TY - JOUR

T1 - tDCS of right-hemispheric Wernicke’s area homologue affects contextual learning of novel lexicon

AU - Гнедых, Дарья Сергеевна

AU - Цветова, Диана Маратовна

AU - Мкртычян, Надежда Андреевна

AU - Благовещенский, Евгений Дмитриевич

AU - Костромина, Светлана Николаевна

AU - Штыров, Юрий Юрьевич

PY - 2024/4/1

Y1 - 2024/4/1

N2 - Numerous studies have shown robust evidence of the right hemisphere's involvement in the language function, for instance in the processing of intonation, grammar, word meanings, metaphors, etc. However, its role in lexicon acquisition remains obscure. We applied transcranial direct current stimulation (tDCS) over the right-hemispheric homologue of Wernicke's area to assess its putative involvement in the processing of different types of novel semantics. After receiving 15 min of anodal, cathodal, or sham (placebo) tDCS, three groups of healthy participants learnt novel concrete and abstract words in the context of short stories. Learning outcomes were assessed using a battery of tests immediately after this contextual learning session and 24 h later. As a result, an inhibitory effect of cathodal tDCS and a facilitatory effect of anodal tDCS were found for abstract word acquisition only. We also found a significant drop in task performance on the second day of the assessment for both word types in all the stimulation groups, suggesting no significant influence of tDCS on the post-learning consolidation of new memory traces. The results suggest an involvement of Wernicke's right-hemispheric counterpart in initial encoding (but not consolidation) of abstract semantics, which may be explained either by the right hemispheres direct role in processing lexical semantics or by an indirect impact of tDCS on contralateral (left-hemispheric) cortical areas through cross-callosal connections.

AB - Numerous studies have shown robust evidence of the right hemisphere's involvement in the language function, for instance in the processing of intonation, grammar, word meanings, metaphors, etc. However, its role in lexicon acquisition remains obscure. We applied transcranial direct current stimulation (tDCS) over the right-hemispheric homologue of Wernicke's area to assess its putative involvement in the processing of different types of novel semantics. After receiving 15 min of anodal, cathodal, or sham (placebo) tDCS, three groups of healthy participants learnt novel concrete and abstract words in the context of short stories. Learning outcomes were assessed using a battery of tests immediately after this contextual learning session and 24 h later. As a result, an inhibitory effect of cathodal tDCS and a facilitatory effect of anodal tDCS were found for abstract word acquisition only. We also found a significant drop in task performance on the second day of the assessment for both word types in all the stimulation groups, suggesting no significant influence of tDCS on the post-learning consolidation of new memory traces. The results suggest an involvement of Wernicke's right-hemispheric counterpart in initial encoding (but not consolidation) of abstract semantics, which may be explained either by the right hemispheres direct role in processing lexical semantics or by an indirect impact of tDCS on contralateral (left-hemispheric) cortical areas through cross-callosal connections.

KW - Wernicke's area

KW - abstract concepts

KW - brain

KW - concrete concepts

KW - cortex

KW - language learning

KW - neuromodulation (noninvasive brain stimulation, NIBS)

KW - right hemisphere

KW - temporo-parietal junction (TPJ)

KW - transcranial direct current stimulation (tDCS)

KW - word acquisition

UR - https://www.mendeley.com/catalogue/fe5e7c39-39b2-3143-951c-b2cef148afbf/

U2 - 10.1016/j.nlm.2024.107905

DO - 10.1016/j.nlm.2024.107905

M3 - Article

VL - 210

JO - Neurobiology of Learning and Memory

JF - Neurobiology of Learning and Memory

SN - 1074-7427

M1 - 107905

ER -