Cognitive Neuroscience Flashcards
Neurons
100 million neurons inside brain
fMRI
When neurons active, burn energy- automatically replenished via blood
Blood contains haemoglobin- possibly to detect blood flow
Distinguish between oxygen-rich and oxygen-depleted blood
Measuring BOLD response, work out parts of brain recently active- used in tasks
Temporal resolution
Structural data
X- claustrophobic, noisy, movement artefacts
X- no metal-based equipment
Magnetocephalogram (MEG)
Pyramidal cells of cortex, when active, create significant magnetic field
MEG records magnetic fields
Synchronous firing of 10,000s neurons required to produce a field large enough to measure
Magnetic fields less distorted by the scalp than electric fields
Temporal and spatial resolution
X- expensive
X- finding out cause and effect
Electroencephalography (EEG)
Measures electrical signals generated by brain through electrodes placed on the scalp
Produced by partial synchronisation of cortical field activity, measured as changes in voltage, recorded at the scalp over time
Analysis may be task dependent or task independent
Temporal resolution
Less subjective to motion artefacts, not claustrophobic
X- spatial resolution
X- pattern of activity, how to determine which brain region caused it?
X- eye blinks= artefact, eliminated via monitoring
Positron Emission Tomography (PET)
Inject tracer element (glucose)
Give task that requires brain activity, measure how much of tracer goes where, compared with resting state
Structural accuracy, direct reflection of activity
No motion artefacts
Relatively pleasant
X-injection of weak radioactive substance—> ethical implications
X- temporal resolution
X- pair with MRI or CT
X- expensive
Transcranial magnetic stimulation (TMS)
Non invasive- depolarisation/ hyperpolarisation of neurons in brain
Electromagnetic induction to induce weak electric currents into cortex
Cause motor evokes potential
Produce temporary lesion, preventing normal function, without long-lasting effects
Neuropsychology
Lesion patients
Phineas Gage- 1840 railroad- irresponsible, disregard for social conventions
Damasio et al- neuroimaging reconstruction demonstrated damage was to orbitofrontal and anterior medial areas of frontal lobes
