Chapter 3: Physiological Bases of Human BEhavior

Chapter 3

PHYSIOLOGICAL BASES OF HUMAN BEHAVIOR

INTRODUCTION

                Organism as diverse as humans and other creatures share many biological processes. However, their unique behavioral capacities depend on the differences in their physiological make- up.

                You and I have a larger repertoire of behavior different from the other grades of beings because we come equipped with a more complex brain and nervous system. The activity of the human brain is so complex that no one has ever come close to duplicate it.

                Your nervous system contains many cells that are busy integrating and relaying information. This could be the reason why many psychologists dedicated their time in exploring the biological bases of human behavior (Weiten, 2008).

                In this section, we take a closer look at the communication in the nervous system.

NERVOUS TISSUE: The Basic Hardware

                Your nervous system is a living tissue composed of cells. The cells in the nervous system fall into two major categories: GLIA AND NEURONS or NERVE CELL.

Neuron

It is the individual cells in the nervous system that receive, integrate and transmit information.  The basic unit of the nervous system is of differing shapes, sizes and function. There are approximately trillion of neurons throughout the body which primarily involved in the control of body activities and behavior.

Parts of Neuron

                CELL BODY/SOMA - contains the nucleus which provides              nourishment and insulation.

                DENDRITES- receive signals from the neighboring neurons and carry them back to the cell body.

                AXONS- relatively longer than the other neurons which                carries messages to the other neuron. Axons terminate in       small bulges called TERMINAL BUTTONS that send messages      to other neurons.

Myelin sheath- these are fatty tissues and proteins surrounding the axons. It prevents interference from electrical signals generated in adjacent axons. You may have heard that the brain consists of the gray and white matter. Gray is the color of the cell bodies and white is the color of myelin sheaths.

Kinds of Neuron According to Speed

                Impulses in the fastest neuron move at a rate of 110 meters per second; in the slowest, 0.5 meters per second. The speed of condition is matched by the thickness of the myelin sheath. The more myelin sheath, the faster the conduction. (Kahayon, 2004)

Kinds of Neuron According to Basic Function

1. Sensory (Afferent neurons)- conveys information from the body’s sense organs to the brain and spinal cord. This is initiated by the receptors- specialized cells in the sense organs, muscles, skin and joints that detect physical or chemical changes and convert these into impulses that pass along the sensory neurons.
2. Motor (Efferent neurons) carry impulses away from the brain and spinal cord to the reacting organs, the muscles and glands.
3. Association/Interneurons- connect the neurons together and and combine the activities of the sensory and motor neurons.

GLIAL CELLS- (Greek word “glia” means glue) these are the non-neural cells that surround the neurons and ensure that it can perform its functions while holding them in place.

                When the neural impulse reaches an axon’s terminal buttons, it triggers the release of chemical messengers called neurotransmitters. The neurotransmitter molecules diffuse across the synaptic cleft and binds through receptor sites on the postsynaptic neuron. A specific neurotransmitter can bind only to receptor sites that its molecular structure will fit into, much like a key must fit the lock (Weiten, 2008).

HOW THE NEURONS FIRE

ALL-or-NONE-LAW

                The firing of neurons occurs at either in full strength or not at all. After each firing, the neuron needs time to recover called the refractory period. During this period, action potential is much less likely to occur ( Miranda, 2008).

                Various neurons transmit impulses at different speeds. Most often, thicker axons transmit neural impulses faster than the thinner ones.

RESTING STATE

        This is the state of the neuron when not firing a neural impulse and when the message arrives, gates in the cell membrane open briefly to allow positively charged ions to rush in rates as high as 100million ions per second (Feldman, 2010).

ACTION POTENTIAL

                This is the time when there is a release of the neural impulse consisting of a reversal of the electrical charge within the axon. After it has occurred, the neuron cannot fire again no matter how much stimulation it receives.

THE SYNAPSE: SENDING THE MESSAGE TO OTHER CELLS

                Two neurons do not actually meet. They are separated by the synaptic cleft which is a microscopic gap between the terminal button of one neuron and the cell membrane of another neuron.

                In this situation, the neurons that send a signal across the gap is called pre-synaptic neuron and the neurons that receive the signals is called the post-synaptic neuron.

NEUROTRANSMITTERS: MESSENGERS OF THE NETWORK

                These are chemicals that carry messages across the synapse or cell body of a receiving neuron.

                It may vary on how intense its concentration that can cause a neuron to fire when it is secreted in one part of the brain and can inhibit the firing of neurons when it is produced by another part (Apruebo, 2009).

                Miranda (2008) presented the five key neurotransmitters according to location and functions.

Neurotransmitter Functions	Location	Functions
1. Acethylcholine	Brain, spinal cord ANS, selected organs	Releases at neuromuscular junctions; involved in memory
2. Norephinephrine	Brain, spinal cord, selected organs	Regulates physical logical arousal; learning, memory and emotion
3. Dopamine	Brain	Linked to muscle activity, emotional arousal, learning memory
5. Gamma Amino	Brain, Spinal cord	Involved in motor behavior and arousal           Butyric Acid (GABA)

ORGANIZATION OF THE NERVOUS SYSTEM

                It is important to understand the organization and functions of the nervous system and its mutually dependent systems and divisions.

A.      Central Nervous System (CNS): Brain-Spinal Cord

  

  BRAIN- Protection: Skull                                                                                  SPINAL CORD-     

                                                                                                                     Protection: Vertebrae

   

                                B. Peripheral Nervous System (PNS):  Extension of CNS

 

                 Somatic System                                  Autonomic System

           Reacts to outside stimuli                          Maintains homeostasis

 

                                                                 Sympathetic System              Parasympathetic System

Response: Involuntary                Response: Normal

 

THE PERIPHERAL NERVOUS SYSTEM

                It is made up of all those nerves that lie outside the brain and spinal cord. The peripheral nervous system can be divided into somatic nervous system and the autonomic nervous system.

