AP Psychology : Unit 3 Biological Bases of Behavior
endorphins
"morphine within" - natural, opiate-like neurotransmitters linked to pain control and to pleasure
explain the three major influences on individual development, according to the biopsychosocial approach
- biological influences: the prenatal environment or individual genetic influences. - psychological influences: gene-environment interaction or beliefs. - social-cultural influences: parental or peer influences
how do neuroscientists study the brain's connections to behavior and mind?
- case studies and lesioning first revealed the general effects of brain damage. - modern electrical, chemical, or magnetic stimulation has also revealed aspects of information processing in the brain. - CT and MRI scans show anatomy. EEG, PET, and fMRI (functional MRI) recordings reveal brain function.
what are the key criticisms of evolutionary psychology, and how do evolutionary psychologists respond?
- critics argue that evolutionary psychologists (1) start with an effect and work backward to an explanation, (2) do not recognize social and cultural influences, and (3) absolve people from taking responsibility for their sexual behavior. - evolutionary psychologists respond that understanding our predispositions can help us overcome them. they also cite the value of testable predictions based on evolutionary principles, as well as the coherence and explanatory power of those principles
following a brain injury, mike struggles to control his emotions and has difficulty establishing new memories. what parts of mike's brain have most likely been affected by his injury?
- damage to the amygdala would make it difficult for mike to control his emotions. - damage to the hippocampus would affect mike's ability to establish new memories.
explain the role that dendrites, axon, and myelin sheath play in sending a message through a neuron
- dendrites receive messages from other neurons - the axon is an extension that makes it possible for the neuron to carry information over greater distances - the myelin sheath covers the axon of some neurons and serves to speed up the action potential
while hiking, ken stumbled and fell down a 10-foot drop-off. upon landing, he sprained his ankle badly. ken was surprised that he felt very little pain for the first half hour. explain how the endorphins and the synapse helped ken feel little pain in the moments after the injury
- endorphins are natural, opiate-like neurotransmitters linked to controlling pain - the synapse is the space between neurons where neurotransmitters like the endorphins carry information that influences how ken feels
how do evolutionary psychologists use natural selection to explain behavior tendencies?
- evolutionary psychologists seek to understand how our traits and behavior tendencies are shaped by natural selection, as genetic variations increasing the odds of reproducing and surviving are most likely to be passed on to future generations. - some genetic variations arise from mutations (random errors in gene replication), others from new gene combinations at conception. - humans share a genetic legacy and are predisposed to behave in ways that promoted our ancestors' surviving and reproducing. - charles darwin's theory of evolution is an organizing principle in biology. he anticipated today's application of evolutionary principles in psychology.
what are genes, and how do behavior geneticists explain our individual differences?
- genes are the biochemical units of heredity that make up chromosomes, the threadlike coils of DNA. - when genes are "turned on" (expressed), they provide the code for creating the proteins that form our body's building blocks. - most human traits are influenced by many genes acting together. - behavior geneticists seek to quantify genetic and environmental influences on our traits, in part through studies of identical (monozygotic) twins, fraternal (dizygotic) twins, and adoptive families. - shared family environments have little effect on personality, and the stability of personality suggests a genetic predisposition
what are the functions of the nervous system's main divisions, and what are the three main types of neurons?
- the central nervous system (CNS)—the brain and the spinal cord—is the nervous system's decision maker. - the peripheral nervous system (PNS), which connects the CNS to the rest of the body by means of nerves, gathers information and transmits CNS decisions to the rest of the body. - the two main PNS divisions are the somatic nervous system (which enables voluntary control of the skeletal muscles) and the autonomic nervous system (which controls involuntary muscles and glands by means of its sympathetic and parasympathetic divisions). - neurons cluster into working networks. - there are three types of neurons: (1) sensory neurons carry incoming information from sense receptors to the brain and spinal cord. (2) Motor neurons carry information from the brain and spinal cord out to the muscles and glands. (3) Interneurons communicate within the brain and spinal cord and between sensory and motor neurons.
what are the functions of the various cerebral cortex regions?
- the cerebral cortex has two hemispheres, and each hemisphere has four lobes: the frontal, parietal, occipital, and temporal. each lobe performs many functions and interacts with other areas of the cortex - glial cells support, nourish, and protect neurons and may also play a role in learning and thinking - the motor cortex, at the rear of the frontal lobes, controls voluntary movements - the somatosensory cortex, at the front of the parietal lobes, registers and processes body touch and movement sensations - body parts requiring precise control or those that are especially sensitive occupy the greatest amount of space in the motor cortex and somatosensory cortex - most of the brain's cortex - the major portion of each of the four lobes - is devoted to uncommitted association areas, which integrate information involved in learning, remembering, thinking, and other higher-level functions - our mental experiences arise from coordinated brain activity
what is the nature and what are the functions of the endocrine system, and how does it interact with the nervous system?
