Cognitive psychology semester 1

Pregunta	Respuesta
What is cognitive psych?	-our PERCEPTION of world around us and how we INTERPRET THE SENSES -the ATTENTIONAL PROCESSES that allow us to focus on stimuli -how our MEMORY operates and how we retrieve information -our LANGUAGE PROCESSES that help us communicate -the processes that contribute to DECISION MAKING
Introspection	We can monitor our own thought processes to understand how they world Anecdotes, stream of consciousness, self-tests. Developed by Wilhelm Wundt. Also known as experimental self-observation.
Problems with introspection	inconsistent results, introspection may be inaccurate, some mental processes might not be amenable to introspection Low generalisability, testability and reliability not possible on children/animals/very ill people
Information processing	Our minds work like a computer. it is possible and desirable to study the internal mental processes that lie between the stimuli (in our environment) and the response we make.
Decomposition	cognition composed of multiple processes e.g multi store model
Representations	cognition acting on and transforming information
embodied cognition	our body shapes how we sense and act on the world; cognition has to be understood in this context. our visual sense provides information about the world that allows us to do things in it, such as walk through doors or catch balls.
Behaviourism	we cannot measure what is going on inside the mind, but we can measure behaviour responses to stimuli careful control of stimuli and measurement of behaviour, usually empirical experiment techniques. problems; doesn't explain everything, e.g. how we can form sentences we haven't heard before.
How to measure magnitude	Present stimulus(standard) assign perceptual value e.g 10 Present another stimulus, ask participant to rate magnitude with respect to standard
The psycho-physical function	Image: 1101 (binary/octet-stream)
Steven's power law	P= KS^(n) P= perceived magnitude S= stimulus intensity K, n= constants (specific to stimulus) empirical law- fitted to data but not absolute
response compression	e.g brightness, loudness, vibration on skin Image: Abc (binary/octet-stream)
response expansion	e.g electric shock, taste of salt, muscle force Image: Abb (binary/octet-stream)
Perceptual threshold	the level of stimulus it takes to go from not experiencing/feeling/seeing to experiencing/seeing/feeling the stimulus Image: 09 (binary/octet-stream)
Threshold finding methods	Method of limits Method of adjustment Method of constant stimuli
Method of limits	1) start with the lowest intensity, feel yes/no? increase again and again till yes. create 1st threshold. 2) start with highest intensity, feel yes/mo? reduce again and again till no. create 2nd threshold. repeat till consistent, find average to determine final threshold -fast but may suffer order effects
Method of adjustment	participants adjust stimulus intensity themselves using e.g. turning nob. aiming for perceptual threshold. can be repeated with different starting intensities. -quickest, but more dependent on participant cooperation
Method of constant stimuli	stimuli are pre-selected by experimenter and run in random order psychometric curve is fit to results every participant gets same experience -stimuli can be presented multiple times, then mean score found very precise but also slow. Image: 223 (binary/octet-stream)
Just noticeable difference (JND)	What is the smallest difference between two stimuli we can detect? present two stimuli on each trial & ask whether they are the same or different.
Relative threshold (for JND)	Image: 333 (binary/octet-stream)
Weber's Law	JND is a constant proportion of the stimulus intensity +/-20% Image: 444 (binary/octet-stream)
The muller-lyer illusion	Lines with outward pointing arrow shafts tend to appear longer than inward ones. Image: 20202 (binary/octet-stream)
Signal detection theory	Perceiver's sensitivity can be distinguished from their bias. All perceivers have bias, and it will be influenced buy the costs and benefits of the response outcomes. need to also ask when stimulus is NOT present. Image: 888 (binary/octet-stream)
Perceptual responses to a stimulus	-describing (indicating characteristics) -recognising (putting in specific category) -detecting (aware of barely detectable aspects of stimulus e.g slight movements) -perceiving magnitude- aware of size/intensity -searching- looking for specific stimulus amongst others
Olfaction	Sense of smell
Gustation	sense of taste
somatosensation	sense of touch
Tactition	Classic sense of skin touch
Equilibrioception	sense of balance and acceleration
Thermoception	sense of temperature
Proprioception	sense of body position and movement
Nociception	sense of pain
Interoception	sense of hunger, bladder, thirst etc.
