Cognitive Psych 1 Flashcards
What does the information-processing approach assume?
humans are ‘stimulus-response machines’ - this isn’t a sufficient enough explanation
What are ‘grandmother cells’?
neurons that fire to particular concepts e.g a certain colour, or names (e.g. Luke Skywalker)
usually found in medial temporal lobe
What is the difference between rate coding and temporal coding?
-Rate coding: The greater RATE of a neuron (s) response is used to code information
-Temporal coding: The greater SYNCHRONY of several neuron’s responses used to code information
What is experimental cognitive psychology?
studying behaviour in a controlled lab setting and shedding light on cognitive processes by using experimental manipulations
What does experimental cognitive psychology prioritise/ not prioritise?
-Prioritises observable behavioural measure such as reaction time
-Does not prioritise underlying brain processes
What is cognitive neuropsychology and what is it’s goal?
-Studying cognition in patients with brain injury
-goal is to find which cognitive functions are impaired after a brain region is damaged
What is cognitive neuroscience and how is it typically studied?
- Relates brain structure and brain function to cognitive processes
- Typically done by recording brain activity while participants perform cognitive tasks
What is EEG? (Electro-physiology) (2 points)
-Electrodes being attached to the scalp to measure single cell brain activity.
-Records neural activity from within axon or outside axon membrane
What is EEG (Electro-encephal-ography)
-Electrodes being attached to scalp to measure a large number of neurons all firing together.
What is ERP’s? (Event Related Potentials)
-Measures EEG response to the same stimulus/task over and over
-Creates an average waveform which generates an event related potential
What is the strength and limitation of EEG/ERP’s
-Strength: good temporal resolution (milliseconds) (also portable and relatively cheap)
-Limitation: Poor spatial resolution
How does MRI (Magnetic Resonance Imaging) work? (5 points)
-Uses strong magnetic and radio waves
-works on hydrogen atoms in the brain which are abundant in water
- These water molecules act as little magnets that align with the magnetic field generated by the MRI
-We then disturb this alignment with short radio frequency pulses
-When the pulse stops the hydrogen atoms return to alignment, which creates a signal detected my MRI sensors
What is structural MRI/ Diffusion tensor imaging?
-Measures the diffusion of water molecules to image white matter (bundles of axons)
What is fMRI (functional magnetic resonance imaging) (3 parts)
-Tracks the flow of oxygenated blood
-active neurons need oxygen, so the brain supplies oxygenated blood to active areas
-oxygenated blood causes less magnetic field disturbance that deoxygenated blood, so active regions would have a higher signal
What is the strength and limitation (2) of MRI’s?
-Strength: very good spatial resolution
-Limitation: poor temporal resolution (seconds)
-Limitation: Not a measure of neurons themselves; relies on the inference that just because part of the brain is using more oxygen it’s firing neurons.
What is TMS? (Transcranial magnetic stimulation)
-A coil is placed over the scalp and delivers short magnetic pulses
-this affects electrical activity in a localised patch of brain tissue
-when used before or during a cognitive task, it can have either a positive or negative effect on performance
What is the strength (2) and limitation of TMS?
-Strength: causal evidence, and mostly non-invasive
-Limitation: stimulation of the brain is relatively week as its from the outside of the head, therefore the effects are usually weak
How does information go from the eye to the brain? (3 points)
- eye focuses light on the retina, which has tiny photoreceptors (cones and rods)
They convert light into electrochemical signals
-these signals travel through the optic nerve to the brain via pathways
-the main areas that this information goes to is the thalamus and cerebral cortex, where visual perception occurs
What is the difference between rods and cones? (2 points each)
- Rods= scotopic vision (vision in dim light) and movement
-Cones= photopic vision (vision in bright light) and colour and sharpness
What visible light colour range is the human eye most sensitive to?
green range
What three colour ranges do we have different cones for absorbing?
red green and blue
What is colour constancy?
the tendency for a surface to always appear as the same colour despite a change in the wavelengths contained in the iluminant (the light on it)
After the retina, what is the parvocellular pathway responsible? (2 points)
-mainly input from cones
-colour and fine detail
After the retina, what is the magnocellular pathway responsible for?
-mainly input from rods
-motion
Which side of the retinas do signals reaching the right side of the visual cortex come from
right side of both retinas
Which side of the retinas do signals reaching the left side of the visual cortex come from
Left side of both retinas
What does this mean in terms of our left and right hemifields?
What we see in our left hemifield is processed by the right side of our brain, and vice versa.
What are receptive fields?
the region of the sensory space (i.e. retina) within which light will cause the neuron to fire
What is retinotopy?
the idea that things that are near to each other are processed by cells that are physically near to each other
What is lateral inhibition and what does it allow us to do?
the idea that one neuron is able to inhibit the activity of a neighbouring neuron. this allows sharply see contrast at edges of objects
What is the five stop pathway to the brain after the retina?
Retina, optic nerve, optic chiasm, lateral geniculate nucleus (LGM), cortical area V1
What is the lateral geniculate nucleus and what is it responsible for?
-part of the thalamus, a subcortical relay for most of the brain sensory input and motor output
-correlates signals from the retina in space and time e.g. “is this object moving towards me?”
What is the primary visual cortex (V1) responsible for?
extracts basic information from the scene e.g. edges, wavelengths of light. It then sends this information for later stages of processing e.g. colour, movement
According to the Functional Specialisation Theory, what are parts of the visual cortex responsible for?
V1 and V2: early stages of visual perception e.g. shapes
V3 and V3a: responsive to form, especially moving objects
V4: responsive to colour
V5/MT: responsive to visual motion
Achromatopsia is damage primarily to which part of the visual cortex?
V4
Akinetopsia is damage primarily to which part of the visual cortex?
V5/MT
Beyond the visual cortex, what are the two important visual pathways?
The ‘Where’ pathway and the ‘What’ pathway
What is the ‘Where’ pathway and what is it concerned with?
parietal/ dorsal pathway, concerned with processing of movement “vision for action”
What is the ‘What’ pathway and what is it concerned with?
temporal/ventral pathway, concerned with processing colour and form “vision for perception”
What are the four stages involved in the model of object processing?
- early visual processing e.g. colour, edges
- perceptual segregation (grouping together visual elements)
- matching grouped visual representation onto a representation of the object already stored in the brain
- attaching meaning the the object based on prior semantic knowledge
What is agnosia, and what are the two types?
impairment in object recognition
Apperceptive agnosia and Associative agnosia
What is apperceptive agnosia and what does it mean? (3 points)
-An impairment in the process which constructs a perceptual representation from vision (e.g. the grouping stage)
-this means seeing the parts but not the whole
-often associated with lateral occipital lobe damage
What is associative agnosia and what does it mean?
-An impairment in the process which maps a perceptual representation into knowledge of the objects functions and associations
- This means seeing the whole, but not its meaning
- Associated with occipito-temporal lobe damage
What is prosopagnosia and what stage is the impairment?
the impairment of face processing that doesn’t come from damage to stages from early visual processing. Instead, it is an impairment in the stage of matching to previously stored information
