Chapter 2 - Cognitive Neuroscience Flashcards
Cognitive Neuroscience
The study of the physiological (biological) basis of cognition (attention, perception, memory)
Levels of Analysis
- idea that a topic can be studied in different ways
Neurons
- create and transmit information about what we experience and know
Nerve Net
- a network of continuously interconnected nerve fibers
- doesn’t stop sending signals
Neuron doctrine
- non-continuous, individual cells transmit signals in the nervous system
cell body
- center of the neuron
- keeps the cell alive
Dendrites
- receive signals from other neurons
axons (nerve fibers)
- transmit signals to other neurons
Synapse
- small gap between the end of a neuron’s axon and the dendrites or cell body of another neuron
neural circuit
- groups of interconnected neurons that are responsible for processing
- neurons aren’t automatically connected to other neurons - they are selective
receptors
- neurons specialized to pick up information from the environment (ex. eye, ear, skin)
resting potential
- difference in charge between the inside and outside of a nerve fiber when the fiber is at rest (no other electrical signals are present)
nerve impulse (action potential)
- electrical response that is propagated down the length of an axon (nerve fibre)
action potential
- travel down a neuron’s axon
- electrical potential responsible for transmitting neural information and for communication between neurons
- firing and then going back to resting state
neurotransmitter
chemical that is released at the synapse in response to incoming action potentials
What can cause an increase in the rate of nerve firing
- increased stimulus intensity (ex. more pressure on someone’s skin)
- when nerve impulses are crowded tightly together, the sensation is more intense
What is the principle/idea of neural representation?
- everything a person experiences is based on representation in the person’s nervous system
Feature detectors
- neurons that respond to specific stimulus features such as orientation, movement, and length
experience-dependent plasticity
- structure of the brain is changed by experience
what do neurons in the temporal lobe respond to?
- complex geometrical stimuli
- faces
what do neurons in the visual cortex respond to?
- simple stimuli
hierarchical processing
- processing that occurs in a progression from lower to higher areas of the brain
sensory coding
- how neurons represent various characteristics of the environment
specificity coding
- idea that an object could be represented by the firing of a specialized neuron that responds only to that object
- this idea is unlikley to be correct
population coding
- representation of a particular object by the pattern of firing of a large number of neurons
sparse coding
- occurs when a particular object is represented by a pattern of firing of only a small group of neurons, with the majority of neurons remaining silent
what is the difference between representation of perceptions vs of memories?
perceptions: neural firing is associated with the stimulus that is present
memories: neural firing is associated with information about the past that has been stored in the brain
basic principles of brain organization
localization of function
- specific functions are served by specific areas of the brain
what is the cerebral cortex
- wrinkled covering of the brain
neuropsychology
- the study of the behaviour of people with brain damage
cortical equipotentiality
- early 1800s
- idea that the brain operated as an invisible whole as opposed to specialized areas
Broca’s area
- in the frontal lobe
- speech production
Broca’s aphasia
- a condition associated with damage to Broca’s area, in the frontal lobe, characterized by laboured ungrammatical speech and difficulty in understanding some types of sentences
Wernicke’s area
- in the temporal lobe
- language comprehension
Wernicke’s aphasia
- a condition, caused by damage to the area, that is characterized by difficulty in understanding language, and fluent, grammatically correct but incoherent speech
- struggle to match words with their meanings
occipital lobe
- where the visual cortex is located
parietal lobe
- responsible for perceptions of touch, pressure, and pain
frontal lobe
- receives signals from all of the senses and is responsible for coordination of the senses
- thinking and problem solving
prosopagnosia
- inability to recognize faces
double dissociation
- procedure that compares 2 people with complimentary damages to their brains (ex. 1 broca, 1 wernicke)
- demonstrates that those 2 areas aren’t linked together and are actually separate areas (ex. speech production and language comprehension come from 2 different areas)
fMRI
- follows blood flow
- produces a map
fusiform face area (FFA)
- an area in the temporal lobe that contains many neurons that respond selectively to faces
parahippocampal place area (PPA)
- an area in the temporal lobe that contains neurons that are selectively activated by pictures of indoor and outdoor scenes
extrastriate body area (EBA)
- and area in the temporal cortex that is activated by pictures of bodies and parts of bodies, but not by faces or other objects
multidimentional nature of cognition
- even simple experiences involve combinations of different qualities (ex. looking at a face is not just a face, there are also emotional factors you recognize, etc)
distributed representation
- occurs when a specific cognition activates many areas of the brain
episodic memories
- memories for events in a person’s life
Neural networks
- interconnected areas of the brain that can communicate with each other
semantic memories
- memories for facts
structural connectivity
- the brain’s “wiring diagram”
- created by nerve axons that connect different brain areas
structural connectivity
- the brain’s “wiring diagram”
- created by nerve axons that connect different brain areas
structural connectivity
track-weighted imaging (TWI)
- based on the detection of how water diffuses along the length of nerve fibers
connectome
- structural description of the network of elements and connections forming the human brain
functional connectivity
- the extent to which the neural activity in separate brain areas is correlated with each other
- if the responses of 2 brain areas are correlated, they are “functionall connected”
testing functional connectivity
resting-state fMRI
- fMRI measured while someone is sleeping
- has become one of the main methods
resting-state funtional connectivity
- a method for determining functional connectivity that involves determining the correlation between the resting-state fMRI in separated structures
Default mode network (DMN)
- network of structures that are active when a person is not involved in specific tasks
- when DMN is active, people’s minds tend to wander (because your brain switched from task-related networks to your DMN)
action potential
impulse responsible for transmitting neural information and for communication between neurons
receptor
specialized neural structure that responds to environmental stimuli, mechanical stimulation, or chemical stimuli
Specificity coding
Population coding
Sparse coding
cortical organization
Phrenology
- idea that different parts of your brain are different parts of your personality
Distributive representation
- characteristic of the brain in which looking at a face activates many areas
Connectome
- structural description of the network of elements and connections forming the human brain
Voxel
- small cube shaped area in the brain used in analyzing data from brain scanning experiments
