Behavioural and electrophysiological evaluation of the impact of different cue types upon individuals with acquired anomia

Abstract

ABSTRACT Background Lexical retrieval models help to determine the locus of difficulty in individuals with anomia. It is generally assumed that phonological cueing facilitates naming in individuals with phonological output lexicon deficits while semantic cueing facilitates naming in those with semantic lexical deficits. Evidence from treatment studies is not always consistent with this assumption, showing positive effects for both types of cues regardless of the types of deficits in some studies. Recently, behavioural and electrophysiological markers for patient engagement and effort during motor rehabilitation have been suggested. Thus, we set out to evaluate, in a preliminary manner, whether there is an association between the locus of the naming difficulty, the relevancy of the type of cue to this locus and the degree of patient cognitive engagement and effort, as measured by these markers. Aims To evaluate the applicability of a behavioural marker of temporary functional change (TFC) and of a single-channel EEG marker, the Brain Engagement Index (BEI), during naming treatment specifically designed to test the efficacy of semantic and phonological cueing treatment in 23 individuals with phonological output lexicon anomia and in four individuals with lexico-semantic anomia following acquired brain damage. Methods and Procedures Two-hundred pictures of nouns were divided into five blocks of 40 pictures each. The blocks were matched in the frequency of use and number of letters. Three of the blocks were non-cued blocks: the pre-treatment block (first block), the 3rd block and the 5th block. The 2nd and the 4th blocks provided either semantic cues or phonological cues simultaneously with the presentation of the picture. The order of the cued sessions varied among the patients. Participants underwent BEI monitoring (EEG) during all sessions. Outcome and Results Most of the individuals, whether with predominantly semantic or phonological impairment, profited immediately from both types of cues. In addition, generalization to non-cued pictures was observed for 23 of the 27 individuals following the cueing blocks. Importantly, this generalization was related to the type of impairment for most participants, but this effect was transient. Finally, it was found that the patients’ impairment interactions with the type of cue used were associated with the degree of patient cue type-induced effort, as could be measured by this temporary generalization (or TFC) and by the BEI.