THE STRUCTURE OF BRAIN:Peripheral Nervous System, Psychoanalytic Model

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Abnormal Psychology PSY404

LESSON 12

THE STRUCTURE OF BRAIN

Neuro-anatomists divide the brain into three subdivisions: the hindbrain, the midbrain, and the forebrain.

Basic bodily functions are regulated by the structures of the hindbrain, which include the medulla, pons,

and cerebellum. The medulla controls various bodily functions involved in sustaining life, including heart

rate, blood pressure, and respiration. The pons serves various functions in regulating stages of sleep. The

cerebellum serves as a control center in helping to coordinate physical movements.

The midbrain also is involved in the control of some motor activities, especially those related to fighting

and sex.

The forebrain evolved more recently than the hindbrain and midbrain and, therefore, forebrain is the site

of most sensory, emotional, and cognitive processes. These higher mental processes of the forebrain are

linked with the midbrain and hindbrain by the limbic system.

The limbic system is made up of a variety of different brain structures that are central to the regulation of

emotion and basic learning processes.

Two of the most important components of the limbic system are the thalamus and the hypothalamus.

The thalamus is involved in receiving and integrating sensory information from both the sense organs and

higher brain structures. The hypothalamus controls basic biological urges, such as eating, drinking, and

sexual activity.

Most of the forebrain is composed of the two cerebral hemispheres. In general, the left cerebral hemisphere is

involved in language and related functions, and the right cerebral hemisphere is involved in spatial organization

and analysis. The two cerebral hemispheres are connected by the corpus callosum, which is involved in

coordinating the different functions that are performed by the left and the right hemispheres of the brain.

The cerebral cortex is the uneven surface area of the brain that lies just underneath the skull. It is the site

of the control and integration of sophisticated memory, sensory, and motor functions. The cerebral cortex

is divided into four lobes.

The frontal lobe is involved in controlling a number of complex functions, including reasoning, planning,

emotion, speech, and movement. The parietal lobe receives and integrates sensory information and also

plays a role in spatial reasoning. The temporal lobe processes sound and smell, regulates emotions, and is

involved in some aspects of learning, memory, and language. The occipital lobe receives and interprets

visual information.

The brain has three sections, the fore brain, the mid brain and the hind brain. It is in the fore brain that

there are two cerebral hemispheres and the thalamus and the hypothalamus. The thalamus relays

information between CNS and the Cerebral Cortex. The hypothalamus regulates hunger, thirst,

temperature. Below the fore brain is the mid brain. The mid brain coordinates communication between

forebrain and hindbrain. The hind brain has structures like the Pons, Medulla, Reticular Activating System

and it is connected to spinal cord. The Pons control sleep, dream and the wake state of an individual,

Medulla control breathing and heartbeat. The reticular activating system screens the incoming information.

Peripheral Nervous System

The peripheral nervous system includes all connections that stem from the central nervous system

and innervate the body's muscles, sensory systems, and organs.

Abnormal Psychology PSY404

The peripheral nervous system itself has two subdivisions

1. The voluntary (intentional) somatic nervous system governs muscular control.

2. The involuntary, autonomic nervous system regulates the functions of various body organs,

such as the heart and stomach. The somatic nervous system controls intentional or voluntary

actions.

The autonomic nervous system is responsible for psycho-physiological reactions are responses that occur

with little or no conscious control. The autonomic nervous system can be subdivided into two branches, the

sympathetic and parasympathetic nervous systems. Psycho-physiological over-arousal and under-arousal

both may contribute to abnormal behavior. For example, over-activity of the autonomic nervous system (a

pounding heart and sweaty hands) has been linked with excessive anxiety. In contrast, chronic autonomic

under-arousal may explain some of the indifference to social rules and the failure to learn from punishment

found in antisocial personality disorder.

The autonomic nervous system consists of sympathetic and para-sympathetic components.

The sympathetic component is active during time of intense arousal i.e. emergency whereas the

parasympathetic component is associated with rest or normal level functioning. Whenever an emergency

situation arises, the sympathetic component is activated and all are bodily indicators such as heartbeat, pulse

rate, body temperature, breathing rate is increased from the normal level to meat the emergency situation

such as (fight or flight). After some time when the fight and flight situation is over, the body must return to

its normal level of functioning so that all our internal organs should not be tired and wired out.

