IB Psychology HL 1/ SL : Biological Approach to Behavior Key Terms

Key Terms

Localization of Function (LOF)

a theory that certain parts of the brain correspond to certain functions and reflects the idea that behavior, emotion, and/or thoughts originate in specific regions of the brain

Relative Localization of Function

the idea of LOF is that some functions may be strictly localized to specific portions of the brain but also supports that some functions may be widely distributed to other portions of the brain

Strict Localization of Function

idea there is a clear and fixed location in the brain for all functions

Hippocampus

portion of the brain responsible for memory processing; transfer of short-term memory to long-term memory

anterograde amnesia

inability to remember new knowledge; inability to form new memories

neuroplasticity

brain’s ability to change as a result of experience

Formation of neural networks

the repetition of tasks strengthens the synapses resulting in dendric branching, leading to an increase of of neural density (grey matter)

neural pruning

brain eliminating extra brain density and synaptic connections because the behavior is discontinued

neuron

brain cell

neurotransmitter

electro-chemical messengers that mediate the events at the synapse by binding to receptor sites to send messages along neural pathways to immediately influence behavior

excitatory neurotransmitter

binds to excitatory receptor sites to generate an action potential (signal) producing stimulating effects on the brain; increase the likelihood of a neuron firing

inhibitory neurotransmitter

bind to inhibitory receptor sites to prevent the receival of action potential by the neuron producing calming effects on the brain

agonists

mimic the effects of a neurotransmitter resulting in the effects of the neurotransmitter being amplified

antagonist

inhibit the action of a neurotransmitter by blocking the receptor site; reducing its effects

acetylcholine (ACh)

excitatory neurotransmitter believed to be involved with learning and memory

scopolamine

antagonist of acetylcholine

physostigmine

agonist of acetylcholine

Magnetic Resonance Imaging (MRI)

produces a high-resolution, 3-D image of brain structure;

MRI (How?)

scanner detects the energy given off by hydrogen atoms in a magnetic field mapping out the brain because difference areas have different concentration of these atoms

hormone

chemical messengers released by endocrine system glands to regulate the body producing longer term effects

oxytocin (love hormone)

a hormone produced by the hypothalamus that is released by the pituitary gland; plays a role in social bonding, spouse fidelity, intergroup conflict, and ethnocentrism

Ethnocentrism

an inter-group bias where one’s own ethnic group is perceived to be more important/superior than others

pheromone

hypothetical (in humans) chemical substances released by one member of a species that affects the behavior of other members of the same species through airborne chemical communication that is detected by the olfactory system; typically communicates mate qualities

anderostadienone (AND)

putative pheromone associated with attraction; secreted by men impacting (most strongly) women

genes

are made up of DNA providing the blueprint for the structure and function of the human body, including behavior.

genetic similarity

idea that individuals who are more strongly related (sharing a larger portion of their genotype) should demonstrate more similar behavior, provided that behavior is heritable

twin studies

compare similarities in behavior between monozygotic twins and dizygotic twins

kinship studies

examine familial relationships to identify the relationship between genetics and environment for a particular trait/behavior

epigenetics

how behavior and environment can change the expression of genes

5-HTT Serotonin Transporter Gene

influences how much serotonin is in the brain impacting one’s vulnerability to contracting depression later in life

serotonin

an inhibitory neurotransmitter responsible for mood regulation and modulating the body’s response to stressful stimuli

polymorphism

a gene’s differing genotype configuration

5-HTT ss polymorphism

have reduced the production of serotonin, limiting the body’s ability to regulate stress response

5-HTT l allele

l alleles seemingly offer protection from stress-related depression; least vulnerability to stress-related depression