- the endocrine system is a set of glands that secrete hormones into the bloodstream, where they travel through the body and affect other tissues, including the brain. the adrenal glands, for example, release the hormones that trigger the fight-or-flight response. - the endocrine system's master gland, the pituitary, influences hormone release by other glands. in an intricate feedback system, the brain's hypothalamus influences the pituitary gland, which influences other glands, which release hormones, which in turn influence the brain.
identify the role of each of the following in listening to and taking notes during a psychology lecture - hippocampus - cerebellum - cerebral cortex
- the hippocampus would play a role in transferring information obtained during the lecture from short-term to long-term memory. - the cerebellum would help the student by providing the fine motor coordination necessary to take notes or type on a laptop during the lecture. - the cerebral cortex is responsible for the higher-order thinking necessary to understand a college lecture.
what are the limbic system's structures and functions?
- the limbic system is linked to emotions, memory, and drives. - its neural centers include the hippocampus (which processes conscious memories); the amygdala (involved in responses of aggression and fear); and the hypothalamus (involved in various bodily maintenance functions, pleasurable rewards, and the control of the endocrine system). - the pituitary (the "master gland") controls the hypothalamus by stimulating it to trigger the release of hormones.
which neurotransmitter inhibits CNS activity in order to calm a person down during stressful situations?
GABA
fMRI (functional MRI)
a technique for revealing bloodflow and, therefore, brain activity by comparing successive MRI scans. fMRI scans show brain function as well as its structure
MRI (magnetic resonance imaging)
a technique that uses magnetic fields and radio waves to produce computer-generated images of soft tissue. MRI scans show brain anatomy
PET (positron emission tomography) scan
a visual display of brain activity that detects where a radioactive form of glucose goes while the brain performs a given task
an individual is having trouble with cognitive tasks related to learning and memory. which of the following neurotransmitters is most likely to be involved with the problem?
acetylcholine
what is the brief electrical charge that travels down an axon called?
action potential
epinephrine and norepinephrine increase energy and are released by the
adrenals glands
opiate drugs such as morphine are classified as what?
agonists, because they mimic other neurotransmitters' pain-diminishing effects
electroencephalogram (EEG)
an amplified recording of the waves of electrical activity sweeping across the brain's surface. these waves are measured by electrodes placed on the scalp
motor cortex
an area at the rear of the frontal lobes that controls voluntary movements
somatosensory cortex
area at the front of the parietal lobes that registers and processes body touch and movement sensations
association areas
areas of the cerebral cortex that are not involved in primary motor or sensory functions; rather, they are involved in higher mental functions such as learning, remembering, thinking, and speaking
the most noticeable difference between human brains and other mammalian brains is the size of what?
association areas
when Klüver and Bucy surgically lesioned the amygdala of a rhesus monkey's brain, what was the impact on the monkey's behavior?
became less aggresive
what is the study of specific genes and teams of genes that influence behavior called?
behavior genetics
phrenology has been discredited, but which of the following ideas has its origins in phrenology?
brain function localization
nerves
bundled axons that form neural "cables" connecting the central nervous system with muscles, glands, and sense organs
a split-brain patient has a picture of a dog flashed to his right hemisphere and a cat to his left hemisphere. he will be able to identify the
cat using his right hand
glial cells
cells in the nervous system that support, nourish, and protect neurons; they may also play a role in learning and thinking.
to walk across a street, a person would rely most directly on which division of the nervous system?
central nervous system
a gymnast falls and hits her head on the floor. she attempts to continue practicing, but has trouble maintaining balance. what part of her brain has probably been affected?
cerebellum
hormones
chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream, and affect other tissues
neurotransmitters
chemical messengers that cross the synaptic gaps between neurons. when released by the sending neuron, neurotransmitters travel across the synapse and bind to receptor sites on the receiving neuron, thereby influencing whether that neuron will generate a neural impulse
hormones are ________ released into the ____________
chemical messengers; bloodstream
what is the "dual processing" being revealed by today's cognitive neuroscience?
