IB Psychology SL/HL- Biological Approach Key Terms

Key terms for Biological Approach SL/HL

MRI

magnetic resonance imaging) is a medical imaging technique used to generate pictures of the human anatomy and other physiological approach inside the body, which is done using strong magnetic fields and radio waves

Localisation of Function

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

Frontal Lobe

the foremost part of the brain responsible for expressive language and for managing higher level executive functions – capacity to plan, organise, initiate, self-monitor and control your own responses. 

Motor cortex

part of the brain coordinating movement across multiple joints and muscle groups to achieve smooth and purposeful actions.

Sensory cortex

part of the brain responsible for making sense out of information gathered by the five senses.

Parietal lobe

necessary for processing sensory information and spatial awareness. 

Occipital lobe

part of the brain responsible for visual perception including colour, form and motion.

Temporal lobe

part of the brain which plays a role in managing emotions, processing information from senses, storing and retrieving memories and understanding language

Cerebellum

part of the brain responsible for coordinating movement and balance

Spatial memory

a type of memory allowing us to remember the location of objects or navigating environment 

Hippocampus

part of the brain, whose major role is rooted in learning and memory. Especially in holding short term memories and transferring them to long term storage in the brain. 

Neuroplasticity

the ability of the brain to form and reorganise synaptic connections (create, destroy, strengthening) in response to learning, experience, forgetting or following an injury. 

Neuron

nerve cells that send messages throughout the human body to and from the brain, which control every human function from breathing, to eating to walking and thinking. 

Neural networks

Networks of neurons (interconnected set of neurons) that carry information throughout body

Neural pruning

The process by which extra neurons and synaptic connections are eliminated due to a lack of potentiation as a result of discontinued behaviour

Long-term potentiation

The repetition of a tasks/behaviours results in neuroplasticity through dendritic branching which leads to an increase in neural density. This strengthens the synapses

Dendritic Branching

The process by which the dendrites of one neuron extend to reach out to other neurons

Dendritic pruning

The removal of synaptic connections

Neurotransmitters

Chemicals that communicate information via electrical impulses throughout the body. 

Excitatory neurotransmitters

A neurotransmitter that binds to the receptor sites and increases the chances of the post-synaptic neuron firing a signal

Inhibitory neurotransmitters

A neurotransmitter that binds to the receptor sites and reduces the chances of the post-synaptic neuron firing a signal

Agonists

drug/substances that bind to a receptor inside/ on the surface of a cell that cause the same action as the substance that usually binds to the receptor

Antagonists

a substance stopping the action/effect of another substance (drug blocking) 

fMRI

(Functional magnetic resonance imaging) an imaging technique used to measure the small changes in blood flow occurring with brain activity, and may be used to examine which parts of the brain handle certain functions and even guide brain treatment. 

Hormones

chemicals released by specific glands in the body to regulate medium- and long-term changes in the body. Some hormones like adrenaline, also act as a neurotransmitter and can produce instantaneous effects on mood and attention 

Pheremones

Chemical secreted by glands to act outside the body (i.e. sweat)

Oxytocin

A hormone commonly labelled the ‘love hormone’, ‘cuddle hormone’ and ‘trust hormone’. It has been shown in to increase trust affection and cooperation in both animals and humans

MHC gene

A gene that provides the genetic code for proteins found on the surfaces of cells that help the immune system recognise foreign substances

Synapse

The space between the end of a nerve cell and another cell 

Kinship

Valuing significant others as though they were members of one's own family. The network of relationships, often based on blood or marriage, that individuals perceive as close, important, and influential, forming the foundation of social identity and social organisation.

Sexual selection

Natural selection arising through preference by one sex for certain characteristics in individuals of the other sex

Androstenes

A form of steroid molecule that can be male (androstadiene) and female (estratetraenol) 

Androstadienone (AND)

A human steroid that is present in male semen and sweat. It heightens sympathetic arousal, alters levels of cortisol, and promotes positive mood state in females. In a nutshell, AND is a testosterone-derived pheromone found in human sweat

Estratetraenol (EST)

Is the female equivalent of AND. It is a oestrogen-derived pheromone found in human sweat. 

Phenotypes

The physical traits and characteristics of an individual and are influenced by their genotype and the environment.  

Genotypes

The genetic make-up of an individual

MAOA gene

A gene whose job it is to make an enzyme called MAOA (Monoamine Oxidase A) 

MAOA (Monoamine Oxidase A)

The enzyme responsible for breaking down a number of neurotransmitters including serotonin. This ‘breaking down’ of serotonin is part of neurotransmission, MAOA is the enzyme that effectively sweeps up any serotonin left in the synaptic gap after neurotransmission is complete. 

Gene

The basic and functional unit of heredity. Made up of DNA. Some genes act as instructions to make molecules called proteins

Diathesis Stress Model

The idea that Diathesis and Stress in combination create aggressive, antisocial behaviour

Diathesis

A predisposition or vulnerability

Monozygotic

Identical twins – fertilisation of one sperm and egg, splits after fertilisation to form 2 identical embryos that share 100% of their DNA

Dizygoticq

Non-Identical twins – two eggs are fertilised by 2 separate sperm, DZ twins share 50% of their DNA

Concordance rates

The presence of the same trait in both members of a pair

Intersexual

A type of selection that occurs between the same sex, direct competition between individuals of the same sex to maintain the ability to pass on their traits.  

Intrasexual

A type of selection that occurs when one sex is able to select a mate, becomes a competition to attract a mate