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Please be aware that this is a student-generated wiki designed for review for my students' AP exams. Come in, look around, and enjoy yourself...just be aware of the nature of this wiki. Even though most everything is correct, I advise caution before citing this as an authoritative source.
  • Human Behavior

  • Everything psychological is simultaneously biological (Meyers 57).

:The study of the nervous system, the brain, spinal cord and neurons.

Biological psychology
  • A branch of psychology concerned with the links between biology and behavior.
  • Biological psychologists gain a better understanding of sleep and dreams, depression and schizophrenia, hunger and sex, stress and disease (Myers 58).
  • Biological Psychologist attempt to understand the relations between nature and nurture.
  • Biological Psychologist also call themselves behavioral neuroscientists, neuropsychologists, or biosychologists (Myers).

Neural Communication
According to Myers, the body is made up of a complex network of neurons which work to help the body communicate with itself. Knowing how these systems work helps us to understand how "we take in information; how we organize, interpret, and store it; and how we use it." Also these systems are bio-psycho-social systems. They are systems that consist of even smaller systems that interact with each other. These all form organs for larger systems for digestion, circulation, and information processing.
  • Neurons- Myers explains it as a nerve cell; the basic building block of the nervous system. "There are many different types of neurons, but all are variations of the same thing" (Myers 58).
  • Neurons are cells with a clearly defined, nucleated cell body. Bundles of neurons make up our nerves (The Princeton Review).
  • "Each part of a neuron consists of a cell body, and its branching fibers" (Myers).
  • A neuron fires an impulse when it receives signals from sense receptors stimulated by pressure, heat, or light, or when it is stimulated by chemical messages from neighboring neurons (Myers).
Parts of the Neuron
  • Cell Body- the cell's life-support center (Myers). Cells are the basic building blocks of all living things. The human body is composed of trillions of cells. They provide structure for the body, take in nutrients from food, convert those nutrients into energy, and carry out specialized functions. Cells also contain the body’s hereditary material and can make copies of themselves (genetics home research).
  • Dendrite- the bushy, branching extensions of a neuron, ending in branching terminal fibers, through which messages pass to other neurons or to muscles or glands (Meyers 58)
    • Besides a dendrite another fiber found within a neuron is an axon
      • An axon's surface is selectively permeable, which means it chooses what may or may not pass through, just like a cell membrane.
  • Action Potential- a neural impulse; a brief electrical charge that travels down an axon. The action potential is generated by the movement of positively charged atoms in and out of channels in the axon's membrane. "...messages pass to other neurons or to muscles or glands," (Meyers 58)
  • Myelin Sheath-The sheath that surrounds the axon of some neurons and helps speed neural impulses by allowing impulses to travel among the interconnected nodes of Ranvier. The impulse will jump from node to node and travel more quickly than it could if it were simply to go down the nerve fiber.
  • Axon- the extension of a neuron, ending in branching terminal fibers, through which messages pass to other neurons or to muscles or glands (58 Myers).
  • Damage to the myelin sheath in nerve cells can have severe effects on the body, and can lead to Multiple Sclerosis, a progressive autoimmune disease which uses the worn away or damaged parts of the myelin sheath in cells of the brain and spinal cord to cause problems with communication within and between neurons. Damage to the myelin sheath (and the nodes of Ranvier) can cause the neural impulse to travel more slowly down the axon, cause trouble with transmission of the impulse, or keep the impulse from being transmitted altogether, effectively paralyzing the neural network. With current medicine, this damage is treatable, to an extent. Life expectancy is average, however, usually one becomes debilitated over time. (MS Gateway)
  • Neurons like batteries, generate electricity from chemical events. The chemistry-to-electricity process involves the exchange of electrically charged atoms called ions(Myers).
    • Measure brain activity in milliseconds and computer activity in nanoseconds since the brain is vastly more complex than a computer (Myers).
  • Resting Potential: When the fluid inside a resting axon has an excess of negatively charged ions, while the fluid outside the axon membrane has an excess of positively charged ions (Myers).
  • Threshold- the level of stimulation required to trigger a neural impulse. When a stimulus is increased above the threshold, the action potential's intensity remains the same. The strength of the stimulus does not affect the action potential's speed (Myers).
    • The neuron receives the signal through the dendrites or cell body, some signals will be excitatory meaning they speed up the neurons, other signals will be inhibitory meaning they slow down the neuron. If excitatory signals subtracted by the inhibitory signals go above the threshold, then an action potential is activated.
  • The action potential transmits down the axon, at the end of the axon terminal, the action potential is transferred in sequence to hundreds of thousands of other neurons and with the body's muscles and glands (Myers).
  • The neuron's reaction is an "all-or-none" response, meaning it will either fire or it will not. The strength of the stimulus does not affect the action potential's speed (Myers).
How Neurons Communicate
"All information processing in the brain involves neurons 'talking to' each other at synapses." - Neuroscientist Solomon H. Snyder (1984)
-The British Psychologist, Sir Charles Sherrington, noticed that the time for neural impulses to travel a neural pathway took longer than he had expected and concluded that there was a brief interruption in the transmission which is now know as the "synapse".
  • Synapse - A gap between nerve ends, where the tip of a nerve cell almost touches another cell to transmit signals.
  • The synaptic gap is less than a millionth of an inch wide (Myers 60).
  • Once the action potential has transmitted down the axon and reached the axon terminal, it activates the release of neurotransmitters.
  • Neurotransmitters - Chemical messengers that pass through the synaptic gap between neurons to transmit signals from one neuron to another. Within 1/10,000th of a second, the neurotransmitter molecules cross the synaptic gap and bind to receptor sites on the receiving neuron. The most well known neurotransmitter is Acetylcholine (ACh) which causes muscles to contract in movement (Myers).
-Spanish anatomist, Santiago Ramon and Cajal discovered, "gaps between individual nerve cells and concluded that the individual neurons must function as independent agents within the nervous system."
  • According to Myers, re-uptake is the process in which the sending neuron reabsorbs the excess neurotransmitters
  • Most neurons have a resting rate of random firing, which either increases or decreases with input from other neurons and from chemicals that affect their sensitivity. If a neuron receives more excitation than inhibitory messages, the cell fires often (Meyers 61).