cognitive neuroscientists and others studying the brain mechanisms underlying consciousness and cognition have discovered that the mind processes information on two separate tracks, one operating at an explicit, conscious level and the other at an implicit, unconscious level. this dual processing affects our perception, memory, attitudes, and other cognitions.
what are the three main criticisms of evolutionary psychology's explanations?
critics of evolutionary psychology's explanations point out that (1) they start with an effect and work backward to propose an explanation; (2) unethical and immoral men could use such explanations to rationalize their behaviors toward women; and (3) this explanation overlooks the effects of cultural expectations and socialization
generally speaking, heritability is the extent to which
differences among people are accounted for by genes
you are aware that a dog is viciously barking at you, but you are not aware of the type of dog. later, you are able to describe the type and color of the dog. this ability to process information without conscious awareness best exemplifies which of the following?
dual processing
morphine elevates mood and eases pain, and is most similar to what?
endorphins
what refers to an effect of life experience that leaves a molecular mark that affects gene expression?
epigenetics
environment
every external influence, from prenatal nutrition to the people and things around us
who proposed that phrenology, studying bumps on the skull, could reveal a person's mental abilities and character traits?
franz gall
damage to what could interfere with the ability to plan for the future?
frontal lobe
glutamate
functions : - a major excitatory neurotransmitter; involved in memory examples of malfunctions : - oversupply can overstimulate the brain, producing migraines or seizures (which is why some people avoid MSG, monosodium gultamate, in food)
GABA (gamma-aminobutyric acid)
functions : - a major inhibitory neurotransmitter examples of malfunctions - undersupply linked to seizures, tremors, and imsomnia
serotonin
functions : - affects mood, hunger, sleep, and arousal examples of malfunctions : - undersupply linked to depression. some antidepressant drugs raise serotonin levels
acetylcholine (ACh)
functions : - enables muscle action, learning, and memory examples of malfunctions : - with alzheimer's disease, ACh-producing neurons deteriorate
norepinephrine
functions : - helps control alertness and arousal examples of malfunctions : - undersupply can depress mood
dopamine
functions : - influences movement, learning, attention, and emotion examples of malfunctions : - oversupply linked to schizophrenia. undersupply linked to tremors and decreased mobility in parkinson's disease
which of the following is most closely associated with the idea of epigenetics?
gene display based on environmental factors
heritability refers to the percentage of what?
group variation in a trait that can be explained by genetics
what was one of the major findings of thomas bouchard's study of twins?
he discovered almost unbelievable similarities between adult identical twins who had been separated near birth
what is heritability?
herability is the proportion of variation among individuals that we can attribute to genes. note: heritability is not the extent to which an individual's traits are genetically determined. rather, it is the extent to which variation among individuals is due to their differing genes. for any trait, heritibality can vary, depending on the population and range of environments studied
Which of the following brain areas is responsible for regulating thirst?
hippocampus
which of the following's primary function is processing memories?
hippocampus
what part of the brain triggers the release of adrenaline to boost heart rate when you're afraid?
hypothalamus
which of the following communicates with the pituitary, which in turn controls the endocrine system?
hypothalamus
during which task might the right hemisphere of the brain be most active?
imagining what a dress would look like on a friend
The dual-processing model refers to what idea?
incoming information is processed by both conscious and unconscious tracks
the peripheral nervous system is what?
is the part of the nervous system that does not include the brain and the spinal cord
which is one of the major criticisms of the evolutionary perspective in psychology?
it analyzes after the fact using hindsight
which region of the brain controls our breathing and heartbeat?
medulla
damage to the hippocampus would result in what?
memory problems
which of the following statements has been supported by the research of evolutionary psychologists?
men are attracted to women who appear fertile and capable of bearing children
cognitive neural prosthetics are placed in the brain to help control parts of the what?
motor cortex
which of the following carries the information necessary to activate withdrawal of the hand from a hot object?
motor neuron
multiple sclerosis (communication to muscles slows, with eventual loss of muscle control) is a result of degeneration in the?
myelin sheath
evolutionary psychologists seek to understand how traits and behavioral tendencies have been shaped by what?
natural selection
human genome (DNA) researchers have discovered that what?
nearly every other human is your genetically identical twin
limbic system
neural system (including the hippocampus, amygdala, and hypothalamus) located below the cerebral hemispheres; associated with emotions and drives
sensory (afferent) neurons
neurons that carry incoming information from the sensory receptors to the brain and spinal cord
motor (efferent) neurons
neurons that carry outgoing information from the brain and spinal cord to the muscles and glands
interneurons
neurons within the brain and spinal cord that communicate internally and intervene between the sensory inputs and motor outputs
one reason that identical twins might show slight differences at birth is?
