Introduction to Cognitive Psychology Flashcards
Experimental Cognitive Psychology
- Studying behaviour in controlled
laboratory settings - Shed light onto cognitive processes by using clever experimental manipulations
- Doesn’t care about the underlying brain processes
- Instead of “brain measures”, cognitive psychology uses behavioural measures
like reaction times (RT) or accuracy as indirect measures
Success of Experimental Cognitive Psychology
- Extremely successful at generating theories about cognition that can be tested in neuroscience etc.
- Has made a huge contribution to
making Psychology a more empirical science
Limitation of Experimental Cog. Psych: Ecological validity
- Tasks are not similar to cognitions that people have on a day to day basis
Limitation of Experimental Cog. Psych: Face Validity
- Only provides indirect measures of cognitive processes
- Can’t feasibly measure actual cognitions like thoughts and memory formation as they are abstract
Cognitive Neuropsychology
- Studying cognition in patients with brain injury
- Goal is to find which cognitive
functions are impaired, and which
ones are preserved when a given
brain region is damaged
*Can assume damage to certain areas leading to a deficit means that area is responsible for that function
Limitations of Cognitive Neuropsychology: No baseline
- We don’t know exactly what the
patient could do before their injury - Can’t compare to the past
Limitations of Cognitive Neuropsychology: Generalisation
Lesions in some areas of the brain are relatively common, while others are very rare
- Means may be generalising the idea that a lesion is harmful/not an issue when it is
Limitations of Cognitive Neuropsychology: Modularity
Cognitive process X is likely
distributed across multiple areas,
not just one
- Have to assume only said area had function
Cognitive Neuroscience
- Relates brain structure and brain
function to cognitive processes - Typically done by recording brain
activity while participants perform
cognitive tasks
Electrophysiology (EEG): Single-Cell Recordings
- Very small electrode records
neural activity from within axon
(intracellular) or from outside
axon membrane (extracellular) - Usually only obtained from
animals - Sometimes we have the rare
chance of recording from
patients with epilepsy - Brain activity can be measured by electrodes already implanted in their brains
Electroencephalography (EEG)
- Electrical activity of a large number of neurons all firing
together, recorded via electrodes on the scalp - Allows us to measure neural activity in essentially real-time
(millisecond scale)
Event-related potentials (ERPs)
Measure EEG response to the same stimulus/task over and over
- Average waveform to generate an “event-related potential” (ERP)
- We can compare the ERPs between different psychological conditions (e.g. attended vs. unattended stimuli)
Advantages of EEG/ERP
Very good temporal resolution (milliseconds) – i.e. when something happens
- Portable and relatively cheap
Limitations of EEG/ERP
Poor spatial resolution (centimeters)
– i.e. where in the brain it happens – There are an infinite number of possible origins for any signal recorded at the scalp, so
we need solid computational models to make an informed guess
Magnetic Resonance Imaging (MRI) - Basic Principles
- Single protons in water molecules tend to align to the powerful
and stable magnetic field generated by the scanner - We then disturb this alignment with short radio-frequency pulses
and measure the resulting change in magnetic field - Different parts of the brain (grey matter, white matter, CSF) take different times to “relax” from the radio frequency disturbance, and show as lighter/darker
