Date of Award


Degree Name

Master of Arts



First Advisor

Dr. Frederick P. Gault

Second Advisor

Dr. Arther G. Snapper

Access Setting

Masters Thesis-Open Access


The effect of the previous history of a single unit on its present firing pattern was studied using classical and operant conditioning. The units were in area 18a of the rat's cortex. It was found that there are polymodal units in that area. The firing pattern can be changed using classical conditioning. The rate of firing can be increased one standard deviation above the mean rate by reinforcing with brain stimulation. The rate can also be changed one standard deviation below the mean rate. This occurs when the trials come at a fixed time and when the trials come at a variable time. The effect, however, is more noticeable when the trials occur at a fixed time.