Midterm 1 Wednesday next week!

Synthesize the Big Picture Understanding Brain-wide neural circuits Extracranial electrophysiology EEG/MEG Metabolic Imaging fMRI/PET Intracranial LFP/single-unit Lesion Studies Computational Models

Lesion Studies Logic of Lesion Studies: – damaged area plays a role in accomplishing whatever task is deficient after the lesion

Lesion Studies Human Lesions – Trauma Frontal lobes are particularly susceptible Some famous cases (e.g. Phineas Gage)

Lesion Studies Human Lesions – Transcranial Magnetic Stimulation Electromagnet Induces current in the brain very transient, very focal reversible “lesion” Believed to be safe sites that can be studied are limited by the geometry of the head

Lesion Studies Making sense of Lesion studies

Lesion Studies Logic of Lesion Studies: – damaged area plays a role in accomplishing whatever task is deficient after the lesion Warning: – This isn’t the same as saying the lesioned area “does” the operation in question – examples: normal behaviour may be altered to accommodate lesion – e.g. sensory loss of one arm favors other arm lesion might cause “upstream problem” or general deficit – e.g. attention problem “looks like” specific deficit if you only test one specific demanding task

Lesion Studies Designing Lesion Studies – “design tasks that diagnose the function of specific operations” – First, use a control group Performance (e.g. accuracy, speed, etc.) Task (e.g. memory task, perception task, etc.) A Lesion X Healthy This difference indicates deficit

Lesion Studies Designing Lesion Studies – “design tasks that diagnose the function of specific operations” – First, use a control group Performance (e.g. accuracy, speed, etc.) Task (e.g. memory task, perception task, etc.) A Lesion X Healthy BUT maybe this is just a general deficit or a consequence of having a ANY brain damage

Lesion Studies Designing Lesion Studies – “design tasks that diagnose the function of specific operations” – Consider another lesion group Performance (e.g. accuracy, speed, etc.) Task (e.g. memory task, perception task, etc.) A Lesion X Healthy Lesion Y

Lesion Studies Designing Lesion Studies – “design tasks that diagnose the function of specific operations” – X marks the double dissociation Performance (e.g. accuracy, speed, etc.) Task (e.g. memory task, perception task, etc.) A Lesion X Healthy Lesion Y

Computational Neuroscience Attempts to simulate a cognitive operation so that the simulation can be studied – Parameters and instructions are explicit and often fairly simple – but the behaviour of the simulation can be quite complex and unpredictable

Computational Neuroscience Neural Networks are a common class of model that simulates learning – McClelland & Rumelhart – Consist of input, output and hidden layers – Connections between layers are governed by rules and adjust over time based on weather the network produced the correct output for a given input – Architecture of neural networks bears an attractive resemblance to real brains But this may be misleading!

Computational Neuroscience Reinforcement Learning (RL) – Sutton & Barto – Attempts to model decisions by simulating agents with two conflicting motivations: Explore – search the environment for something good Exploit – engage in a single behaviour that is good – Decision is based on amount of reward provided by a given choice of action

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