The Biological Perspective
These review notes by
Tina Fuller
Gaby Perez
Vanessa Espinoza
Describe
and evaluate the cultural context and development, the conceptual framework, the
methodology, and the application of the biomedical model.
Cultural context and development:
- Darwin (Evolution – Natural Selection)
- Dualism
- Later shift from Dualism to Materialism
Conceptual Framework (Key Concepts):
physiological
(biological) concepts affect behavior.
Neurotransmitters (excitatory,
inhibitory).
The Brain (localization of
functions).
Bodily Rhythms
Methodology:
Correlational studies, double blind trials,
experiments (use of animals and humans = ethically controversial), interviews,
case studies and questionnaires.
Applications:
- comparison with other perspectives
- application of genetic research and ethical implications
- changes in education, work and therapy.
Describe
and evaluate theories and empirical studies within this perspective.
Theories:
Biological
researchers tend to view behavior has purely physical.
Their basic assumption is that the brain determines behavior.
Dualism
– the view, first attributed to Descartes, that mind and body are distinct,
Descartes believed that the two could interact via the pineal gland in the
brain. However, now most
psychologist disregard this assumption.
Materialism
– assumption that all behavior has a physiological basis.
The
two primary concerns of the biological perspective are the workings of the
nervous system, and the role of hereditary on behavior.
Heredity
– the biological transmission of characteristics from one generation to the
other. This is a main aspect of the
biological approach.
Natural Selection
– the evolutionary process by which those random variations within a species
which enhance reproductive success lead to perpetuation of new characteristics,
in essence, individuals possessing traits which enhance survival and
reproduction are likely to have more offspring (Darwin).
Empirical Studies:
Darwin
– His theory of natural selection published in his book “The Origin of
Species” (1859) was a major influence on the biological perspective.
Darwin was advocating not only the inheritance of characteristics, but
also an evolutionary link between humans and all other species.
Even though, his theory caused much controversy, it laid the basis for
the study of hereditary influences on behavior.
1861
– A French doctor, Paul Broca, encountered a case in which a man lost
the ability to speak coherently after a head injury. Later, Broca, was able to demonstrate, by post mortem
autopsy, that the cause of the man’s deficit lay in damage to a specific point
in the brain. The proof of this
localization of function (connecting a specific behavior to a specific brain
area) was crucial to this perspective.
Wernicke
- Interested in psychiatry, traditionally he studied
anatomy initially and neuropathology later. He published a small volume on
aphasia which vaulted him into international fame. In it was precise
pathoanatomic analysis paralleling the clinical picture. He is best known for
his work on sensory aphasia and poliomyelitis hemorrhagia superior. The
aphasia syndrome, as described by Wernicke in 1908, consists of loss of
comprehension of spoken language, loss of ability to read (silently) and write,
and distortion of articulate speech. Hearing is intact. Wernicke aimed at a
natural system for the classification of mental disorders, chiefly based on the
anatomy and pathology of the nervous system. His pattern of thought was based on
the concept that psychiatric diseases were caused by disturbances of the
associative system. It was, in other words, a sort of localisation doctrine.
1950s
-Sperry severed the optic chiasm (the place where nerve cells from the
two eyes cross) and corpus callosum of monkeys. Each eye went to one half of the
brain. It proved that each half of the brain became two separate learning
centers. Sperry got together people who had their Corpus Callosum split to try
and control their sever epilepsy. He showed them different visual stimuli really
quickly so only one visual field could take up the information, and then got the
patient to identify the word in different ways. He also tried this using touch
identification and by showing two different symbols to either visual field. He
found that the right visual field was connected to the left side of the brain
and vice versa and that the Left side of the brain could write it or say the
information, and the right side could identify the information by pointing.
Still this gave no indication of what might happen in humans. One obvious difference between primates and people is that
monkeys do not speak, and Broca has shown that speech was found in only one
hemisphere. Consequently, no one
was sure what would happen if the hemispheres were separated in a person.
Implications:
Support of localization of the brain theory. Mirror sites, connecting to old
memories.