The Somatic Nervous System

                This is made up of nerves that connect to voluntary skeletal muscles and to sensory receptors. These nerves are the cables that carry information from receptors in the skin, muscles and joints to the central nervous system to the muscles.

These functions require two kinds of nerve fibers:

ü      AFFERENT nerve fibers are axons that carry information inward to the central nervous

        system from the periphery of the body.

ü  EFFERENT nerve fibers are axons that carry information outward from the central nervous system to the periphery of the body (Weiten, 2009).  

The Autonomic Nervous System

                It is concerned with parts of the body that keeps us alive- the heart, blood vessels, glands, and other organs that operate involuntarily without our awareness.

                The autonomic nervous system mediates much of the physiological arousal when people experience emotions. Based on the above discussion, it is divided into sympathetic and parasympathetic division.

The Sympathetic Division

                It is primarily located on the middle of the spinal column—running from near the top of the ribcage to the waist area.  It is usually called as the “fight-or-flight system” because it allows people and animals to deal with different kinds of stressful events.              Emotions during these events might be anger (hence, the term fight) or fear (the term flight, obviously) or extreme joy and excitement. Yes, even joy can be stressful. The sympathetic division’s job is to get the body ready to deal with the stress (White, 2009).

The Parasympathetic Division

                If the sympathetic division can be called the fight-or-flight system, the parasympathetic division might be called the eat-drink-and-rest system.

                 The neurons of this division are located at the top and bottom of the spinal column, on either side of the sympathetic division neurons (para means “beyond” or “next to” and in this sense refers to the neurons located on either side of the sympathetic division neurons).

                The parasympathetic division’s job is to restore the body to normal functioning after a stressful situation ends. It slows the heart and breathing, constricts the pupils and reactivates digestion and excretion.

                Signals to the adrenal glands stop because the parasympathetic division is not connected to the adrenal glands. In a sense, the parasympathetic division allows the body to put back all the energy it burned—which is why people are often hungry after the stress is all over. It also functions on most ordinary, day-to-day functioning such as regular heartbeat, normal breathing and digestion (White, 2009).

THE CENTRAL NERVOUS SYSTEM

Brain

                This is the true core of nervous system. It takes information from senses, processes it, makes decisions and sends commands to the rest of the body (White, 2009).

Modern Brain Scanning Techniques: Providing Snapshots of its Internal Works

1. Electroencephalogram (EEG)- records electrical activity in the brain through electrodes placed on the outside of the skull. The device is used to assess brain damage, epilepsy and other problems.
2. Positron Emission Tomography (PET)- scans show the biochemical activity within the brain while hearing, seeing, thinking and speaking.

        It measures the amount of glucose in various areas of the   

      brain, and then sends this information to a computer for 

      analysis.

3. Functional Magnetic Resonance Imaging (fMRI)- scans provide a detailed, three-dimensional computer-generated image of the brain structures and activity by aiming a powerful magnetic field at the body. Through fMRI, it is possible to produce a vivid, detailed image of the functioning of the brain.
4. Computerized/Computed Tomography (CT) scan- produces a three-dimensional image obtained from X-rays of the head that are assembled into a composite image by a computer. It provides valuable information about the location and extent of damage involving stroke, language disorder or loss of memory.
5. Transcranial Magnetic Stimulation (TMS)- one of the newest types of scan. By exposing a tiny region of the brain to a strong magnetic field, TMS causes a momentary interruption of electrical activity. The procedure is sometimes called a “virtual lesion” because it produces effects analogous to what would occur if areas of the brain were physically cut. The enormous advantage of TMS, of course, is that the virtual cut is only temporary (Fedman, 2010,/Santrock,2005,/ White, 2009).

MAJOR PARTS OF THE BRAIN

                A human brain which can easily be held in one hand, weighs about 1,350 grams or 3 pounds, and has the consistency of a firm Jell-O. The brain is protected by a thick skull and covered with thin, tough, plastic -like membranes.

                 If shot in the head, he may or may not die depending on which area is damaged. For example, damage to an area in the forebrain would result in paralysis, damage to an area in the midbrain would result in coma but damage to an area in the hindbrain would certainly result in death (Plotnik,et.al., 2008).

                Let’s begin to explore the brain by looking into the major areas: the forebrain, the midbrain and the hindbrain.

The Hindbrain

                It is located at the skull’s rear, which is the lowest portion of the brain. The hindbrain has three identified structures: the medulla, the pons and the cerebellum.

• Medulla- it controls some sensitive body functions such as breathing, heartbeat, blood pressure and body posture. Medulla begins where the spinal cord enters the skull.

• Pons- joining two halves of the cerebellum, this lies adjacent to it containing large bundles of nerves, the pons acts as neurotransmitter of motor information, coordinating muscles and integrating movement between the right and left halves of the body. It is involved in regulating sleep ( Feldman, 2010).

• Cerebellum- extends from the rear of the hindbrain, just above the medulla and behind the pons. It consists of two-rounded structures thought to play important roles in motor coordination (Santrock, 2005).  It is also involved in several intellectual functions ranging from the analysis and coordination of sensory information to problem solving (Feldman, 2010).

                The cerebellum is also involved in performing timed motor responses such as those needed in playing games or sports, and in automatic or reflexive learning, such as blinking the eye to a signal which is called as classical conditioning (Plotnik et al., 2008).

