Biological Approach: Brain & Behaviour Flashcards
Magnetic Resonance Imaging (MRI)
- Structural imaging create images of brain structure
- Is a composite image of several images of the brain (3D)
- The image can either be viewed as a slice of the brain from any angle, or it can be used to create a 3D of the brain
- Images are useful for observing structure of the brain
- Images are created using the magnetic field of the MRI to interact with the hydrogen atoms, which are magnetic, present in the water molecules in the brain tissue
Functional Magnetic Resonance Imaging (fMRI)
- Measures brain activity by detecting changes in blood flow
- Indicates which areas of the brain are active when engaged in a behavioural cognitive process
- Measures BOLD (blood oxygen level dependent) signal, which reflects changed in blood oxygenation (active areas of the brain require more oxygen)
- Changing levels of oxygen are detected by the magnetic field (oxygenated blood is less magnetic) via the hydrogen atoms
- Most-used brain scanning technology in research today
- Allows us to see how the brain reacts to outside forces and what parts it uses (e.x. music, pain, movement)
Strengths of Brain Scans
- Non-invasive and minimal harm to participant
- Images have high resolution
- Scanning techniques are practical and can allow for researcher triangulation in the analysis of data
Limitation of Brain Scans
- Unnatural environment for cognition
- Indirect measurement
- “Exaggerated” colours (fMRI)
- Sampling/population bias
- Extraneous variables
- Expensive to use and acquire
- (MRI) only indicates structure, it doesn’t map what’s happening in the brain
- Brain areas activate for various reasons
- MRI is correlation since static images while causational for fMRI is limited to basic activities
Theory of Localisation of Function
Theory that specific areas of the brain are responsible for particular mental processes and behaviours. Different regions of the brain are specialised for different tasks
Hippocampus location and function
Found deep in the temporal lobe, in the limbic system. Its function is critical to memory formation
Hippocampus responsible for the …
- Process of short-term memory (STM) to long-term memory (LTM)
- Formation of declarative memories (semantic facts and episodic events)
- Spatial memories (pathways and routes)
Examples include the function of bees, first time driving, and the fastest route home.
Neurons
Nerve cells that make up your nervous system and are responsible for all bodily functions and behaviour
Neurons Function
They send electrochemical messages to and from the brain in response to stimuli, either for the external environment or from internal changes within the body
Action Potentials
Electrical impulses that travel down the axon when a neuron is firing
Neurotransmitters
Chemical messengers that carry signals either between neurons, or from a neuron to a target cell
Acetylcholine
- Neurotransmitter involved in thought, learning and memory
- Activates muscle action in the body and is also associated with attention and awakening
- Released in the synapse
Agonists
Chemicals that attach to a receptor, stimulate the cell, causing a response
Antagonists
Drugs that fit into receptor sites, blocking the neurotransmitter action and preventing action potential
Endogenous Agonists
Agonists that occur naturally in the body and are biologically part of the nervous system as hormones and neurotransmitters (e.x. acetylcholine)
Exogenous Agonists
Agonists that come from exterior sources like drugs and toxins (e.x. scopolamine)
Excitatory neurotransmitters
Neurotransmitters that make action potentials more likely (e.x. acetylcholine)
Inhibitory Neurotransmitters
Neurotransmitters that make action potentials less likely
Neuroplasticity
Describes the changes in neural pathways and synapses due to changes in behaviour, environment, thinking, and emotions
Dendritic Branching
When high levels of stimulation and numerous learning opportunities lead to an increase in density of neural connections
Synaptic Pruning
The removal of synapses that are no longer needed, making the functioning of active synapses more efficient
Long-Term Potentiation (LTP)
When synapses become stronger through repeated use and high stimulation
Grey Matter
Composed of cell bodies, making up 60% of the brain
White Matter
Composed of the myelin sheath that protects axons, making up 40% of the brain
