Chapter 2: Cognitive Neuroscience Flashcards
The study of the physiological basis of cognition
Cognitive Psychology
A topic can be studied in a number of different ways, with each approach contributing to its own dimension of our understanding
Levels of analysis
The idea that individual cells transmit signals in the nervous system, and that these cells are not continuous with other cells.
Neuron doctrine
The metabolic centre of the neuron
Cell body
Branch out from the cell body, receive signals from other neurons
Dendrites
Long processes that transmit signals to other neurons
Axons
Small gap in between the end of an axon and the dendrites/cell body of another
Synapse
Groups of interconnected neurons which are in turn connected
Neural circuits
Neurons that are specialized to pick up information in the environment
Receptors
What are the three main concepts introduced by Cajal?
Individual neurons, synapses, and neural circuits
Value (millivolts) at which neurons stay when there are no signals
Resting potential (-70 millivolts)
Energy transmitted down an axon when a neuron is stimulated
Nerve impulse (leading to action potential)
What property makes action potentials ideal for transmitting signals over a distance?
No change in height or shape (signal remains the same size)
What happens when an action potential reaches a synapse?
Neurotransmitters are released
What is the relationship discovered by Adrian between the intensity of a stimulus and nerve firing?
Electrical signals are representing the intensity of the stimulus - the more intense the stimulus, the greater the rate of nerve firing - and this is related to the magnitude of the experience
How can different qualities and experiences of stimuli be explained?
Different stimuli activate different neurons and areas of the brain.
Explain the principle of neural representation.
Everything that a person experiences is based on representations in the person’s nervous system.
Neurons that respond to specific stimulus features.
Feature detectors
Phenomenon in which the structure of the brain is changed by experience.
Experience-dependent plasticity
Explain Blakemore and Cooper’s (1970) experiment on experience-dependent plasticity?
Reared kittens in an environment with only verticals, found that visual cortex was reshaped such that it responded mainly to neurons
Progression from lower to higher levels of the brain
Hierarchical processing
The problem of neural representation for the senses
Problem of sensory coding
How neurons represent various characteristics of the environment
Sensory code
The representation of a particular object by the pattern of firing of a large number of neurons
Population coding
When a particular object is represented by a pattern of firing of only a small group of neurons
Sparse coding
Specific functions are served by specific areas of the brain
Localization of function
Layer of tissue about 3mm thick which covers the brain
Cerebral cortex
Located below the cortex
Subcortical areas
The study of the behaviour of people with brain damage
Neuropsychology
Describe characteristics of Broca’s aphasia
Slow, laboured, ungrammatical speech
Describe characteristics of Wernicke’s aphasia
Fluent, grammatically correct speech that tends to be incoherent
Name key pieces of evidence for the localization of function in the brain
Broca’s and Wernicke’s areas
WW1 damage to the occipital lobe (blindness)
Recording from single neurons
Brain imaging (fMRI research)
Where is the auditory cortex?
Upper temporal lobe
Where is the somatosensory cortex?
Parietal lobe
Which area of the brain is associated with sensory coordination and higher functioning
Frontal lobe
An inability to recognize faces
Prosopagnosia
Describe double dissociation
Damage to one area 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
Explain how fMRI works
Oxygen binds to hemoglobin in the blood, increasing its magnetic properties such that when a magnetic field is presented to the brain, oxygenated hemoglobin molecules respond more strongly
Damage to which part of the brain causes prosopagnosia?
Fusiform face area (FFA)
Area associated with spatial layout
Parahippocampal place area (PPA)
Area associated with bodies and parts of bodies
Extrastriate body area (EBA)
Explain the principle of cognition saying that most of our experience is multidimensional
Even simple experiences involve combinations of different qualities
Activates many areas of the brain
Distributed representation
Memories for events in a person’s life
Episodic memories
Memories for facts
Semantic memories
Interconnected areas of the brain that can communicate with each other
Neural networks
What are the four principles associated with neural networks?
- There are structural pathways called networks
- Within the structural pathways are functional pathways that serve different functions
- Networks operate dynamically
- There is a resting state of brain activity
The brain’s “wiring diagram” created by nerve axons that connect different brain areas
Structural connectivity
Structural description of the network of elements and connections forming the human brain
Connectome
Imaging technique based on how water diffuses down the length of nerve fibres
Track-weighted imaging (TWI)
The extent to which activity in two areas of the brain are correlated
Functional connectivity
Name a method to determine functional connectivity
Resting-state fMRI
Describe the four steps in resting-state functional connectivity tests
- Use task-related fMRI to determine a brain location associated with a task
- Measure resting-state fMRI at the seed location
- Measure resting-state fMRI at the test location
- Calculate the correlation between the seed and test location responses
A network of structures that respond when a person is not involved in specific tasks
Default mode network (DFM)
What are the 3 key questions?
The representation question: “How are cognitions represented by neural firing?”
The organization question: “How are cognitions localized in different areas of the brain?”
The communication question: “How are different areas of the brain connected and how do they communicate?”
