Research methods in neuroscience Lenka Sakálošová Contents •Overview and approaches to measurement •Electrophysiology: EEG, iEEG... •MRI & fMRI (Petra Zemánková, PhD) •TMS & rTMS (Pavlína Linhartová) •MAFIL lab visit: practical demonstration • • Breadth of neuroscience Questions we can ask •Basic research •What does it do? How does it work? •Applied research •What can we influence? How? • e.g. cognitive modelling e.g. Brain-computer interface, cognitive enhancement Methods of studying the nervous system (how we get answers) •1. Examining case studies—identifying interesting events that have occurred naturally and using these events to develop hypotheses that can be tested in future experiments •2. Screens—performing unbiased searches for anatomical structures, neurons, proteins, or genes that could play a role in a subject of interest •3. Description—using techniques that allow a scientist to observe the nervous system without manipulating any variables •4. Manipulation—testing hypotheses by determining the effect of an independent variable on a dependent variable •loss-of-function (also called “necessity”') •gain-of-function (also called “sufficiency”) • Techniques we use to get the answers •Structural / functional •Invasive / non-invasive •Task-dependent / resting-state •In vivo / post mortem •Observation/manipulation(perturbation) •Fast event or long-therm development •Microscopic to whole-brain scale • •Structure • •Function • structural MRI Functional MRI (fMRI) •Task-dependent •Resting state •In vivo •Post mortem histology fMRI •Invasive • •Non-invasive • ECoG: electrocorticogram Scalp EEG •Observation • •Manipulation • Temporal scale Whole-brain neuroimaging methods in human cognitive neoroscience •Electrophysiology (EEG, MEG) •MRI (fMRI, DTI, spectroscopy), •PET and SPECT •Perturbation (TMS, TCS) • • • • • Stimulation: non-invasive Transcranial direct current stimulation Stimulation: non-invasive Transcranial magnetic stimulation Deep brain stimulation https://www.youtube.com/watch?v=wZZ4Vf3HinA Neurophysiology methods •a. Neuron (unit) activity •Single-unit: spike trains from single isolated neurons in the brain •Multi-unit: spike trains from multiple neurons in the brain b.Population (field potential or field) activity •Electroencephalogram (EEG): recording of cortical electrical activity from extracranial sensors •Magnetoencephalogram (MEG): recording of cortical magnetic activity from extracranial sensors •Local Field Potential (LFP): recording of cortical electrical activity from microelectrodes in cortex • Intracranial EEG (iEEG): recording of cortical electrical activity from macroelectrodes in cortex •Electrocorticogram (ECoG): recording of cortical electrical activity from macroelectrodes on surface of cortex Neurophysiology: „brainvawes“ •Electrical activity recorded via electrodes (mostly) •Excellent temporal resolution, bad spatial Neural basis Neural basis Recording EEG data •Nothing beats clean data Event-related potentials Event-related potentials • Topography Power spectrum analysis Contrast problem • Not-so-much-neuro neuroimaging •Heart rate •Respiratory rate •Skin conductance •Eyetracking • Solution to limitations... •Multimodal approach • Most important things: •Great question •Well-selected measurement method(s) •Meticulous experiment administration •Clean data •Honest and robust statistics •Reasonable interpretation • •