How Neurotransmitters Influence Us
According to Myers,"a particular neural pathway in the brain may use only one or two neurotransmitters and that particular neurotransmitters may have particular effects on behavior and emotions." Within our brains are chemicals which influence and control our everyday habits, thoughts, emotions, and behavior. Some neurotransmitters and their functions from Myers are:
  • Acetycholine(ACh) - enables muscle action, learning, and memory.
1.An ACh, is the messenger at every junction between a motor neuron and a skeletal muscle. (Myers)
If the transmission of ACh is blocked, our muscles cannot contract. (Myers) Can also mark Alzheimers disease (Myers 62).
-Botulin, a poison that can form in improperly canned food, causes paralysis by blocking ACh release from the sending neuron (Meyers 63).
  • Dopamine - Influences movements, learning, attention, and emotion.
-Excess dopamine receptos activity is linked to the mental disorder schizophrenia. When starved of dopamine though, the brain produces the tremors
and decreased mobility of Parkinson's disease (Meyers 62).
  • Serotonin - Affects mood, hunger, sleep, and arousal--undersupply can cause depression and prozac and other antidepressants increase the levels of serotonin in the brain (Myers 62).
  • Norepinephrine - Helps control alertness and arousal--an undersupply can depress mood (Myers).
  • GABA(gamma-aminobutyric acid) - A major inhibitory neurotransmitter--an undersupply is linked to seizures, tremors, and insomnia (Myers).
  • Glutamate - A major exictatory neurotransmitter; involved in memory--oversupply can overstimulate the brain causing migraines or seizures (Myers 62).
  • Adrenaline- hormone produced by the adrenal glands (adrenal glands produce epinephrine and norepinephrine, which are hormones that prepare the body for stressful incidents), affects heart rate, blood vessels, and air ways. This is usually produced when you are under a lot of stress, "fight or flight" response.
  • One of the most important discoveries about Neurotransmitters happened when Candace Pert and Solomon Snyder (1973) observed morphine (opiate) being taken up in the parts of the brain responsible for pain and mood sensations. This experiment led to the discovery that if there were opiate receptors in the brain that the body must have natural opiates, endorphins (Myers 63).
  • If one were to flood the brain with artificial opiates, the brain would cease to produce natural opiates, then if one stops using artifical opiates the body will be deprived of both artificial and natural opiates which results in agony until the body begins production of natural opiates again or resumes using artificial opiates (Meyers 63).
  • Endorphins- "morphine within", according to Myers- natural, opiate-like neurotransmitters linked to pain control and to pleasure.
  • Endorphins explain the phenomenon of "runners high" or help explain why acupuncture is an effective form of pain relief.
"when it comes to the brain, if you want to see the action, follow the neurotransmitters." -Neuroscientist Floyd Bloom (1993)