1960s
– In Los Angeles, Philip Vogel was trying to treat patients with a long
history of epilepsy. While in many
cases epileptics could be treated with anti-seizure drugs, these patients did
not respond to the drug treatment. When
all treatments failed, Vogel tried a new and radical approach: by cutting the
fibres of the corpus callosum, he hoped to restrict the seizure activity to one
hemisphere and thus prevent major seizure attacks. While he knew of Sperry’s work, and there had been
occasional clinical reports of damage to the corpus callosum, no one had
purposely separated the hemispheres before.
Medically, the treatment worked, and it reduced the frequency of more
limited seizures. Initial
observations suggested that the patients were normal, everyday actions such as
walking and eating seemed to occur naturally.
However after further testing, they found that the patients behaved in
many ways as if they had two independent streams of conscious awareness, one in
each hemisphere, each of with is cut from and out of contact with the mental
experience of the “other”. In
other words, two minds functioning separately from each other.
To assess the effects of the surgery, the researchers had to use
techniques whereby information was presented to only one hemisphere.
The simplest case, involved touch: if the split brain person were given
an object in there life hand while blindfolded, the left hand could pick it out
again, by touch, from a selection of several objects.
However, if the right hand attempted to pick out the article previously
held in the left hand, it did no better than chance.
In the case of vision, the situation is a bit more complicated, because
each eye is connected to both hemispheres.
The division of visual processing is such that the visual world of both
eye is divided in two, so that the objects on the left side of the visual world
are seen by the right hemisphere, while objects on the right side are seen by
the left hemisphere, regardless of which eye is used.
Since only the left hemisphere had language, the split brain person
presented with a word or picture on the left side (conveyed to the right
hemisphere) could not say what they had seen.
The left hemisphere also specializes in logic and math skills. They also discovered that the right hemisphere has musical
and spatial abilities which the left hemisphere lacks. However the right hemisphere is not completely ignorant of
language because if a split person was presented with a word or picture, it can
point to a corresponding word or picture. Thus,
if the right hemisphere sees the word “key”, the left hand can correctly
choose a key.
Explain
how cultural, ethical, gender, and methodological considerations affect the
interpretation of behaviour from a biological perspective.
Effectiveness of the perspective in explaining
psychological and/or social questions:
Comparison with other perspectives on questions
such as aggression, gender differences or stress.
It addresses the question of gender differences: Nature or nurture? When
looking at gender differences it looks at issues such as sex, relationships,
eating disorders etc. Eating
disorders have many causes, they can be physiological, cultural, emotional.
Society’s impact on women and the correlation that exists between
eating disorders and genders is studied as the great difference from male: to
female ratio increases (1:7).
Gender:
There are a great deal of differences between males and females, in terms of
physiology and personality. However, in terms of the brain, there is a distinct
difference between the two genders. Females actually have a larger and more
developed corpus callosum than men, which suggests that they have better
communication between the two sides of the brain. While the male brain is, on
average, approximately 10 percent larger than the female brain, females have a
larger frontal lobe than men, which might explain the fact that women seem to
have a heightened perception of emotions than men. Females have evolved
mechanisms that enable them to detect men that will transfer resourced to their
offspring (i.e. health and paternal investment). Males, however, have evolved
mechanisms that enable them to detect females that promise rapid production of
offspring, and disinclination to mate with other men (i.e. health, fertility,
and faithfulness). This could explain why men expect women to be faithful, and
why women seek out faithful men, however males do not feel compelled to remain
faithful to women.
Methodological:
Invasive vs. non-invasive techniques. Invasive techniques, such as split brain
studies are not only un-ethical, but leave patients in what can be considered a
worse condition than their previous one. Although when the corpus callosum was
cut on severe epileptics, their seizures stopped, but so did the communication
between left and right brain. These techniques are dangerous and messy.
Non-invasive techniques, however, such as MRI, CAT scans, or PET scans, are
safer, and are a lot more helpful in determining areas of the brain which may be
malfunctioning.
