Sensitive method for the detection of experimental brain lesions

Small anterior lesions were placed unilaterally in 7 albino rats whose opposite hemispheres had previously been trained in diametrically opposed pattern-discrimination habits. Performances mediated by the lesioned hemisphere were significantly impaired, implicating extrastriate anterior cortex in the mediation of pattern discrimination. Traditional methods entailing the use of far more massive anterior lesions have failed to detect similar effects.