Structural Imaging
This X-ray technique was the first method for 3D imaging of the human brain in vivo, but is considered invasive due to mild radiation exposure.
What is a CT scan (Computed Tomography)?
EEG records the graded potentials of large populations of neurons, which are typically generated by these two types of post-synaptic potentials.
What are EPSPs and IPSPs (Excitatory and Inhibitory Post-Synaptic Potentials)?
This functional imaging technique involves injecting a radioactive isotope to track metabolic demand, allowing researchers to image specific molecules like dopamine receptors.
What is Positron Emission Tomography (PET)?
This therapy involves the intentional induction of seizures via electrical currents at the scalp.
What is Electroconvulsive Therapy (ECT)?
In TMS, this peak-to-peak amplitude measurement is used to estimate corticospinal tract excitability.
What is a Motor-Evoked Potential (MEP)?
This specific MRI technique relies on the restricted, non-random diffusion of water molecules to image white matter tracts.
What is Diffusion-Weighted Imaging (DWI)?
This is the term for the brain's electrical response time-locked to a specific stimulus, such as the Late Positive Potential (LPP) or N170.
What is an Event-Related Potential (ERP)?
Standard fMRI primarily relies on this contrast, which tracks the ratio of oxygenated to deoxygenated hemoglobin.
What is BOLD (Blood-Oxygenation Level Dependent) contrast?
Early animal work established that in direct current stimulation, this specific electrode depolarizes neurons.
What is the Anode (or Anodal electrode)?
This emerging, non-invasive stimulation technique uses mechanical interaction with brain tissue to target deep cortical structures.
What is Transcranial Focused Ultrasound Stimulation (TfUS)?
In structural MRI, this specific time constant refers to how long it takes for protons to realign with the B0 axis.
What is T1 recovery (or longitudinal relaxation time)?
This technique detects tangential magnetic fields using SQUIDs and offers great temporal resolution with less signal distortion from the skull.
What is Magnetoencephalography (MEG)?
This function describes the delayed pattern of increased blood flow to an active brain region over several seconds.
What is the Hemodynamic Response Function (HRF)?
ECT is highly effective for treatment-resistant depression, but carries a well-known risk of this temporally-graded memory deficit.
What is retrograde amnesia?
Deep-Brain Stimulation (DBS) is highly specific, but its major downside compared to TMS or tDCS is this characteristic.
What is its high invasiveness (or requirement for surgery)?
This technique varies the resonant frequency of RF pulses to image the 20% of brain material that isn't water, making it useful for studying neurotransmitter concentrations.
What is Magnetic Resonance Spectroscopy (MRS)?
György Buzsáki and others suggest that the coupling of this oscillatory feature helps distributed neural circuits communicate and encode information.
What is phase (or phase coupling)?
In fMRI, this type of scan measures spontaneous fluctuations in brain activity without requiring the subject to perform a specific task.
What is Resting-State fMRI?
This physical principle explains how TMS induces a secondary current in brain tissue using a changing magnetic field.
What is Electromagnetic Induction?
Repetitive TMS (rTMS) applied at low frequencies like 1 Hz generally produces this type of after-effect, as opposed to higher frequencies like 5 Hz.
What is an inhibitory after-effect?
In an MRI scanner, protons align with the B0 magnetic field and experience this type of "wobble" or spin around the longitudinal axis.
What is precession?
Because of the orientation of the magnetic fields it detects, MEG is largely "blind" to this specific type of dipole, which is easily seen on EEG.
What is a radial dipole?
To isolate the brain activity associated with a specific cognitive process, researchers compare the T2* weighted images from a psychological condition of interest against those from a baseline or comparison condition.
What is BOLD Subtraction Logic?
Blocking voltage-gated sodium channels with this specific drug eliminates the effect of anodal, but not cathodal, tDCS.
What is Carbazepine (CBZ)?
For treatment-resistant depression, a personalized DBS approach targeted the intersection of the forceps minor, uncinate fasciculus, frontostriatal fibres, and this white matter pathway.
What is the cingulum bundle?