Cognitive Neuroscience (1) – Lectures
Lecture 1: Introduction & EEG Methods
Tuesday 11 november – Naber
Introduction
Cognition consist of many different aspects.
• Visual perception
• Auditory perception
• Motor
• Attention and controlling it
• Memory
• Emotion & social skills
• Language
• Executive functions
• Decision making
• Etc.
These specific functions are studied by using neuro measures.
• EEG/MEG
• fMRI/DTI/MRS
• Electrophysiology
• fNIRS/EROS
• Physiology
• Gene expression
• Food supplements & pharmacology
• TMS/tDCS
• Optogenetics
• Etc.
History of neuroscience
Franz Joseph Gall suggested that surface of the head depends on mental skills.
• Different areas on the skull each represent a different skill.
• Phrenology
This method is not a valid way to study the brain.
In modern neuroscience, we use a more advanced approach; a modern version of
phrenology.
• Focus on functional differentiation of the brain.
o Functions are defined by thorough experimentation
o Multidisciplinary research
o Not just size of brain areas
Anatomy & structure
Brain anatomy
• Many different types of cells, connections, and neurotransmitters.
Brodmann was the first to map the cortex based on cell types.
• More detailed maps followed later.
Each neuron type has a different function.
There is a link between the structure and the function.
1
,Neuron: four main aspects
Input side: dendrites
Output: axon terminals (synaptic terminals)
Transfer: axon
Modulator: cell
Glial cells: support the neurons.
Neurons differ from normal cells;
• Axon and dendrites are specialized structures to transmit and receive information through
action potentials.
• They tend not to reproduce after birth.
o As you grow older, the connection between neurons change.
• Connections do alter.
• Each cell type has its own specialized function.
Damage to anatomy (clinical neuropsychology)
Main topics studied in clinical neuropsychology:
• Stroke
o Most common type of trauma.
▪ Blood leaks into brain tissue.
▪ Clot stops blood supply to an area of the brain.
• Tumors or infections (or insects)
• Trauma (football)
• Epilepsy & lesions
• Genetic manifestations
• Neural degeneration (MS, Alzheimer)
Measuring brain activity
• Action potentials (electrophysiology)
• Local field potentials; group of neurons (electrophysiology)
• Electromagnetic fields at scalp (EEG/MEG)
o Pick up voltage changes that happen inside the brain.
• Manipulating neural activity (TMS/tDCS)
• Blood oxygenation (fMRI; PET; fNRIS)
Electrophysiology measure voltage changes.
Get information about a very small area in the brain; localize brain area to very high detail.
We do learn from animal studies.
• Electrodes put on top of the cortex.
• Receptive field = neurons that are only receptive to stimulus that are presented in the
receptive field.
2
,Brain elements:
• Neurotransmitters (synaptic transmission)
• Hormones
Pharmacology: influence neurons/neurotransmitters by injection.
Food supplements: choline → acetylcholine (neurotransmitter; coordinate movements)
Brain computation:
• Making models of the brain to improve applications (FaceBook, Google).
• Are these good models of the brain?
o In some cases they are, in some cases they are not.
• Object classifier
Summary cognitive neuroscience:
Defining steps/networks in information processes by using neuroscientific methods.
• Study methods to measure and manipulate the brain.
• Study cognitive functions
3
, EEG Methods
ElectroEncephaloGraphy
• Electro = electromagnetic fields
• Encephalo = related to the brain
• Graphy = descriptive science
What does it measure?
Differences in voltage across the scalp.
• Reflects post-synaptic potentials (PSP): difference in voltage along axons
o Both inhibitory and excitatory PSP
• Reflects local field potential.
o Not single action potentials but a summation of many neurons.
When is the measurement good?
• Mass activity
o Many neurons with the same alignment.
• Synchronized activity
o Not individual action potentials.
• Close to the scalp
o Scalp and skull is not a good conductor; smears out the signal.
• No noise sources
o Electronic devices → artefacts in the data.
EEG electrode layouts
The more the better?
→ yes, but takes more time.
32-64 electrodes = enough for P100, N200, P3, etc.
