Shining Light into Adolescent HIV Neuroplasticity: A Study of the Prefrontal Cortex Using Functional Near Infrared
Sizwe Zondo1, Kate Cockcroft2, Candida da Silva Ferreira Barreto3
1Psychology, Rhodes University Psychology Clinic, Grahamstown, Eastern Cape, South Africa.
Background:
The human immunodeficiency virus (HIV) crosses the blood-brain barrier, compromising cortical networks and cognition. Neuropharmacological intervention in the form of combination antiretroviral therapy (cART) does not reverse cognitive decline in pediatric and adolescent HIV. In search of options to enhance cognition in affected adolescents, we evaluated the effectiveness of attention training.
Methods:
The training was evaluated by pairing participants' outcomes on the Stroop Colour Word Test (SCWT), a test of attention and inhibitory control, to brain hemodynamic responses measured by functional near-infrared spectrometry (fNIRS) both prior to, and after, the training. Changes in oxygenated haemoglobin in the prefrontal cortex during the SCWT were compared in 15 HIV+ participants who received attention training with that of 13 HIV+ participants who did not receive the intervention.
Results:
Intragroup analyses showed differences in oxygenated haemoglobin levels between congruent and incongruent conditions of the SCWT only for participants who received the attention training. Specifically, improved behavioural performance on SCWT for the attention group was associated with a significant decrease in oxygenated haemoglobin in the dorsolateral prefrontal cortex, and frontopolar brain areas in the training group. Decreased hemodynamic activation in the training group suggests greater neural efficiency in completing cognitive tasks.
Conclusions:
Findings suggest that customised attention training maybe an effective complementary adjunct to cART for children and adolescents living with HIV.
