Psychology chapter 3 Flashcards
evolution
the change in the frequency of genes occurring in an interbreeding population over generations
Human Genome Project
a massive effort to identify the components of the entire human genome
monozygotic twins
come from a single ovum (egg), which makes them genetically identical (almost 100% genetic similarity)
heritability
a statistic, expressed as a number between zero and one, that represents the degree to which genetic differences between individuals contribute to individual differences in a behaviour or trait found in a population
evolutionary psychology
attempts to explain human behaviours based on the beneficial function(s) they may have served in our species’ development
DNA (deoxyribonucleic acid)
a molecule formed in a double-helix shape that contains four nucleotides: adenine, cytosine, guanine, and thymine
hunter-gatherer theory
links performance on specific tasks to the different roles performed by males and females over the course of our evolutionary history
epigenetics
changes in gene expression that occur as a result of experience and that do not alter the genetic code
behavioural genetics
the study of how genes and the environment influence behaviour
genes
the basic units of heredity; genes are responsible for guiding the process of creating the proteins that make up our physical structures and regulate development and physiological processes throughout the lifespan
homozygous
if two corresponding genes at a given location on a pair of chromosomes are the same
heterozygous
if two corresponding genes at a given location on a pair of chromosomes differ
longitudinal studies
studies that follow the same individuals for many years, often decades
CRISPR
a technique that allows genetic material to be removed, added, or altered in specific locations of the genome
natural selection
the process by which favourable traits become increasingly common in a population of interbreeding individuals, while traits that are unfavourable become less common
behavioural genomics
the study of DNA and the ways in which specific genes are related to behaviour
chromosomes
structures in the cellular nucleus that are lined with all of the genes an individual inherits
phenotype
the physical traits and behavioural characteristics that show genetic variation, such as eye colour, the shape and size of facial features, intelligence, and even personality
dizygotic twins
fraternal twins come from two separate eggs fertilized by two different sperm cells that share the same womb; these twins have approximately 50% of their genetics in common
genotype
the genetic makeup of an organism—the unique set of genes that comprise that individual’s genetic code
endorphin
a hormone produced by the pituitary gland and the hypothalamus that functions to reduce pain and induce feelings of pleasure
axon terminals
bulb-like extensions filled with vesicles (little bags of molecules)
norepinephrine
(also known as noradrenaline) a monoamine synthesized from dopamine molecules that is involved in regulating stress responses, including increasing arousal, attention, and heart rate
acetylcholine
one of the most widespread neurotransmitters within the body, found at the junctions between nerve cells and skeletal muscles; it is very important for voluntary movement
serotonin
a monoamine involved in regulating mood, sleep, aggression, and appetite
stem cells
a unique type of cell that does not have a predestined function
resting potential
relatively stable state during which the cell is not transmitting messages
cell body
the part of a neuron that contains the nucleus that houses the cell’s genetic material
neurogenesis
the formation of new neurons
ion channels
small pores on the neuron’s cell membrane
GABA (gamma-amino butyric acid)
the primary inhibitory neurotransmitter of the nervous system, meaning that it prevents neurons from generating action potentials
refractory period
1) brief period in which a neuron cannot fire; (2) a time period during which erection and orgasm are not physically possible
presynaptic cell (or presynaptic neuron)
is the neuron that releases its neurotransmitters into the synapse
neurotransmitters
the chemicals that function as messengers allowing neurons to communicate with each other
agonists
drugs that enhance or mimic the effects of a neurotransmitter’s action
adrenal glands
a pair of endocrine glands located adjacent to the kidneys that release stress hormones, such as cortisol and epinephrine
action potential
a wave of electrical activity that originates at the beginning of the axon near the cell body and rapidly travels down its length
dendrites
small branches radiating from the cell body that receive messages from other cells and transmit those messages toward the rest of the cell
myelin
a fatty sheath that insulates axons from one another, resulting in increased speed and efficiency of neural communication
axon