Sensation	The passive process of bringing information form the outside world into the body and to the brain
Perception	the active process of selecting, organising and interpreting the information brought to the brain by senses.
Transduction	the conversion of physical stimulus/energy into electrical signal (neural activity)
Chemoreception	taste/smell chemicals in food/air
Mechanoreception	Physical touch pressure on cells or sound vibration in the air
Photoreception	light picked up by slight
Hearing	Sound waves are funnelled along the ear canal to the ear drum and on to the cochlea. Hair cells along the Basilar membrane pick up the vibrations. Different frequencies cause the Basilar membrane to vibrate at different points. The human ear can perceive frequencies between
vision	Light enters the eye through the pupil. Focussed (inverted) onto the retina. Retina is covered with photoreceptor cells. Rods (125 million for dim light) & cones (6 million for bright light). The area of highest density of cones is called the Fovea
Touch	Receptors within the skin respond to pressure. vibration and movement. Different types of receptor cells respond to different types of stimulation. Sensitivity varies across body part with density of mechanoreceptors. Can be measured using two-point discrimination technique. Image: Download (1) (binary/octet-stream)
Smell	Even more poorly understood than taste. Cells in the nasal cavity respond directly to chemical compounds. Approx 1000 types of receptor molecules located in olfactory receptor cells. Olfactory
Taste	Not well understood. About 10,000 taste-buds on tongue- not distributed by class of flavour. Taste buds are continually destroyed and replaced.
Somatosensory cortex	Found in parietal lobe. each area of the body maps to a particular part of somatosensory cortex. different body parts are not represented evenly Image: 4444 (binary/octet-stream)
Gestalt Laws	German for 'form' or 'shape'. Laws/principles: explain how parts are arranged into forms/objects perceived as a whole. Similarity, proximity, continuation, closure, simplicity(pragnanz).
Similarity	Elements that look similar will be perceived as being part of the same form Image: 2323 (binary/octet-stream)
Proximity	Elements that are close together will be perceived as belonging together Image: 7777 (binary/octet-stream)
Good continuation	We perceive lines as following a smooth course Image: Continuation 600x450 (binary/octet-stream)
Closure	boundary isn't necessary for us to perceive form. When small elements are arranged in groups we tend to perceive them as larger figures. This can lead to us seeing illusory lines that do not exist. Image: 12111 (binary/octet-stream)
Common fate	elements that move together tend to be grouped together
Symmetry	elements that are symmetrical tend to be grouped together.
Parallelism	elements that are parallel tend to be grouped together
Simplicity (pragnanz)	We organise a scene according to its simplest form Image: 3636 (binary/octet-stream)
Investigating feature representation	Idea: record from a single neuron, present different visual stimuli, check which ones elicit a response.
Optic nerve and thalamus	Responsive to dot-like circular visual stimuli: centre-surround organisation. Light centre and dark surround or vise versa.
Hubel and Wiesel	Measure response to lines in different places, at different orientations in cortex. Neural encoding is firing rate. For a single cell, highest firing rate is to a specific orientation in a specific position. Interpretation is that highest firing rate= greatest sensitivity Image: 0000000 (binary/octet-stream)
Edge detection	the visual system can extract lines/edges from things that we see to process it. Image: Werwer (binary/octet-stream)
Feature representation in visual cortex	receptive fields are built up by combining receptive fields of neurons in the thalamus. Hierarchical processing. Receptive fields get larger as one ascends the hierarchy. Receptive fields get more complex. Image: Asasa (binary/octet-stream)
Top-down cues	The context we perceive a stimulus in can change our perception of it. Our environment gives us clues when the stimulus is ambiguous Image: Download (2) (binary/octet-stream)
Top down vs bottom-up	Bottom up- processing the stimuli influences what is perceived (data driven). Top down- background knowledge and expectations influence what is perceived (knowledge driven)
Perceptual contancy	Colour is processed in context. What is surrounding an object effects the perceived colour. Effects are strong Image: Jkjkj (binary/octet-stream)
How do we resolve ambiguities?	We need to decide which visual scene caused the image on the retina. -Assumptions and cues are combined to make a best guess at what it is we're seeing. -Cues: features of the image that give us clues as to nature of stimulus. -Assumptions: expectations about what we will see or what different cues mean.
