cognitive essential reading Flashcards
who potentially gave the first psychology lecture?
william james
what did aristotle argue for?
the tabula rasa and philosophical empircism
what topic emerged in the 17th and 18th century western europe?
epistemology- the study of how knowledge is aquired- a major interest of enlightenment philosophers
what did descartes argue for?
dualism- the body and the mind are two distinct entitities that interact
what is phrenology and who developed it?
specific mental abilities and characteristics, ranging from memory to the capacity for happiness are localised in specific regions of the brain- detect by measuring bumps
gall developed it
what field emerged in the middle of the 19th century and was benefitted from the work of german scientists?
physiology
what is sensory perception?
the way we interpret and process signals recieved via our senses
what is structuralism?
used by wundt to analyse the basic elements that constitute the mind
what is introspection?
the subjective observation of one’s own experience
what is visual acuity?
the ability to see fine detail, which is the smallest line of letters that a typical person can read from a distance of 20ft
what is 20/20 vision associated with?
the snellen chart
what animals have a greater visual acuity than humans?
hawks, eagles, owls and raptors- eight times greater than humans (20/2)
what is visible light the product of?
the portion of the electromagnetic spectrum that we can see
the physical dimension of amplitude of a light wave results in what psychological dimension?
brightness
the physical dimension of length of a light wave results in what psychological dimension?
hue or what we perceive as colour
the physical dimension of purity of a light wave results in what psychological dimension?
saturation or richness of colour
what is the intensity of a light wave?
how high the peaks are
what is the purity of a light wave?
number of wavelengths
what is light adaptation?
when the iris contracts and the size of the pupil reduces therefore the amount of light passing through decreases
what is the retina?
the light sensitive tissue lining the back of the eyeball behind the iris
what is accomodation?
the muscles inside the eye change the shape of the lens to focus objects at different distances, making the lens flatter for objects that are far away and rounder for nearby objects therefore maintaining a clear image on the retina
what is the medical term for nearsightedness?
myopia- where the eyeball is too long so images are focused in front of the retina
what is the medical term for farsightedness?
hyperopia-when the eyeball is too short so the images are focused behind the retina
what do cones detect?
colour and operate in normal daylight conditions and allow us to focus on fine detail
what do rods detect?
active only under low light conditions and allow for night vision, only grey vision
what is the fovea?
an area of the retina where vision is the clearest and there are no rods at all
what are cognitive processes based on?
internal representations (primarily of an external world)
what are the three distinct layers of the retina?
photoreceptors in the innermost layer
bipolar cells in the middle layer
retinal ganglion cells in the outermost layer
are the axons and dendrites of photoreceptors and bipolar cells longer than than ones of the RGCs?
no, they are shorter
what do bundled RCG axons form?
the optic nerve
what is a blind spot?
a hole formed by the optic nerve where there is neither rods not cones so no mechanism to sense light
what are the three approaches to pattern recognition?
template matching
feature matching
structural analysis
what is a receptive field?
the region of the sensory surface that when stimulated causes a change in the firing rate of that neuron
what is lateral inhibition?
opposing excitatory and inhibitory cells interact which means that the signals they send through the bipolar cells to the RGC are based on differing levels of receptor activation
what is an on-centre cell?
central excitatory zone surrounded by a doughnut-shaped inhibitory zone
what is an off-centre cell?
central inhibitory zone surrounded by an excitatory zone
response of an on-centre TGC
when a small spot of light excatly fills the excitatory zone it elicits the strongest response whereas light falling on the surrounding inhibitory zone elicits the weakest response or no response at all
response of an off-centre TGC
a small spot shining on the central inhibitory zone elicits a weak response and a spot shining on the surrounding excitatory zone elicits a strong response in the RGC
what happens if the entire receptive fiels is stiumlated?
excitatory and inhibitoey activations cancel out due to lateral inhibition and the RGC’s response will look similar to its response in the dark
what does lateral inhibition allow the visual system to do?
reveals how the visual system begins to encode the spatial structure of a scene
the retina is organised in this way to detect edges
what is the shortest visible wavelength perceived as?
deep purple
what is the longest visible wavelength perceived as?
red
pigments and their wavelengths for cones
red (long)
green (medium)
blue (short)
what is additive colour mixing?
a white surface reflects all the visible wavelengths of light and lighting designers have since used this to create colours by combining various amounts of primary colours
what is subtractive colour mixing?