The Midbrain

                It is located between the hindbrain and the forebrain. It is an area in which many nerve-fiber systems ascend and descend to connect the higher and lower portions of the brain.

                In particular, the midbrain relays information between the brain and the eyes and ears. The ability to attend to objects visually, for example, is linked to one bundle of neurons in the midbrain.

                Parkinson’s disease, deterioration of movement that produces rigidity and tremors, damages a section near the bottom of the midbrain (Santrock, 2005).

               

Two systems of the midbrain that are of special interest:

Reticular Formation- diffused collection of neurons involved in stereotyped patterns of behavior such as walking, sleeping or turning to attend to a sudden noise.

Small groups of neurons that use the neurotransmitter serotonin, dopamine and norepinephrine. Although these two groups contain relatively few cells, they send their axons to a remarkable variety of brain regions, perhaps explaining their involvement in high-level, integrative factors (Santrock,2005).

The Forebrain

                The forebrain is the largest part of the brain, has left and right sides that are called hemispheres.

                The hemispheres, connected by a wide band of fibers, are responsible for an incredible number of functions, including learning and memory, speaking and language, having emotional responses, experiencing sensations, initiating voluntary movements, planning and making decisions (Plotnik et al., 2008).

THE CEREBRAL CORTEX: Our New Brain

                In Latin, cortex means “cover” which is referred to as the new brain because of its relatively recent evolution.

                It consists of a mass of deeply folded, rippled, convoluted tissue.

                Although only about one-twelfth of an inch thick, if flattened out, cover an area more than two feet square (Feldman, 2010).

                It is the highest region of the forebrain where the highest mental functions, such as thinking and planning takes place (Santrock, 2005).

                The cortex is divided into two hemispheres called CEREBRAL HEMISPHERES, which are connected by a thick, tough band of neural fibers (axons) called CORPS CALLOSUM (literally means “hard bodies” as calluses on the feet are hard (White, 2009).

               

The cortex has four major sections called LOBES.

1. Frontal lobe-(Broca’s Area) lies at the front center of the cortex; involved with personality, emotions and motor behaviors.
2. Parietal lobe- area at the top of the head functions with perception and memory experiences; also involved in spatial location, attention and motor control.
3. Temporal lobe- (Wernickes’s Area) found in the lower center portion of the cortex just above the ears which involved with hearing, language processing and memory.            
4. Occipital lobe- found at the back of the head which is involved with vision.

                The four sets of lobes are physically separated with deep grooves called SULCI.

               

                There are three main areas in the cerebral cortex: (1) the motor areas, (2) the sensory areas, and (3) the association areas.

1. Motor Areas- Located just behind the frontal lobes which are largely responsible for the body’s voluntary movement. 

        For example, the control movements that is relatively large        scale and requires little precision, such as the movement of            a knee or hip, is centered in a very small space in the motor        area.

                        In contrast, movements that must be precise and            delicate, such as facial expressions and finger movements               are controlled by a considerably larger portion of the motor        area. (Feldman, 2010)

2. Association Areas- Areas within each lobe of the cortex is responsible for the coordination and interpretation of information as well as higher mental processes such as thought, language, memory and speech. (White, 2009).
3. Sensory Areas- Areas of the cerebral cortex that includes three regions: (1) processes information about body sensations including touch and pressure, (2) relating to sight and (3) relating to sound (Feldman, 2010).

THE LIMBIC SYSTEM:  Old Brain

                The limbic system (the word limbic means, marginal) and its structures are found in the inner margin of the upper brain which includes the thalamus, hypothalamus, and amygdale. In general, the limbic system is involved in emotions, motivation and learning (White, 2009).

                The limbic system is often referred to as our primitive, or animal brain because its same structures are found in the brains of animals that are evolutionarily very old, such as alligators (Plotnik et al.,2008).

Thalamus (inner chamber)

                The part of the brain located in the middle of the central core that acts primarily to relay information about senses (Feldman, 2010).

Hypothalamus (below the inner chamber)

                The hypothalamus regulates body temperature, thirst, hunger, sleeping and waking, sexual activity and emotions. It seats right above the pituitary gland, which is called as the “master gland” because it controls the functions of all the other endocrine glands that will be discussed later in this chapter. ]

                The hypothalamus controls the pituitary, so the ultimate regulation of hormones lies with the hypothalamus (White, 2009).

Hippocampus (Greek word for sea horse)

                Curved structure located inside the temporal lobe which is responsible for the formation of long-term memories and the storage of memory for location of objects (White, 2009).

Amygdala (almond)

                It is the area of the brain located near the hippocampus. Amygdala receives input for all the senses.

                It plays a major role in evaluating the emotional significance of stimuli and facial expressions, especially those involving fear, distress and threat (Plotnik et al., 2008).

THE CHEMICAL CONNECTION: THE ENDOCRINE GLANDS

               

Another body’s communication system is the endocrine system. ENDORINE SYSTEM is a chemical communication network that sends messages throughout the body via the bloodstream (Feldman, 2010).

                Glands are organs in the body that secrete chemicals. Some glands, such as salivary glands and sweat glands secrete their chemicals directly onto the body’s tissues through tiny tubes, or ducts. This kind of gland affects the functioning of the body but doesn’t really affect behavior.

                Other glands called ENDOCRINE GLANDS, which have no ducts and secrete their chemicals directly into the bloodstream. The chemicals secreted by this type of gland are called HORMONES (White, 2009).

A. Pituitary Gland: The Master of Hormonal Universe (White, 2009)

Pituitary gland is located in the brain itself, just below the hypothalamus.

It is called as the master gland because it is the one that controls or influences all of the other endocrine glands.

                The pituitary gland is divided into the anterior (front) and posterior (back) sections.

