Lecture 2 - Neurobiological Foundations Flashcards
What are models of the mind?
These are representations of structures or processes that help us simplify, visualise or explain the respective structure or process.
What are the 2 types of models?
Structural models
Process models
What are process models?
Illustrate how a process operates
Breaking processes down into units and subprocesses
- flow diagrams
What are structural models?
Represent structures in the brain that are involved in specific functions
Useful for localization, visualization, brain comparison.
What is cognitive neuroscience?
The study of the physiological basis of cognition.
What are the levels of analysis?
Different points in understanding cognitive phenomena
- context
- individual differences
- experience
- emotions
- brain regions
- neural communication
- hormones
What are neurons?
Cells specialised to create, receive and transmit information in the nervous system
What are the structures in a neuron?
Cell body
Dendrites - receive messages
Axon - passes messages on (outgoing signals)
Action potential - electrical signal travelling down axon
Myelin sheath - covers axon of some neurons
Terminals - form junctions
Dendrites (incoming signals)
What is a nerve net?
Interconnected neurons
- continuously interconnected
- allows nonstop continuous communication of signals
What is the neuron doctrine?
(Ramon and Cajal)
Argue that nerve nets are not continuous but rather made up of individual cells that transmit in the nervous system
Neurons form connections to specific neurons resulting in groups of interconnected neurons which together form neural circuits
What are receptors?
Neurons that receive information from outside the senses
How do we measure how neurons communicate?
Electronic amplifiers that are sensitive enough to pick up and amplify a single neuron firing
First recorded by Adrian in 1920s with micro electrodes placed near axons
What is the synapse?
Space between axon of one neuron and dendrite or cell body of another.
What is resting potential?
When a nerve is at rest
What is action potential?
Neuron receives signal from environment (impulse) which briefly raises the relative voltage in the neuron. Information travels down the axon of that neuron to the dendrites of another neuron.
The size of the action potential is always the same but the firing rate depends on stimulus intensity.
Low-intensity stimulus: slow firing (a).
High-intensity stimulus: fast firing (c).
How do neurons communicate across the synapse?
When the action potential reaches the end of the axon, synaptic vesicles open and release chemical neurotransmitters. Synaptic transmission is not an electrical transport of signals but a biochemical one
What are neurotransmitters?
chemicals that affect the electrical signal of the receiving neuron, cross the synapse and bind with the receiving dendrites.
What is the principle of neural representation?
Everything a person experiences is based on representations in the person’s nervous system.
=Everything you experiences is reflected/represented somewhere in the neural system
What are feature detectors?
neurons that respond best to a specific stimulus.
discovered by Hubel & Wiesel (1960s) in research with visual stimuli in cats.
each neuron in the visual area of the cortex responded to a specific type of stimulation
This means that multiple feature detectors represent different aspects of objects
What is experience dependent plasticity?
the structure of the brain changes with experience.
What is sensory coding?
= the problem of neural representation for the senses
= sensory code refers to how neurons represent various characteristics of the environment
What are the three types of sensory coding?
- Specificity coding:representation of a stimulus by the firing of specifically tuned neurons specialized to respond only to a specific stimulus (grandmother cells/neurons)
- Population coding:representation of a stimulus by the pattern of firing of many neurons.
- Sparse coding:representation of a stimulus by a pattern of firing of only a small group of neurons, with most neurons remaining silent.
What is localisation of function?
Specific functions are served by specific areas of the brain.
Cognitive functioning declines in specific ways, when certain areas of the brain are damaged (e.g. by age, disease, or trauma)
Cerebral cortex (3-mm-thick layer covering the brain) contains mechanisms responsible for most cognitive functions.
What are the functions of the frontal lobe?
Motor cortex
- Motor control
- Action knowledge
- ‘Muscle memory’
Executive Control
- Focus/ conscious attention
- Knowledge coordination
- Evaluation of information
Abstract thinking & Problem solving
What are the functions of the parietal lobe?
- Sensory cortex
- Attention
- Imagination & Creativity
- Knowledge integration
What are the functions of the occipital lobe?
Visual cortex
- Visual perception
- Categorization
What are the functions of the temporal lobe?
Memory and Remembering
- Knowledge categories
Language
- Auditory perception & parsing
Hearing
What are the functions of the cerebellum?
Movement coordination
Balance
Rhythm
Proprioception
What are the functions of the brain stem?
Basic biological functions
- Breathing
- Heart rate
What are the primary receiving areas for the senses?
Occipital lobe: vision
Parietal lobe: touch, temperature, and pain
Temporal lobe: hearing, taste, and smell.
Where is coordination of information received from all senses?
Frontal lobe
What are the areas specialised for language?
Broca’s area, in the frontal lobe - Language production is impaired by damage to this area.
Wernicke’s area, in the temporal lobe - Language comprehension is impaired by damage to this area.
What is double dissociation?
When damage to one part of the brain causes function A to be absent while function B is present … and damage to another area causes function B to be absent while function A is present.