The effects of drugs can either excite or inhibit neurons' firing.
  • Agonists - drug molecule that is similar to the neurotransmitter that copies its effects or that blocks a neurotransmitter's reuptake (Myers).
  • Reuptake is the process in which neurotransmitters are reabsorbed by a sending neuron (Myers 61).
    • Many drugs increase the variability of selected neurotransmitters by blocking their reuptake (Myers 61).
-Some opiate drugs, for example, produce a temporary "high" by amplifying normal sensations of arousal or pleasure. (Meyers 63).
  • Antagonists - a drug molecule that inhibits a neurotransmitter's release (Myers). It may also be compared to a natural neurotransmitter to be used for it receptor site and may block whats its supposed to do but not stimulate the receptor.
  • It is difficult to design a new drug, because our bodies have a blood-brain barrier that allows the brain to keep out unwanted chemicals. Some chemicals simply do not fit and will not get through(Myers).

When outside drugs are brought in they can mess up the natural function of the brain and stop producing chemicals your body needs.
  • I.e. A drug addict will stop producing precious chemicals over time because there is a supply of it and no need to produce it any longer. If the supply is taken away it causes major pain and disruption but over time will start to produce the chemical naturally like it used to. (Myers)

Neural Networks
  • The human brain contains about 30 billion neurons, 10,000 contacts each, so we have over 300 trillion synaptic connections (Myers). This allows the human brain to perform complicated tasks and analyses in a relatively short amount of time and facilitates the growth and development of neural networks.
  • neurons cluster into work groups called neural networks, where they network with each other so they can have short, fast connections
  • learning occurs as feedback strengthens results that produce certain results (Myers)
    • piano practice, braille reading, etc- any kind of learning/practice
  • neural networks are interconnected with each other- what distinguishes them are their specific functions
  • The brain functions similar to a computing machine, it receives information, it interprets it and decides responses.(Myers)
  • The neural networks can reconnect and transform itself to adapt to new information and skills that show the maturity of the host.

Nervous System

  • Nervous System: the body's speedy, electrochemical communication system, consisting of all the nerve cells of the peripheral and central nervous system. (Myers 65)
  • Central Nervous System (CNS)- consists of the brain and the spinal cord, is the headquarters of the nervous system, and interprets information/messages.
  • Peripheral Nervous System (PNS)- links CNS to the body's sense receptors, muscles and glands by means of nerves which are bundles of sensory and motor axons. (Myers) and has two components, the Somatic and Autonomic nervous systems.
Information travels in the nervous system through three types of neurons. (Myers 65)
  • Interneurons - CNS neurons that internally communicate and intervene between the sensory inputs and motor outputs, the central nervous system controls the interneurons
  • Motor Neurons - neurons than carry outgoing information from the CNS to muscles and gland. The central nervous system sends instructions to the body's tissues via the motor neurons.
  • Sensory Neurons - Neurons that carry incoming information from the body's tissue and sensory organs to the brain and the spinal cord which process the information
    • Reflexes- a simple, automatic,inborn response to a sensory stimulus, such as the knee-jerk response.(Myers)
      • This reflex only involves the spinal cord. The information reaches the brain after we pull away from a hot stove or our knee jerkes.
    • A spinal reflex pathway is made up of a single sensory neuron and a single motor neuron.
    • The sequence of the transmission of a simple reflex is sensory neuron to inter neuron to motor neuron. (Study Guide)
    • Autonomic Nervous System - the part of the peripheral nervous system that controls the glands and the muscles of the internal organs (for ex: the heart)
      • Sympathetic Nervous System - the division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations.
      • In this state, heart and blood sugar increases, digestion decreases, arteries constrict, perspiration begins, pupils dilate
      • The sympathetic nervous system produces the fight or flight response, which is the SNS preparing the body to either fight or flee in order to protect oneself from a threat, said to be an inborn* response.
      • The sympathetic system would increase your heart rate, slow your breathing, raise your blood sugar, dilate your arteries, and cool you with perspiration. Your body would be alert, wide awake, and ready for action
      • Parasympathetic Nervous System - the division of the autonomic nervous system that calms the body, conserving its energy
      • The parasympathetic Nervous System produces the opposite affect of the Sympathetic Nervous System after the stress subsides.
      • In this state, heart rate slows muscles relax, digestion increases, pupils constrict
    • Example: If you are in a life or death situation and you need to act quickly, the Sympathetic Nervous System arouses your body, preparing you to defend yourself or do what you have to do. However, when the life or death situation is over, the Parasympathetic Nervous System is what calms your body down and brings it back to normal.
    • Somatic Nervous System - the division of the peripheral nervous system that controls voluntary movements through the body’s skeletal muscles. For example, the somatic nervous system will report to your brain the current state of our skeletal muscles and carry out instructions, triggering to type our keyboards.
According to Myers, our nervous system has a few million sensory neurons, a few million motor neurons, but billions and billions of inter neurons.