·               Anterior Pituitary

It regulates growth through secretion of growth hormones and produces hormones that control the adrenal cortex, pancreas, thyroid and gonads.

·                                 Posterior Pituitary 

                The rear portion of the pituitary gland that regulates water         and salt balance

B. Pineal Gland (White, 2009)

                Pineal gland is also located in the brain near the back. It secretes hormones called MELATONIN, which regulates the sleep-wake cycle.

C. Thyroid Gland (White, 2009)

                The thyroid gland is located inside the neck and secretes hormone called THYROXIN that regulates metabolism.

D. Pancreas (White, 2009)

                The pancreas controls the level of blood sugar in the body by secreting INSULIN and GLUCAGONS.  If the pancreas secretes too little insulin, it results in diabetes. If it secretes too much insulin, it results to hypoglycemia or low blood sugar, which causes a person to feel hungry all the time and often become overweight as a result.

E. Gonads (White, 2009)

                The gonads are sex glands, including the ovaries in the female and testes in the male. They secrete hormones that regulate sexual behavior and reproduction. They do not control all sexual behavior, though. In a very real sense, the brain itself is the master of the sexual system—human sexual behavior is not controlled totally by instincts and the actions of the glands as in the animal world but also by psychological factors such as attractiveness.

F. Adrenal Glands (White, 2009)

                Everyone has two adrenal glands, one on top of each kidney. By etymology, renal comes from the Latin word meaning “kidney”, and ad is Latin for “to”, so adrenal means “to or on the kidney”.

                Each adrenal gland is divided into two sections, the ADRENAL MEDULLA and the ADRENAL CORTEX.

 It is the adrenal medulla that releases ephinephrine and norepinephrine when people are under stress and that aids in sympathetic arousal.

                The adrenal cortex produces over 30 different hormones called CORTICOIDS (also called steroids) that regulate salt intake, help initiate and control stress reactions and also provides a source of sex hormones in addition to those provided by the gonads.

                One of the most important of these adrenal hormones is CORTISOL, released when the body experiences stress both physical stress (illness, surgery, or extreme heat or cold) and psychological stress (such as emotional upset)

Chapter 2: Factors of Development

Chapter 2

FACTORS OF DEVELOPMENT

INTRODUCTION:

               

You acquired your eyes from your mother and the color of your hair from your father. But where did you get your bubbly personality? Did you also learn this from your parents or was it determined by your genes?         

Similarities and differences among individuals raise one of the fundamental questions: How can we distinguish between environmental causes and hereditary causes of behavior? This question exemplifies the nature-nurture issue.                

                Think for a minute about a particular characteristic that you and several people in your family have, such as intelligence, good looks, or a friendly, outgoing personality. Why is this trait so prevalent? Is it because you inherited the trait from your parents? Or is it because of where and how you and your parents were brought up?      

Answers to these questions illustrate different positions on the nature-nurture issue, which involves the degree to which genetic or hereditary influences and experiential or environmental influences determine the kind of person you are.

Developmental psychologists today agree that both nature (an organism’s biological inheritance) and nurture (an organism’s environmental experiences) interact to produce specific developmental patterns and outcomes.

The Role of Maturity in Heredity

                Maturation is an extension of heredity. It is the unfolding of all hereditary potentials of an individual. It refers to the changes the body undergoes in such a way that it is ready to function.

A.      Maturity follows an orderly manner.

B.      Maturity is not uniform for all individuals.

C.      Maturity follows the growth pattern of the individual.

ü  Cephalocaudal law states that development spreads from head to foot.

ü  Proximodistal law states that development spreads from the trunk to extremities.

Human Development

                Human development refers to the study of human cycle from conception to death. It focuses on the continuous chronological processes or changes which are cumulative. It encompasses the physical, cognitive, and socio-emotional changes that occur in an individual.

 

PRENATAL DEVELOPMENT: Conception to Birth

Chromosomes are rod-shaped structures that contain all basic hereditary information of an organism. At conception, an organism has twenty three pairs of chromosomes.

enes are smaller units that are composed of sequences of DNA (deoxyribonucleic acid) through which genetic information is transmitted. Genes produce the particular characteristics of each person. A child’s sex is determined by a particular combination of genes.

                                                XX combination results to a female child

                                                XY combination results to a male child

DETERMINATION OF TWINS

Fraternal twins

                Fraternal twins are conceive when a mother releases two separate eggs and these are fertilized by two separate sperm to form two separate embryos and then make two separate babies. Fraternal twins share up to 50% of their genes. Fraternal twins can be boy/boy, girl/girl, or boy/girl sets.

Identical twins

                With identical twins, one egg from the mother is fertilized by one sperm from the father, and the embryo splits and two fetuses grow. If the zygote splits very early (in the first 2 days after fertilization) they may develop separate placentas and separate sacs. These are called dichorionic, diamniotic (or 'di/di') twins. 

                While all fraternal twins are 'di/di', this occurs 20 - 30% of the time in identical twins. Most of the time in identical twins the zygote will split after 2 days, resulting in a shared placenta, but two separate sacs. These are called monochorionic, diamniotic ('mono/di') twins. Finally, the zygote may split extremely late, resulting in conjoined twins (Siamese twins).

GENETIC DEFECTS

Phenylketonuria (PKU) refers to a child who is not able to produce an enzyme that is required for normal development. This results to profound mental retardation caused by an accumulation of poisons.

1)      Sickle-cell anemia refers to the disease characterized by abnormally shaped red blood cells. Children with the disease may have poor appetites, swollen stomachs, yellowish eyes and cognitive difficulties. They frequently die during childhood (Schatz, Finke, Kellett & Kramer, 2002; Helps, Fuggle, Udwin & Dick, 2003).