3D shape cues	We have learnt the physics of how light works in terms of shadows/high points. This allows us to interpret 3D in images Image: Erere (binary/octet-stream)
Two streams of visual perception	The 'what' pathway: shapes, objects. Ventral, to inferior temporal lobe. The 'where' pathway: Motion. Dorsal, to superior parietal lobe. Image: Picture1 (binary/octet-stream)
Challenges for cognitive neuroscience	-Complex systems (around 1 million neurons in 1 cubic mm of brain. -Signal to noise ratio (needle in haystack) -Between-individual differences -Within-individual differences
Cognitive neuroscience techniques	Brain structure: Anatomical dissection MRI Brain function: Single electrode stimulation EEG, ERP fMRI MEG PET TMS Neuropsychology: Data from individuals with brain damage
fMRI	when neurons are active, they burn energy. This is automatically replenished via the blood. Blood contains haemoglobin so its possible to detect blood flow. It is possible to distinguish between oxygen-rich vs oxygen-depleted blood. We can work out which parts of the brain are being used
Advantages and disadvantages of fMRI	+Tells us which parts of the brain are used in tasks +Reasonable temporal resolution +Get structural data within same session. -Claustrophobic, very noisy, movement artefacts -Can't have any metal -isn't a direct measure of activity.
MEG: Magneto-encephalography	Pyramidal cells of the cortex, when active, generate a significant magnetic field. MEG records theses fields. For both MEG and EEG the synchronous firing of 10,000s of neurons is required to produce a field which is large enough to measure. Magnetic fields are less distorted by scalp than electrical
Advantages and disadvantages of MEG	+excellent temporal resolution +good spatial resolution -Expensive -The inverse problem for finding what causes what.
EEG	EEG measures electrical signals generated by the brain through electrodes placed at the scalp. Signals are produced by partial synchronisation of cortical field activity and are measured in changes of voltage. Electrodes are placed on scalp, connected with conductive gel. An amplifier measured the difference in voltage between the active electrode and reference electrode.
Advantages and disadvantages of EEG	+very good temporal resolution +Less subject to motion artefacts & not claustrophobic. -Weak spatial resolution -Inverse problem- given a pattern of activity, how do you determine which brain regions caused it?
What method is best for spatial resolution?	1St- fMRI 2nd- MEG 3rd- EEG
Epoch	EEG epoching is a procedure in which specific time-windows are extracted from the continuous EEG signal. These time windows are called “epochs”, and usually are time-locked with respect an event e.g. a visual stimulus
What is best method for temporal resolution	1st- EEG & MEG 3rd- fMRi
PET =: position emission tomography	inject a tracer element into blood stream. Give some task that requires brain. Measure how much of tracer goes where in the brain. Stats are done on how this compares with the resting state.
Advantages and disadvantages of PET	+reasonable structural accuracy +direct reflection of activity +no motion artefacts +relatively pleasant -injection of very weak radioactive substance -no temporal resolution -expensive -may need to do MRI or CT as well.
TMS: Transcranial magnetic stimulation	non-invasive method causing depolarisation or hyperpolarisation of neurons in the brain (i.e increase or decrease activity) -uses electromagnetic induction to induce weak electrical currents in cortex. Can cause motor evoked potential (twitches) can stimulate temporary lesion of brain by preventing normal function.
Meta analysis of the efficacy of rTMS in psychiatric disorders	40 studies on depression: 751 patients treated with rTMS. Applied to dorsolateral prefrontal cortex. Results indicate that rTMS to either left or right, has a medium-sized positive effect on depression. (with some minor side effects).
Advantages and disadvantages of TMS	+near portable +can stimulate or lesion -difficult to specify precise regions -only surface regions
Where was phineas gage's damage?	orbitofrontal and anterior medial areas of frontal lobes.
inattentional blindness	the failure to see visible and otherwise salient events when paying attention to something else
Attention as an information filter	Our attention acts as a filter, there are an infinite amount of things that we could be attending to in the environment at any time.. We filter out irrelevant information to our task goals and focus on what is most relevant.
Broadbent (1958)	Image: Jjjj (binary/octet-stream)
Treisman's development of broadbent's model	Image: Dddd (binary/octet-stream)
Cocktail party effect	Attention focuses on meaning from environment. E.g hearing our name in someone else's conversation. Creation of meaning Evidence that information is not entirely ignored.
