cog semester 1 Flashcards
what is the mind
- structure that recalls memories, solves problems, considers possibilities and makes decisions
- also creates representations of the world so we can act in it to achieve our goals
rationalism
the idea we are born with understanding and just need to deduce and reality is an inherently logical structure
empiricism
knowledge is slowly increased by interacting with the world, concepts and beliefs are understood only by experience
what was the 1st cognitive experiment
donder’s subtraction method (1868) - if you measure 2 variations of the same function that only differ in one way, the observed difference is attributed to the IV
how to show activation using Donder’s work
build up an activity and the the difference in brain activation, time and action can be attributed to each stage
what is structuralism and who was involved
Wundt
approach that attempts to explain functions of the mind and shows that we can break down processes into their elements to understand them
the forgetting curve - who created it and what does it show
ebbinghaus
shows how long people need to memorise a list of items, and how quickly you can forget and relearn vs learning something new
functionalism
studying the mind based on observations and focusing on mental processes
how can you use diagrams for the brain
- process models to show how functions work together
- structural models to help visualise, show localisation and compare species’ brains
- use brodmann areas - numerical labels for the brain that link to specific functions
describe the structure of a neuron
cell body, long dendrites to receive info, shorter fluid filled axons send info, covered in myelin sheath
what did Ramon y Cajal discover?
nerve nets were made up of individual cells that transmit in the nervous system and that there are neurocircuits or small groups of neurons. this was proved by the golgi stain technique - saw individual units connected together
how to measure neuron interaction
with microelectrodes placed near axons that are strong enough to amplify single neuron firings - first completed by edger adrain in 1920s
what is the principle of neural representation
the idea that everything a person experiences is based on representations in the NS via action potentials
what are feature detectors
neurons that respond best or exclusively to specific stimuli
what did hubel and wiesal find (1960s)
cat research
each neuron in visual area of the occupital responded to certain type of stimuli - meaning multiple feature dectors rep different aspects of objects
where are feature detectors highly specialised?
the fusiform gyrus in the temporal cortex has many - for faces (we cannot ignore them) words, objects, shapes, bodies, places
how do feature detectors develop
blake and coops showed that perceptions are determined by the neurones that fire - applied to speech shows that babies have capacity to produce sound attributed to any language to as we get older - much harder outside own language
what is hierarchical processing
how info is processed from low-high areas of the brain - edges to lines to faces
what is specificity processing and how is it limited
the idea that stimuli is represented by one specific neuron firing (e.g the britney spears neuron) - however neurons are more likely to respond to several faces as there are too many stimuli in the world to have one neuron dedicated to each
what is sensory coding
how neurones represent various characteristics of the environment in separate categories (smell, touch, sight)
what is population coding
representing stimuli via neuron patterns - e.g for faces - x amount of neurons for several faces that fire in dif patterns
sparse coding
most effective method - represent faces by pattern of firing a small group of neurons whist the rest remain silent - meaning there can be some overlap with those that rep diff faces
what kind if neuron firing is associated with memory
likely to be sparse and population coding
the role of broca’s and wernicke’s areas
b - left frontal lobe is specialised for speech
w - temporal lobe for language comprehension
how do you prove localisation of function
double dissociation
- taking patients with brain damage to either area A or B. this causes A to function and B to be absent and the reverse applies
how does fMRI work
blood flow increases in areas used for cog tasks, haemolglobin contains magnetic iron ion so lights up. brain activity seen when O2 released - becomes more magnetic,is an indirect measure of neural activity
what is distributed representation (and example in faces)
cognitive function activate many areas of the brain - this compliments localisation
e.g faces - first occuptial, highly activates fusiform (in temporal) plus other areas when emotion and attraction are considered
the pain matrix as a neural network
functions include: determining location and sensory aspect, emotional aspect, significance, memory and direct attention to or away from pain
what is EEG
no invasive hat - studies synchrony and functional connectivity between cortical areas and takes event related potentials
what is TMS
direct measure of neural networks
- magnetic coil that is placed near head to temporarily stimulates and inhibits brain regions - can map cog functions
distal and perceptual objects
what is in the environment and what we perceive are two different things - we perceive uniquely and this is our interpretation
ventral stream of perception
temporal lobe down to perception and categorisation
dorsal stream of perception
up to parietal love for action
why can’t computers copy human perception
- inverse projection problem: objects far apart or at different angles creat similar images on the retina only we can detect
- computers see via edges and don’t interpolate missing parts, may comvine objects
- only we have viewpoint invariance - multiple viewpoints based on their rotation
bottom up and top down perception of pain
BU - depends on stimulation of receptors
TD - pain management - direction attention to or away, what is ecpects and changing attention away for pain like in injections
top down processing in language
our experience shapes language - being able to segment speech (end and beginning) and transitional probabilities
what are helmholtz’s unconscious inferences
perceptions as a result of unconscious assumptions made about the environment using own knowledge- infer based on probability
what does gestalt believe about perception
determined by specific organising principles not just light waves. organisation is bottom up. role if experience is minor compared to built in principles but can have some influence
gestalt - figure ground principle
there must be a distinction between and object and it’s background
principle of good continuation
the assumption of how lines work as following the smoothest path
law of pregnanz
principle of simplicity or good figure - understanding patterns to make the result the most simple outcome (olympic rings)
principle of similarity
similar things appear grouped together
bayesian inference
estimation of a probability of a given outcome is influenced by the prior probability (existing beliefs) and the likelihood of an outcome
role of motivation in perception
we see what we want to see in early perception - seen in study where hungry people saw food related words faster than non hungry people and faster than neutral words
how does perception and action interact
movement means me need to constantly perceive changes - for example all the mechanisms needed to pick up a mug of tea
this physiology suggests two streams of processing
what is the perception pathway
the ventral stream with is the visual cortex to temporal lobe
what is the action pathway
the dorsal stream which is visual cortex to parietal lobe
what is broadbents filter/early selection model
- number it’s sensory inputs travels through bottle
- filters message before info is analysed for meaning
- filter only lets attended features pass and then this can travel to short/long term memory
treimans attenuation model
- info travels to dictionary unit then memory
- analyses incoming messages in terms of physical characteristics, language and meaning
- attended message has full strength but does not completely discard unattended
how does mckay show unconscious bias in hearing
attended ear heard ambiguous sentence and other had biasing words that may contextualise
found that biasing words affected what they thought the message meant but were unaware of the presentation of the biasing words
how does perceptual load work
low load tasks take up less of the capacity and can leave resources available for processing unattended task-irrelevant stimuli
how do eye movement differ in top and and bottom up
bottom up - new scene
top down - making breakfast - know where to look and results in scanning based on knowledge factors
driving and attention
- highly automised in easy conditions
- phone use (held and handsfree) missed twice as many red lights and took longer to brake
- talking on the phone uses cog resources - is not about holding the phone
- easier to become distacted when something else in mind
change attention
not attending leads to difficulty in detecting change but is easy to notice once it is pointed out
the binding problem
when features of an object combine to create a perception - the problem is how it does this
feature attention theory
preattentitive stage - automatic - objects are analysed into features and occurs before perception
focused attention stage - attention plays key role and features are combined into an object
illusory conjunction
where features from different objects are inappropriately combined when they are quickly looked at, because features are free floating and so the focused attention stage is combined