one twin's placenta may have provided slightly better nourishment
consciousness
our awareness of ourselves and our environment
which branch of the nervous system calms a person?
parasympathetic
which of the following endocrine glands may explain unusually tall height in a 12-year-old?
pituitary
which is the most influential of the endocrine glands?
pituitary glands
occipital lobes
portion of the cerebral cortex lying at the back of the head; includes areas that receive information from the visual fields.
parietal lobes
portion of the cerebral cortex lying at the top of the head and toward the rear; receives sensory input for touch and body position.
frontal lobes
portion of the cerebral cortex lying just behind the forehead; involved in speaking and muscle movements and in making plans and judgments
temporal lobes
portion of the cerebral cortex lying roughly above the ears; includes the auditory areas, each receiving information primarily from the opposite ear
what best describes genetic mutation?
random errors in gene replication
why is the pituitary gland called the "master gland"?
responding to signals from the hypothalamus, the pituitary releases hormones that trigger other endocrine glands to secrete hormones that in turn influence brain and behavior
an individual experiences brain damage that produces a coma. which part of the brain was probably damaged?
reticular formation
The hypothalamus is a(n) ________ center for the brain.
reward
when there is a negative charge inside an axon and a positive charge outside it, the neuron is
said to have a resting potential
juanita does not feel like getting out of bed, has lost her appetite, and feels tired for most of the day. which of the following neurotransmitters likely is in short supply for juanita?
seratonin
what neurotransmitters are most likely in undersupply in someone who is depressed?
serotonin and norepinephrine
stimulation at a point on what may cause a person to report being touched on the knee?
somatosensory cortex
what is a function of the left hemisphere?
speech
what is the purpose of the myelin sheath?
speed the transmission of information within a neuron
which division of the nervous system produces the startle response?
sympathetic
which of the following is sometimes referred to as the brain's train hub, because it directs incoming sensory messages (with the exception of smell) to their proper places in the brain?
thalamus
cerebellum
the "little brain" at the rear of the brainstem; functions include processing sensory input, coordinating movement output and balance, and enabling nonverbal learning and memory
brain plasticity refers to which of the following?
the ability of brain tissue to take on new functions
medulla
the base of the brainstem; controls heartbeat and breathing
genes
the biochemical units of heredity that make up the chromosomes; segments of DNA capable of synthesizing proteins
how does the biopsychosocial approach explain our individual development?
the biopsychosocial approach considers all the factors that influences our individual development: biological factors (including evolution, genes, hormones, and brains), psychological factors (including our experiences, beliefs, feelings, and expectations), and social-cultural factors (including parental and peer influences and cultural attitudes and norms)
endocrine system
the body's "slow" chemical communication system; a set of glands that secrete hormones into the bloodstream
nervous system
the body's speedy, elctrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous systems
central nervous system (CNS)
the brain and spinal cord
plasticity
the brain's ability to change, especially during childhood, by reorganizing after damage or by building new pathways based on experience
genome
the complete instructions for making an organism, consisting of all the genetic material in that organism's chromosomes
sympathetic nervous system
the division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations
parasympathetic nervous system
the division of the autonomic nervous system that calms the body, conserving its energy
somatic nervous system
the division of the peripheral nervous system that controls the body's skeletal muscles. also called the skeletal nervous system
pituitary gland
the endocrine system's most influential gland. under the influence of the hypothalamus, the pituitary regulates growth and controls other endocrine glands
neurogenesis
the formation of new neurons
what does a PET scan best allow researchers to examine?
the functions of various brain regions
what are the mind's two tracks, and what is "dual processing"?
the human brain has separate conscious and unconscious tracks that process information simultaneously. in vision, for example, the visual action track normally guides our conscious visual processing, while the visual perception track normally operates unconsciously, enabling our quick recognition of objects
cognitive neuroscience
the interdisciplinary study of the brain activity linked with cognition (including perception, thinking, memory, and language)
interaction
the interplay that occurs when the effect of one factor (such as environment) depends on another factor (such as heredity)
cerebral cortex
the intricate fabric of interconnected neural cells covering the cerebral hemispheres; the body's ultimate control and information - processing center.