2)      Tay-Sachs Disease refers to a disease wherein the body is not capable of braking down fats.

3)      Down Syndrome which is one of the causes of mental retardation refers to a disease wherein the zygote receives an extra chromosome at the moment of conception. If the mother is over 35 at the time of conception, there is a higher chance for the baby to develop Down Syndrome. 

STAGES OF PRENATAL DEVELOPMENT

                Fertilization, wherein a single sperm cell from the male penetrates the female’s ovum is the onset of conception.

Germinal Period – weeks 1 and 2

                The zygote is a single cell with 23 chromosomes from the mother and 23 from the father. After 1 week and many cell divisions, the zygote is made up of 100 to 150 cells. By the end of the second week, the mass of cells has attached to the uterine wall.

Embryonic Period – weeks 3 through 8

                The embryonic period is characterized by the emergence of the neural tube, which eventually becomes the spinal cord, the appearance of eyes and the differentiation of the cells of the heart. Arm and leg buds emerge during the fourth week. Heartbeat begins, arms and legs become more differentiated, the face starts to form and the intestinal tract appears at 5 to 8 weeks.

Fetal Period – 2 through 9 months

                The fetal period is illustrated by mature organs and muscles. During this time, the mother feels the fetus move for the first time. Eyes and eyelids are completely formed at 6 months. Fine layer of hair, grasping reflex and irregular breathing also begins at this point. At 7 to 9 months, the fetus is much longer and functions of organs step up.

STAGES OF HUMAN DEVELOPMENT

                Everyone undergoes different stages of growth. Each stage represents significant changes and different problems an individual goes through in one’s lifespan.

Infancy – 1 month to 1 year

A. Physical Changes

Growth is more rapid in infancy than in any other period. Infants double their weight by 3 months and triple by their 1^st birthday. Roughly 40% of the body’s energy is devoted to growth. Most of the remaining energy is used for digestion, respiration and physical activity.

An infant’s feelings of hunger, pain, when it smiles, laughs, its efforts to sit upright all reflect the function of the brain and the nervous system.

An adult’s brain weighs a little less than 3 pounds and would easily fit into a pair of hands.

At birth, it weighs 25% of the weight of an adult brain. In the months after birth, the brain grows rapidly so does its structures.

In return, the child learns more things such as motor skills, perception, reaching and grasping.

Reflexes refer to unlearned, involuntary responses that occur automatically in the presence of certain stimuli that are critical for survival.

a)      Rooting reflex refers to an instance when newborns turn their heads toward things that touch their cheeks.

b)      Sucking reflex prompts infants to suck at things that touch their lips.

c)       Gag reflex refers to clearing the throat.

d)      Startle reflex refers to series of movements in which an infant flings out the arms, fans the fingers and arches the back in response to sudden noise.

e)      Babinski reflex is characterized by a baby’s toes fanning out when the outer edge of the sole of the foot is stroked.

B. Cognitive Changes

                Cognitive development refers to how a person perceives, thinks and gains an understanding of his or her world through the interaction and influence of genetic and learned factors.

                Jean Piaget believed that from early on, a child acts like a tiny scientist who is actively involved in making guesses or hypotheses about how the world works. Piaget believed that children learned to understand things, such as what to do with blocks,        through two active processes that he called assimilation and       accommodation.

                Assimilation is the process by which a child uses old methods or experiences to deal with new situations. While accommodation is the process by which a child changes old methods to deal with or adjust to new situations.

               

C. Emotional Changes

                Emotional development refers to the influence and interaction of genetic factors, brain changes, cognitive factors, coping   abilities, and cultural factors in the development of emotional   behaviors, expressions, thoughts and feelings (Goldsmith, 2003).

                One reason each of the sextuplets develop different emotional make up so very early in life involves something called temperament. Temperament refers to relatively stable and long lasting individual differences in mood and emotional behavior, which          emerge early in childhood because these differences are largely influenced by genetic factors.

On the bases of ratings in a study             done in infants regarding temperament, researchers divided infants into four categories (Thomas & Chess, 1977).

1.       Easy babies, who made up 40% of the sample, were happy and cheerful, had regular sleeping and eating habits, and adapted quickly to new situations.

2.       Slow-to-warm-up babies, who made up 15% of the sample, were more withdrawn, were moody, and tended to take longer to adapt to situations.

3.       Difficult babies, who made up 10% of the sample, were fussy, fearful of new situations, and more intense in their reactions. During the course of the seven-year study, difficult babies developed more serious emotional problems than easy or slow-to-warm-up babies.

4.       No-single-category babies, who made up 35% of the sample, had a variety of traits and could not be classified into one of the other three categories.

D. Social Changes

                One of the best-known theories is that of Sigmund Freud, who said that each of us goes through five successive psychosexual stages.

The psychosexual stages are five different developmental period – oral, anal, phallic, latency and genital stages – during which the individual seeks pleasure from different areas of the body that are associated with sexual feelings.

He emphasized that a child’s first five years were most important to social and personality development.

               

·                     Oral Stage is the stage from early infancy to the first 18 months of life. According to Freud, it is a time when the infant’s pleasure seeking is centered on the mouth. Such pleasure seeking activities include sucking, chewing, and biting.

·                     Anal stage lasts from the age of about 1 & ½ to 3 and is a time when the infant’s pleasure seeking is centered on the anus and its functions of elimination.

·                     Phallic stage lasts from about age 3 – 6 and is a time when the infant’s pleasure seeking is centered on the genitals.

·                      Latency stage lasts from about age 6 to puberty.It is a time when the child represses sexual thoughts and engages in nonsexual activities, such as developing social and intellectual skills.

