Chapter – 2.3
Learning:
Habituation and Imprinting, Trial and Error Learning
Every animal goes through life experience because of which there is a
change in its behaviour. This change allows the animal to adapt itself
and handle new situations in a different manner that benefits it. The
ability to learn varies in different species. This is based on the level of
development of the nervous system. The learning ability includes
simple modification of innate or stereotyped behaviour or very
complex ones such as reasoning in higher primates. Learning could
be a short term one such as imprinting that occurs in the early years
of one’s life or learning to ignore stimuli that do not benefit it as in
habituation. Trial and error learning is seen in animals that are trained
in the laboratory. Here a reward or punishment is used to train them.
Most animals have the ability to learn from past experiences. Of all the
behavioural characteristics of an animal the ability to learn is considered to be
the most striking. Learning is a process that has a long lasting effect, enables the
animal to adapt and has an influence on its behaviour. Learning could be a
simple modification of any innate behaviour or it could be complex like
reasoning in the case of man.
It was Thorpe who defined learning as, ‘the process that manifest itself by
adaptive changes in individual behaviour as a result of past
experience.’
Learning can only be measured by recalling and recognition or testing the
memory. Nursery children recite rhymes and poems what they learn. Students
are graded on what they learn by conducting a written exam. Recognition is
used to measure learning as done in a practical exam. The student needs to
identify specimens and slides what he has seen earlier. The physiology of
learning is the formation of memory traces in the brain. This is a permanent
change that allows us to recollect or recall what we have learnt.
The ability to learn varies in different animals depending on the development of
their nervous system. The ability of an invertebrate like an annelid or arthropod
is lower than that of the vertebrates. Even among vertebrates the ability to learn
vary depending on the class they belong to. Mammals have a higher capacity to
learn and among mammals, man is the smartest and has the highest learning
ability.
There are various types of learning according to Thorpe,
a. Habituation
b. Conditioned reflex or classical conditioning
c. Trial and error learning
d. Latent learning
, 250 Introductory Zoology – VIII
e. Insight learning
f. Imprinting
HABITUATION
The simplest type of learning seen throughout life is habituation. This occurs in
every animal and in day-to-day activities. It does not require any special training.
Habituation is defined as, ‘the waning or a gradual decrease in response to
repeated exposure to stimulus.’
The animal or human being will show a startle response to the first cracker
during Diwali. After some time when many crackers are bursting the response
will decrease and finally there will be no reaction. People living near an airport
get used to the loud noise made by the air crafts that land and take off every
minute.
The story of the shepherd boy calling, ‘wolf, wolf’ is the best example for
habituation. The villagers responded to his call and were fooled. Thus when he
called ‘wolf, wolf’ the third time they failed to respond.
The waning (decline) and finally lack of a response is because the animal or
the person realizes that the stimulus is not of any importance to it or has no
significance or in plain words it is a useless stimulus. Habituation is the loss
of an old response. Animals that are exposed repeatedly to a stimulus with no
reward or punishment fail to respond eventually.
Habituation is seen in most animals, there are several examples such
as,
a. The frog or toad presented with non-edible object initially puts out its
tongue to capture the prey but later ignores it
b. The birds such as crows and sparrows get used to the presence of
scarecrow in a field.
c. The workers in a paint factory get used to the smell of paints while a first
time visitor cannot bear it.
d. Nereids reared in the laboratory was used to study habituation. The nereides
were reared in glass tube in muddy bottom aquarium. Nereid put out their
anterior end to feed. If disturbed by a jerking of the aquarium, a bright light,
shadow passing above them or even touching them immediately causes them
to withdraw. This response slowly wanes or decreases if they are subjected to
repeated stimulus
e. The snail placed on a glass table will retract into its shell immediately when
the glass is tapped. When it emerges from its shell and this is repeated it will
eventually show no reaction.
f. The fishes in an aquarium will respond to a visitor who puts his finger into
the water thinking it is going to be fed. If no food is given the fishes learn to
ignore the visitor.
g. The chick pecks at any small object on the ground but later it stops pecking
at non-edible objects.
Habituation is an important learning behaviour that allows the animal to adjust to
its environment. However it has been noticed that after some time the animal
may forget to show habituation and begin to respond again. This is because
there is recovery or reinforcement.