synapse
the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron. the tiny gap at this junction is called the synaptic gap or synaptic cleft
corpus callosum
the large band of neural fibers connecting the two brain hemispheres and carrying messages between them
threshold
the level of stimulation required to trigger a neural impulse
axon
the neuron extension that passes messages through its branches to other neurons or to muscles or glands
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
autonomic nervous system (ANS)
the part of the peripheral nervous system that controls the glands and the muscles of the internal organs (such as the heart). its sympathetic division arouses; its parasympathetic division calms
dual processing
the principle that information is often simultaneously processed on separate conscious and unconscious tracks
natural selection
the principle that, among the range of inherited trait variations, those contributing to reproduction and survival will most likely be passed on to succeeding generations
heritablity
the proportion of variation among individuals that we can attribute to genes. The heritability of a trait may vary, depending on the range of populations and environments studied
biological psychology
the scientific study of the links between biological (genetic, neural, and hormonal) and psychological processes
peripheral nervous system (PNS)
the sensory and motor neurons that connect the central nervous system (CNS) to the rest of the body
epigenetics
the study of environmental influences on gene expression that occur without a DNA change
evolutionary psychologist
the study of the evolution of behavior and the mind, using principles of natural selection
behavior genetics
the study of the relative power and limits of genetic and environmental influences on behavior
molecular genetics
the subfield of biology that studies the molecular structure and function of genes
what do neurotransmitters cross to carry information to the next neuron?
the synaptic gap
within what brain region would damage be most likely to disrupt your ability to skip rope? your ability to sense tastes or sounds? in what brain region would damage perhaps leave you in a coma? without the very breath and heartbeat of life?
these regions are, respectively the cerebellum, the thalamus, the reticular formation, and the medulla. these questions assess your understanding of the essential functions of the lower-level brain areas
why do researchers find the study of fraternal twins important?
they are the same age and are usually raised in similar environments, but they do not have the same genetic code
chromosomes
threadlike structures made of DNA molecules that contain the genes
lesion
tissue destruction. a brain lesion is a naturally or experimentally caused destruction of brain tissue
in an effort to reveal genetic influences on personality, researchers use adoption studies mainly for what purpose?
to evaluate whether adopted children more closely resemble their adoptive parents or their biological parents
interneurons are said to
transmit and process information within the brain and spinal cord
identical twins (monozygotic twins)
twins who develop from a single fertilized egg that splits in to, creating two genetically identical organisms
fraternal twins (dizygotic twins)
twins who develop from separate fertilized eggs. they are genetically no closer than brothers and sisters, but they share a fetal environment
amygdala
two lima-bean-sized neural clusters in the limbic system; linked to emotion
are men more likely to initiate sexual activity than women?
yes
how does information flow through your nervous system as you pick up as a fork? can you summarize this process?
your central nervous system's hungry brain activates and guides the muscles of your arm and hand via your peripheral nervous system's motor neurons. as you pick up the fork, your brain processes the information from your sensory nervous system, enabling it to continue to guide the fork to your mouth. the functional circle starts with sensory input, continues with interneuron processing by the central nervous system, and finishes with motor output
dr. nation is a biopsychologist interested in studying genetic influences on brain development. briefly describe a twin study dr. nation might design to investigate the research question: "how do genetics and early environmental influences interact to impact how brains develop?" use the following terms in context in your description: - genes - heritability - epigenetics - fraternal or identical twins - fMRI
- genes; in the study, dr. nation would be interested in identifying sets of genes, functional segments of DNA strands, that influence how brains develop - heritability; one of the major goals of dr. nation's study would be to focus on how much the diversity of brain development within a group can be attributed to genetic factors. if dr. nation can describe this, he will be describing the heritability of brain development - epigenetics; because dr. nation is a biopsychologist, he knows that brain development, like all physical and mental development, occurs through the interaction of environmental and biological factors. dr. nation will probably use findings in the field of epigenetics to describe environmental triggers that turn genes on and off and influence brain development - fraternal or identical twins; because dr. nation is using a twin study, he might use the different characteristics of fraternal and identical twins to try to isolate the impact of genetics on brain development. because identical twins are genetically identical, and fraternal twins share half of their genetic material, these 2 groups can be used in twin studies to isolate the impact of genetics on specific characteristics - fMRI; because dr. nation is studying brain development, he may want to use an fMRI machine; it can look at both the structure of the brain and the activity level in parts of the brain during specific tasks.
what is heritability, and how does it relate to individuals and groups?
