Table 1

Neurological imaging and measurement techniques

TechniqueRole of TechniqueAdvantagesLimitations
Positron Emission Tomography (PET)Three-dimensional functional imaging of a radioactive tracer (injected the body).Reasonable spatial resolution.Requires injection of radionucleotide, expensive (require full time staff & radionucleotide cost), restricted movement environment, not portable.
Functional Magnetic Resonance Imaging (fMRI)Measure three-dimensional changes in cerebral blood flow overlaid on a magnetic resonance imaging brain map.High spatial resolution.Expensive (require full time staff), restricted movement environment, not portable. Reliant upon neurovascular coupling, which is the interpretation of the blood oxygen level dependent (BOLD) signal. Low temporal resolution.
Transcranial Magnetic Stimulation (TMS)Sends a magnetic burst targeted toward a general anatomic region.Non-invasive, can be used to elicit motor evoked potentials (MEPs) with measurable amplitude and latency using surface electromyography (EMG).Requires high level of training to deliver, and interpret. Variability can be high depending on relative positions of coil, and participant. Low spatial resolution.
Magnetoencephalography (MEG)Measures magnetic fields from cerebral sources.High temporal resolution.Expensive (require full time staff), requires high level of training to deliver, and interpret, restricted movement environment, not portable.
Electroencephalography – Surface (EEG)Records spontaneous electrical activity from the central nervous system relative to a reference electrode.High temporal resolution, records electrical responses concurrently with presentation of other stimuli.Requires high level of training to deliver, and interpret. Surface recorded, and not time locked to external pre-cognitive stimuli, spatial resolution limited.
Somatosensory Evoked Potentials – Short Latency (SEPs)Responses of PNS and CNS to time locked and consistent stimulation producing electrical activity as consistent measureable waveforms that can be averaged for clean interpretation. Measured using surface EEG.Time locked to stimulus (consistent), early peaks are pre-cognitive in response to stimulation.Requires high level of training to deliver, and interpret. Surface recorded, spatial resolution limited to peak interpretation.
Event Related Potentials (ERPs)Brain response directly related to a sensory, motor or cognitive event. Waveforms are averaged by repeated exposure to the “event” or stimuli of interest. Measured using surface EEG.High temporal resolution (<1 ms)Poorly defined spatial resolution. Requires high level of training to deliver, and interpret.
Source LocalizationMathematical model for data de-convolution, allows for de-blurring of scalp EEG.Improves EEG spatial resolution from a centimetre scale on the cortex to a millimetre scale.Requires high level of level of training to deliver, and interpret
Standardized Weighted Low-Resolution Brain Electromagnetic Tomography (swLORETA)Mathematical model used to determine the depth of source localization of EEG signals.Improves EEG and Source Localization interpretation.Requires high level of level of training to deliver, and interpret.