PSYC 4100 Test 2
theory of natural selection
characteristics that enhance an animal's ability and survive and therefore reproduce will be passed onto future generations - visual system may have been shaped to contain neurons that respond to things that are frequently found in the environment - ex: more neurons that respond to horizontals and verticals than neurons that respond best to oblique orientations
change blindness
difficulty in detecting changes in similar but slightly different scenes that are presented one after another - large changes - continuity errors too
central vision
area one is looking at - fovea: small area of retina that looks at central Vision stimuli, much better detail vision than the peripheral retina (rest of the scene)
light-from-above assumption
assumption that light is coming from above - heuristic that can influence how we perceive 3D objects that are illuminated
focused attention stage in FIT
attention is focused on an object and the independent features are combined
Anne trainman
attenuation model of attention - modification to Broadbent - selection occurs in 2 stages with the filter replaced by an attentuator, which analyzes the incoming message in terms of 1. physical characteristics: high or low pitched, fast or slow 2. language 3. meaning
default mode network
becomes activated when a person is not involved in a task - activity here usually associated with mind wandering
stimulus salience
bottom-up factors that determine attention to elements of a scene - ex: color, contrast, orientation - saliency map: map of a scene that indicates the stimulus salience of areas and objects in the scene * ex: person in a red shirt next to all people in white shirts would get high marks for salience because the brightness of red contrasts
occlusion
brain automatically fills in what it can't see or hear
filter model of attention
broadbent, early selective attention model - filter based on physical characteristics (ex: mayor or female voice and then filter out the rest) - filter out information before analyzing for meaning - intended to explain the results by Colin Cherry's experiment
divided attention
can we pay attention to 2 things at once? - fixed capacity of attention- does the task take all your attention (if so cannot divide it) if it doesn't then you can divide
attenuator
changes strength of message - unattended message not totally lost but weakened
semantic regularities
characteristics associated with the functions carried out in different types of scenes (what makes sense in this context) - scene schema: knowledge of what a given scene typically contains that creat expectations that contribute to our ability to perceive objects and scenes
divided attention becomes more difficult when tasks are harder
easy to drive and talk at the same time if traffic is light on a familiar road, but if traffic increases, flashing construction ahead signs and the road becomes rutted, you may have to stop convo or turn off the radio to devote all cognitive resources to driving
what is the purpose of perception
enable us to interact with the environment - outcome of an interaction between bottom-up and top-down
continuity errors
errors in film, when changes occur from 1 scene to another that do not match - apple turning into banana - paying attention to plot and won't notice, but if seen movie a lot and don't have to focus hard on the plot, you may notice
the law of pragnanz/principle of good figure/principle of simplicity
every stimulus pattern is seen in such a way that the resulting structure is as simple as possible - ex: Olympic Rings seems as 5 circles not 9 shapes
peripheral vision
everything off to the side of central vision
perceptual puzzles
ex: looking at a city scene and there is a dark spot on a skyscraper- can tell it's a shadow, but it is hard to indicate what the reasoning for it being a shadow is
multiple personalities of a blob
identical blobs perceived as different objects depending on their orientation and the context within which they are seen - human advantage over computers due to the additional top-down knowledge available to humans - what types of objects typically occur in specific types of scenes
apparent movement
illusion of movement perception that occurs when stimuli in different locations are flashed one after another with the proper timing - ex: electronic signs that display moving advertisements
stimula on retina is ambiguous
image received is ambiguous: image could be a number of different things - ex: objects that create the same image on the retina- further and bigger (look smaller) or closer and smaller (look bigger) - brain automatically calculates this, but computers can't - inverse projection problem
mirror neurons
in the premotor cortex, originally discovered in monkeys, respond both to observing someone else carrying out an action and when the monkey itself carries out the action - evidence in humans too
Balint's syndrome
inability to focus attention on individual objects because of parietal lobe damage - patient RM: when presented with 2 different letters of different colors 9red T and blue O) he reported illusory conjunctions on 23% of trails - illustrated a breakdown in the brain that can reveal processes that are not obvious when the brain is functioning normally
prior probability/prior
initial belief about the probability of an outcome
operant conditioning
intermittently reinforced to strengthen future phone-clicking behavior
what is the purpose of mirror neurons
involved in determining the goal or intention behind an action - number of different intentions can be associated with perception of the same action
top-down processing
involves a person's knowledge or expectations - sequence originates in the brain - knowledge-based processing - uses knowledge of the environment - higher level - heuristics
transitional probabilities
likelihood that 1 sound will follow another within a word - every language has these for different sounds
late selection model