- heritability describes the extent to which variation among members of a group can be attributed to genes. - heritable individual differences (in traits such as height or intelligence) do not necessarily imply heritable group differences. genes mostly explain why some people are taller than others, but not why people are taller today than they were a century ago
what does it mean to say that the heritability of height is 90 percent? what does that tell us about the contribution of genetics to any one person's height?
- heritability refers to how much of the variability in the heights of a group of people can be attributed to genetics. - heritability tells us nothing about how much of a person's height is caused by genetics. heritability only applies to groups.
why do researchers study the brains of nonhuman animals?
- human brains are too complex to study meaningfully
to what you extent can a damaged brain reorganize itself, and what is neurogenesis?
- if one hemisphere is damaged early in life, the other will pick up many of its functions by reorganizing or building new pathways. this plasticity diminishes later in life - the brain sometimes mends itself by forming new neurons, a process known as neurogenesis
what is included in the biopsychosocial approach to individual development?
- indevelopment results from the interaction of biological, psychological, and social-cultural influences. - biological influences include our shared human genome; individual variations; prenatal environment; and sex-related genes, hormones, and physiology. - psychological influences include gene-environment interactions; the effect of early experiences on neural networks; responses evoked by our own characteristics, such as gender and personality; and personal beliefs, feelings, and expectations. - social-cultural influences include parental and peer influences; cultural traditions and values; and cultural gender norms
brain lateralization means that each hemisphere has its own functions. give an example of both a left hemisphere and a right hemisphere function. then explain how the two hemispheres communicate with one another
- left hemisphere functions include language, math, and logic. - right hemisphere functions include spatial relationships, facial recognition, and patterns. - the corpus callosum carries information back and forth between the two hemispheres.
- how might an evolutionary psychologist explain gender differences in sexuality and mating preferences?
- men tend to have a recreational view of sexual activity; women tend to have a relational view. - evolutionary psychologists reason that men's attraction to multiple healthy, fertile-appearing partners increases their chances of spreading their genes widely. - because women incubate and nurse babies, they increase their own and their children's chances of survival by searching for mates with the potential for long-term investment in their joint offspring.
what is the promise of molecular genetics research?
- molecular geneticists study the molecular structure and function of genes, including those that affect behavior - psychologists and molecular geneticists are cooperating to identify specific genes—or more often, teams of genes—that put people at risk for disorders
explain the two positions in the nature-nurture debate
- nature refers to the contributions of heredity and inborn, biologically determined aspects of behavior and mental processes. - nurture refers to the contributions of environment and the way individuals are raised
what are the parts of a neuron, and how are neural impulses generated?
- neurons are the elementary components of the nervous system, the body's speedy electrochemical information system - a neuron receives signals through its branching dendrites, and sends signals through its axons - some axons are encased in a myelin sheath, which enables faster transmission - if the combines received signals exceed a minimum threshold, the neuron fires, transmitting an electrical impulse (the action potential) down its axon by means of a chemistry-to-electricity process. the neuron's reaction is an all-or-none process
how do neurotransmitters influence behavior, and how do drugs and other chemicals affect neurotransmission?
- neurotransmitters travel designated pathways in the brain and may influence specific behaviors and emotions - acetylcholine (ACh) affects muscle action, learning, and memory - endorphins are natural opiates released in response to pain and exercise - drugs and other chemicals affect brain chemistry at synapses - agonists excite by mimicking particular neurotransmitters or by blocking their reuptake - antagonists inhibit a particular neurotransmitter's release or block its effect
if a person accidentally touches a pan filled with hot water on the stove, they will immediately move their hand away from the hot pan before yelling out in pain. use the following terms to explain what is involved in this reaction. neurotransmitters - the endocrine system - thalamus - amygdala - sensory cortex - pain reflex
- neurotransmitters; neurons release neurotransmitters, which influence movement. these neurotransmitters are passed from one neuron to the next, enabling movement like drawing a hand away from a hot pan - the endocrine system; hormones will be released to help react to this emergency situation. the adrenal glands will trigger the fight-or-flight response, releasing hormones that increase heart rate, blood pressure, and blood sugar, providing the person with a surge of energy, and helping to arouse the body in this time of stress - thalamus; the thalamus acts as the brain's sensory router and will receive the pain information that was sent to the brain. the message will be transferred to the sensory cortex - amygdala; this part of the brain is linked to strong, primal emotions and would be involved in the emotional experience of burning your hand in hot water (e.g., shouting or crying, etc.) - somatosensory cortex; the somatosensory cortex, located in the parietal lobes, is the specific area that registers and processes body touch and movement sensations. so the specific spot of the brain that knows that pain has been inflicted would be located in this area - pain reflex; when our skin touches something very hot or very cold, a special reflex is activated. the impulse travels from the skin to interneurons in the spinal cord, which activate motor neurons leading to muscles that would jerk our hand away from the hot water
explain four of the important ideas behind natural selection
- organisms' varied offspring compete for survival. - certain biological and behavioral variations increase an organism's reproductive and survival chances in a particular environment. - offspring that survive are more likely to pass their genes to ensuing generations. - over time, population characteristics may change
how do heredity and environment work together?