Spatial attention	Our attention focuses like a spotlight. Can be narrow or broad. Move around rather than focusing on everything at once
Target detection study Laberge	5 items in different locations, participants looking for the specific item (stimulus), reaction times recorded on how fast it took participants to see stimulus. Reaction times were quicker when stimulus was in the more central location, slower in periphery Image: Cccc (binary/octet-stream)
Exogenous cue	Most likely to appear in the periphery. Visual appearance of something, e.g. object, flash of light. Valid or invalid depending on if the cue appears in the same place as target stimulus or not Image: Yyyy (binary/octet-stream)
Endogenous cue	Symbolic cue, usually appears in the centre of our vision. Our brain processes the symbol and will shift our vision accordingly. Valid or invalid depending on if the symbolic cue directs our vision in the correct manner or not. Image: Sss (binary/octet-stream)
Stimulus onset asynchrony (SOA)	time between onset of first stimulus and onset of second stimulus
Inter-stimulus interval (ISI)	Time between offset of first stimulus and onset of second stimulus
inhibition of return	exogenous cue followed by a delay suppresses attention. Inhibition of return helps to facilitate attention switching
Navon task	changing our spotlight of attention to narrow (local) vs broad (global) depending on task Image: 444222 (binary/octet-stream)
Stroop task	Integrating different stimulus features. Difficult to suppress our automatic tendency to read Image: 67676 (binary/octet-stream)
Adleman et al	positive correlation between age and stroop-related activation in: left parietal and parieto-occiptal corticies left lateral prefrontal cortex left anterior cignulate
Attention capture	our attention can easily be captured by something that is different
Stare in the crowd effect	We can easily find faces that are looking directly at us compared to finding faces looking in other directions Image: Aasa (binary/octet-stream)
Global and local attention	we cannot see global and local motion at the same time. The right posterior parietal cortex plays an important role in directing attention between local and global information. Spatial and feature-based attention are closely related and this is processed in the anterior intraparietal sulcus
The simon effect	if info is presented to left ear, were are more likely to react if we are using our left hand. consistent representations are easier to compute. incompatibilities tax attention
Covert attention	attention in a separate location to our eye movements
Overt attention	attention to the location we are focused on
How do our eyes work?	Image: Mmm (binary/octet-stream)
Saccades	fixation for 100-350 m/s then shifting fixation to something else. Most common type of eye movement. 3-5 every second
Microsaccade	large eye movements, aiming fo a particular location, however we may slightly over or under shoot, therefore we will need to make a minor adjustment (microsaccade) to get to the right location.
Smooth pursuit	movement of the eyes very steadily, e.g. when tracking something movement
Glissades	similar to a microsaccade, slight curve in the end of the eye movement to land in the right location.
Optokinetic nystagmus	rare. tracking when flicking back to the centre, e.g. when looking our of window in a vehicle.
Vestibular ocular reflex	keeps our eyes fixated on a location whilst out head is moving.
What can eye tracking tell us?	distribution of attention -what was noticed -indicates what is deemed important -order of importance
culture shapes how we look at faces	Image: Eeew (binary/octet-stream)
task goal alters scan paths	what we see is linked to our cognitive goals
Heat maps	give clear visual representation of vision paths. darker areas identify the main attention points. Image: 235123 (binary/octet-stream)
eye tracking and reading	eye tracking can show us how we read. -word processing -sentence processing -comprehension we mostly fixate on the beginnings of words and sometimes miss smaller/joining words.
Eye trackers as research tools	The earliest eye trackers were built in late 1800's Older eye trackers used a bite bar as standard modern eye trackers use desktops or mobile glasses-like trackers
How do eye trackers work?	eyes are recorded with mini cameras. beams of infra-red light are reflected in the eye to see a clear image of pupil. 3-5 fixations per second measures saccades, blink rate and pupil dilation.
eye movements in sport	cricket: batsman is fixated ahead of the ball, where it will bounce, rather than following the ball itself. Their eye movements are ahead of the tracking of the ball.
Theory of mind 'mentalising'	being aware that other people have their own thoughts, feelings and decisions. autism diagnosis often associated with difficulties in unconscious theory of mind.
lab vs real settings	different patterns of attention depending on whether or not real people are present, or if you are in a 'real world' or lab based setting.