messages can be selected at a later stage of processing primarily based on meaning - mcKay: most of the incoming information is processed is selected - depending on the observer's task and type of stimuli presented: early selection can happen in some conditions and later selection under others
attenuation model of attention
model of selective attention (intermediate selection) 1. attenuator analyzes the incoming message and lets through the attended message and the unattended message but at a lower strength 2. message analyzed by dictionary unit, which each has a threshold for being activated
multi-tasking fact
most people simply cannot successfully perform 2 or more tasks simultaneously without declines in performance
what type of processing does feature analysis involve
mostly bottom-up, but some situations use top-down ex: illusory conductions less likely to occur when participants are told they are being shown a tire, carrot and lake - more likely to perceive the triangular "carrot" as being orange - in everyday experience top-down combines with feature analysis to help us perceive things accurately
movement facilitates perception
movement helps us perceive objects in the environment more accurately - moving reveals aspects of objects that are not apparent from a single viewpoint (provides added information that results in more accurate perception)
scenes contain high level information
moving objects to scenes adds another level of complexity - many objects may require reasoning to figure out a scene - cues about the scene need to be programmed into a computer
mirror neuron system
network in human brains discovered with fMRI that have mirror neuron properties
where pathway/dorsal pathway
neural pathway extending from the occipital lobe to the parietal lobe that is associated with neural processing that occurs when people locate objects in space - roughly corresponds to the action pathway
what pathway/ventral pathway
neural pathway extending from the occipital lobe to the temporal lobe that is associated with perceiving or recognizing objects - corresponds with the perception pathway
is hands-free less dangerous
no - cognitive load of talking is distracting
scene schema
observer's knowledge about what is contained in typical scenes, top down processing - ex: people look longer at things that seem out of place in a scene
pre attentive stage in FIT
occurs before we focus attention on an object - automatic, unconscious and effortless - features of objects are analyzed independently in separate areas of the brain and not yet associated with a specific object
selective attention
paying attention to 1 things and ignoring others
Hermann von Helmholtz
realization that the image on the retina is ambiguous - particular pattern on the retina can be caused by a large number of objects in the environment - unconscious interference
bottom-up processing
starts with the information received by the receptors - pattern of neural firing - lower levels of the cortex - sequence of events from eye->brain - date-based processing
colin cherry
studied attention using dichotic listening: different stimuli presented to each ear - participant focuses on the message in 1 ear (attended ear) and to repeat what she or he is hearing aloud (shadowing) - participants could not hear what was said to the unattended ear
measuring cognitive distraction in the automobile
study from the AAA foundation for traffic safety - voice activated activities are more distracting than hands-on or hands-free
object discrimination problem
task is to remember an object based on its shape and choose it when presented with another object after a delay - associated with the "what" processing stream (temporal lobe)
landmark discrimination problem
task is to remember an object's location and to choose that location after a delay - associated with research on the where processing stream (parietal lobe)
inverse projection problem
task of determining the object that caused a particular image on the retina - involves starting with retinal image and extending rays out from the eye - humans typically solve the inverse projection problem easily, but it still poses serious challenges to computer-vision systems
is texting and driving or drunk driving more dangerous
texting is 6x more dangerous
processing capacity
the amount of information people can handle and sets a limit on their ability to process incoming information
example of automatic processing
- forgetting if you locked the door or not - driving somewhere and cannot remember the trip once getting to destination - not paying attention to fingers while texting
principles by Gestalt psychologists
- good continuation - pragnanz/law of good figure/simplicity - similarity - law of proximity - law of familiarity - law of common fate
limitations on attention
1. selective attention 2. distraction 3. divided attention 4. attention capture
cell phone timeline
- 1973: cell phone invented (could talk for 30 minutes then charge for 10 hours) - later 1990s: cell phone use in cars is routine - 2001 first law (NY) banning hand-held use - mid 2000s: texting becomes common place - 2007: first law (WA) banning texting while driving
compare Helmholtz, regularities of the environment, bayesian interference and gestalt psychology
- Helmholtz, regularities and bayes: we use data about the environment gathered through past experiences to determine what is out there (top-down) - gestalt: principles of organization are built in (bottom-up)
biasing words and late selection
- attended ear: "they were throwing stones at the bank" - unattended ear: some participants "___ river" and others heard "____ money" -> how does one interpret the attented ear - biasing word (money or river) affected the participants' choice even though they were unaware of the biasing words - get meaning from unattended words -> shift focus to perceptual load
a computer-vision system that perceives objects and a scene