·                     Genital stage, which lasts from puberty through adulthood, is a time when the individual has renewed sexual desires that he or she seeks to fulfill through relationships with members of the opposite sex.

Early Childhood (2 - 6 years)

A. Physical Changes

                During this period, children's bodies change proportions               and they start to look more like adults than babies. Arms and legs    stretch to catch up and balance out the head and trunk. Children              also begin to lose their "baby fat" as they develop straighter bodies with             the strong muscles necessary for work and play.

                Children should get plenty of exercise and sleep, and eat a          balanced diet in order to continue to develop strong muscles and       bones and to maintain a healthy weight.

Sleep patterns change during early childhood and are affected by cultural expectations. It is normal for preschool children to develop bedtime rituals that delay going to sleep. Prolonged bedtime struggles or persistent nightmares may indicate emotional disturbances that need attention.

B. Cognitive Processes

Attention refers to a process that determines which sensory information receives additional cognitive processing. When infants or children are presented with a strong or unfamiliar stimulus, orienting response usually occurs. These responses indicate that the child has noticed the stimulus.

Example:  A person fixes eyes on the stimulus, changes in

                  heart rate and brain wave activity.

Habituation refers to the diminished response to a stimulus as it becomes more familiar after repeated presentations of a stimulus. The orienting response and habituation are useful to infants and children. Orienting makes the infant aware of potentially important or dangerous events in the environment. Habituation keeps infants from wasting too much energy on non-significant events.

C. Socio-emotional Development

Attachment refers to an enduring socio-emotional relationship that when formed by children with adults will result to their survival. This person is usually the mother but need not be.

School Age (7 – 12 years)

A. Physical Changes

                Boys and girls are about the same size for most of these years, but girls are most likely than boys to enter puberty toward the end                of the grade school years. Once girls enter puberty, they grow rapidly    and become bigger than boys their age.

According to Erik Erikson, the challenge for the school age children is termed industry versus inferiority. Children can achieve industry by mastering knowledge and intellectual skills. When they do not, they can feel inferior.

B. Cognitive Changes

                Jean Piaget is best known for describing the changes or different stages in cognitive development that occur betweeninfancy               and adulthood (Bjorklund, 2005).

Piaget’s cognitive stages refer to              four different stages – sensorimotor, preoperational, concrete                 operations and formal operations – each of which is more advanced       than the preceding stage because it involves new reasoning and        thinking abilities.

Table 1: Piaget’s Cognitive stages of Development

STAGE	APPROXIMATE AGE	CHARACTERISTICS
Sensorimotor	Birth – 2 years	Infant’s knowledge of the world is based on senses and motor skills. By the end of the period, uses mental representation.
Preoperational thought	2 – 6 years	Child learns how to use symbols such as words and numbers to represent aspects of the world but relates to the world only through his or her perspective.
Concrete operational thought	7 years – early adolescence	Child understands and applies logical operations to experiences provided they are focused on the here and now.
Formal operational thought	Adolescence and beyond	Adolescent or adult thinks abstractly, deals with hypothetical situations, and speculates about what may be possible.

C. Socio - Emotional Changes

     Attachment

The socio-emotional relationship that develops between an infant and a parent is the baby’s 1^st relationship. It should be satisfying and trouble free to set the stage for later relationships.

   Attachment is an enduring socio-emotional relationship that      when formed by children with adults will result to their survival. This person is usually the mother but need not be.

       

Forms of Attachment

1.  Secure Attachment

Baby may or may not cry when the mother leaves but when she returns, the baby wants to be with her. If the  baby is crying, it stops.

2. Avoidant Attachment

                Baby is not upset when the mother leaves and when     she returns, may ignore her by looking away. Babies look as if they’re saying “You left me again, I always have to take care of myself.”

3. Resistant Attachment

                Baby is upset when mother leaves and remains upset when she returns and is difficult to comfort. “Why do you do this? I need you desperately and you leave me without warning.”

4.  Disorganized Attachment

                Baby seems confused when mother leaves and when she returns as if not really understanding what is happening.                                                 “What’s happening? I want you to be here, but you left and now you’re back. I don’t get what’s going on.” 

Adolescence (13 – 20)

A. Physical Changes

                The appearance of body hair, the emergence of breasts and the enlargement of the penis and testicles are all signs that the child is gone and the adolescent has arrived. Adolescents are more concerned about their overall appearance than children and adults.

Signs of Physical Maturation

Puberty denotes two general types of physical changes that mark the transition from childhood to adulthood.

1.       Bodily Changes include a dramatic increase in height and weight as well as changes in the body’s fat and muscle content. Girls typically begin their growth spurt about 2 years before boys do. They start the growth spurt at about age 11 while boys start the growth spurt at about age 13. This 2 year difference in growth spurt can lead to awkward social interactions between 11-12 year old boys and girls because the girls are often taller and look much more mature than the boys.

2. Sexual maturation includes changes in primary sex characteristics which refer to organs that are directly involved in reproduction and changes in secondary sex characteristics which are physical signs of maturity not directly linked to the reproductive organs.

                Menarche refers to the onset of menstruation which typically occurs at age 13. On the other hand, spermarche refers    to the first spontaneous ejaculation which occurs at about age 13.           Initial ejaculations often contain few sperm. Only years later are there sufficient sperm to fertilize an egg.

B. Cognitive Changes

                As you remember, Piaget’s theory of cognitive development states that we all go through four distinct cognitive stages.

As we go  through each stage, we acquire a new and distinct kind of reasoning and thinking that is different from and more advanced than the reasoning abilities we possessed at our previous stage.

Stage 4: Formal Operations

The formal operations stage, the last of Piaget’s four cognitive stages, extends from about age 12 through adulthood.

