The response of the central auditory system to nonsense syllables in normal hearing adults with and without HIV/AIDS: an fMRI study
Keywords:blood oxygenation level dependent (BOLD), cluster of differentiation 4 (CD4), binaural, Brodmann areas, Wernicke’s area
Aim The aim of this study was to apply fMRI to comparatively evaluate any activation in the central auditory nervous system (CANS) to nonsense syllables sound in normal hearing adults with and without HIV/AIDS.
Objective To determine the response of the central auditory nervous system (CANS) to nonsense syllables sound in normal hearing adults with and without HIV/AIDS, using fMRI.
Method A between-group comparative design was used to determine and compare the response of the CANS to nonsense syllables stimuli of a sample of 15 normal hearing participants without HIV/AIDS and 12 normal hearing participants with HIV/AIDS. Structural and fMRI images were acquired during a listening task where nonsense syllables were presented binaurally using earphones. Stimuli were presented with a block design with two conditions: silence (baseline) of twenty seconds, and the stimuli task tone of twenty seconds. Each block was repeated four times. The blood oxygen level-dependent (BOLD) technique was employed.
Results Both groups showed activation in all the region of interests (ROIs) of the CANS. The mean percentage signal change in BA41 and BA42 differed significantly between the two groups with a p-value of 0.03. The control group showed a significantly greater increase in neuronal activity caused by cerebral blood flow than the HIV/AIDS group.
Conclusions This study indicates that BOLD fMRI provides the possibility to display brain regions responding to specific auditory stimuli applied during the scanning session. These differences could not have been observed with any other basic audiometric test procedure.
LicenseCopyright on all published material belongs to the Society of Radiographers of South Africa (SORSA).
I hereby understand and declare that:
- All proprietary rights other than copyright are reserved to the authors, as well as the right to reproduce original figures and tables from this item in their future works, provided full credit is given to the original publication The South African Radiographer ISSN 0258 0241.
- In consideration of the reviewing and editing done by the editors of The South African Radiographer of the above named manuscript, the author/s hereby transfer, assign, or otherwise convey all copyright ownership world-wide, in all languages, to the Society of Radiographers of South Africa in the event that this manuscript is accepted for publication.
- If the manuscript has been commissioned by another person or organisation, or if it has been written as part of the duties of an employee, that full authorization has been given by the representative of the commissioning organisation or employer to be published in the The South African Radiographer.