- designing a computer vision system that can actually perceive the environment and recognize objects and scenes is more complicated than making a Star Wars movie - driverless cars now available - programs have been created that can describe pictures of real scenes
objects hidden or blurred
- even when objects are partially obscured we know they continue * computers need to be programmed/told this - people can identify blurred faces
how can one focus attention so distractors do not interfere
- high load condition: when task is hard enough there are not enough leftover resources to get distracted - distractors will not affect reaction time
attending and perceiving in everyday life
- if not paying attention, object will not be perceived - focus on whats important to make optimal use of limited processing resources - warning system that responds to motion or intense stimuli, which causes us to rapidly shift our attention to things that might signal danger
threshold (low v high)
- low: common/important words (your name, shocking words, relevant words), weak signal in unattended channel can activate word - high: uncommon and irrelevant words * all people have different thresholds for different words
2 phenomenons that cannot be explained early selection model
1. pop-out phenomenon ex: someone in a crowded room yelling "Danielle" -> Broadbent says you wouldn't hear because it gets filtered out 2. dear aunt Jane - left ear: dear 7 Jane - right ear: 9 Aunt 6 -> people say "dear aunt Jane" - mixture of filtered and unfiltered
how do we make sense of our environment
- object identification: what is it? what do I need to do? - death/location: where is it/how far away? - color - movement
flanker compatibility task
- press left key if a or b is in the center - press right key if c or d is in the center * BAB- compatible- distractors compatible (fastest response) * CAC- incompatible: competing interests (slowest) * XAX- neutral: x doesn't have an associated button (intermediate) ^ different reaction times suggest that distractor stimuli are still processed
using bayesian interference to diagnose a cough for a cold or lung disease
- prior probability: high probability for cold and heart burn (belief about frequency) - likelihood: symptoms mostly match cough and lung disease -> cough most likely due to cold
2 types of information used by the human perceptual system
1. environmental embers stimulating the receptors 2. knowledge and expectations that the observer brings to the situation
heuristics
- rules of thumb - learned though experience - usually work Ex: people in back of room are still the same size as people in the front - sometimes trick you (ex: optical illusions, brain games) - light from above: generally light comes from above and this makes shadows act in a predictable way
why is it so difficult to design a perceiving machine
- stimulus on retina is ambiguous - objects can be hidden or blurred - objects look different from different viewpoints - scenes contain high-level information
Milner and goodie's 2 pathways
1. perception pathway: corresponds to the what pathway 2. action pathway: occipital lobe to the parietal lobe that is associated with neural processing that occurs when people take action (corresponds to the where pathway)
change detection
1 picture is presented followed by another picture and the task is to determine the difference between the 2
2 conclusions by Wertheimer from apparent movement phenomenon
1. apparent movement cannot be explained by sensations because there is nothing but dark space between the flashing lights 2. the whole is different than the sum of its parts (became one of the basic principle of Gestalt psychology)
flow of information in early selection model
1. sensory memory: holds all the incoming information for a fraction of a second and then transfers all of it to the filter 2. filter: identifies the message being attended to based on physical characteristics (speaker's ton of voice, pitch, speed and accent) and only lets the attended message pass to the detector 3. detector: processes the information from the attended message to determine higher-level characteristics (meaning) 4. sends information to short-term memory (holds info for 10-15 seconds) and long-term memory (can hold information indefinitely)
driver distraction trait
1. visual: looking at road 2. cognitive: paying attention 3. manual: hands on wheel ** texting takes away all 3
international journal of computer vision
1987, first journal devoted solely to computer - papers from the first issues considered topics such as how to interpret line drawings of curved objects and how to determine the 3D layout of a scene based on a film of movement through the scene
defense advanced projects agency's (DARPA) grand challenge
2014, task is to drive 150 miles from the starting point to Vegas only using GPS coordinates to define the course and computer vision to avoid obstacles - best: achieved by a vehicle that only traversed 7.3 miles before getting stuck - driverless cars now available today
gestalt psychologists
30 years after helmoltz - reaction to structuralism (rejection) - Max wertheimer: stroboscope to detect apparent movement - realized that perception is based on more than patterns of light and dark on the retina, but my specific organizing principles - intrinsic laws: although a person's experience can influence perception, the role of experience plays a minor role compared to perceptual principles
stroop effect
JR Stroop, person is instructed to respond to 1 aspect of a stimulus, such as the color of ink that a word is printed in and ignore another aspect, such as the color of the word names -> word yellow printed in pink, wanna say yellow not pink
cocktail party effect
ability to focus on 1 stimulus while filtering out other stimuli
viewpoint invariance
ability to recognize an object seen from different viewpoints - ex; still know what a chair is even from behind - people can do this, but computer vision systems require a laborious process with complex calculations designed to determine which points of an object match in different views