128 electrodes = enough for localization.
4
Lecture 1: Introduction & EEG Methods
Tuesday 11 november – Naber
Introduction
Cognition consist of many different aspects.
• Visual perception
• Auditory perception
• Motor
• Attention and controlling it
• Memory
• Emotion & social skills
• Language
• Executive functions
• Decision making
• Etc.
These specific functions are studied by using neuro measures.
• EEG/MEG
• fMRI/DTI/MRS
• Electrophysiology
• fNIRS/EROS
• Physiology
• Gene expression
• Food supplements & pharmacology
• TMS/tDCS
• Optogenetics
• Etc.
History of neuroscience
Franz Joseph Gall suggested that surface of the head depends on mental skills.
• Different areas on the skull each represent a different skill.
• Phrenology
This method is not a valid way to study the brain.
In modern neuroscience, we use a more advanced approach; a modern version of
phrenology.
• Focus on functional differentiation of the brain.
o Functions are defined by thorough experimentation
o Multidisciplinary research
o Not just size of brain areas
Anatomy & structure
Brain anatomy
• Many different types of cells, connections, and neurotransmitters.
Brodmann was the first to map the cortex based on cell types.
• More detailed maps followed later.
Each neuron type has a different function.
There is a link between the structure and the function.
1
,Neuron: four main aspects
Input side: dendrites
Output: axon terminals (synaptic terminals)
Transfer: axon
Modulator: cell
Glial cells: support the neurons.
Neurons differ from normal cells;
• Axon and dendrites are specialized structures to transmit and receive information through
action potentials.
• They tend not to reproduce after birth.
o As you grow older, the connection between neurons change.
• Connections do alter.
• Each cell type has its own specialized function.
Damage to anatomy (clinical neuropsychology)
Main topics studied in clinical neuropsychology:
• Stroke
o Most common type of trauma.
▪ Blood leaks into brain tissue.
▪ Clot stops blood supply to an area of the brain.
• Tumors or infections (or insects)
• Trauma (football)
• Epilepsy & lesions
• Genetic manifestations
• Neural degeneration (MS, Alzheimer)
Measuring brain activity
• Action potentials (electrophysiology)
• Local field potentials; group of neurons (electrophysiology)
• Electromagnetic fields at scalp (EEG/MEG)
o Pick up voltage changes that happen inside the brain.
• Manipulating neural activity (TMS/tDCS)
• Blood oxygenation (fMRI; PET; fNRIS)
Electrophysiology measure voltage changes.
Get information about a very small area in the brain; localize brain area to very high detail.
We do learn from animal studies.
• Electrodes put on top of the cortex.
• Receptive field = neurons that are only receptive to stimulus that are presented in the
receptive field.
2
,Brain elements:
• Neurotransmitters (synaptic transmission)
• Hormones
Pharmacology: influence neurons/neurotransmitters by injection.
Food supplements: choline → acetylcholine (neurotransmitter; coordinate movements)
Brain computation:
• Making models of the brain to improve applications (FaceBook, Google).
• Are these good models of the brain?
o In some cases they are, in some cases they are not.
• Object classifier
Summary cognitive neuroscience:
Defining steps/networks in information processes by using neuroscientific methods.
• Study methods to measure and manipulate the brain.
• Study cognitive functions
3
, EEG Methods
ElectroEncephaloGraphy
• Electro = electromagnetic fields
• Encephalo = related to the brain
• Graphy = descriptive science
What does it measure?
Differences in voltage across the scalp.
• Reflects post-synaptic potentials (PSP): difference in voltage along axons
o Both inhibitory and excitatory PSP
• Reflects local field potential.
o Not single action potentials but a summation of many neurons.
When is the measurement good?
• Mass activity
o Many neurons with the same alignment.
• Synchronized activity
o Not individual action potentials.
• Close to the scalp
o Scalp and skull is not a good conductor; smears out the signal.
• No noise sources
o Electronic devices → artefacts in the data.
EEG electrode layouts
The more the better?
→ yes, but takes more time.
32-64 electrodes = enough for P100, N200, P3, etc.
128 electrodes = enough for localization.
4
