Methods used for studying brain development Lecture #2 Methods used for studying brain development

Food for thought How can you get inside someone’s brain without really getting “inside” their brain? What would you do to study brain development? What can we learn about brain from studying behavior (and vice versa)?

Outline Methods used to measure brain development Lesion studies

Outline Methods used to measure brain development Lesion studies EEG

Outline Methods used to measure brain development Lesion studies EEG ERP

Outline Methods used to measure brain development Lesion studies EEG ERP Imaging Studies

Outline Methods used to measure brain development Lesion studies EEG ERP Imaging Studies Animal Studies

Outline Methods used to measure brain development Lesion studies EEG ERP Imaging Studies Animal Studies Neuropsychological Studies

Outline What’s so great?

Outline What’s so great? What’s the problem?

Lesion Studies Damage to a particular part of the brain can result in specific behavioral effects

Lesion Studies Damage to a particular part of the brain can result in specific behavioral effects Examples Amygdala (emotion)

Lesion Studies Damage to a particular part of the brain can result in specific behavioral effects Examples Amygdala (emotion) Hippocampus (memory)

Lesion Studies Damage to a particular part of the brain can result in specific behavioral effects Examples Amygdala (emotion) Hippocampus (memory) Visual cortex (blindsight)

Lesion Studies Damage to a particular part of the brain can result in specific behavioral effects Examples Amygdala (emotion) Hippocampus (memory) Visual cortex (blindsight) Parietal cortex (attention)

Lesion Studies Damage to a particular part of the brain can result in specific behavioral effects Examples Amygdala (emotion) Hippocampus (memory) Visual cortex (blindsight) Parietal cortex (attention) Left hemisphere (language)

Lesion Studies What’s so great?

Lesion Studies What’s so great? What’s the problem?

Electroencephalography (EEG) Measures “brain waves”

Electroencephalography (EEG) Measures “brain waves” Gross measure of integrity of the brain as a system

Electroencephalography (EEG) Measures “brain waves” Gross measure of integrity of the brain as a system Can be used as a very low level indicator (is this person alive)

Electroencephalography (EEG) Measures “brain waves” Gross measure of integrity of the brain as a system Can be used as a very low level indicator (is this person alive) Can also be used to measure behavior Depression

Electroencephalography (EEG) How does it work?

Electroencephalography (EEG) How does it work? Brains produce electricity

Electroencephalography (EEG) How does it work? Brains produce electricity Neurons do their business basically by acting like wires

Electroencephalography (EEG) How does it work? Brains produce electricity Neurons do their business basically by acting like wires Electrodes placed on scalp record brain electrical activity

Electroencephalography (EEG) How does it work? Brains produce electricity Neurons do their business basically by acting like wires Electrodes placed on scalp record brain electrical activity Measures include the amount of activity in particular frequency bands

Electroencephalography (EEG) How does it work? Brains produce electricity Neurons do their business basically by acting like wires Electrodes placed on scalp record brain electrical activity Measures include the amount of activity in particular frequency bands Power

Electroencephalography (EEG) How does it work? Brains produce electricity Neurons do their business basically by acting like wires Electrodes placed on scalp record brain electrical activity Measures include the amount of activity in particular frequency bands Power Activation

Electroencephalography (EEG) How does it work? Brains produce electricity Neurons do their business basically by acting like wires Electrodes placed on scalp record brain electrical activity Measures include the amount of activity in particular frequency bands Power Activation Activation in a particular frequency range

EEG What’s so great?

EEG What’s so great? What’s the problem?

Event – related Potentials (ERP) Definition:

Event – related Potentials (ERP) Definition: Brain electrical activity that comes from simultaneous firing of synapses, and is related to a specific event.

Event – related Potentials (ERP) Definition: Brain electrical activity that comes from simultaneous firing of synapses, and is related to a specific event. How do you measure them?

Event – related Potentials (ERP) Definition: Brain electrical activity that comes from simultaneous firing of synapses, and is related to a specific event. How do you measure them? Electrodes placed on the scalp record brain activity

Event – related Potentials (ERP) Definition: Brain electrical activity that comes from simultaneous firing of synapses, and is related to a specific event. How do you measure them? Electrodes placed on the scalp record brain activity Activity is recorded in response to a specific discrete event.