According to Myers, "every cell nucleus in your body contains the genetic master code for your entire body."
DNA is a coiled chain molecule which holds chromosomes and genes. - Myers

  • Chromosomes - threadlike structures made of DNA molecules that contain genes (Myers)
  • Humans contain 23 pairs of chromosomes
  • Humans receive half of their chromosomes from each parent,23 chromosomes from mother and father
  • Genes- biochemical units of heredity that make up the chromosome; determines your individual biological development (Myers)
  • Our genes are defined by a four-letter alphabet of life, composed of biochemical letters (A, T, C, G) called nucleotides (Myers)

According to Myers, "Human traits are influenced by gene complexes- many genes acting in concert."
Ex. Our Eye color, Hair color, skin color, and athletic potential.
Ex. How tall someone is reflects the height of their face, the size of their vertebrae, the length of their legs bones, and so forth- each of which are influenced by different genes (Myers).

According to Myers, "Complex human traits such as intelligence, happiness, and aggressiveness are similarly influenced by groups of genes."

Genome: The complete instructions for making an organism, or in each cell of a multicellular organism,consisting of all the genetic material in its chromosomes (Myers). It is what makes us human rather than any animals.

Along with being biologically defined, gender is also socially constructed
-Gender Roles are our expectations about the way men and women behave (Myers 127).
-Typically, in most cultures around the world men dominate women, this is because women are seen as the lesser sex.
-Gender identity is "one's sense of being male or female" (Myers 128). Gender identity is an inevitable result of society assigning every person to a gender.
-Another result of this gender assignment is becoming Gender-typed. Gender-typing is "the acquisition of a traditional masculine or feminine role" (Myers 129). This means that children become aware of their gender and act accordingly When boys become gender-typed they will act in traditionally masculine ways such as participation in sporting activities and showing their strength. Likewise, when girls becomes gender-typed they will act in traditionally feminine ways such as showing interest in fashion and acting delicate.
The social learning theory states that we learn social behaviors by observing and imitating and by being rewarded or punished (Myers 129). and example of this that relates to gender would be when your parents encourage you to be rough and strong if your a guy; if you get hurt they encourage you to not cry because bib boys don't cry (Myers)
Gender schema theory states that children learn from their cultures a concept of what it means to be male and female and that they adjust their behavior accordingly.
  • Gender -typing: the process when young children learn what motives, behaviors and values are considered appropriate for their gender within their culture.
sexual orientation describes to whom one may be attracted to, emotionally and sexually.
- There are stil debates on what factors affect sexallity weather it is nurture or nature or both ,several factors are said to make up someones sexual attractions , factors such as, he time period,culture, an genes all have to do with someone's sexual orientation.
- A study by Roy Baumeister, Kathleen Catanese, and Kathleen Vohs tells us that men have the stronger sex drive.
-Casual hit and run sex is more frequent with traditional masculine males.(Myers)
-Gender in psychology the characteristics, whether biologically or socially influenced, by which people define male and female (Myers)
-Most frequently desires sex, thinks about sex, masturbates, initiates sex and sacrifices more for sex are males, found in a study by cross-cultural psychologist Marshall Segall in 1990 (Myers)
-Gay men report more interest in uncommitted sex as well as a high responsiveness to visual stimuli and are more concerned with the partners physical attractiveness, says a study by Bailey & others in 1994. (Myers)

