Definitions Flashcards
Aphasia
Language disorder, as. result of a stroke or brain injury, that affects a persons ability to communicate
fMRI
A safe and non invasive technique that detects changes in blood flow which correlates with neuronal activity
TMS
A non-invasive technique that disrupts specific brain activity for a fraction of a second
Action Potential
the change in the voltage inside a cell (relative to outside the cell) taking place at one section of the neuron at a time
Agonists
Drugs that occupy receptors and activate them
Antagonists
Drugs that occupy receptors but block receptor activation
Place cells
When our brain enters a space, it assigns certain positions to different cells and therefore these neurons respond at different spaces
Grid cells
Our brain assigns certain cells to certain positions in a grid like structure of spatially even triangles.
Psychophysics
the relationship between the physical world and the psychological world (via the neural world)
Signal Detection Theory
Allows us to separate sensitivity from response bias
Sensitivity
How well can you distinguish between when the stimulus is present or absent. Sensitivity means you have a high hit rate AND a low false alarm rate
Weber law
Discrimination threshold increases proportionally to baseline/reference stimulus increases - must be 8%
Trichromatic Theory
Colour perception is mediated by cones. There are 3 cone types: S-cones are most sensitive at short wavelengths (blue), M-cones at medium wavelengths (green) and L-cones at long wavelengths (red). Your brain perceives colour based on the combination of photoreceptors that are activated at a specific location.
Dark Adaptation
The transition of the retina from the light adapted to dark adapted state
Colour Opponency
Colour perception involves opponent processing of two pathways: Red/green and yellow/blue. When you stare deeply at something that is blue/yellow - all the blue/yellow cells are saturated, they adapt to the stimulus and stop responding. When you move your eyes to something that is right, the blue/yellow cells are tired so the red/green cell system dominates your field of vision.
Perceptual Constancy
Objects maintain their properties even when the context changes their physical characteristics
uncrossed disparity
object that are further away from the fixation point will fall on corresponding points in the retinas of the two eyes - making them single and in depth
retinal disparity
The difference in the images seen by the two eyes due to their slightly different positions. This difference helps the brain to perceive depth and distance.
crossed disparity
Objects closer to the fixation point will fall on non-corresponding points in the retinas of the two eyes. For examples, if you hold your finger close to your face and look at it with both eyes, you’ll notice that your finger appears to be double. This is because the image of your finger falls on different points in your left and right eyes.
Vergence
When we look at things that are very close, our eyes stop moving in parallel and move inward. The brain can interpret eye muscle movement to decide how much vergance and guess how far away things are
Texture gradient
things that are closeup (high resolution, good detail) things that are further away (low resolution, less detail)
Linear perspective
parallel lines come closer together off into the distance
Ariel perspective
There are water molecules in the air, and with things that are further away wehave to look through more water molecules, makes them hazy and slightly grey/blue
Interposition/occlusion
things closer to me will block things further away from me
Bottom up processing
Data driven processing that uses incoming information to drive perception
Top down processing
conceptually driven processing whereby experience and knowledge drive perception
Change blindness
A psychological phenomenon where people fail to notice changes in their environment when their attention is focused elsewhere.
Feature integration theory
Searching for one feature (colour, shape) can be done automatically. It “pops out”. It takes the same amount of time, no many how many items you have to search.
Searching for a combination of features requires controlled attention. You need to apply attention to each item, one at a time. More items requires more time.
Selective attention
The ability to prioritise some information while ignoring other information
Broadbent’s Filter Theory
Attention narrows the flow of information into awareness - only what we attend to will get meaning analysis
Treisman’s Attenuation Model
Attended messages pass through clearly. Unattended messages are weakened. Sometimes they break through
Deutsch & Deutsch late selection model:
We process everything for meaning, but only selected information makes it into our awareness.
The Biased Competition Model of Attention
attention is a competition between bottom-up and top-down factors, with the most salient or relevant stimuli being selected for further processing.
The Switch Cost
the cognitive effort required to shift attention between different tasks or stimuli. It can lead to reduced performance and increased errors when multitasking.
Cue dependency principle
The strength of a memory depends on the number and informativeness of its cues
Encoding specificity principle
Cues are most effected if they are encoded along with the to-be-remembered information.
SAVINGS
the reduction in time required to learn a second time
