Processing Speed Mediates Visual Attention in Patients With Remitted Major Depression

V Ucheagwu, F Udoh, R Ugokwe-Ossai, J Ezeokana, J Osaai
2015 Cross-Cultural Communication   unpublished
Information processing and attention in psychiatric patients have received limited research interests among neuroscientists. This has further limited clinical interventions in neuropsychological areas of psychiatric disorders. The present study was on processing speed and visual attention in patients with remitted major depression (RMD). Forty two participants were recruited for the study. Twenty one (21) of them were patients with RMD while the other 21 were healthy controls (HC). Four
more » ... (HC). Four instruments were used to assess processing speed (TMT A and TMT B) and visual attention (Letter Cancellation TaskS (LCT): Coloured and black-white), while the between group quasi experimental design was used. The findings of the study showed significant differences between RMD and HC on time taken to complete TMT A: F(1,35)=11.01, TMT B: F(1,35)15.50; LCT (coloured) F(1,35)=19.04, LCT (Black-white) F1(1,35)=29.65 at p < 0.05 level of testing. Similarly the path model analysis showed that TMT B mediates significantly TMT A (overall processing speed) on time taken to complete LCT (Colored): B=0.62, and LCT (Black and White): B=0.77. The discussion of the study centered on the roles of the ability to shift the task in visual attention search and likely tendency that visual search has common neural circuitry pathway with ability to shift task.