During this stage, adolescents and adults develop the abilities to think about abstract, or hypothetical concepts, to consider an issue from another’s viewpoint, and to solve cognitive problems in a logical way.

Having the ability to think about and discuss abstract concepts means that adolescents can critically consider their beliefs, attitudes, values and goals as well as discuss a wide range of topics important to their becoming adults.

C. Emotional Changes

A distinctive landmark in adolescence is a romantic relationship which becomes common as children develop and their function changes.

In younger adolescents, romantic relationships offer companionship like that provided by a best  friend and an outlet for sexual exploration. In older adolescents, trust and support become important features of romantic relationships.

Parenting Styles

• Authoritarian parenting combines high control with little warmth. Parents lay down the rules and expect them to be followed without discussion. There is little give and take between parents and children because they do not consider children’s needs or wishes.
• Authoritative parenting combines a fair degree of parental control with being warm and responsive to children. They explain rules and encourage discussion.
• Permissive parenting offers warmth and caring but little parental control. They generally accept their children’s behavior and punish them infrequently.
• Uninvolved parenting provides neither warmth nor control. They provide for their children’s basic physical and emotional needs but little else.

 D. Social Changes

Erik Erikson conceptualized the psychosocial stages of development. Each of which contained a unique psychosocial conflict which every individual should surpass in order for him or her to live a healthy life.

Stage 1: Infancy

Infancy stage lasts from birth to 1 year. The conflict of    this stage is trust VS mistrust. Babies learn either to trust or mistrust that others will care for their basic needs, including nourishment, sucking, warmth, cleanliness, and physical contact.

Stage 2: Early Childhood

Early childhood stage lasts from 1 – 3 years. The conflict of this stage is autonomy VS shame and doubt. According to Erikson, children learn either to be self-sufficient in many activities including toileting, feeding, walking, and talking, or to doubt their own abilities.

Stage 3: Play Age

Play age stage lasts from 3 – 6 years. The conflict of this stage is initiative VS guilt. Children want to undertake many                 adult-like activities, sometimes overstepping the limits set by parents and feeling guilty.

Stage 4: School Age

School age stage lasts from 7 – 12 years. The conflict of this stage is industry VS inferiority. During this stage, children busily learn to be competent and productive or feel inferior and                                              unable to do anything well.

Stage 5: Adolescence

                Adolescence stage lasts from 12 – 20 years. The conflict of this stage is identity VS role confusion. Adolescents try to figure out, “Who am I?” They establish sexual, ethnic, and career identities, or are confused about what future                 roles to play.

Stage 6: Young Adulthood

Young adulthood stage lasts from 20-40 years. The conflict of this stage is intimacy VS isolation. Erikson believed that during this stage, young adults seek companionship and      love with another person or become isolated from others.

Stage 7: Middle Adulthood

This stage lasts from 40-65 years. The conflict of this stage is generativity vs stagnation. Middle adulthood is a time for helping the younger generation develop worthwhile lives; otherwise, lack of involvement leads to a feeling of stagnation. 

Stage 8: Late Adulthood

Late adulthood stage starts at age 65 and lasts up to        death. The conflict of this stage is integrity VS despair. Older     adults try to make sense out of their lives, either seeing life as meaningful whole or despairing at goals never reached and questions never answered.

Emerging Adulthood

                The transition from adolescence to adulthood is now referred to as emerging adulthood (Arnett, 2007). The age range for emerging adulthood is approximately 18-25 years of age.

                During this stage, many  individuals are still exploring which career path they want to follow, what             they want their identity to be, and which lifestyle they want to adopt.

                Most     young adults are in the best physical shape of their lives. The early 20s are the best years for strenuous work, and trouble-free reproduction.

Five Key Features Characterizing Emerging Adulthood:

1.       Identity exploration especially in love and work characterizes the many key changes in identity of emerging adults.

2.       Instability refers to residential changes, instability in love, work and education.

3.       Self-focus characterizes an emerging adult who has a great deal of autonomy in running his/her own life.

4.       Feeling in between because many emerging adults do not consider themselves adolescents yet but still not yet full-fledged adults.

5.       The age of possibilities refers to the time when individuals have an opportunity to transform their lives.

Middle Adulthood (30 – 50)

A. Physical Changes

                One of the most visible physical changes in middle adulthood is appearance. By the 40s or 50s, the skin has begun to wrinkle and sag.

                Individuals lose height and gain weight in middle age. Middle adults become more concerned about health by the 40s.

                For women, entering middle age also means that menopause will occur soon. Menopause produces uncomfortable symptoms insome women such as hot flashes, nausea, fatigue and rapid heartbeat.                

B. Cognitive Development

                Technology and information change rapidly. To keep up with these changes, for most people, college education will probably not be the last educational experience they have in their careers; workers in medicine, nursing, psychology are not required to obtain continuing education credits to stay current in their fields.

                Organizations offer         workshops for their employees, cable channels also offer educational programming.

       

Adult learners differ from younger counterparts in several ways:

1. They have higher need to know why they should learn something before undertaking it.
2. Adults enter a learning situation with more and different experience on which to build.
3. They are most willing to learn those things they believe are necessary to deal with real world problems rather than abstract, hypothetical situations.
4. Most adults are more motivated to learn by internal factors (self esteem, personal satisfaction) than external factors (job promotion, pay raise).

C. Emotional Changes:  Letting Go of Children

                Sometime during the middle age, parents experience 2 positive developments with regard to their children. Suddenly, their children see       them in a new light and the children leave home. When children become young adults, parent-child relationships improve.

                A key     factor    in making this transition as smoothly as possible is the extent to which parents foster and approve of their children’s attempts at being independent.