Event – related Potentials (ERP) Definition: Brain electrical activity that comes from simultaneous firing of synapses, and is related to a specific event. How do you measure them? Electrodes placed on the scalp record brain activity Activity is recorded in response to a specific discrete event. Averaging over enough trials gets rid of the “noise” of the background EEG.

ERP (continued) What do they look like?

ERP (continued) What do they look like? Components seen in infants Nc Component

ERP (continued) What do they look like? Components seen in infants Nc Component PSW

ERP (continued) What do they look like? Components seen in infants Nc Component PSW P300

ERP (continued) What do they look like? Components seen in infants Nc Component PSW P300 Sensory Components

ERP (continued) What do they look like?

ERP (continued) What do they look like? What can you learn from them? Components seen in infants Nc Component PSW P300 Sensory Components What can you learn from them? Examples Language and early phonological development

ERP What’s so great?

ERP What’s so great? What’s the problem?

Imaging CAT Scans

Imaging CAT Scans Useful for describing overall brain structure

Imaging CAT Scans PET Scans Useful for describing overall brain structure PET Scans

Imaging CAT Scans PET Scans Useful for describing overall brain structure PET Scans Good measure of blood flow in brain

Imaging CAT Scans PET Scans Useful for describing overall brain structure PET Scans Good measure of blood flow in brain Poor resolution

Imaging CAT Scans PET Scans Useful for describing overall brain structure PET Scans Good measure of blood flow in brain Poor resolution Involves radiation

Imaging (continued) MRI

Imaging (continued) MRI Excellent resolution for structure of the brain

Imaging (continued) MRI Excellent resolution for structure of the brain Example - Myelin

Imaging (continued) MRI fMRI Excellent resolution for structure of the brain Example - Myelin fMRI

Imaging (continued) MRI fMRI Excellent resolution for structure of the brain Example - Myelin fMRI Excellent resolution

Imaging (continued) MRI fMRI Excellent resolution for structure of the brain Example - Myelin fMRI Excellent resolution Provides image of blood flow in the brain

Imaging (continued) MRI fMRI Excellent resolution for structure of the brain Example - Myelin fMRI Excellent resolution Provides image of blood flow in the brain Example - Working Memory

Imaging Studies What’s so great?

Imaging Studies What’s so great? CAT Scan

Imaging Studies What’s so great? CAT Scan PET Scan

Imaging Studies What’s so great? CAT Scan PET Scan MRI

Imaging Studies What’s so great? CAT Scan PET Scan MRI fMRI

Imaging Studies What’s so great? What’s the problem?

Imaging Studies What’s so great? What’s the problem? CAT Scan

Imaging Studies What’s so great? What’s the problem? CAT Scan PET Scan

Imaging Studies What’s so great? What’s the problem? CAT Scan PET Scan MRI

Imaging Studies What’s so great? What’s the problem? CAT Scan PET Scan MRI fMRI

Animal Studies You can look directly at brain with animals Whatever you want to look at Do specific lesions

Animal Studies What’s so great?

Animal Studies What’s so great? What’s the problem?

Neuropsychology Behavioral method derived from lesion and animal studies

Neuropsychology Behavioral method derived from lesion and animal studies These behaviors are associated with parts of the brain from lesion, animal, or imaging studies

Neuropsychology Behavioral method derived from lesion and animal studies These behaviors are associated with parts of the brain from lesion, animal, or imaging studies You can measure the function of the brain indirectly

Neuropsychology Behavioral method derived from lesion and animal studies These behaviors are associated with parts of the brain from lesion, animal, or imaging studies You can measure the function of the brain indirectly Example: Autism

Neuropsychological Studies What’s so great?

Neuropsychological Studies What’s so great? What’s the problem?

All of the above? There are advantages to combining these methods. What might these be?

All of the above? There are advantages to combining these methods. What might these be? Look at behavior to determine what you’re really measuring – converging measures

All of the above? There are advantages to combining these methods. What might these be? Look at behavior to determine what you’re really measuring – converging measures What if an imaging study shows something different than lesion studies or animal studies always have?

All of the above? There are advantages to combining these methods. What might these be? Look at behavior to determine what you’re really measuring – converging measures What if an imaging study shows something different than lesion studies or animal studies always have? Complementary resolution advantages

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