Lecture 1 Flashcards
1
Q
Information Processing Approach
A
- Humans are S-R machines
- Info comes in through senses
- All information is serial (one step at a time)
- Bottom up processing = all processes are directly triggered by the stimulus
2
Q
Information Processing Approach (Criticisms)
A
- Doesn’t allow for parallel processing = can’t process more than one thing at a time
- Ignores top down processing = your influence on a stimulus to change perception of it
- Oversimplification
3
Q
Bottom up processing: representation in our heads
A
- Mental representation = our own stimulations and interpretations of the world
- Neural representation = patterns of brain activity that represent the outside world
4
Q
Rate vs Temporal Coding
A
- Rate coding = the faster the neurons respond, the faster the coding of information
- Temporal coding = the greater the synchrony of neurons the faster the coding of information
5
Q
Study Cognition
A
- Experimental Cognitive Psychology
- Cognitive Neuropsychology
- Cognitive Neuroscience
6
Q
Experimental Cognitive Psychology
A
- Controlled lab setting
- Manipulation
- Uses behavioural measures e.g. reaction times as indirect measures rather than brain measures
- Successful at generating testable theories
7
Q
Experimental Cognitive Psychology: Limitations
A
- Ecological validity
- Only provides indirect measures of cognitive processes
- Doesn’t capture what is going on in the brain
8
Q
Cognitive Neuropsychology
A
- Studies cognition in brain-damaged patients
- Looks for what cognitive functions are impaired
9
Q
Cognitive Neuropsychology: Limitations
A
- Difficult to get pre vs post measures of patient’s performance
- Brain damage affects several brain areas / several functions
- Individual differences
10
Q
Cognitive Neuroscience
A
- Relates brain structure and brain function to cognitive processes
- Records brain activity whilst ppts perform cognitive tasks
11
Q
Tools to Study the Brain
A
- Single-Cell Recordings
- EEG
- ERP
- MRI
- fMRI
- Transcranial Magnetic Stimulation (TMS)
- Alternating Current Stimulation (tDCS/tACS)
12
Q
Single-Cell Recordings
A
- Small electrode records neural activity from within axon or outside axon membrane
- Only done in animals but occasionally epileptic patients
13
Q
EEG
A
- Records electrical activity over large number of neurons (via electrodes on scalp)
Measures neural activity in real-time (ms scale)
14
Q
ERP
A
-EEG in response to specific stimulus presented multiple times
15
Q
Advantages/Disadvantages of EEG
A
Advantages
- ->Good temporal resolution (ms)
- ->Portable and cheap
Disadvantages
- ->Poor spatial resolution (where in brain it occurs)
- ->Infinite number of possible origins for any signal recorded at scalp = need computer to make informed guess
16
Q
MRI
A
- Magnetic field has effect on single protons found in water molecules which align
- Alignment disturbed by short radio frequency pulses
- Measure change in magnetic field
- Returning to relaxed state takes different amounts of times for different tissues
- This produces lighter or darker images
17
Q
Structural MRI
A
- Static image of brain
- Based on fact different tissues have different properties
- Aquire slices that are 2D images of brain
- Combine all slices and reconstruct representation of brain
- Because adult brains have plasticity (grey matter), structural imaging can also teach us about function
- Can measure white matter through diffusion tensor imaging:
- -> Investigates how cognition is supported by connections between brain regions
18
Q
Functional MRI
A
- Measures blood-oxygenation level dependent signal (BOLD)
- Hemodynamic Response Function (HRF) = BOLD signal changes in response to stimulus
- Active neurons need oxygen
- Brain supplies oxygen to active areas
- Oxygenated blood = causes less magnetic field disturbance than deoxygenated blood –> active brain regions will have higher signals
- Subtraction logic:
- -> Measure BOLD while participants conduct 2 tasks and subtract average brain scan during one task from the other task
19
Q
Advantages/Disadvantages of fMRI
A
Advantages --> Good spatial resolution = mm Disadvantages -->Poor temporal resolution because HRF is slow (5 seconds to reach its peak) --> Not a measure of neurons themselves --> Many brain areas can be active --> Correlational
20
Q
Transcranial Magnetic Stimulation (TMS)
A
- Uses short magnetic pulses that quickly affects electrical activity in a localised patch of brain tissue under coil
- Applied before/during cognitive task
- Can have positive/negative effect on task performance
21
Q
Alternating Current Stimulation (tDCS/tACS)
A
- Uses small current flowing from one cathode to an anode
-Can either flow constantly (tDCS) or alternates (tACS) - tDCS = areas under the cathode are inhibited, areas under anode thought to be excited
- tACS = induces oscillations at different frequencies
= Both very poor replicability
22
Q
Advantages of Brain Stimulation
A
- Causal evidence
- Non-invasive
23
Q
Disadvantages of Brain Stimulation
A
- Stimulation to brain is weak as happens outside of head
- Risk to individuals with history of epilepsy
