24
JERALD J. BERNSTEIN
ments of the feeding dance and low intensity feeding commonly seen
in normal goldfish. In contrast, stimulation of the lateral and medial
olfactory regions of the telencephalon usually did not produce full intention feeding movements. Stimulation of lower brain centers such as the
vagal or facial lobes of the medulla, valvula cerebelli, or cerebellum did
not elicit feeding behavior (Grimm, 1960).
The brain of fish has been stimulated to ascertain if areas of the
nervous system can be used as positive or negative reinforcement during
operant conditioning. Portions of the telencephalon ( Boyd and Gardner,
1962) were stimulated with chronically implanted monopolar electrodes
while the animal was being trained. Tests were made in free operant
behavioral situations. In the first series of experiments the animals were
tested on a side preference test. Currents of between 5 and 150 mA were
delivered to goldfish when on one side and not on the other side of an
aquarium. Light was the cue for the association by the fish for the
appropriate side of the aquarium during electrical stimulation. The
animal was thus free to receive or avoid electrical stimulation by swimming toward or away from the side of the aquarium at which he was
stimulated. With progressive current two telencephalic implants ( which
are difficult to locate anatomically) acted as negative (aversive) stimuli.
One implant in the optic tectum acted as positive reinforcement at high
lcvels of stimulation. After these tests, animals were trained to strike a
target to get a train of electrical impulses to the brain. Animals with
telencephalic implants did not learn the task. However, stimulation of
the anterior optic tectum resulted in the fish hitting the target in order
to produce self-stimulation ( Boyd and Gardner, 1962).
Not only does stimulation of the telenccphalon elicit feeding behavior
and appear to be a positive or negative reinforcer, but also it appears
to have other effects on what might be determined as feeding behavior.
Clark et al. (1960) found that stimulation of the telencephalon
produced movement of the barbels in the maxillary region of the catfish.
These responses were extremely stable, and stimulation of the telencephalon would invariably elicit barbel movement. Repeated stimulation
of the telencephalon elicited barbel movement in repeatable patterns as
if a topography of representation for such movements occurred in the
neural mechanisms of the telencephalon (Clark et al., 1960).
I. Regenerative Capacity of the Telencephalon
The regenerative capacity of the telencephalon of fish is related to
the age of the animals and to the species of fish involved. The olfactory
JERALD J. BERNSTEIN
ments of the feeding dance and low intensity feeding commonly seen
in normal goldfish. In contrast, stimulation of the lateral and medial
olfactory regions of the telencephalon usually did not produce full intention feeding movements. Stimulation of lower brain centers such as the
vagal or facial lobes of the medulla, valvula cerebelli, or cerebellum did
not elicit feeding behavior (Grimm, 1960).
The brain of fish has been stimulated to ascertain if areas of the
nervous system can be used as positive or negative reinforcement during
operant conditioning. Portions of the telencephalon ( Boyd and Gardner,
1962) were stimulated with chronically implanted monopolar electrodes
while the animal was being trained. Tests were made in free operant
behavioral situations. In the first series of experiments the animals were
tested on a side preference test. Currents of between 5 and 150 mA were
delivered to goldfish when on one side and not on the other side of an
aquarium. Light was the cue for the association by the fish for the
appropriate side of the aquarium during electrical stimulation. The
animal was thus free to receive or avoid electrical stimulation by swimming toward or away from the side of the aquarium at which he was
stimulated. With progressive current two telencephalic implants ( which
are difficult to locate anatomically) acted as negative (aversive) stimuli.
One implant in the optic tectum acted as positive reinforcement at high
lcvels of stimulation. After these tests, animals were trained to strike a
target to get a train of electrical impulses to the brain. Animals with
telencephalic implants did not learn the task. However, stimulation of
the anterior optic tectum resulted in the fish hitting the target in order
to produce self-stimulation ( Boyd and Gardner, 1962).
Not only does stimulation of the telenccphalon elicit feeding behavior
and appear to be a positive or negative reinforcer, but also it appears
to have other effects on what might be determined as feeding behavior.
Clark et al. (1960) found that stimulation of the telencephalon
produced movement of the barbels in the maxillary region of the catfish.
These responses were extremely stable, and stimulation of the telencephalon would invariably elicit barbel movement. Repeated stimulation
of the telencephalon elicited barbel movement in repeatable patterns as
if a topography of representation for such movements occurred in the
neural mechanisms of the telencephalon (Clark et al., 1960).
I. Regenerative Capacity of the Telencephalon
The regenerative capacity of the telencephalon of fish is related to
the age of the animals and to the species of fish involved. The olfactory