Analysis of brain activation and wave frequencies during a sentence completion task: a paradigm used with EEG in aphasic participants

Claudia Lima; Jeferson Andris Lopes; Victor Souza; Sarah Barros; Ingrid Winkler; Valter Senna

doi:10.7717/peerj.15518

Analysis of brain activation and wave frequencies during a sentence completion task: a paradigm used with EEG in aphasic participants

PeerJ. 2023 Jun 12:11:e15518. doi: 10.7717/peerj.15518. eCollection 2023.

Authors

Claudia Lima¹, Jeferson Andris Lopes², Victor Souza³, Sarah Barros⁴, Ingrid Winkler⁵, Valter Senna¹

Affiliations

¹ MCTI, Senai Cimatec University Center, Salvador, Bahia, Brazil.
² Brasilia Technical School, Brasília, Federal District, Brazil.
³ São Rafael Hospital, Salvador, Bahia, Brazil.
⁴ Neurological Rehabilitation Sector, CEPRED, Salvador, Bahia, Brazil.
⁵ GETEC, Senai Cimatec University Center, Salvador, Bahia, Brazil.

Abstract

Aphasia is a language disorder that occurs after brain injury and directly affects an individual's communication. The incidence of stroke increases with age, and one-third of people who have had a stroke develop aphasia. The severity of aphasia changes over time and some aspects of language may improve, while others remain compromised. Battery task training strategies are used in the rehabilitation of aphasics. The idea of this research is to use electroencephalography (EEG) as a non-invasive method, of electrophysiological monitoring, with a group of aphasic patients in rehabilitation process in a prevention and rehabilitation unit of the person with disabilities of the Unified Health System (SUS), of reference in the state of Bahia-Brazil. In this study, the goal is to analyze brain activation and wave frequencies of aphasic individuals during a sentence completion task, to possibly assist health professionals with the analysis of the aphasic subject's rehabilitation and task redefinition. We adopted the functional magnetic resonance imaging (fMRI) paradigm, proposed by the American Society for Functional Neuroradiology as a reference paradigm. We applied the paradigm in the group of aphasics with preserved comprehension, right hemiparesis, and left hemisphere injured or affected by stroke. We analyzed four electrodes (F3/F4 and F7/F8) corresponding to the left/right frontal cortex. Preliminary results of this study indicate a more robust activation in the right hemisphere (average of aphasics), with a difference of approximately 14% higher in Theta and Alpha frequencies, with 8% higher in low Beta (BetaL) and with approximately 1% higher in high Beta frequency (BetaH), Gamma frequency was higher by approximately 3% in the left hemisphere of the brain. The difference in electrical activation may be revealing to us a migration of language to the non-language dominant hemisphere. We point to possible evidence suggesting that EEG may be a promising tool for monitoring the rehabilitation of the aphasic subject.

Keywords: Aphasia; Brain activation; Electroencephalography; Language rehabilitation.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Aphasia* / etiology
Brain / diagnostic imaging
Electroencephalography / adverse effects
Humans
Language
Stroke* / complications

Grants and funding

This work was suported by the Bahia State Research Support Foundation (FAPESB), process 0195/2019 and the National Council for Scientific and Technological Development (CNPq), Proc. 308783/2020-4. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.