Profound skill is common	e.g. walking, talking, writing, reading, driving cars
Stroop task- what is automatic?	word-reading is automatic because of extensive practice doing this in life. Colour naming is a controlled process, we have to think about our answers. You only see that word-reading interferes with colour-naming if you run the right control conditions that make them conflict.
Serial search	aka feature search controlled, effortful, slow, adaptive
Parallel search	aka conjunctive search automatic, easy, quick, learn over extensive practice or innate
Skill is...	the development of habits through practice
Action slip	When habitual action intrudes when performing another task. e.g. putting milk in cupboard and cereal in fridge.
When automatic processing hinders performance	Novel task demands Mismatch between practised skill and environment Attentional lapse (or overload)
Cost-benefit analysis	Weighing up +'s and -'s All decisions are infinitely complex It is impossible to be 100% certain It is impossible to know all relevant information
Perfect decisions are impossible	Information is limited Information is ambiguous Time for decisions is limited Cognitive resources are limited
Heuristic	A heuristic is a rule-of-thumb -"principle with broad application that is not intended to be strictly accurate or reliable for every situation" Heuristics produce systematic errors ("biases") Heuristic- method of deciding
three heuristics which are responsible for a range of biases and errors:	-Representativeness -Availability- to judge the probability or frequency of an item by easy of which they come to mind -Adjustment and anchoring- people will make an estimate and then adjust. Irrelevant information can bias the initial estimate. Adjustments can be insufficient.
Insufficient adjustment	people estimated: 1x2x3x4x5x6x7x8x9 = 512. But estimated: 9x8x7x6x5x4x3x2x1 = 2250 People anchor their guesses to the first couple digits of sum- they incorrectly anchor leading to insufficient adjustment
Irrelevant anchors	e.g. take last three digits of your phone number, add 400, call this X. Which year was Attila the Hun defeated? Peoples guesses are strongly effected by the irrelevant information
Framing	How the costs and benefits of a situation are described. Same things can be framed differently. framing affects which decisions seem reasonable. Peoples 'mental accounting' differs for gains vs losses, & risks vs sure things.
what makes a good heuristic	applicable in many circumstances doesn't require lots of information or effort on average works
optimal vs adaptive decision	optimal-takes in all information, 100% correct answer, takes very long time adaptive- on average serves well, gives quick answer
Recognition heuristic	relying on recognition can help us- we are more likely to have heard of larger cities as they will be more popular destinations. Therefore we are more likely to guess their population as bigger compared to an unknown city.
BIases are not mere errors	mistakes are one-off, systematic errors are consistent. biases are making the wrong choice but for a reason. visual illusions reveal normal mechanisms of perception- heuristic errors reveal normal mechanisms of reasoning
Reasons we might make systematic errors	using a strategy optimised for a different environment considering a (different) bundle of choices Using a different cost/benefit analysis
where will you see biases	will see them wherever there are heuristics, they are a normal part of cognitive processes. found in any decision that is made frequently
Meta-cognition	meta means 'after' or 'beyond' in greek. refers to dealing with an abstraction of an original concept. Thinking about thinking.
Confirmation bias	a preference for seeking information that can only confirm your existing beliefs, rather than contradict it. About active search for information, not just whether you believe information when you encounter it
Ways of making wason task easier	discussing in small groups making question less abstract
factors that affect ease of fluency (processing)	prior presentation stimulus properties individual differences
Mental contamination	People's opinions are distorted by their experience of the environment, and they mis-attribute these feelings to the stimulus not the actual cause.
Illusion of explanatory depth (IoED)	If you asked people on the street if they know how a refrigerator works, most would respond, yes. But ask them to then produce a detailed, step-by-step explanation of how it works and you would likely hear silence or stammering. Most people feel they understand the world with far greater detail, coherence, and depth than they really do
Dunning kruger effect	cognitive bias in which people of low ability have illusory superiority and mistakenly assess their cognitive ability as greater than it is. The cognitive bias of illusory superiority comes from the inability of low-ability people to recognize their lack of ability
Well defined problems	clear goal-state & constraints (jigsaw, win a football match)
Ill defined problems	no clear goal-state & constraints (how to live a good life, to succeed at uni)
functional fixedness	a side effect of which representations are primed
analogical transfer	learn about something, inspires you to think about other problems in a different way

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