Brain and Cognition - The Student’s Guide to Cognitive Neuroscience.
H 1 : Introducing cognitive neuroscience
The mind-body problem refers to the question of how physical matter (the brain) can produce
mental experiences like feelings, thoughts and emotions (our mind).
Three frameworks have been put forward to solve it :
- Dualism: the mind and brain are made up of different kinds of substance (René Descartes)
- Dual-aspect theory: the mind and brain were two different levels of explanation for the same thing,
but not two different kinds of things (Spinoza)
- Reductionism: although cognitive, mind-based concepts are currently useful for scientific
exploration, they will eventually be replaced by purely biological constructs. (Churchland, Crick)
psychologie is terug te voeren op fysiologisch niveau, mind = uitkomst van body.
Phrenology : individual differences in cognition can be mapped on the differences in skull shape
(Gall, Spurzheim). Skull shape has nothing to do with cognitive function. conclusies trekken uit de
vorm van de hersenen.
But the basic idea of different parts of the brain serving different functions was true: functional
specialization.
Top-down processing : later stages can influence the outcome of early ones (e.g. memory influences
on perception).
The methods of cognitive neuroscience can be placed on a number of dimensions:
- Temporal resolution: the accuracy with which one can measure WHEN an event is occurring.
EEG, MEG, TMS and single-cell recording have millisecond resolution, which is good.
PET and fMRI have temporal resolutions of minutes and seconds.
- Spatial resolution: the accuracy with which one can measure WHERE an event is occurring.
fMRI has very good spatial resolution, but bad temporal resolution.
MEG has a potentially good spatial resolution, while EEG/ERP has a poor spatial resolution.
H 3 : The electrophysiological brain
Neuronal activity generates electrical and magnetic field that can be measured electrophysiologically
either invasively (single-cell recording) or non-invasively (EEG). single-cell recordings & PET zijn
invasive, de rest is dat niet.
When populations of neurons are active in synchrony they produce an electric field that can be
detected at the scalp (EEG). When many such waves are averaged together and linked to the onset of
a stimulus (or response), then an event-related potential (ERP) is obtained.
An ERP (event-related potential) waveform is an electrical signature of all the different cognitive
components that contribute to the processing of that stimulus. Systematically varying certain aspects
of the stimulus or task may lead to systematic variations in particular aspects of the ERP waveform.
This enables inferences to be drawn about the timing and independence of cognitive processes.
H 1 : Introducing cognitive neuroscience
The mind-body problem refers to the question of how physical matter (the brain) can produce
mental experiences like feelings, thoughts and emotions (our mind).
Three frameworks have been put forward to solve it :
- Dualism: the mind and brain are made up of different kinds of substance (René Descartes)
- Dual-aspect theory: the mind and brain were two different levels of explanation for the same thing,
but not two different kinds of things (Spinoza)
- Reductionism: although cognitive, mind-based concepts are currently useful for scientific
exploration, they will eventually be replaced by purely biological constructs. (Churchland, Crick)
psychologie is terug te voeren op fysiologisch niveau, mind = uitkomst van body.
Phrenology : individual differences in cognition can be mapped on the differences in skull shape
(Gall, Spurzheim). Skull shape has nothing to do with cognitive function. conclusies trekken uit de
vorm van de hersenen.
But the basic idea of different parts of the brain serving different functions was true: functional
specialization.
Top-down processing : later stages can influence the outcome of early ones (e.g. memory influences
on perception).
The methods of cognitive neuroscience can be placed on a number of dimensions:
- Temporal resolution: the accuracy with which one can measure WHEN an event is occurring.
EEG, MEG, TMS and single-cell recording have millisecond resolution, which is good.
PET and fMRI have temporal resolutions of minutes and seconds.
- Spatial resolution: the accuracy with which one can measure WHERE an event is occurring.
fMRI has very good spatial resolution, but bad temporal resolution.
MEG has a potentially good spatial resolution, while EEG/ERP has a poor spatial resolution.
H 3 : The electrophysiological brain
Neuronal activity generates electrical and magnetic field that can be measured electrophysiologically
either invasively (single-cell recording) or non-invasively (EEG). single-cell recordings & PET zijn
invasive, de rest is dat niet.
When populations of neurons are active in synchrony they produce an electric field that can be
detected at the scalp (EEG). When many such waves are averaged together and linked to the onset of
a stimulus (or response), then an event-related potential (ERP) is obtained.
An ERP (event-related potential) waveform is an electrical signature of all the different cognitive
components that contribute to the processing of that stimulus. Systematically varying certain aspects
of the stimulus or task may lead to systematic variations in particular aspects of the ERP waveform.
This enables inferences to be drawn about the timing and independence of cognitive processes.
