Neurons (Structure)
What is a neuron?
Specialized cells that create and transmit information about what we experience and know.
What is an action potential and what happens to the membrane potential when one occurs?
The mode through which a neuron transports electrical signal, causing a neuron to depolarize/gets less negative
WHat are the four lobes of the brain and their functions?
Frontal: planning, organizing, inhibition
Parietal: touch, pressure, pain
Temporal: memory, hearing
Occipital: vision
Name three examples of localization of function and what they did to the people who experiences it (class examples).
Broca’s Area: severe speech production problem
Wernicke’s Area: severe speech comprehension
problem
Prosopagnosia: inability to recognize faces (able to describe a face, just not name it)
What are the three main ways that imaging techniques vary?
What they measure
Temporal Resolution: the time in which they can capture information
Spatial Resolution: the neural level and specificity with which they can capture information
What is the Neuron Doctrine?
Bonus: who proposed it?
The fundamental principle of neuroscience that individual cells (neurons) transmit signals in the nervous system, and that these cells are not continuous.
Proposed by Nobel Prize winner, Santiago Ramon y Cajal
What are the three main properties of action potentials?
Threshold potential: point at which an action potential is initiated (-65mV)
Repolarization: when a neuron gets more negative following an action potential
Hyperpolarization: a brief dips below the resting potential, which temporarily prevents another action
potential from occurring
What are the primary subcortical structures of the brain and their functions.
Thalamus: relay station; connects various parts; regulates states of consciousness (e.g., asleep, awake, in coma)
Amygdala: fear and other emotional processing
Hippocampus: memory and spatial processing
What is Capgras Syndrome and what does it teach us about distribution of function in the brain?
Recognize faces, but no emotional arousal. Think close friends, family are imposters. Caused by a disconnect between facial recognition areas.
Shows us that most experiences are multidimensional/involve a combination of different qualities.
What does single-cell recording capture and what is its temporal and spatial resolution like?
Bonus: what did it help discover
Measures electrical activity of a single neuron
Great temporal resolution
Great spatial resolution
Discovered feature detectors--neurons that respond best to a specific stimulus
What are the three primary structures of a neuron and their functions?
Cell body/soma: contains the mechanisms needed to keep the cell alive
Dendrites: branch out from the body and receive electrical signals from other neurons.
Axons: usually a long projection that is filled with fluid and conducts electrical signals to transmit them to other neurons. Fires action potentials
What are the properties of action potentials and how they communicate.
All or nothing response: once initiated, action potentials go at full strength, always at the same speed and size
Intensity: is communicated through frequency of action potentials firing
What does neuropsychology investigate?
Explores what brain regions are responsible for cognitive abilities by exploring what happens when they are damaged or removed
What are neural networks?
Interconnected areas of the brain that can communicate with each other.
What is hierarchical processing?
Processing starts with simple stimuli in one part of the brain and as the signal moves to other parts, processing involves increasingly complex information.
What is a nerve impulse?
The mode through which a neuron transports
electrical signal (information)
Describe the Principle of Neural Representation
Everything a person experiences is based on representations in the person’s nervous system. This representation is created by action potentials, which neurons and neuronal circuits are firing, and the frequency by which they fire creates every experience you have.
How was Phineas Gage an example of neuropsychology?
A tamping iron penetrated his frontal lobe, leaving him with personality changes and an inability to meet the demands of his job anymore.
What is structural versus functional connectivity?
Structural Connectivity: brain’s “wiring diagram” created by nerve axons that connect different brain areas (the roads and highways)
Functional Connectivity: the extent to which neural activity in two brain areas are correlated (how the roads and highways are used)
What does EEG capture and what is its temporal and spatial resolution like?
Measures ERP: Event-Related Potentials (electrical activity of the whole brain)
Excellent temporal resolution
Poor spatial resolution
What is a resting membrane potential and what voltage is associated with it?
The difference in the charge inside vs. outside the neuron when the neuron is “at rest” = about -70 mV
What happens when an action potential reaches the end of the axon? That is, how do neurons communicate with each other across the synapse?
Hint: involves neural circuits, the synapse, and neurotransmitters
Neurons are connected to other neurons in groups called neural circuits. Neurons must communicate across the synapse--the small space between neurons. When the action potential reaches the end of the axon, neurotransmitters are released. These change the voltage of the postsynaptic neuron, which can initiate an action potential
What is the localization of function versus distributed representation?
Localization of Function: specific functions are served by specific areas of the brain
Distributed Representation: specific cognitive functions activate many areas of the brain
What are some common functional networks?
Visual, somato-motor, dorsal attention, executive control, and default mode.
What does fMRI capture and what is its temporal and spatial resolution like?
Bonus: what is the logic underlying fMRI
Measures changes in blood flow across the brain
Great spatial resolution
Okay, but not great, temporal resolution (seconds instead of milliseconds)
Brain activity causes blood flow, so measuring blood flow measures brain activity