mixing paint works in the opposite way to mixing light as these pigments absorb different colours from the visible spectrum
this means removing light from the mix creats black
the darker the colour, the less light it contains which is why black surfaces reflect no light
what are the teo stages of processing in the human visual system?
encoding- occurs in the retina
processing- requires the brain
what is trichroamtic colour representation?
pattern of responding across the three types of cones provides a unique code for each colour
sex-linked colour deficiency
affects men much more often than women as it is usually linked to the X chromosome
what is the colour-opponent system?
second stage of colour representation where pairs of visual neurons work in opposition, red against green and blue against yellow
opposite pairs have evoloved to enahce colour perecption by taking advantage of excitatory and inhibitory stiumulation…
red-green cells are excited in response to wavelengths corresponding to red and inhibited in response to wavelengths corresponding to green
blue-yellow cells increase their firing rate in response to blue wavelengthd and decrease in response to yellow wavelengths
colour aftereffects
when you look at something green, the cones that respond most strongly to green become fatigued over time and this leads to an imbalance in the inputs to the red-green colour opponent neurons
primary visual pathway
optic nerve
optic tract
lateral geniculate nucleus in the thalamus
superior colliculus
area V1 in the occipital cortex
what is the initial processing region in the brain?
area V1 which has a topographic visual organiastion
what is topographic visual organisation?
adjacent neurons process adjacent portions of the visual field
what did hubel and wiesel 1962, 1998 find about selective response to bars and edges?
neurons in the visual cortex selectively respond to bars and edges in specific oreintations in space
therefore some neurons in area V1 fire when an object in a vertical orientation is perceived and others in a horizontal orientation
visual streaming
projects from the occipital cortex to visual areas in other parts of the brain
ventral (below) visual stream
travels across the occipital lobe into the low levels of the temporal lobes and includes brain areas that represent an objects shape and identity (what it is)
dorsal (above) visual stream
travels up from the occipital lobe to the parietal lobes (including some of the middle and upper levels of the temporal lobes) connecting with brain areas that identify the location and motion of an object (where it is) aka where/how pathway
patient D.F. case study
suffered permanent brain damage following exposure to carbon monoxide
a large region of the lateral occipital cortex was destroyed, an area oin the ventral stream that is very active when people recognise wobjects
DFs ability to recognise objects by sight was greatly impaired although her ability to recognise objects by touch was normal
what does the case study of D.F. suggest about visual representation?
the visual representation of objects and no memory for objects was damaged=visual form agnosia
what is visual form-agnosia?
the inability to recognise objects by sight
what is optic ataxia?
damage to the dorsal stream causes difficulty using vision to guide their reachinf and grasping movements
ventral stream is not impacted to they can recognise what objects are
what is the binding problem?
concerns how features are linked together so that we seen unified objects in our visual world rather than free-floating or miscombined features
what is illusory conjunction?
a perceptual mistake where features from multiple objects are incorrectly combined
triesman and schmidt (1982)
showed study participants visual displays in which black digits flanked colour letters the instructed them to first report the black digits and second to describe the coloured letters
participants frequently reported illusory conjuctions, claiming to have seen, for example, a green A or a purple X instead of the purple A and the green X that had actually been shown
feature integration theory (triesman 1998)
proposes that attention binds individual features together to comprise a composite stimulus
attention provides the glue necessary to bind features together and illusory conjunctions occur when it is difficult for participants to pay full attention to the features that need to be glued together
patient R.M. case study
suffered strokes that destroyed his left and right pariteal lobes
although many aspects of his visual function were intact, he had severe problems attending to spatially distinct objects
he displayed an abnormally large number of illusory conjunctions even when he was given as long as 10 seconds to look at the displays
damage to the upper and posterior portions of the parietal lobe
produces problems with focused attention, resulting in binding problems and increased illusroy conjunctions
what is synaesthesia?
the perceptual experience of one sense that is evoked by another sense
the most common is number-colour matching
what does ramachandran hypothesis about syneasthesia?
arises separately because the separate modalities are initially all interconnected during the early postnatal months as part of the typical brain growth that takes place during the first year of life
whereas most of us lose interconnections between different modalities for some reason synaesthetes maintain many
synaesthesia is an instance of…
atypical feature binding
the colour feature is not present in the external stimulus
what brain region is implicated in synaesthetic individuals?
