TY - JOUR
T1 - tDCS of right-hemispheric Wernicke's area homologue affects contextual learning of novel lexicon
AU - Gnedykh, Daria
AU - Tsvetova, Diana
AU - Mkrtychian, Nadezhda
AU - Blagovechtchenski, Evgeny
AU - Kostromina, Svetlana
AU - Shtyrov, Yury
N1 - Publisher Copyright:
© 2024 Elsevier Inc.
PY - 2024/4
Y1 - 2024/4
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 - 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 - Wernicke's area
KW - word acquisition
UR - http://www.scopus.com/inward/record.url?scp=85186489666&partnerID=8YFLogxK
U2 - 10.1016/j.nlm.2024.107905
DO - 10.1016/j.nlm.2024.107905
M3 - Journal article
C2 - 38403010
AN - SCOPUS:85186489666
SN - 1074-7427
VL - 210
JO - Neurobiology of Learning and Memory
JF - Neurobiology of Learning and Memory
M1 - 107905
ER -