                Because when children leave home, emotional bonds are disrupted. Women who define themselves more in the role as a mother tend to report more distress and negative mood.

                Some events in a woman’s life during the middle adulthood include becoming divorced, losing a job or caring for a sick parent.

D. Social Change:  Meaning of Work

                Did you ever stop thinking about why we fight the commuting crowds to get to work? For some, work is a source of prestige, social recognition and a sense of worth.

                For others, the excitement, creativity and the opportunity to give something of themselves make work meaningful.

                For most, the main purpose of work is to earn a living. The meaning most of use derive from working includes both the money and personal growth.

Gender Differences in Occupational Selection

                Traditionally, men have been groomed from childhood for future employment. Boys learn at an early age that men are known by the work they do and they are strongly encourage to think about what occupation they would like to have.

                Occupational achievement is stressed as a core element of masculinity. Women used to enter traditional, female dominated occupations such as secretarial, teaching and social work jobs. Nowadays, more opportunities are open for women.

                A growing number of women work in occupations that have been traditionally dominated by men such as construction and engineering.

Late Adulthood (50 – 60)

A. Physical Changes

                Older adults may experience a gradual decline in height because of loss of bone, a further decrease in output of lungs and kidneys, an increase in skin wrinkles, and deterioration in joints.           Sensory organs become less sensitive, resulting to less acute vision, hearing and taste. The heart becomes less effective at pumping blood.

                Menopause occurs in women at about age 50 which results in cessation of both ovulation and the menstrual cycle. Most experience hot flashes, sleep disturbance and dryness of the vagina. Menopause, together with other stressful issues, can          make    

women become moody, depressed, anxious and angry.               However, there is little or no change in the ability to become sexually aroused or to reach orgasm.

                Men on the other hand may require more time and stimulation to have an erection and to reach orgasm. Their decreased sexual abilities can make them uncomfortable and threaten their self-esteem.

                However, having longer periods of stimulation, improving intimate communication and using more imaginative sexual activity can usually compensate for men’s decreased self-confidence (Bartlik & Goldstein, 2001).

               

B. Cognitive Changes

    Attention

                Researchers view attention as having three major components: selection, vigilance and control (Parasuraman, 1998).    Selective attention involves the selection of relevant information and inhibition of irrelevant information. Older adults tend to perform poorer than younger adults on most selective attention tasks (McDowd & Shaw, 2000).

                Vigilance, also called sustained attention, involves the maintenance of attention over time. Whether vigilance ability declines with age is uncertain (Rogers & Fisk, 2001).

                Attentional control refers to people’s abilities to focus, switch and divide attention. If older adults are told where to focus their attention, if a cue is provided to help them shift attention or if the task is simple, then they perform about as well as younger adults. But if the rate at which attention must be shifted is fact or if the task is complex, older adults do less well.

Memory

                Older adults typically do worse on tests of episodic recall; age differences are less on recognition tasks. Differentiating memory changes associated with aging from memory changes due to     disease should be accomplished through comprehensive               evaluations.

C. Emotional Changes

                     In general, older adults have fewer relationships and develop fewer new relationships than younger or middle-aged adults         (Carstensen, 1995). This decline in number does not merely reflect the loss of relationships to death or other means.

                Rather, the changes       reflect a more complicated process (Carstensen, 1993, 1995). This process termed socio-emotional selectivity, implies that social                contact is motivated by many goals, including information seeking, self-concept, and emotional regulation.

               

Widowhood

                The impact of widowhood goes well beyond the ending of a long-term partnership (Martin-Matthews, 1999; Miller, et al., 2004).                       Widowed people may be left alone by family and friends who do not     know how to deal with a bereaved person. As a result, widows and           widowers may lose not only a spouse but also those friends and family                 who feel uncomfortable including a single person rather than a couple in social functions. (Felber, 2000).

                Men and women react differently to widowhood. In general, those who were most dependent on their spouses during the marriage report the highest increase in self-esteem in             widowhood because they have learned to do the tasks formerly done by their spouses (Carr, 2004).

                Widowers are at high risk of dying themselves soon after their spouse either by suicide or by natural causes (Osgood, 1992).

D. Social Changes

                Quality care-giving by family members are needed by older adults. Unfortunately, some older adults who need quality care-giving           by family members or in nursing homes do not receive it. In some cases,              older adults are treated inappropriately.

Defining Elder Abuse and Neglect

Physical abuse:

• the use of physical force that may result in bodily injury, physical pain, or impairment.

Sexual abuse:

• nonconsensual sexual contact of any kind.

Emotional or psychological abuse:

• infliction of anguish, pain, or distress.

Financial or material exploitation:

• the illegal or improper use of an older adult’s funds, property or assets.

Abandonment:

• the desertion of an older adult by an individual who hadphysical custody or otherwise had assumed responsibility for providing care for the older adult.

Neglect:

• refusal or failure to fulfill any part of a person’s  obligation or duties to an older adult.

Self-neglect:

• the behaviors of an older person that threaten his or     her own health or safety, excluding those conscious and voluntary             decisions by a mentally competent and healthy adult.

The Final Passage Ethical Issues in Death

Euthanasia

                Euthanasia can be carried out in two different ways: active and passive.

·                     Active euthanasia involves the deliberate ending of someone’s life, which may be based on a clear statement of the person’s wishes or be a decision made by someone else who has the legal authority to do so.

                Usually, this involves situations in which people are in a persistent vegetative state or suffer from the end stages of a terminal disease.

·                     On the other hand, passive euthanasia involves allowing a person to die by withholding available treatment.

                For example, chemotherapy might be withheld from a cancer patient; a surgical procedure might not be performed; or food could be withdrawn.