Compare
theories, empirical studies and the conceptual framework of this model with the
other perspectives.
|
Biological |
Psychodynamic |
Learning |
|
Key
terms and concepts: Physiological (biological) concepts affect behavior. Hormones,
Endocrine gland, Drugs, Stress, Sleep, Materialism, Hereditary, Central
nervous system etc. |
Key terms and concepts:
archetypes, defense mechanisms, ego, id, superego, psychosexual
stages of development, inferiority complex, Oedipal conflict, conscious
etc. |
Key terms and concepts:
Reinforcement (positive/negative), operant conditioning, learning,
classical conditioning, conditioned response, conditioned stimulus,
schedules of reinforcement, shaping etc.
|
|
Key theorists: Sperry, Vogel, Broca, Wernicke
|
Key theorists: Freud, Jung, Adler |
Key theorists: Watson, Skinner, Thorndike |
|
Assumptions: Based on the assumption of
materialism, which asserts that all behavior has a physiological basis. Genes have evolved over
millions of years to adapt behavior to the environment. Therefore, much
behavior will have a genetic basis. |
Assumptions: Attempts to understand
behavior in terms of the workings of the mind, with an emphasis on
motivation and the role of past experience.
Emphasizes the importance of innate drives, the continuity of
normal and abnormal behavior and the role of the unconscious mind. By making the assumption of psychic determinism, views all
behavior as having a meaning. |
Assumptions: Emphasizes the study of
observable responses, and rejects attempts to study internal processes
like thinking. Focus on learning as a primary
factor in explaining changes in behavior.
Parsimony: The principle that
states that one should always seek the simplest possible explanation for
an event. Associationism: Mental processes, particularly
learning, are based on forming connections between ideas and/or events.
|
|
Methodology: Correlational
studies, double blind trials, experiments, interviews, case studies and
questionnaires. |
Methodology: Case studies, interviews |
Methodology: Experiments, interviews,
surveys, observation |
Identify
and explain the strengths and limitations of biological explanations of
behaviour.
Strengths
– with the biological approach a better understanding of how the brain works
has been achieved. Such as with
Broca’s work, “localization of the brain” psychologists were able to
connect a specific behavior to a specific area of the brain).
Also the developments of techniques to study the brain have improved with
time. Different techniques are EEG,
MRI, CAT scans, PET.
The
biological perspective has also helped us understand the effect that drugs have
in the organism (such as cocaine, alcohol etc) and understand what happens to
different areas of the brain and to neurotransmitters.
The study of psychoactive (mind affecting) drugs is a concern in both
psychology and medicine, and has given rise to a hybrid field called
psychopharmacy. This extensive
study has helped to understand in depth humans’ behavior under the influence
of drugs. Another strength of this
perspective is the understanding of the effects of hormonal change on behavior.
Limitations – the biological approach emphasizes “getting inside the black box”, that is look at internal structure of the organism. However, they do not take in to account outside factors, such as the environment, effect of society, family etc. on behavior. Not every behavior can be explained solely on the brain. Other past experiences can have an effect on our behavior. Such as when trying to understand aggression and why someone might change acquire a violent behavior. The biological perspective proposes that in order for a person’s behavior to change drastically, two out of these three things must happen: 1) caused by physical damage to the brain, 2) have a mental disease, 3) or have been abused as a child. This last one however does not seem to go with the perspective since it takes into account past experiences.
Explain
the extent to which free will and determinism are integral in this perspective.
Free
Will:
Since this perspective acknowledges the presence of the mind (basic
assumption of materialism), and focuses on how processes in the brain account
for behavior, it can be assumed that free will is integral to this perspective.
However, such theories as those that explain aggression, suggest that there are
some behaviors which are hereditary and which we have no control over.
Determinism:
The biological perspective is deterministic in that
it states that certain psychological (personality) traits are pre-determined, or
inherited. The emphasis on genetics and the biological basis of behavior makes
determinism integral to this perspective.
Explain
and evaluate claims that correlates exist between physiological and
psychological behaviour.
·
Localization
of function: it
has been determined that certain areas of the brain are primarily used for
certain functions and determine specific behaviors. This also allows us to
determine the effects of damage on these particular areas of the brain.
Discuss
controversies surrounding a reductionist approach, as adopted by many biological
psychologists.
The biological approach can be said to be a reductionist approach because it focuses specifically on neurological processes. It doesn’t take other possible explanations of behavior into account, such as cognitive processes (mental models), or the role of the environment.