speech segmentation
ability to tell when 1 word in a conversation ends and the next one begins - physical sound signal for speech is generally continuous and when there are breaks in the sound they do not necessarily occur between words - aided by knowing the meaning of words
Mario Iacoboni
code the why of actions and respond differently to different intentions - response of these neurons is determined by the sequence of motor activities that could be expected to happen in a particular context - respond to different intentions as they are responding to the action happening plus the sequence of actions that is most likely to follow given the context (neuron's firing may be based on the sequence of actions that are most likely to occur in a particular context)
continuous partial attention
constant switching from 1 activity to another
dictionary unit
contains words stored in memory which each have a threshold for being activated
the interaction of perception and action
coordination is continually occurring between perceiving stimuli and taking action toward these stimuli - ex: picking up cup of coffee- perceiving the position of the cup, hand and fingers relative to cup, while calibrating actions in order to accurately grasp the cup and pick up without spilling coffee
neville moray
dichotic listening experiment and presented the listener's name to the unattended ear, about 1/3 of participants detected it - information presented to the unattended ear is processed enough to provide the listener with some awareness of its meaning
Walter Schneider and richard shiffrin
experiments involved divided attention because they required the participants to carry out 2 tasks simultaneously 1. holding information about target stimuli in memory 2. paying attention to a series of distractor stimuli to determine whether 1 of the target stimuli is present among these distractor stimuli - practice made it possible for the participants to divide their attention to deal with all of the target and test items simultaneously - automatic processing results from many trails without intention and at a cost of only some of a person's cognitive resources
just in time strategy
eye movements occur just before we need the information they will provide - timing of when people look at specific places is determined by the sequence of actions involved in the task - scanning is influenced by people's predictions about what is likely to happen
overt attention
eye movements of attention - can see attentional shifts by observing where the eyes are looking - studied using an eye tracker
Prosopagnosia
face blindness
inattention deafness
focusing on a difficult visual task results in impaired hearing
regularities in the environment
frequently occurring characteristics 1. physical 2. semantic
law of familiarity
groups together stimuli in meaningful or familiar ways
Nill Lavie
how do people ignore distracting stimuli when they are trying to focus their attention on a task - processing capacity and perceptual load
G. di Pelligrino
how neurons in the monkey's premotor cortex fired as it performed an action like picking up a piece of food - neurons that fired to observing the experimenter pick up the food were the same ones that had fired earlier when the monkey picked up the food -> mirror neurons
what is the gateway to all other cognitions
perception
principle of good continuation
points that when connected result in straight or smoothly curving lines are seen as belonging together and the lines tend to be seen in such a way as to follow the smoothest path - objects that are overlapped by other objects are perceived as continuing behind the overlapping object (ex: coiled rope)
ungerleider and mishkin
presented monkey with 2 tasks 1. object discrimination problem 2. landmark discrimination problem
fixation
problem solving, people's tendency to focus on a specific characteristic of the problem that keeps them from arriving at a solution - in perception and attention: a pausing of the eyes on places of interest while observing a scene
experience sampling
procedure developed to answer the question "what percentage of the time during the day are people engaged in specific behavior" - having people report what they are doing when they receive signals at random times during the day
brain ablation
procedure in which a specific area is removed from an animal's brain - usually done to determine the function of this area by assessing the effect on the animal's behavior
precueing/location-based visual attention
procedure in which participants are given a cue that will usually help them carry out a subsequent task - Posner - CogLab: presented with a cue telling you where to direct attention - faster reaction when target is the same as cue (valid trial) - information processing is more effective at the place where attention is directed
attention
process of concentrating on specific features of the environment or on certain thoughts or activities - limited: cannot pay attention to everything in the environment
statistical learning
process of learning about transitional probabilities and other characteristics of language - infants start as young as 8 months
load theory of attention
proposal that the ability to ignore task-irrelevant stimuli depends on the load of the task the person is carrying out - high load tasks result in less distraction
perception
recognizing, organizing and interpreting information from senses - based on: past experiences and expectations - interpretation (not an exact copy of the world) - can change with more information (ex: further away vs closer) - reasoning and problem solving (ex: feeling around dark kitchen, not likely a mailbox in there) - brain process although feels automatic
physical regularities (3)
regularly occurring physical properties of the environment - oblique effect - light from above assumption - multiple personalities of a blob
100-car naturalistic driving study
