Visual evoked potential study in slow learners.

Slow learners are individuals with low achievement and comparably low IQ scores. It may be a symptom reflecting a larger underlying problem in them. Sensory neural processing of visual information can be one of the contributory factors for their underachievement. The present study was undertaken to examine the integrity and function of visual pathway by means of Visual Evoked Potential (VEP). Pattern reversal VEP was performed on seventeen slow learners. Fifteen age and sex matched children with good school performance and normal IQ were taken as controls. There was significant prolongation of N75 component of VEP in slow learners. The latencies of P100 and N145 were also increased but could not reach the level of significance. Our findings are suggestive of the presence of a weaker VEP response in slow learners indicative of a deficit early in the visual processing. There is some abnormality in the geniculate afferents to V1 which is consistent with a defect in the magnocellular pathway at the level of Visual Area 1 or earlier.