Sexuality and Evolution
Evolutionary psychologists use the theory of natural selection to explain the difference in genders expectations and sex. Women being more relationally concerned and men have sex for recreational reasons (Myers). When searching for a long-term partner, men seek fertile-appearing women, while women seek mature and affluent men (Myers). According to studies done by David Buss and an international team of collaborators, men in 37 countries, from Australia to Zambia, judge women as more attractive if they have attractive physical features such as a youthful and healthy appearance(Myers 105). Women, on the other hand, preferred men who had resources and social status (Myers 105). Regardless of cultural variations in ideal weight -men feel most attracted to women whose waists are a third narrower than their hips- a sign of future fertility (Singh,1993)
  • There are critics of the evolutionary explanation. The explanation seems to always start with an effect and work backwards proposing and explanation. And with evolutionary psychology, it's proven that humans are not hard-wired. Our cultural expectations and what we find is attractive changes over time (Myers 106).
  • Evolutionary psychologists re-butt these criticisms by saying that their science is "reverse engineering" and that humans have great capacities for learning and social progress (Myers 107).
Behavior Genetics:
-Behavior genetics is the study of the relative power and limits of genetic and environmental influences on behavior.
-Environment is every non-genetic influence, from prenatal nutrition to the people and things around us.(Myers)
-Fraternal twins are twins who develop from separate eggs. They are genetically no closer than brothers and sisters, but they share a fetal environment.
-Identical twins are twins who develop from a single fertilized egg that splits in two, creating two genetically identical organisms.
  • To better understand genetics and environmental influence, there has been thousands of studies on twins. For example, studies of nearly 13,000 pairs of Swedish twins, of 7000 Finnish twin pairs, and of 3810 Australian twin pairs provided consistent evidence that on both extra-version and neuroticism, identical twins are much more similar than fraternal twins (Myers 108).
-Neuroimaging is medical images that show the brain. It also allows us to study and see how the brain works.
-Heritability tell us what percentage of traits are because of genetic factors. Traits (height, intelligence, eye color etc.) are either due to genetic or environment there are no half-halves. If heritability of intelligence is 70%, that means 70% of the people will have inherited intelligence. (Myers)
-Studying separated twins was a breakthrough in the "nature vs. nurture" debate.
-Since separated twins still have many similarities, although not as much as twins reared together, they illustrate why scientific thinking has shifted toward a greater appreciation of genetic influences.
Environmental Influence
  • Culture: the enduring behaviors, ideas, attitudes, and traditions shared by a large group of people and transmitted from one generation to the next. (Myers 121)
    • For example, an American and a Russian will likely be very different due to cultural influences and social norms found in their country.
  • Norm: an understood rule for accepted and expected behavior. (Myers 123)
    • An example of a norm would be the unspoken rule of not talking in an elevator.
    • An example of a violation of a social norm would be, when a stranger comes and sits right next to a family in a mall's food court when there are plenty of available seats elsewhere.
    • An example of violating a social norm is when men go to the urinals, they are not supposed to be next to eachother they are to always leave a space in between.
  • Personal space: The buffer zone we like to maintain around our bodies (Myers 123)
    • cultures tend to have different view on how much personal space one needs. in Saudi Arabia, people typically require les personal space than do members of some European and North American groups (Myers 122).
  • Memes: self-replicating ideas, fashions, and innovations passed from person to person, they can serve as messages that carry some form of cultural ideas to people. (Myers 123) Memes can be spread through speech, gestures, or even in participating or behaving in a certian way.

