Three groups of Ss, normal controls, severely depressed and mildly depressed, were compared on several objective tasks. Only the speed of perception of three dimensional objects differentiated satisfactorily between the groups. It was concluded that severely depressed Ss differed from both normals and mildly depressed Ss on the complex speed tasks.

1975) Intellect and serum uric acid: An optimal concentration of serum urate for human learning?, Social Biology, 22:3, 229-234,