transports information in the form of electrochemical reactions from the cell body to the end of the neuron
hormones
chemicals secreted by the glands of the endocrine system
glial cells
specialized cells of the nervous system that are involved in mounting immune responses in the brain, removing waste, and synchronizing the activity of the billions of neurons that constitute the nervous system
synapse
an area consisting of a neuron’s axon terminals and a different neuron’s dendrites; these structures are separated by a microscopic space into which neurotransmitters can be released
hypothalamus
a set of nuclei found on the bottom surface of the brain that are involved in regulating motivation and homeostasis by stimulating the release of hormones throughout the body
testosterone
a hormone that is involved in the development of sex characteristics and the motivation of sexual behaviour
endorphin
a hormone produced by the pituitary gland and the hypothalamus that functions to reduce pain and induce feelings of pleasure
postsynaptic cell (or postsynaptic neuron)
is the neuron that receives neurotransmitters from the presynaptic cell
epinephrine
a hormone and neurotransmitter created in the adrenal gland on the kidneys
all-or-none principle
individual nerve cells fire at the same strength every time an action potential occurs
pituitary gland
the master gland of the endocrine system that produces hormones and sends commands about hormone production to the other glands of the endocrine system
glutamate
most common excitatory neurotransmitter in the brains of vertebrates
neurons
one of the major types of cells found in the nervous system, which are responsible for sending and receiving messages throughout the body
reuptake
a process whereby neurotransmitter molecules that have been released into the synapse are reabsorbed into the axon terminals of the presynaptic neuron
synaptic cleft
the minute space between the axon terminal (terminal button) and the dendrite
antagonists
i nhibit neurotransmitter activity by blocking receptors or preventing synthesis of a neurotransmitter
dopamine
a monoamine neurotransmitter involved in such varied functions as mood, control of voluntary movement, and processing of rewarding experiences
multiple sclerosis
a disease in which the immune system does not recognize myelin and attacks it—a process that can devastate the structural and functional integrity of the nervous system
cerebral cortex
the convoluted, wrinkled outer layer of the brain that is involved in multiple higher functions, such as thought, language, and personality
autonomic nervous system
the portion of the peripheral nervous system responsible for regulating the activity of organs and glands
hippocampus
critical for learning and memory, particularly the formation of new memories
cerebral hemispheres
nearly symmetrical halves of the brain that contain the same structures
peripheral nervous system (PNS)
a division of the nervous system that transmits signals between the brain and the rest of the body and is divided into two subcomponents, the somatic system and the autonomic system
neuroplasticity
the capacity of the brain to change and rewire itself based on individual experience
thalamus
a set of nuclei involved in relaying sensory information to different regions of the brain
amygdala
facilitates memory formation for emotional events, mediates fear responses, and appears to play a role in recognizing and interpreting emotional stimuli, including facial expressions
corpus callosum
a collection of neural fibres connecting the two cerebral hemispheres
somatic nervous system
consists of nerves that control skeletal muscles, which are responsible for voluntary and reflexive movement; it also consists of nerves that receive sensory input from the body
Huntington’s disease
a condition involving uncontrollable movements of the body, head, and face
brainstem
the “stem” or bottom of the brain and consists of two structures: the medulla and the pons
forebrain
the most visibly obvious region of the brain, consists of all of the neural structures that are located above the midbrain, including all of the folds and grooves on the outer surface of the brain; the multiple interconnected structures in the forebrain are critical to such complex processes as emotion, memory, thinking, and reasoning
limbic system
an integrated network involved in emotion and memory
frontal lobes
important in numerous higher cognitive functions, such as planning, regulating impulses and emotions, language production, and voluntary movement
hemispheric specialization
a phenomenon where the two sides of the cortex often perform very different functions
trophic factors
can stimulate the growth of new dendrites and axons
temporal lobes
located at the sides of the brain near the ears and are involved in hearing, language, and some higher-level aspects of vision such as object and face recognition
neglect (or visual neglect)