The Tools of Discovery
  • Lesion- tissue destruction, A brain lesion is a naturally or experimentally caused destruction of brain tissue. (Myers 70)
  • Electroencephalogram-an amplified recording of the waves electrical activity that sweep across the brain's surface. These waves are measured by electrodes placed on the scalp.(Myers)
  • "By surgically lesioning or electrically stimulating specific brain areas, by recording the electrical activity and displaying neural activity , neuroscientists explore the connections among brain, mind, and behavior." (Myers)
  • Ex.) Surgical lesions of tissue in a specific brain area in an animal can cause their eating habits to change. If the hypothalamus were to be affected, the rat's brain could be essentially programmed to either eat less or to overeat, depending on which part was altered by the lesion.
  • Clinical Observations- the oldest method of studying brain mind connections is to observe the effects of brain diseases and injuries. Such method help physicians notice that damage to one side of the brain often caused numbness or paralysis on the opposite side, Suggesting that the right side of the brain is wired to the brain's left side and vice versa.
Neuroimaging Techniques
  • CT(computed tomography) (also referred to as a Computerized Axial Tomography or CAT) scan- a series of x-ray photographs taken from different angles & combined by computer into a composite three-dimensional picture of the brain's structure. (Myers)
  • PET (position emission tomography) scan - a visual display of brain activity that defects where a radioactive form of glucose goes while the brain performs a given task.
  • MRI(magnetic resonance imaging)- a technique that uses magnetic fields and waves to produce computer-generated images that distinguish among different types of soft tissue; allows us to see structures within the brain.(Myers)
  • Ex: MRI scans of bilingual people's brains reveal that second languages are represented in the same area as the first if learned early, and in different areas if learned late. (Meyers 71).
  • Functional MRI scans display that men's brains have a different active "left brain areas", however, women's brains are active on both sides. (Myers)
  • A Functional MRI is a new technology that combines elements of the MRI and PET scans. It shows details of brain structure with information about blood flow in the brain, tying brain structure to brain activity during cognitive tasks. (Barron's Review Book)
  • MEG (magnetoencephalography)- is an imaging technique used to measure the magnetic fields produced by electrical activity in the brain (Myers)
Lower Level Brain Structures
  • The human brain represents 1/45th of the body's weight.(Myers 72)
  • brainstem- the oldest part and central core of the brain, beginning where the spinal cord* swells as it enters the skull; the brainstem is responsible for automatic survival functions. (Myers 72)
    • This is where the crossover point lies. This is where neurons connected from say the left side of your brain, crosses and connects with the right side of your body. Same concept applies to the right side of your brain, neurons crossover at this point to connect with the left side of your body.
  • medulla- the base of the brainstem; controls heartbeat and breathing. (Myers 72)
  • reticular formation - a nerve network in the brainstem that plays an important role in arousal (Myers 72)
    For example, Giuseppe Moruzzi and Horace Magoun discovered that electrically stimulating the reticular formation of a sleeping cat almost instantly produced an awake, alert animal. Magoun also severed a cat's reticular formation...The effect? The cat lapsed into a coma from which it never awakened. (Myers 72)
  • thalamus- the brain's sensory switchboard, located on top of the brainstem; it directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla. (Myers)
    • The thalamus receives information from all the senses except smell and routes it to the higher brain regions that deal with seeing, hearing, tasting, and touching. (Myers)
    • The thalamus further appears to coordinate the brain's electrical oscillations, which slow during sleep and speed up to produce waking consciousness. (Myers)
  • The brainstem, including the medulla, is an extension of the spinal chord. The thalamus is attached to its top. The reticular formation passes through both structures. (Myers 73)

Cerebellum-the "little brain" attached to the rear of the brainstem; it helps coordinate voluntary movement and balance. The cerebellum also enables one type of nonverbal learning and memory. If the cerebellum is injured, one would have difficulty walking, keeping balance, or even something as trivial as shaking hands. Their movements would be jerky and exaggerated (Myers).The cerebellum enables one type of nonverbal learning and memory. (Myers)
  • An example, of how important the cerebellum is when the great baseball player Sammy Sosa smacks a home run with a perfectly timed swing of the bat[give his cerebellum some credit] (Myers 73).
    • Located inside the brainstem, the reticular formation lies between your ears (Myers 72).
    • Extends from the spinal cord right up to the thalamus (Myers 72).
    • Therefore, when the spinal cord's sensory input travels to the thalamus, some of the input reaches the reticular formation, which helps filter incomplete stimuli and relays important information to other areas of the brain according to Myers.

  • Hippocampus - Involved in the formation of memory. I.E. Helpful for musicians to memorize how to play their musical instrument according to Myers. The Hippocampus is also important to spatial navigation.

