Cognitive Psychology Flashcards
What is Decarte’s error?
Thinking that the brain and the mind are two separate phenomena. That there is a difference between what is physical and what is psychological. They are actually the same thing
Describe Marr’s Levels of explanation
- Computational level: What the system does and what the purpose is
- Algorithmic/Representational level: What processes does the system use, what representation does it use
- Implementation/Physical level: What does the system look like. How is it physically realised?
Theory on where thoughts come from
Every decision/thought is based on what happened before it. There is no origin; everything is a consequence of environment
5 techniques for measuring cognitive activity
- Behavioural paradigms
- Psychophysiology
- fMRI
- Electroencephalography (EEG)
- Transcranial magnetic stimulation (TMS)
What are behavioural paradigms?
For example, measuring reaction times
What is psychophysiology?
For example, studying decision making based on an eye tracker, or by measuring skin conductance
What does an fMRI measure?
Blood Oxygen Level Dependent (BOLD) signal
Blood flow correlates with brain activity
How does an MRI work?
Giant magnet (cooled by helium) creates strong magnetic field
Magnetic field aligns hydrogen atoms
Scanner transmits radiofrequency (RF) waves
Causes hydrogen atoms to change spin direction
When they change back, they release electromagnetic energy
Energy detected by detection coils
Tissue type can be inferred by how quickly the energy is released after the RF is turned off
Pros of fMRI
Sensitive
High spatial resolution
Can scan the entire brain - even deep layers
Cons of fMRI
Low temporal resolution - paradigm has to either be slow or jittered, which can affect behaviour
High type 1 error rate
Provides evidence for correlation, not causation
How are fMRI scans compared?
Mass Univariate Approach
Brain image divided into VOXELS
BOLD signal compared on voxel-by-voxel basis, like running a t-test between every voxel
What is Electroencephalography?
Many electrodes placed on scalp (scalp cap)
Electrodes measure event-related potentials
Same event repeated many times
Calculate average signal
Pros of EEGs
High temporal resolution
Cons of EEGs
Low spatial resolution
Provides evidence for correlation, not causation
Potential for Type 1 errors - not as high as fMRI though
Can measure cortex but not deeper brain areas
What is transcranial magnetic stimulation?
Metal coil used to generate a magnetic field
Changing the magnetic field induces a current (electromagnetic induction)
Disrupts part of the brain - observe if this has an affect on a certain behaviour
