Approaches to human cognition Flashcards
What is the aim for studying cognition?
to understand the workings of the human mind by studying behaviour using experimental methods
what are the types of processing
Parallel: processes occurring at the same time as each other (talking while driving)
Serial:
- discrete serial processes = when there are two separate processes that happen one after the other (turn on ignition, step on accelerator)
- cascaded processes: happen one after the other but overlapping
Bottom-up processing: external stimulus causes internal cognitive processes to occur, producing the desired response
Top-down: processing influenced by the individual’s expectations and knowledge
What are the 4 different approaches to study cognition?
Cognitive psychology: uncover nature of human cognition by observing BEHAVIOUR
Cognitive neuroscience: attempt to use information about BEHAVIOUR and the BRAIN to understand human cognition
Cognitive neuropsychology: understand human cognition by studying BRAIN-DAMAGED patients
Computational Cognitive Science: use computational MODELS to further understanding of cognition
Cognitive psychology typically uses an experimental method, meaning:
Experimental method used to test a research hypothesis.
- IV: variable manipulated by the experimenter, needing at least 2 levels (conditions)
- Factorial design combines more than 1 IV: measuring drug dosage and participant’s sex
- DV: what is measured
Describe the phonological similarity effect
Phonological similarity is when the stimuli sound like each other –> phonologically similar stimuli are less easily recalled in the correct order when tested with an immediate serial recall task, irrespective of the presentation mode (spoken or visually presented).
What are the implications of the phonological similarity effect?
Verbal short term memory uses a speech-based code. Visually presented letters are re-coded into a speech-based format.
Visually presented letters are re-coded into a speech-based format.
Describe computational models:
Programming computers to mimic some aspects of human cognitive functioning.
A simulation compares the model’s behaviour to human behaviour.
What are some techniques used in Cognitive neuroscience?
- Single-unit recordings: measuring single neurons
- Event-related potentials (ERPs): measure of the brain activity at the scalp
- Positron emission tomography (PET): brain imaging technique (less used)
- Functional magnetic resonance imaging: blood oxygen level dependent contrast, can be used to look at dynamic activity
- Magneto-encephalography (MEG): uses magnetic field to measure brains activity
- Transcranial magnetic simulation (TMS): applying a current to make temporary brain damage
Key terms for evaluating the neuroscience methods
Temporal resolution - the accuracy of measuring when the event occurs in the brain
Spatial resolution - the accuracy of measuring where an event occurs in the brain
Invasiveness - is the equipment located internally or externally
Describe ERPs and their limitations
Event Related Potentials non invasively measure electrical activity in the brain with electrodes placed on the scalp.
Limitations:
- requires many trials because the signal is weak
- limitation spatial resolution, but high temporal resolution (skull and brain tissue distort electrical fields, largely blind to subcortical activity)
- poor spatial resolution
Describe fMRI
Functional Magnetic Resonance Imaging
Measures changes in the blood flow during cognitive activity - where brain regions have a higher ratio of oxygenated to deoxygenated haemoglobin (different magnetic property). Blood oxygen level dependent signal.
Non-invasive
High spatial resolution
Limitation = poor temporal resolution
Describe MEG
Magneto-Encephalography
- uses a superconducting quandtum interference device to measure the magnetic fields produced by the electrical activity
- high temporal resolution
- moderate spatial resolution
- isn’t limited in the same way that EEG is because the skull is transparent to magnetic fields
Limitations:
- expensive
- discomfort for the participant
Describe Transcranial Magnetic Stimulation
- very brief magnetic pulse creates a short lived magnetic field simulating a temporary lesion
Describe the aims of cognitive neuropsychology
Patterns of cognitive performance (both intact and impaired) shown by brain-damaged patients.
Assumptions:
- functional modularity: cognitive systems consists of numerous, independent processing units and modules exhibit domain specificity
- anatomical modularity: each module is located in a specific brain region