    • The hippocampus is found in both hemispheres of the brain but damage to only one side will traditionally not restrict recall of memories.
The Limbic System
  • Limbic System - a doughnut-shaped system of neural structures at the border of the brainstem and cerebral hemispheres, according to Myers.
    • Associated with emotions such as fear and aggression and drives such as those for food and sex. (Myers)
    • includes the hippocampus, amygdala, and hypothalamus. (Myers)
    • located in the forebrain region
  • Amygdala- two almond-shaped neural clusters that are components of the limbic system and are linked to emotion. The amygdala influences fear and aggression, but it is an overgeneralization to say that it is the control center for fear and aggression. (Myers 74)
    • Connects emotions with memories
    • Ex) A psychologist named Heinrich Kluver and neuroscience Paul Bucy surgically lesioned the part of a rhesus monkey's brain, that included the amygdala. This resulted in the ill tempered monkey to become very mellow (Myers 74)
  • Hypothalamus- a neural structure lying below the thalamus: it directs several maintenance activities (eating, drinking, body temperature), helps govern the endocrine system via the pituitary gland (sometimes called the "master gland"; regulates growth and controls other endocrine glands under the influence of the hypothalamus), and is linked to emotion (Myers)
    • divided into lateral and ventromedial hypothalamus. The combination of the two regulates eating behaviors and body weight. The lateral hypothalamus is the "on switch" for eating, while the ventromedial is the "off switch" for eating. (Talamo)
    • Hypothalamus monitors blood chemistry and takes orders from other parts of the brain.
  • According to Myers, many researchers believe that a person with reward deficiency syndrome , a genetically disposed deficiency in the natural brain systems for pleasure and well being that leads people to crave whatever provides that missing pleasure or relives negative feelings, can develop addictive disorders like alcoholism. (Myers 76)
The Endocrine System
  • The Endocrine system is the second body communication system whose glands secrete hormones. (Myers)
  • Hormones are chemical messengers that originate in one tissue and affect another. They influence human interest in aggression, sex, and food. (Myers)
    • The hormone testosterone is one of the most important hormones in the human body and is present in both males and females, although it is present in far greater amounts in males. Testosterone's presence allows for the growth of facial hair and muscle mass among other things
    • The hormones glucagon and insulin are also two of the most important hormones in the human body as they regulate blood sugar. Insulin reduces blood sugar levels, whereas glucagon increases levels.
  • The most influential endocrine gland is the pituitary gland; a pea-sized structure in the base of the brain. It is controlled by the hypothalamus. It also regulates growth and controls other endocrine glands (Myers)
  • the feedback system: brain -> pituitary -> other glands -> hormones -> brain (Myers 95)
  • Adrenal Glands- a pair of endocrine glands just above the kidneys. The adrenals secrete the hormones epinephrine (adrenaline) and nonepinephrine (non-adrenaline), which helps to arouse the body in times of stress (Myers 95).

The Cerebral Cortex
  • Association Areas - are areas uncommitted to sensory/motor functions, and are involved with the thinking, remembering, speaking tasks
  • Cerebral Cortex -the intricate fabric of interconnected neural cells that covers the cerebral hemispheres; the body's ultimate control and information-processing center. (Myers)
    • wrinkled outer alter of the brain
    • "Larger cortex of mammals offers increased capacities for learning and thinking, enabling them to be more adaptable" (Myers 76)
- "With the elaboration of the cerebral cortex, tight genetic controls relax and the organism's adaptability increases." (Myers)
  • Glial Cells - "Glue cells" that guide neural connections, provide nutrients and insulating myelin, and mop up ions and neurotransmitters. Glial cells are also believed to communicate with neurons, so they may participate in information transmission and memory. (Myers 77)

  • Broca's Area-an area of the frontal lobe that controls language expression-usually located in the left hemisphere, that directs the muscle movements involved in speech (Myers 82).
    • According to Myers, damage to the Broca's area would make a person unable to form words but would still be able to sing familiar songs (82).
  • Wernicke's Area-controls language reception-a brain area involved in language comprehension and expression; usually located in the left temporal lobe according to Myers. Damage to this area in stroke patients would result in receptive aphasia or the inability to comprehend speech (Myers).
  • Aphasia-language impairment that is usually caused by left hemisphere damage either to Broca's ares (speaking impairment) or to Wernicke's area (impairing understanding) (Myers 82).

The Four Lobes
  • "These lobes are convenient geographic subdivisions separated by prominent folds" (Myers 78)
  • Frontal Lobe: front of the head, "involved in speaking and muscles movements and making plans and judgements" (Myers 77)
    • One of the two language centers is in the frontal lobe. Most people have these language centers in the left hemisphere.This is referred to as the Broca's area. The Broca's area is involved in the creating of the muscle movements involved in speech. Aphasia can occur if the Broca's area is damaged. This may hinder an individual's ability to speak, because the individual would be unable to control the muscles required to speak. [1]
    • We can see exactly how important the frontal lobe can be when looking at the case involving Phineas Gage and the metal rod that went through the frontal lobes, separating his ability of muscle movements from his ability to make plans or judgements
    • The motor cortex lies near the back end of the frontal lobe. Messages (electrical impulses across neurons, which are translated into neurotransmitters across each synapse) are sent from the motor cortex to other areas in the body to control muscles. The upper area of the body corresponds to the bottom area of the motor cortex. So muscle movements involving our face and neck are controlled by the bottom of the motor cortex. Our legs and feet on the other hand are controlled through the upper portion of the motor cortex. [2]

  • Parietal Lobe: toward the top back of the head, involved in sensation (Myers 77)
    • The somato-sensory cortex lies in the parietal lobes, behind the motor cortex in the frontal lobe. This cortex is involved in sensations relating to touch. Signals are sent from other areas of the body to this cortex. The top of the sensory cortex receives signals from the bottom areas of our body, while the bottom of the cortex receives signals from the top of our body. [3]