Learning:
Habituation and Imprinting, Trial and Error Learning
Every animal goes through life experience because of which there is a
change in its behaviour. This change allows the animal to adapt itself
and handle new situations in a different manner that benefits it. The
ability to learn varies in different species. This is based on the level of
development of the nervous system. The learning ability includes
simple modification of innate or stereotyped behaviour or very
complex ones such as reasoning in higher primates. Learning could
be a short term one such as imprinting that occurs in the early years
of one’s life or learning to ignore stimuli that do not benefit it as in
habituation. Trial and error learning is seen in animals that are trained
in the laboratory. Here a reward or punishment is used to train them.
Most animals have the ability to learn from past experiences. Of all the
behavioural characteristics of an animal the ability to learn is considered to be
the most striking. Learning is a process that has a long lasting effect, enables the
animal to adapt and has an influence on its behaviour. Learning could be a
simple modification of any innate behaviour or it could be complex like
reasoning in the case of man.
It was Thorpe who defined learning as, ‘the process that manifest itself by
adaptive changes in individual behaviour as a result of past
experience.’
Learning can only be measured by recalling and recognition or testing the
memory. Nursery children recite rhymes and poems what they learn. Students
are graded on what they learn by conducting a written exam. Recognition is
used to measure learning as done in a practical exam. The student needs to
identify specimens and slides what he has seen earlier. The physiology of
learning is the formation of memory traces in the brain. This is a permanent
change that allows us to recollect or recall what we have learnt.
The ability to learn varies in different animals depending on the development of
their nervous system. The ability of an invertebrate like an annelid or arthropod
is lower than that of the vertebrates. Even among vertebrates the ability to learn
vary depending on the class they belong to. Mammals have a higher capacity to
learn and among mammals, man is the smartest and has the highest learning
ability.
There are various types of learning according to Thorpe,
a. Habituation
b. Conditioned reflex or classical conditioning
c. Trial and error learning
d. Latent learning
, 250 Introductory Zoology – VIII
e. Insight learning
f. Imprinting
HABITUATION
The simplest type of learning seen throughout life is habituation. This occurs in
every animal and in day-to-day activities. It does not require any special training.
Habituation is defined as, ‘the waning or a gradual decrease in response to
repeated exposure to stimulus.’
The animal or human being will show a startle response to the first cracker
during Diwali. After some time when many crackers are bursting the response
will decrease and finally there will be no reaction. People living near an airport
get used to the loud noise made by the air crafts that land and take off every
minute.
The story of the shepherd boy calling, ‘wolf, wolf’ is the best example for
habituation. The villagers responded to his call and were fooled. Thus when he
called ‘wolf, wolf’ the third time they failed to respond.
The waning (decline) and finally lack of a response is because the animal or
the person realizes that the stimulus is not of any importance to it or has no
significance or in plain words it is a useless stimulus. Habituation is the loss
of an old response. Animals that are exposed repeatedly to a stimulus with no
reward or punishment fail to respond eventually.
Habituation is seen in most animals, there are several examples such
as,
a. The frog or toad presented with non-edible object initially puts out its
tongue to capture the prey but later ignores it
b. The birds such as crows and sparrows get used to the presence of
scarecrow in a field.
c. The workers in a paint factory get used to the smell of paints while a first
time visitor cannot bear it.
d. Nereids reared in the laboratory was used to study habituation. The nereides
were reared in glass tube in muddy bottom aquarium. Nereid put out their
anterior end to feed. If disturbed by a jerking of the aquarium, a bright light,
shadow passing above them or even touching them immediately causes them
to withdraw. This response slowly wanes or decreases if they are subjected to
repeated stimulus
e. The snail placed on a glass table will retract into its shell immediately when
the glass is tapped. When it emerges from its shell and this is repeated it will
eventually show no reaction.
f. The fishes in an aquarium will respond to a visitor who puts his finger into
the water thinking it is going to be fed. If no food is given the fishes learn to
ignore the visitor.
g. The chick pecks at any small object on the ground but later it stops pecking
at non-edible objects.
Habituation is an important learning behaviour that allows the animal to adjust to
its environment. However it has been noticed that after some time the animal
may forget to show habituation and begin to respond again. This is because
there is recovery or reinforcement.