- our genetic predispositions and our surrounding environments interact. environments can trigger gene activity, and genetically influenced traits can evoke responses from others. - the field of epigenetics studies the influences on gene expression that occur without changes in DNA
why are psychologists concerned with human biology?
- psychologists working from a biological perspective study the links between biology and behavior - we are biopsychosocial systems, in which biological, psychological, and social-cultural factors interact to influence behavior
doctors sometimes have to remove a portion of the brain to control life-threatening seizures. describe what the results of the removal of a portion of the motor cortex would be and explain how this procedure might be affected by brain plasticity
- removing part of the motor cortex will result in paralysis in the parts of the body associated with the removed tissue - because of brain plasticity, the person's brain may be able to change and reorganize new pathways based on experience. this is more likely if the person is a child
while walking barefoot, you step on a piece of glass. before you have a chance to consciously process what has happened, you draw your foot away from the glass. identify and explain the three types of neurons that deal with information regarding this painful stimulus
- sensory neurons carry information from the point of the injury to the central nervous system. - interneurons are neurons within the brain and spinal cord. interneurons would help you interpret the pain and enable your brain to send out marching orders. - motor neurons carry the instruction from the central nervous system to activate the muscles in your leg and foot.
name and describe the components and subcomponents of the peripheral nervous system
- somatic nervous system. the somatic nervous system controls voluntary movement of the body. - autonomic nervous system. the autonomic nervous system controls the glands and the internal organs. - sympathetic nervous system. the sympathetic nervous system is the division of the autonomic nervous system that arouses the body in times of emergency (fight or flight). - parasympathetic nervous system. the parasympathetic nervous system is the division of the autonomic nervous system that calms the body when no emergency exists (rest and digest).
what do split brains reveal about the functions of our two brain hemispheres?
- split-brain research (experiments on people with a severed corpus callosum) has confirmed that in most people, the left hemisphere is the more verbal, and that the right hemisphere excels in visual perception and the recognition of emotion. - studies of healthy people with intact brains confirm that each hemisphere makes unique contributions to the integrated functioning of the brain.
because jerry suffered severe seizures, his neurosurgeon decided to "split his brain." what does this mean? how might a psychologist use people who have had split-brain surgery to determine the location of speech control?
- splitting his brain involves severing the corpus callosum, so information cannot travel between the 2 brain hemispheres. - language is a left-hemisphere function. - when an image is projected to the left visual field, it is processed in the right hemisphere of the brain. jerry would not be able to say what he saw, because the severed corpus callosum prevents the information from traveling from the right hemisphere to the speech center (broca's area) in the left hemisphere.
what structures make up the brainstem, and what are the functions of the brainstem, thalamus, and cerebellum?
- the brainstem, the oldest part of the brain, is responsible for automatic survival functions. its components are the medulla (which controls heartbeat and breathing), the pons (which helps coordinate movements), and the reticular formation (which affects arousal). - the thalamus, sitting above the brainstem, acts as the brain's sensory control center. the cerebellum, attached to the rear of the brainstem, coordinates muscle movement and balance and also helps process sensory information.
