Self and Memory 217“9x6” b2726 Self and the Phenomenon of Life: A Biologist Examines Life from Molecules to Humanityplace. Fantasy enjoys even more freedom and may have contradictory
or illogical contents. Nevertheless, some traces of reality remain. For
instance, when I fantasize a Pegasus, both the horse and the wings are
real but the combination is not logical. If fantasy appears involuntarily
and is believed by the subject to be true, it becomes hallucination, a
symptom commonly seen in schizophrenia.
That memory and imagination are closely related has been borne
out in clinical neurology. Patients having lesions to the hippocampus not
only lose their memories but also their ability to imagine. They produce
only fragmented images lacking coherence.^8
10.4 Animal Learning
Implicit (non-declarative) animal learning can be of non-associative or
associative type. One example of non-associative learning is habituation,
in which an animal learns to ignore a repeated stimulus if it turns out
to be benign. A simple associative learning is the classical conditioning
discovered by Pavlov early in the 20th century. During his research on
the physiology of digestion in dogs, Pavlov observed that the dogs not
only salivated in the presence of meat powder (a natural stimulus), but
also in the presence of the laboratory technician who normally fed them,
even in the absence of the food. Pavlov figured that the dog responded
(salivation) to a neutral stimulus (person) by associating it with a natural
stimulus (food). He then used a bell to call the dogs to their food and,
after repetitions, the dogs started to salivate to the sound of the bell. In
classical conditioning, a neutral stimulus (called conditioned stimulus or
CS) is paired with and precedes a significant stimulus (called uncondi-
tioned stimulus or US), which normally elicits an innate, often reflexive,
response (called unconditioned response or UR). After repetition, the
two stimuli become associated and the animal responds (called condi-
tioned response or CR) to the conditioned stimulus alone.
Operant conditioning is a paradigm of associative learning in which
one particular stimulus interacts with a specific behavioral response,