Franz Joseph Gall suggested that surface of the head depends on mental skills. He is one of the firsts linking the brain to cognition.
Can modern phrenology be seen as modern cognitive neuroscience?
- Yes:
- Functional differentiation of the brain
- No:
- Functions are defined by thorough experimentation
- Multidisciplinary research
- Not just size of brain areas
Brodmann was the first to map the cortex based on cell types. More detailed maps followed later.
The structure of the brain has a reason: function.
You can measure brain activity using
- Action potentials (electrophysiology)
- local field potentials (electrophysiology)
- Electromagnetic field at scalp (EEG/MEG)
- Manipulating neural activity (TMS/tDCS)
- Blood oxygenation (fmri)
Brain elements: neurotransmitter & hormones. You can add pharmacology and food supplements.
Brain computation: making models of the brain to improve applications (facebook, google).
Cognitive neuroscience defines steps/networks in information processes by using neuroscientific methods.
EEG (ElectroEncephaloGraphy):
- Measures the differences in voltage across the scalp
- Reflects post-synaptic potentials (PSP): difference in voltage along axons.
- Both inhibitory and excitatory psp
- Reflects local field potential not a single action potential but a summation of many neurons
When is the measurement good?:
- Mass activity
- Synchronized activity
- Close to the scalp
32-64 electrodes are enough to measure time effects.
Advantages EEG:
- Temporal characteristics
- ERP’s
EEG measures the voltage potentials and MEG measures the magnetic field. MEG is similar to EEG, but better localization and most sensitive to activity originating from sulci.
EEG = relatively cheap, measures more neurons.
MEG = expensive, better localization
EEG & MEG same temporal resolution, MEG better spatial resolution.
So slow waves = low arousal
Fast waves = high arousal
Gamma (32Hz>) = superlearning
Beta (16-31Hz) = processing information, analytical thinking
Alpha (8-15Hz) = Eyes closed or very relaxed
Theta (4-7Hz) = Sleep, REM, dreaming, deep meditation
Delta (<4Hz) = deep dreamless sleep
ADHD = hyperactive, but less cortical arousal
Treating ADHD = increase arousal with medicine
Each frequency reflects a different mental state.
Average ERP’s to cancel out the noise.
Questions? Let me know in the contribution section!
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