parietal lobe
consistent with the idea that parietal activity is related to attentional processes needed for binding, other experiments have shown that synaesthetic bindings, such as seeing a particular digit in a particular colour, depend on attention
what is a modular view?
specialised brain areas, or modules, detect and represent faces or houses or even body parts
what is modularisation?
the process of relatively encapsulated function
theories of modularisation
- some perceptual categories such as faces may have a degree of prespecified organization in the brain
- some theorists argue that we have built-in perceptual templates for recognizing faces, which is why newborn babies prefer to look at faces shortly after birth
- others argue that modularization emerges as a consequence of exposure and expertise
quiroga et al 2005
- electrodes were placed on the temporal lobes of people who suffer from epilepsy
- then the volunteers were shown photographs of faces and objects as the researchers recorded their neural responses
- the researchers found that neurons in the temporal lobe respond to specific objects viewed from multiple angles and to people wearing different clothing and facial expressions and photographed from various angles
what is perceptual constancy?
even as aspects of sensory signals change, perception remains consistent
gestalt perceptual grouping rules
simplicity
closure
continuity
similarity
proximity
common fate
gestalt grouping: simplicity
idea behind pragnanz (good form)
when confronted with two or more possible interpretations of an objects shape, the visual system tends to select the simplest or most likely interpretation
gestalt grouping: closure
we tend to fill in missing elements of a visual scene, allowing us to perceive edges that are separated by gaps as belonging to complete objects
gestalt grouping: continuity
edges or contours that have the same orientation have what the gestaltists called good continuation and we tend to group them together perceptually
gestalt grouping: similarity
regions that are similar in colour, lightness, shape or texture are perceived as belonging to the same object
gestalt grouping: common fate
elements of a visual image that move together are perceived as parts of a single moving object
identifying figures- gestalt theory
identify a figure apart from the background, e.g words on a page
size- gestalt theory
whats figure and whats ground, smaller regions are likely to be figures, such as tiny letters on a big paper
movement- gestalt theory
dyanmic object moving around a static environment
edge assignment- gestalt theory
given an edge, or boundary, between figure and ground, which region does that edge belong to? If the edge belongs to the figure, it helps define the object’s shape, and the background continues behind the edge
what is a template?
a mental representation that can be directly compared to a viewed shape in the retinal image
bruce and young model of face recognition (1986)
you have to be sensitive to features of a face (two eyes, a nose and a mouth)
if they are present we need to look at how they are arranged of configured in terms of spacing
these two operations are part of the structural encoding
what is structural encoding?
how a pattern is represented
what does structural encoding do to additional processing stages?
feeds into additional processing stages that deal with identifying emotional expressions, dynamics of any faciall movememts, specific identifying features and the face recognition stages
if the face is someone they recognise they are able to identify them as familiar and remember their name
this multistage model explains why people recognise, fail to recognise or recognise faces and not know someones name
how do we perceive depth?
monocular depth cues
what are monocular depth cues?
aspects of a scene that yield information about depth when viewed with only on eye
what do monocular depth cues rely on?
the relationship between distance and size
with one eye closed the retinal image of an object…
grows smaller as the object moves farther away and larger as it moves closer
our brains routinely use these differences in retinal image size (relative size) to perceive distance
what is familiar size?
a type of monocular depth cue
our visual system automatically corrects for size differences and attributes them to differences in distance
what are monocular cues also called?
pictorial depth cues because they are present even in 2D paintings, photographs and videos where the 3D of depth is not really there
what are 4 examples of monocular depth cues?
linear persepective, texture gradient, interposition and relative height
what is linear perspective?
parallel lines converge as they recede into the distance
what is texture gradient?
arises when you vire a more or less uniformly patterened surface because the size of the pattern elements as well as the distance between them grows smaller as the surface recedes from the observer
what is interposition?
one object partly blocks another
what is relative height?
depends on your field of vision
objects that are closer to you are lower in your visual field, while faraway objects are higher
why do binocular depth cues exist?
because we have stereoscopic vision (having space between our eyes means that each eye registeres a slighly different view of the world)
what is binocular disparity?
the difference in the retinal images of the two eyes that provides information about depth
what is motion parallax?