charlotte is 88 years old and is feeling the effects of her long life. she suffered a stroke five years ago, which left the right side of her body limp. she also sometimes has trouble understanding when she is asked questions. her doctors believe that she also may be suffering from the beginning stages of alzheimer's disease. define each of the following terms and explain how each might contribute to charlotte's current circumstance. - motor cortex - acetylcholine - association areas - plasticity - epigenetics
- the motor cortex is responsible for directing movements. the left motor cortex controls the right side of the body while the right motor cortex controls the left side of the body - because charlotte's right side is limp, the damage from her stroke most likely occurred in the left hemisphere and potentially in her left motor cortex, which would leave her with little muscular control over the right side of her body - acetylcholine is a neurotransmitter that plays a role in muscle action, learning, and memory - if charlotte suffers from alzheimer's disease, it is possible that the neurons responsible for producing acetylcholine have deteriorated - association areas are the areas of the cerebral cortex not directly involved in motor or sensory functions; rather they are involved in higher-order thought processes such as learning, memory, and thinking - if charlotte's association areas have been damaged, it may be difficult for her to integrate new ideas. she may also have trouble retrieving memories that were once easily recalled - plasticity is the brain's ability to create new neural pathways. this often occurs in response to brain injuries and occurs most efficiently in children - because of charlotte's age, her brain will not have the ability to build an abundance of new neural networks, and if she has not recovered from her injury in a few months time, she is likely to make little progress in her recovery - epigenetics is the study of environmental influences on gene expression, which occur without DNA change - perhaps charlotte has a predisposition for alzheimer's disease. If she was in an environment which was not enriching and cognitively engaging, it may have made alzheimer's disease more likely. on the other hand, despite having a genetic predisposition for alzheimer's disease, if charlotte was exposed to an enriching environment, her disposition may not have been expressed
anthony attends a high school band concert. first, identify and explain which two lobes of his brain are most important for watching and listening to the concert. second, explain which lobe of the brain is most responsible for analyzing the music and finding personal meaning
- the occipital lobes comprise the visual processing center that allows anthony to watch the concert. - the temporal lobes comprise the auditory processing center that allows anthony to listen to the concert. - the frontal lobes are the home of the higher-order thinking skills that allow anthony to analyze the music and find personal meaning.
how do nerve cells communicate with other nerve cells?
- when action potentials reach the end of an axon (the axon terminals), they stimulate the release of neurotransmitters - these chemical messengers carry a message from the sending neuron across a synapse to receptor sites on a receiving neuron - the sending neuron, in a process called reuptake, then reabsorbs the excess neurotransmitter molecules in the synaptic gap - if incoming signals are strong enough, the receiving neuron generates its own action potential and relays the message to other cells
computer-enhanced X-rays used to create brain images are known as
CT (computed tomography) scans
a researcher interested in determining the size of a particular area of the brain would be most likely to use what kind of test?
MRI
which of the following scanning techniques measures glucose consumption as an indicator of brain activity?
PET scan
CT (computed tomography) scan
a series of x-ray photographs taken from different angles and combined by computer into a composite representation of a slice of the brain's structure (also called CAT scan)
reflex
a simple, automatic response to a sensory stimulus, such as the knee-jerk response
surgical stimulation of the somatosensory cortex might result in the false sensation of what?
a bad odor
DNA (deoxyribonucleic acid)
a complex molecule containing the genetic information that makes up the chromosomes
split brain
a condition resulting from surgery that isolates the brain's two hemispheres by cutting the fibers (mainly those of the corpus callosum) connecting them
myelin sheath
a fatty tissue layer segmentally encasing the axons of some neurons; enables vastly greater transmission speed as neural impulses hop from one sausage-like node to the next
antagonist
a molecule that, by binding to a receptor site, inhibits or blocks a response
agonist
a molecule that, by binding to a receptor site, stimulates a response
neuron
a nerve cell, the basic building block of the nervous system
reticular formation
a nerve network that travels through the brainstem and thalamus and plays an important role in controlling arousal
action potential
a neural impulse; a brief electrical charge that travels down an axon
hypothalamus
a neural structure lying below (hypo) the thalamus; it directs several maintenance activities (eating, drinking, body temperature), helps govern the endocrine system via the pituitary gland, and is linked to emotion and reward
how do neurons communicate with one another?
a neuron fires when excitatory inputs exceed inhibitory inputs by a sufficient threshold. when the resulting impulse reaches the axon's end, it triggers the release of chemical messengers called neurotransmitters. after crossing a tiny space between one neuron's terminal branch and the next neuron's dendrite (the synaptic gap), these molecules chemically activate receptor sites on neighboring neurons
dendrites
a neuron's bushy, branching extensions that receive messages and conduct impulses toward the cell body
all-or-none response
a neuron's reaction of either firing (with a full-strength response) or not firing
reuptake
a neurotransmitter's reabsorption by the sending neuron
phrenology
a now abandoned study of the shape of skull as indicative of the strengths of different faculties
adrenal glands
a pair of endocrine glands that sit just above the kidneys and secrete hormones (epinephrine and norepinephrine) that help arouse the body in times of stress
refractory period
a period of inactivity after a neuron has fired
mutation
a random error in gene replication that leads to a change
