The Event-Related Potential (ERP) We have an ERP waveform for every electrode

The Event-Related Potential (ERP) We have an ERP waveform for every electrode Sometimes that isn’t very useful

The Event-Related Potential (ERP) We have an ERP waveform for every electrode Sometimes that isn’t very useful Sometimes we want to know the overall pattern of potentials across the head surface – isopotential map

The Event-Related Potential (ERP) We have an ERP waveform for every electrode Sometimes that isn’t very useful Sometimes we want to know the overall pattern of potentials across the head surface – isopotential map Sometimes that isn’t very useful - we want to know the generator source in 3D

Brain Electrical Source Analysis Given this pattern on the scalp, can you guess where the current generator was?

Brain Electrical Source Analysis Given this pattern on the scalp, can you guess where the current generator was?

Brain Electrical Source Analysis Source Analysis models neural activity as one or more equivalent current dipoles inside a head-shaped volume with some set of electrical characteristics

Brain Electrical Source Analysis This is most likely location of dipole Project “Forward Solution” Compare to actual data

Brain Electrical Source Analysis EEG data can now be coregistered with high- resolution MRI image

Intracranial and “single” Unit Single or multiple electrodes are inserted into the brain “chronic” implant may be left in place for long periods

Intracranial and “single” Unit Single electrodes may pick up action potentials from a single cell An electrode may pick up the combined activity from several nearby cells – spike-sorting attempts to isolate individual cells

Intracranial and “single” Unit Simultaneous recording from many electrodes allows recording of multiple cells

Intracranial and “single” Unit Output of unit recordings is often depicted as a “spike train” and measured in spikes/second Stimulus on Spikes

Intracranial and “single” Unit Output of unit recordings is often depicted as a “spike train” and measured in spikes/second Spike rate is almost never zero, even without sensory input – in visual cortex this gives rise to “cortical grey” Stimulus on Spikes

Intracranial and “single” Unit By carefully associating changes in spike rate with sensory stimuli or cognitive task, one can map the functional circuitry of one or more brain regions What are the advantages and limitations of this approach?

Your Research Proposal Project A research proposal attempts to persuade the reader that: – The underlying question is highly important – The proposed methodology and experimental design is the best available approach – That you have the knowledge and talent to do the proposed research – That you have a research program worth funding L

Your Research Proposal Project A research proposal is therefore similar to many other situations in which you will try to persuade someone of something – The skill is portable L

Your Research Proposal Project As in other situations, your reader should be assumed to be unconvinced and thus unwilling to spend much time and energy entertaining your argument! You must make your argument easy and fast The key to that is organization L

Research Proposals Should be “Theory Driven” Most proposals are organized around a specific theory What is the difference between a theory and a question? L

The Parts of a Research Proposal Background Statement of the theory Prediction(s) that follow from the theory Experimental Method and Design Timeline Budget References L

The Parts of a Research Proposal Background Statement of the theory Prediction(s) that follow from the theory Experimental Method and Design Timeline Budget References L These aren’t necessary for your project

Assignment Rules: – Must be human Cognitive Neuroscience – Experimental approach may involve animal research only if this is the best way to test your theory Studying humans is preferable to studying animals when you have a specific theory about human cognition One moves to animal research because it tells you something that human research cannot If this applies to your theory, you will make this constraint explicit in your proposal L