for “couch” some people rather use “canapé” and other “divan”), while the modal names are unfortunately taken from databases collected with young adults (Alario & Ferrand, 1999; Bonin et al., 2003). That’s why we did not remove or consider as errors those items for which a participant systematically produced a synonym, especially that the experimental design involves intra-item manipulation and analyses.

3 Only a few errors (3 occurrences) were mixed errors.

Additional information

Funding

This work was supported by Swiss National Science Foundation (SNSF) [grant number 105314_146113/1].