Psychosocial influences on brain structures and functions

Psychosocial influences on brain can be studied by the case of a man who had been successful as an

accountant, husband and father. He had a brain surgery for a brain tumor after his surgery, he returned to

work but he failed in his job, separated from his family and got involved in lengthy and un-controllable

compulsive rituals. Most of his time was consumed washing, dressing and rearranging his room. So he was

suffering from OCD (Obsessive Compulsive Disorder) for this case, the lesion in the brain while operating

his brain, tumor might be responsible for his OCD.

A boy's mother was killed in an accident shortly after his birth. His legal father married another woman

when the boy was three years old. The boy's step mother began a course of physical and psychological

abuse that will make you shiver. For years, the boy was locked in a closet. He was deprived of food and

water. His brother and sister would sneak food to him. He was even beaten by a broom stick. This extreme

abuse retarded the child's intellectual, emotional and social growth.

A number of similar cases have been reported. Children after getting out of these constraints conditions are

admitted in the psychiatric hospital resume their normal growth.

David Spiegel a psychiatrist at Stanford University in 1986, study 86 women with advance breast cancer.

This breast cancer was expected to kill them within two year's time. The prognosis was very poor. These

women were provided group psychotherapy to relieve their anxiety, depression and pain. All patient had

routine medical care for their cancer, in addition 50 patient of the 86 met with their therapist for

psychotherapy once a week in small groups. Dr. Spiegel's therapy did magic, the group receiving therapy

lived twice as long on average as the control group. These findings do not say that psychosocial

interventions cure advanced cancer, but they certainly point to one thing that psychological factors affect

physical processes involved in life threatening diseases. There is a good evidence that reducing stress and

giving patient's better cooping procedures and a sense of control seems to boost immune system

functioning.

Abnormal Psychology PSY404

William Greenough and his colleagues in 1990 studied that the nervous system of the rats raised in enriched

highly stimulated environment developed differently from those rats that were couch potatoes. The active

rats had many more connections between nerve cells in the Cerebellum and grew many more dendrites.

Through this experiment, the scientists learn that our nervous system is constantly changing as a result of

learning and experience even in old age and some of these changes are permanent.

The biomedical model takes in to account the concept of disease, the ties between brain and

psychopathology, the link between biological and environmental stress.

Psychoanalytic Model

This model studies psychopathology with reference to unconscious, childhood experiences and intra-

psychic conflict.

Psychoanalysis was pioneered by Sigmund Freud (1856-1939). He learned the art of Hypnosis in France. He

experimented with somewhat different procedures of Hypnosis. He used Hypnosis in an innovative way.

He encouraged his patients to talk freely about their problems, conflicts and fears .He discovered the

unconscious mind and its influence in psychopathology by using the techniques of Free Association, Dream

Analysis and Freudian Slips.

Structure of the mind: According to Freud the mind consists of Id which operates on pleasure principle, it

is childish and immature. Libido provides energy to Id, Ego and Superego. Ego operates on Reality

Principle and it is the master control .It works on logic and reason .The Superego it operates on the moral

principle and it is the conscience of the Psyche. The Ego mediates and resolves conflict between Id and

Superego.

Defense Mechanism or Coping Styles

The Ego battles with Id and Superego to resolve conflicts, at times the resulting anxiety is so overwhelming

that the Ego has to adopt unconscious protective processes called Ego Defense Mechanisms or Coping

Styles. They have following characteristics in common

a. Operate at unconscious level.

b. Distort reality.

c. Protect the Ego.

d. All normal and abnormal individuals both use these in their daily life.

Some important ego defense mechanisms are following

1-Denial 2- Displacement, 3- Projection, 4- Reaction formation, 5- Repression, 6-Rationalization, 7-

Sublimation.

Psychosexual Theory of Development

Freud proposed a theory of development. This is known as the psychosexual theory of development. The

main emphasis in this theory is on the physical and psychological development.

Psychosexual theory of development

1. Oral stage -birth to18 months

2. Anal stage-18 months to 3 years

3. Phallic stage -3 to 6 years

4. Latency stage

5. Genital stage-6 to 12 years

The stages of development represent patterns of gratifying our basic the needs, those needs which are not

gratified appear as fixations or psychopathologies at later adulthood

Oral stage fixations include fingernail biting, chewing pencils.

Freud is the first personality theorist to discuss the developmental perspective in the study of abnormal

behavior.

Psychoanalytic- Therapy It focuses on unconscious processes, conflicts and past experiences.

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