Cog Psych Exam 2

Bottom-up processing

straight from the visual system (activation of photoreceptors, pathways to the brain, “raw data”

also known as simple processing

basic sensory signals and then our interpretation

top-down processing

combines cognitive and visual information form the “higher” areas (unconscious processing)

uses context clues about the world to interpret the stimulus (interpret what we expect the object to be given what we known about various real-life scenarios)

Hermann von Helmholtz

proposes that the image projected onto our retinas is not the scene we actually see as our perception is a combination of properties within the scene itself or hints about the scene

Known as the Unconscious Inference

What principle did Helmholtz come up with

The Likelihood Principle

what is most likely in a scenario based on our lived experience - use this to make quick inferences

Gestaltism

how we group objects and we use different principles to perceive objects as whole

Max Wertheim

came up with the grouping priciples propsed by gestalt principles

Proimity

Similarity

Objects that share some property (size, color, shape) tend to be perceived as related

Common motion

If objects appear to be moving in a similar manner, they are perceived as a group

Symmetry/parallelism

symmetrical or parallel objects are seen as related to one another

Good continuation

objects that appear to be continuous are typically perceived as the same object or part of that group of objects

Closure

we fill in gaps to perceive complete, whole objects

Good form

we prefer the simplest, most regular, most stable formation of a scene

Figure/ground

we organize a scene into object that stands out (the figure) and a background behind it (the ground)

Apparent motion

Brain automatically groups objects that move across retinal space as a single, moving object

Apparent motion quartet

we assume two dots that appear on one side of the screen, disappear, and two different dots appear on the other side of the screen as moving

but if you cover up half the screen so you can’t see the second dots you will still perceive that motion for a few seconds

What do Gestalt psychologist argue

gestaltism arose in opposition to Wundt’s structuralism (experience is built through basic perception/sensation)

argued that we do not perceive the world as a combination of more basic sensations

said that our perceptual system adds some information in between the flashing lights, which is outside of the baseline sensory information

The oblique effect

we tend to be better at responding to horizontal and vertical information and we have more neurons that respond to this information

The theory of natural selection related to the oblique effect

we have evolved under environments that mostly had vertical and horizontal visual cues and we then specialized in vertical/horizontal orientation

What did Gauthier find

Greeble experiment - show people random 3d objects and then taught them about the “greeble” structure

found that after being taught in the second exposure FFA (face recognition) responded much more than previously

showed that even in a short period of time our brains tune to the information provided

Brain ablation in monkeys helped with what

helped us map out where/what streams or what happens when certain cuts in the brain affect what

What did Pelligrino discover

discovered mirror neurons - neurons that responded while observing others and allows us to map this on our on behavior

divided attention

managing attention on multiple sensory inputs

Focused attention

being acutely aware of one thing at a time

Why is it harder to process two of the same thing

we are better at identifying a face and a scene presented at the same time instead of two faces or scenes bc we have different areas (FFA and PPA) that process this information and therefore is less likely to override the system

Selective attention

allows use the bring certain cues to our immediate attention

dichotic listening

used to test selective attention where they would play two different audio files in each ear and ask the participant to repeat what they heard in one ear but not the other

could remember what they were told to attend to but not anything from the other audio file

Filter theory of attention

All sensory information is coded, but only certain bits are encoded or attended to

Why does the cocktail party effect work

important words like your name bypass filters

Broadbent’s Early Selection Model

Messages are sent through a filter that identifies key stimulus (based on properties) and then a detector takes information about the attended message and processes high-level characteristics like meaning and then it goes to memory

helped create a testable hypotheses for attentional processes

Neville Moray

Tested attended vs unattended information via dichotic listening and found that participants actual remember some information and switched between attended message to unattended back to attended

Anne Treisman

took what Broadbent found and moray found and proposed a model which would allow for some information in the “ignored” ear to be attended to

Attenuator analyzes messages for physical characteristics, language, and meaning

Treisman’s attenuation model of attention

Sensory memory takes all incoming sensory information

filter ids the key stimulus based on properties then filter

then attenuator into a dictionary unity and then to memory

Dictionary unit (apart of Treisman’s attenuation model of attention)

every word has a certain threshold for being activated, the lower the threshold, the more likely it is to be activated

more important words have a lower threshold

Late Selection Model proposed by Donald Mackay

suggested that incoming information is processed at the level of meaning first, then the message-to-be-processed is selected

messages are selected is dependent on meaning not early factors such as physical characteristics or semantic meaning

Attention occurs after stimuli have been fully processed

Perceptual load

determined by:

processing capacity- limit of processable information

Perceptual load - task difficulty

Stroops effect

demonstrates how difficult some task-irrelevant stimulus are to ignore

inattentional blindness

even when looking directly at a stimulus if you don’t attend to it, you will not perceive it

Change blindness

given complex information or scenes we find it difficult to attend to multiple pieces of information presented

seen in films - they assume most people won’t pick up on continuity errors in complex scenes so they don’t edit them out

Attentional blink

brief period after attending to a specific stimulus during which we may miss new information

Why is attention selective

our full recognition of objects requires integration of information coded by cells distributed in multiple locations of the brain

distributed representation

representation that is distributed across multiple brain regions

Binding problem

what happens when multiple objects are present that activate all four neurons at the same time?

the visual system must sort out which features should be bound to which objects

Feature integration theory (FIT) - Treisman

visual system processes info in two-step process

Preattention stage and focused attention stage

Preattention (FIT)

all information about shape, orientation, color, curvature is taken in from sensory cues

features are unbound, can be incorrectly conjoined with other features, if not given enough time objects may never leave this stage

Illusory conjunctions

when you attention is never allowed to focus on the sensory stimuli, mistakes in binding can persist

Focused attention (FIT)

less likely you will make illusory conjunctions and perception will match the actual sensory cues more closely

Where is binding happening

in frontal regions

MT and V4 feed forward to more conscious regions of the brain that process this info but its slow and effortful

if info has not been fully processed only partial bits of info will be perceived