research project that verified the seriousness of driver attention - 80% of crashes and 67% of near crashes: the driver was inattentive in some ways 3 seconds before - one of the most distracting activities was pushing buttons on a cell phone or similar device
principles of perceptual organization
rules proposed by the Gestalt psychologists to explain how small elements of a scene or a display become perceptually grouped to form larger units - these laws are described as heuristics
visual search
scanning a scene to find a specific object - being involved in a high-load task increases the chances of missing other stimuli
conjunction search
searching among distractors for a target that involves 2 or more features, such as horizontal and green - feature search: searching among distractors for a target item involving 1 feature such as horizontal - useful for studying binding because finding the target involves scanning a display in order to focus attention at a specific location
steps of sensory input to interpretation
sensory input from environment (sight, pressure etc) -> translated into electrical and chemical signals of neurons (specialized cells) -> neural signals processed by nervous system (ex: sight processed by visual cortex) -> sensation -> sensations assigned a meaning (ex: need to move/respond? etc) -> perception: interpreting sensations
covert attention
shifting attention while keeping eyes still - attentional shift cannot be seen by observing the person
principle of similarity
similar things appear to be grouped together - color, size, shape or orientation
David strayer and William Johnston
simulated driving task that required participants to apply the breaks as quickly as possible in response to a red light - same decreases in performance regardless of participants using hands-free or handheld device
experience dependent plasticity
the brain's functioning can be tuned to operate best within a specific environment - continued exposure to things that occur regularly in the environment can cause neurons to become adapted to respond best to these regularities ex: Blakemore and Cooper- must have experience with different line orientations to develop normally, cats raised in all vertical cannot see different orientation ex: greebles- when told to name them, look more like faces
perceptual load
the difficulty of a task - low-load: easy, well-practiced tasks that use a small amount of a person's processing capacity - high-load: difficult and not as well practiced, use more of a person's processing capacity
binding
the process by which features such as color, form, motion and location are combined to create our perception of a coherent object - how an objects individual features become bound together (binding problem) is addressed by Treisman's feature integration theory
neuropsychology
the study of behavior of people with brain damage - studying the functioning of animals and humans with brain damage can reveal important principles about the functioning of the normal (intact) brain
law of common fate
things moving in the same direction are grouped together
law of proximity
things near each other are grouped together
bayesian interference
thomas bales: our estimate of the probability of an outcome is determined by 2 factors 1. prior probability/prior - belief about frequency 2. likelihood - mathematical procedure in which the prior is multiple by the likelihood to determine the probability of the outcome
mind wandering
thoughts that come from within a person often unintentionally - daydreaming in early research - ex: doing math problems and suddenly realize thinking about what you're going to do later - mindless reading/zoned out reading: while reading, suddenly realize that you have no idea what you have just read because you were thinking about something else
feature integration theory (FIT)
trainman, attention to perceive objects as a whole 1. preattentive stage 2. focused attention stage - evidence: illusory conjunctions - visual alphabet: at the beginning of the process information of these components exist independently of each other (letter tiles scrambled from Scrabble) then the individual features combine to form perceptions of whole objects (tiles to words)
transduction
translation of sensory input from environment (sight, pressure etc) into electrical and chemical signals of neurons
illusory conjunctions
treisman and schmidt - features are "free floating" prior to attention - dividing attention across 2 tasks: identifying the numbers and shapes - ex: after being presented with the display in which the small triangle is red and the small circle is green, participants might report seeing a small red circle and a small green triangle - in the preattentive stage each feature exists independently of the others- redness and curved are not associated with a specific object and can be combined incorrectly if there is more than 1 object
oblique effect
vertical and horizontal orientations can be perceived more easily than other (slanted) orientations
likelihood principle
we perceive the object that is most likely to have caused the pattern of stimuli we have received - the extent to which the available evidence is consistent with the outcome - unconscious interference: our perceptions are the result of unconscious assumptions (inferences) that we make about the environment * resembles problem solving * Helmholtz
same-object advantage
when attention is directed to 1 place on an object, the enhancing effect of that attention spreads to other places on the object -> faster responding that occurs when enhancement spreads within an object
perceptual rule of overlap
when objects overlap the one underneath usually continues behind the one on top
inattention blindness
when people are unaware of clearly visible stimuli if they are not directing their attention to them
can my perception differ from other people's around me
yes- interpretation - YOUR interpretation of YOUR environment constructs of the brain - ex: color- brain's perception of different wavelengths (ex: the dress)