Chapter 3: BIological Psychology Flashcards
what are chromosomes?
- structures in the cell nucleus that contain the genes an individual inherits
- Get half chromosomes from parents
- XY - male
- XX - female
what is DNA?
- deoxyribonucleic acid
- a double helix molecule that contains 4 types of nucleotides (A, C, T, G)
- blue print for what makes us us
what are genes?
basic unit of herdity; guides protein synthesis
what are genotypes?
genetic makeup of an organism
what are phenotypes?
- observable characteristics, including physical structures and behaviours
- Ex. height: interaction btwn genotype and environment
what does homozygous mean?
- inherited same version of gene from fathers chromosome and mothers chromosome
- When genes @ particular location are the same on each chromosome
what are heterozygous mean?
- when the genes @ a particular location are diff on each chromosome
what does dominant mean?
that genes and the genes assoc. w/ will always be expressed, doesn’t matter what its paired w/
what does recessive mean?
only expressed if paired w/ another recessive gene
what does polygenetic mean?
multiple genes contribute to the trait
what does behavioural genetics mean?
evaluating how genes and environment influence behaviour by studying people of varying relatedness
what are twin studies?
- Study of pairs of people that differ in how related they are to each other
- The more similarly genetic people are, they should have similar genetic outcomes
- Monozygotic (identical) vs dizygotic (fraternal) twins
what are Concordance rates?
degree of similarity btwn pairs of individuals
what are adoption studies?
- Comparing adopted child and biological parents
- If adopted kid more similar to bio parents than adopted, suggests that genetics has strong influence on that trait
- More like bio parents = nature
- More like adoptive = nurture
what is heritability?
- ranges form 0 to 1
- Measures degree to which genetics explains individual diffs or variance in a behaviour or trait
- Isn’t fixed
- The diffs btwn 2 pairs of individuals that we can attribute to a behaviour/cause - NOT THE ENVIRONMENT ANY DIFFS MEASURED BETWEEN THEM IS BC OF THEIR GENETICS
- h^2 = 0.99 means 99% of this difference can be attributed to genetics
what are behavioural genomics?
- study of DNA and ways in which specific genes are related to behaviour
- Human genome project - mapped entire genetic code of a human being
- Can sequence people’s genomes as see common abnormal sequences among diseases
how do single genes affect behaviour?
- Any complex phenomena is caused by many genes
- Combinations of genes influence behaviour, one gene isn’t limited to 1 trait
Genes code for proteins and combine and get involved in diff
Proteins used in diff structures and ways i n the body
Inheritance of a gene isn’t guarantee that characteristic will be expressed
what is evolution?
can be thought of as change in frequency of genes occurring in a pop over generations
what did darwin believe about evolutionary psychology?
- natural selection
- Didn’t know how selection developed on the gene basis
- Certain genes become more frequent over time = natural selection
how does genetics influence human mate preferences?
- Preferences likely shaped by differing evolutionary pressures on each sex
- Females = prefer strong, committed, and financially secure males
- Males = prefer youthful, physically beautiful females
- No limit on # of sperm that can be developed
- Reproductive success is only limited by the number of partners they can acquire over their lifetime
- Comes down to reproductive biology
- Females have more cost assoc. w/ reproduction (limited production of eggs in a lifetime)
what are the sex differences in cognition?
- diff hormone lvls can affect cognitive processes
- Testosterone effects
- Males tend to do spatial stuff faster than females
- Female better at language, spatial memory
- Statistical vs practical significance
- Hunter gatherer explanation vs. byproduct of other evolutionary changes
- Some say males better at spatial bc they were hunters, females had to remember location of food sources bc gatherers
- Environment always play a role
- Stereotypes of women and men
- Stereotype that women are bad at math - has nothing to do w/ biological/genetic reason, more has to do w/ our expectations
what is a neuron?
- Basic units of behaviour
- Have billion neurons in our brain
- Soma: top
- Dendrites connect to others - that’s how neurons communicate w/ each other
what are the types of neurons?
sensory neurons, motor neurons, interneurons
what are sensory neurons?
collect info from external world through our 5 senses, and communicates it to spinal cord or brain
what are motor neurons?
move info from brain/spinal cord to muscles to help us move our bodies and create a motor response
what are interneurons?
- connect sensory neuron to motor neuron to create circuit to create reflex arc
- Helps us make quick reactions to stuff (Ex. putting hand on a hot stove top)
- Take signal from neuron, route it through spinal cord, connect it to motor neuron and send signal to muscles to pull hand back
what is neural plasticity?
- brain’s ability to change structure and function
- Brain cells change according to our experiences
- Brain previously thought to be unchanging outside critical developmental window during childhood
- Thought that brain damage was permanent
- Most of brain’s plasticity comes from changes to existing neurons themselves
- Dendritic branching and formation of dendritic spines
what is adult neurogenesis?
- formation of new neurons that are integrated into adult brain
- Only few parts of brain capable of neurogenesis
- Takes weeks to happen
what is branching?
when neuron develops more branches, increases potential of that neuron to connect w/ other neurons
what is human echolocation?
- When people are blind, the back of the brain starts to be recruited for non-visual tasks
- Tiny microphones placed in ears of blind echolocators as they tried to identify various objects
- Researchers played back recording during fMRI scan = activation of primary visual cortex in brain
- Able to echolocate (using sound to see)
- Feedback of sound allows them to know where things are in their environment
what are glial cells and types?
- variety of cell types that support functions for neurons
- Microglia: engulf debris and mounts immune response (body guards of neurons)
- Oligodendrocytes: produce extension that wrap axons in myelin
- Astrocytes: provide physical support and delivers energy to neurons, glue of the brain
what is MS (multiple sclerosis)?
- Result of malfunctioning glial cells
- Myelin created by oligodendrocytes become target of the immune response for microglia
- Glial incorrectly labels - Myelin as a foreign pathogen that’s not supposed to be in body and then destroy it
- Causes loss of saltatory conduction - slows electrical signals down length of neuron, neurons can’t communicate like they should
- Body deteriorates and people lose independence over time
what are cations?
- +Vely charged ions
- Ex. sodium (Na), potassium (K)
what are anions?
- -vely charged ions
- Ex. Cl, -vely charged proteins
what is concentration gradient?
- ions will move from areas of high concentration to areas of low concentration
what is electrostatic pressure?
- repulsion of like charges, attraction of opposite charges
- Similar charges will move away from one another
- If ions have opposite charges, they’ll attract
what is the synaptic cleft?
- small space btwn terminal button and dendrite of another neuron
- Interact w/ receptor sites on dendrite of neuron
- Grab neurotransmitters which can cause action potentials to start in the neuron
- Neurotransmitter = key, receptor = lock
- Specific shaped receptors for specific neurotransmitters
what is reuptake?
- process whereby released neurotransmitters are absorb into the axon terminals of the presynaptic neuron
- Recycling process
- Ex. SSRI (selective serotonin reuptake inhibitors)
how do SSRI’s (selective serotonin reuptake inhibitors)
work?
- Preventing reuptake of serotonin
- If a cell can’t uptake serotonin bc of a drug, the serotonin transmitters will just float btwn the neurons
- If they’re available and continue to bind these receptors on the dendrite of the post synaptic neuron = continue to cause action potentials and activity
what are excitatory neurotransmitters?
- make action potentials more likely to occur
- Want to depolarize neuron and bring it closer to the threshold for action potential to occur
what are inhibitory neurotransmitters?
decrease likelihood of action potential occurring ; brings it further away from the threshold of action potential
what is glutamate?
primary excitatory neurotransmitter/most abundant, going to make action potentials more likely to occur