plain the situation. This is reminiscent of the behavior of anosognosia
patients, in which the nondamaged left hemisphere may create sto-
ries to explain away the damage resulting from the right-hemisphere
lesion.
This may also relate to what is happening when psychological de-
fense mechanisms are operating. Psychological defenses, as described
by Sigmund Freud (1856-1939) and others, are cognitive strategies
we use to protect ourselves from experiencing thoughts and feel-
ings that might provoke anxiety or otherwise bothersome feelings.
Such strategies may be stories (rationalization, projection, reaction
formation, and so forth) or out-and-out forgetting (repression,
suppression). Importantly, these strategies are out of our awareness
—that is, they are unconscious—in that we are not aware of the moti-
vations for the defensive action. Whether Freudian defenses use some
of the same underlying neurology as what is happening in split-brain
patients and anosognosia is unknown, but there certainly are signifi-
cant behavioral similarities.
(^)
Original Left-hand copy Right-hand copy
Figure 18.4. Drawing (left) as copied by a split-brain patient with his left hand
and his right hand.
Picture this: a right-handed split-brain patient is shown the drawing
on the left in Figure 18.4 and asked to copy it, once using his left hand