a situation in which the patient does not attend to anything that appears in the left half of his or her visual field
cerebellum
(Latin for “little brain”) is the lobe-like structure at the base of the brain that is involved in the monitoring of movement, maintaining balance, attention, and emotional responses
Tourette’s syndrome
a condition marked by erratic and repetitive facial and muscle movements (called tics), heavy eye blinking, and frequent noise making such as grunting, snorting, or sniffing
reticular formation
extends from the medulla upwards to the midbrain (described shortly) and is involved with attention and alertness
cortical deafness
problems with hearing despite the fact that the patient’s ears work perfectly
basal ganglia
a group of three structures that are involved in facilitating planned movements, skill learning, and integrating sensory and movement information with the brain’s reward system
occipital lobes
located at the rear of the brain and are where visual information is processed
sympathetic nervous system
responsible for the fight-or-flight response of an increased heart rate, dilated pupils, and decreased salivary flow—responses that prepare the body for action
parasympathetic nervous system
helps maintain homeostatic balance in the presence of change; following sympathetic arousal, it works to return the body to a baseline, nonemergency state
Parkinson’s disease
a condition marked by major impairments in voluntary movement
parietal lobes
involved in our experiences of touch as well our bodily awareness
central nervous system (CNS)
consists of the brain and the spinal cord
midbrain
resides just above the hindbrain, primarily functions as a relay station between sensory and motor areas
lesioning
a technique in which researchers intentionally damage an area in the brain
transcranial magnetic stimulation (TMS)
a procedure in which an electromagnetic pulse is delivered to a targeted region of the brain
positron emission tomography (PET)
a type of scan in which a low level of a radioactive isotope is injected into the blood, and its movement to regions of the brain engaged in a particular task is measured
diffusion tensor imaging (DTI)
a form of structural neuroimaging allowing researchers or medical personnel to measure white-matter pathways in the brain
computerized tomography (CT) scan
a structural neuroimaging technique in which x-rays are sent through the brain by a tube that rotates around the head
functional magnetic resonance imaging (fMRI)
measures brain activity by detecting the influx of oxygen-rich blood into neural areas that were just active
functional neuroimaging
a type of brain scanning that provides information about which areas of the brain are active when a person performs a particular behaviour
sham group (or sham lesion group)
a set of animals that go through all of the surgical procedures aside from the lesion itself in order to control for the effects of stress, anesthesia, and the annoyance of stitches. An example of the lesion method is found in studies of spatial learning
magnetic resonance imaging (MRI)
a structural imaging technique in which clear images of the brain are created based on how different neural regions absorb and release energy while in a magnetic field
magnetoencephalography (MEG)
a neuroimaging technique that measures the tiny magnetic fields created by the electrical activity of nerve cells in the brain
structural neuroimaging
a type of brain scanning that produces images of the different structures of the brain
electroencephalogram (EEG)
measures patterns of brain activity with the use of multiple electrodes attached to the scalp
What are behaviours influenced by?
genes
How many genes do humans have
20 000- 25 000
6000 and 7000 are active in the human brain.
Which group provides insight into how genetics affect behaviour
twins
A heritability of 0 or 1
means that genes do not contribute to individual differences in a trait, whereas a heritability of 1.0 indicates that genes account for all individual differences in a trait.
What do heritability scores tell us?
tell us the degree to which genetics explain differences between people with that trait. S
When studying adopted children
the biological parents are the nature and adopted family is nurture
What factors can influence whether genes are turned on or off
diet, stress level, and sleep
What separated our species, Homo sapiens, from other animals?
(1) larger frontal lobes than other species
(2) had brains with more folds, thus allowing for more brain cells to be squeezed inside their skulls.
What is the primary purpose of neurons?
is to “fire,” to receive input from one group of neurons and to then transmit that information to other neurons
axon hillock
These impulses from other cells will travel across the neuron to the base of the cell body
If the axon hillock receives enough stimulation from other neurons, it will initiate a chemical reaction that will flow down the rest of the neuron.
