Neural Coding + Research Methods + Interference + Neuroimaging

Rate Coding

firing rate represents presence and intensity of a single stimulus; x axis is spikes

Population Coding

firing rate of multiple neurons representing stimuli; x-axis is neurons

Temporal Coding

changes in firing within set window of time of single neuron; x axis is time

Optogenetics

increase/decrease of firing rate of neurons of interest with light-sensitive proteins, allowing control of cell activity; better for shorter time periods and higher temporal control

Designer Receptors Activated by Designer Drugs (DREADDS)

synthetic receptors that control neural activity changing permeability to ions;  better for long periods of times 

Single Unit Recording

measurement of electrical activity from individual neurons using extracellular microelectrodes; measures extracellular environment relative to inside (e.g. Na+ leaving)

Electroencephalography (EEG)

measures electric potentials generated with scalp electrodes; good temporal resolution

Magnetoencephalography (MEG)

Measures magnetic fields generated by brain activity; noninvasive

Electrocorticography (ECoG)

measures localization of signals from brain area with electrodes (medically) placed on surface of brain under skull (intracranial); good temporal

Transcranial Magnetic Stimulation (TMS)

nonsurgical magnetic scalp stimulation (across cranium) that activates/inactivates a focused area depending on stimulation parameters

Deep Brain Stimulation (DBS)

Intracranial electric stimulation that implants deep-brain electrodes (medically) sending electrical impulses to brain; e.g. Parkinson’s Disease video

Closed loop stimulation

Stimulation electrode records signal while analyzing whether biological signal is present or not (and it’s strength)

Magnetic Resonance Imaging (MRI)

Creates structural images of brain with magnetic fields without XRay; white/grey matter is visible

functional Magnetic Resonance Imaging (fMRI)

Measures blood oxygenation to study brain function; decent spatial resolution

Positron Emission Tomography (PET)

Noninvasive radioactive molecules (ligands) for measuring neurotransmitter reception activity; nicotine example