a depth cue based on the movement of the head over time (e.g close objects in car moves quickly but faraway move slowly)
the speed and direction of the iages on your retina depend on where you are looking and how far away
what two phenomena are essentially the same?
depth perception from motion parallax and binocular disparity because both involve mentally comparing retinal image information from multiple viewpoints
what is optic flow?
the pattern of motion that accompanies an observers forward movement through a scene (a form of motion parallax)
At any given point, the scene ahead moves outwards from the point towards which the observer is moving. this kind of motion parallax is therefore useful for navigation while walking, driving or landing an aeroplane
examples of incorrectly perceived distance affects the perception of size
ames room
moon illusion
what is MT?
a region in the middle of the temporal lobe specialised for the visual perception of motion and brain damage in this area leads to a deficit in normal motion perception
motion perectpion
like colour perception operates in part on opponent processes and is subject to sensory adaptation
a motion aftereffect called the waterfall illusion is analogous to colout aftereffects
evidence from fMRIS indictaed that when people experience the waterfall illusion while viewing a stationary stimulusm there is increased activity in the MT
what is apparent motion?
perception of movement as a result of alternating signals appearing in rapid succesion in different locations
video tech and animation depend on apparent motion
what is the cartesian theatre?
a mental screen or stage on which things appear to be presented for viewing by your minds eye
what is the hard problem of consciousness?
the difficulty of explaining how subjective experience could ever arise
what is the homunculus problem?
the difficulty of explaining the experience of consciousness by advocating another internal self
what is the problem of other minds?
the fundamental diffivulty we have in perceiving the consciousness of others
what are qualia?
subjective experiences we have as part of our mental life (mental states)
what is materialism?
the philosophical position that mental states are a product of phsyical systems alone (dehumanised vision of humans being a ‘meat machine’)
what is anthropomorphism?
the tendency to attribute human qualities to nonhuman things. In considering others as having minds, we all too readily assume that they exhibit the same mental life we ourselves experience
gray et al (2007) dimensions of mind perception
when ppts judged the mental capacities of 13 targets, two dimensions of mind perception were discovered
- capacity of experience=abilities of pain or pleasure
- capacity of agency=plan or exert self-control
what is the mind-body problem?
the issue of how the mind is related to the brain and body
descartes said that the human body is a machine made of physical matter
the mind is a separate entity made of a thinking substance
libet (1985) EEG
participant was asked to move fingers at will while simultaneously watching a dot move around the face of a clock to mark the moment at which the action was consciously willed
meanwhile, EEG sensors timed the onset of brain activation and EMG sensors timed the muscle movement experiment showed that brain activity (EEG) precedes the willed movement of the finger (EMG), but that the reported time of consciously willing the finger to move follows the brain activity
what is choice blindness?
when people are unaware of their decision-making processes and justify achoice as if it were already decided
johansson et al (2005)
participants were shown two female faces and asked to choose which female was more attractive and then justify why they picked one face over another
every so often the faces were cleverly switched by sleight of hand
most adults did not notice the switch and then explained why the face they had just rejected was the more attractive one
what is change blindness?
unawareness of significant events changing in full view
oswald et al (1960) dischotic listening
people are more sensitive to their own name than other names even during sleep
four basic properties of consciousness
intentionality of consciounesness
unity
selectivity- links to dichotic listening
transcience
inattention blindness (simons and chabris 1999)- unitty of consciousness
half the adults failed to notice was a man wearing a gorilla suit strolling among the players, beating his chest and then strolling off again
what is selective attention?
process whereby we focus mental processing on a limited range of events
what is an information bottleneck?