  • Occipital Lobe: at the back of the head and used in vision, each lobe receives visual information for the opposite side's eye (Myers 77)
    • The occipital lobe is home to the visual cortex, which is in charge of receiving the visual stimulation. Damage this can hinder an individuals vision.
  • The occipital lobe is in the cerebral cortex located in the rearmost portion of the head. A significant function of the occipital lobe is that it has the primary visual cortex ( local orientation, spatial-frequency and color properties within small receptive fields)
  • Temporal Lobe: this lobe lies above the ears (temporal lobes are located near the temples), receives auditory information mostly from the opposite ear, associated with auditory areas. (Myers) The temporal lobe decides whether or not we hear someone, it receives sensory information and interprets all the pitches and voices around us.

  • *** The other language center is the Wernicke's area. It is located in the temporal lobe. Damage to the Wernicke's area may impair the ability to comprehend language. Additionally, one may be able to speak fluently in respect to how speech sounds with damage to this area, but correct grammar and syntax will not be employed.
    • An example is the accident that happened to Phineas Gage
Brain Reorganization
  • Plasticity- is the brains capacity for modification, as evidenced by the brain reorganization following damage (Meyers 84) [4]
    • Neural tissue can reorganize but damaged neurons will not heal.
      • One such case is that once the spinal cord is severed, then one would most likely be permanently paralyzed (Myers)
    • Our brains are also most plastic while we are in our early childhood. (Myers)

Our Divided Brains
Corpus Callosum: the large band of neural fibers connecting the two brain hemispheres and carrying messages between them (Myers)
      • Must be severed in order to stop the communication between the left and right hemispheres of the brain (Myers)
      • Corpus Callosum may also be severed to end epileptic seizures
    • Split Brain - "a condition in which the two hemispheres of the brain are isolated by cutting the connecting fibers between them" (Myers 87)
      • Although split brain surgery can be used to help those who have seizures, it can create a conflict between the left and right hemispheres: making one become conflicted with one's rational and true desires. This surgery is called a Corpus Callosotomy.
      • However, personalities and intellect are not affected by a split brain; most patients wake up normally after the surgery as well.
      • Those who do have split brains are able to develop abilities like writing with both hands simultaneously.
    • In an early split brain experiment conducted by Gazzaniga (1967) asked split brain patient to stare at a dot as he flashed HE-ART on a screen. Thus, HE appeared in their left visual field (which transmits to the right brain) and ART in their right field (which transmits to the left brain.) As he asked what they had seen, the patients said they saw ART and were startled when their left hand, which is controlled by the right brain, pointed to HE. (Myers 86)

Our brain is divided into two hemispheres:
  • The left hemisphere: processes reading, writing, speaking, mathematics, and comprehension skills
    • Deaf people uses left hemisphere to process language.
    • A left brain person tends to be logical, verbal, and able to deal with things in sequence.
  • The right hemisphere: perceives objects easily, understands simple requests, understands emotions, recognizes aces, and is more engaged with quick emotions.
    • A right brain person is skilled at spatial relations, and able to deal with things all at once.
  • Integration: Complex activities seem to emerge from the activities of both hemispheres working together. (Myers 88)
Example: "most people recognize a picture faster and more accurately when it is flashed to the right hemisphere. But there recognize a word faster and more accurately when it is flashed to the left" (Myers 88)
  • Occasionally, hemispheric specialization has been even more dramatically displayed by briefly sedating an entire hemisphere
  • Babies can exhibit asymmetry, by favoring the left side of their mouth when beginning a smile, and the right side when using baby language, or "babbling" (Myers 89)

Is Handedness Inherited?
~ Judged by old cave drawings and such it is found that humans have long used their right hands more frequently than their left.
~A study showed that genetically identical twins aren't likely to share the same Handedness.
~ These findings proved that along with the universal provenance of right handers indicate that either genes or some prenatal factor influneces handedness.(89).
~ Just like pros and cons in righthanded people left handed people seem to struggle with awkward scissors and elbow touching when eating. A big con about being left handed is that they seem to dissapear with age. (90).
  1. ^ Barron's AP Psychology 5th Edition, McEntarffer and Weseley, pg. 86-87
  2. ^ >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Barron's AP Psychology 5th Edition, McEntarffer and Weseley, pg. 86-87
  3. ^ Barron's AP Psychology 5th Edition, McEntarffer and Weseley, pg. 86-87
  4. ^ Barron's AP Psychology 5th Edition, McEntarffer and Weseley, pg. 86-87