The results of the experiment 
shown in the previous diagram 
are plotted in degrees, against 
the distance the electrode had 
traveled. (Because the electrode 
was so slanted that it was 
almost parallel to the cortical 
surface, the track distance is 
almost the same as the distance 
along the surface.) In this 
experiment 180 degrees, a full 
rotation, corresponded to about 
0.7 millimeter.

    In such penetrations, the 
direction of orientation shifts 
may be clockwise or 
counterclockwise, and most 
penetrations, if long enough, 
sooner or later show shifts in 
the direction of rotation; these 
occur at unpredictable 
intervals of a few millimeters. 
The graph to the left shows an 
example of a sequence with 
several such reversals.