where the channel of information processing has a limited capacoty because the volume of data is too much
deutsch and deutsch (1963) response selection model
information bottleneck but the limited capacity occured after the signals were processed but before a response could be made
lavie (1995) load model
where task difficulty determines whether selection is early or late
the task is typically difficult in terms of ‘perceptual load’, for example a demanding task with lots of possible targets, whereas studies that report late selection are comparatively lighter in terms of load, for example a simple task with a single target
unilateral visual neglect
where patients fail to notice or attend to stimuli that appear on the side of space opposite the site of a hemispheric lesion
most typically found in patients with lesions of the right parietal lobe which produces a loss of attention in the left visual field
smith et al (2007)
when asked to draw a clock face, they may either ignore the digits 7 to 12 or try to squeeze all 12 digits into the right side of the clock
most common measure of neglect
line bisection task (albert 1973)
line bisection task
patient is presented with a straight line and has to draw a mark to bisect the line in the middle
left neglect patients usually place the mark much closer to the right side
if lines of different lengths are presented, the amount of error towards the right side proportional to the length of each line
balints syndrome
an attentional disorder where the patient loses the ability to voluntarily shift visual attention to new locations which is associated with damage to both sides of the brain
blindsight
residual vision in the absence of cortical processing caused by damage to area V1 of the primary visual cortex
patient DB case study
adult who had also had part of his visual cortex removed to treat a tumour
he was blind in the corresponding portion of the visual field
however, when he was forced to guess, D. B. could accurately detect a target presented in the affected region even though he was unable to be describe it
although he could detect targets, D. B. reported being blind and consciously unaware of what he seemed to be ‘seeing
atkinson and shiffrin (1968) multi store model
information enters a temporary sensory memory
then to STM
then LTM
sperling (1960)
researcher flashed letters on a screen for 1/20th of a second
when asked to remember ask 12 letters they had just seen, ppts recalled fewer than half of them
they used tones to signify the first, second or third row
all letters were therefore encoded
what is iconic memory?
fast-decaying store of visual information
what is echoic memory?
fast-decaying store of auditory memory
peterson and peterson (1959)
after seeing each string of nonsense trigrams ppts were asked to count backwards from 100 by thress
memory declined rapidlly from approximatley 80% after a 3 second delay to less than 20% after a 20 second delay
what is the definition of a concept?
a mental representation that griups or categorises shared features of related objects, events or other stimuli
what is category-specific deficit?
an inability to recognise objects that belong to a particular category while leaving the ability to recognise objects outside the category undisturbed
adam- category-specific deficits
16 year old boy who suffered a stroke the day he was born
had severe difficulty recognising faces and other biological objects
when shown a picture of a cherry he identified it as a chinese yo-yo and when shown a picture of a mouse he said it was an owl
he made errors like these on 79% of animal pictures and 54% of the plant pictures
he only made 15% errors when identifying pictures of nonliving things such as spatulas and brooms
neuropsychology of cateogory-specific deficts
deficits usually result when an individual suffers a stroke or other trauma to areas in the left hemisphere of the cerebral cortex
damage to the front part of the left temporal lobe results in difficulty identifying…(category-specific deficits)
humans
damage to the lower part of the left temporal lobe results in difficulty identifying…(category-specific deficits)
animals
damage to the region where the temporal lobe meets the occipital and parietal lobe impairs… (category-specific deficits)
the ability to retrieve the names of tools
family resemblence theory (rosch 1973)
where members of a category have features that appear to be characteristic of category members but may not be possessed by every members
prototype theory
our psychological categorisation is organised around the properties of the most typical members of the category
exemplar theory
we make category judgements by comparing a new instance with stored memories of other instances of the category (medin and schaffer 1978)
ashby and ell (2001) neuropsychology
the visual cortex is involved in forming prototypes, whereas the prefrontal cortex and basal ganglia are involved in learning exemplars
this suggests that exemplar-based learning involves analysis and decision making (prefrontal cortex) whereas prototype formation is a more holistic process involving image preocessing (visual cortex)
marsolek (1995)
participants classified prototypes faster when the stimuli were presented to the right visual field, meaning that the left hemisphere received the input first
participants classified previously seen exemplars faster when images were presented to the left visual field (meaning that the right hemisphere received the input first)
rational choice theory
we make decisions by determining how likely something is to happen, judging the value of the outcome, and then multiplying the two (edwards 1955)
what is availability bias?
items that are more readily available in memory are judged as having occured more frequently
what are framing effects?
occur when people give different answers to the same problem depending on how the problem is phrased
if people are told that a particular drug has a 70% effectiveness rate, they’re usually pretty impressed: 70% of the time the drug cures what ails you sounds like a good deal
tell them instead that a drug has a 30% failure rate – 30% of the time it does no good – and they typically perceive it as risky
sunk-cost fallacy
one of the most striking framing effects which occurs when people make decisions about a current situation based on what they have previously invested in the situation
what is prospect theory? (tversky and kahneman 1992)
people choose to take on risk when evaluating potential losses and avoid risks when evaluating potential gains
1. people simplify the available informatiom
2. people choose the prospect they believe offers the best value
