Flashcards PNB 2XA3 - Midterm 1 - Lectures 1-9

Introspectionism

studying conscious mental events by asking the person to introspect on what's going on inside their mind

Introspectionists

Wilhelm Wundt, Edward Titchener, William James

What did the 3 introspectionists focus on?

Mental experience quality, intentionality importance, volition to conscious thought, creative synthesis

Behaviourism

Theoretical construct in any science is meaningful only to extent it's observable --> can only use observations of stimulus to response to study behaviour

Advantage of behaviourism

Deals entirely with observables

Disadvantage of behaviourism

Can't produce detailed or adequate accounts of complex cognitive functioning b/c internal thought is a necessary construct to this

Psychophysics

The study of the measurable relationship between physical stimuli and the sensations/perceptions they produce

What gave mechanism credibility as a way to study the mind?

Psychophysics

Kantian logic?

Transcendental method can be used to determine/make inferences about the underlying causes that lead to observed effects

How are models used in psychology?

As analogies to study mental processes w/ a language of communication

In the computer model what is the input?

Environmental energy --> information

In the computer model what is the coding and representation?

Psychological processes

In the computer model what is storage and retrieval?

Memory

Waugh and Norman (1965) cognitive model?

Stimulus --> sensory storage --> short-term memory (w/ rehearsal loop to remain in short-term or it's forgotten) --> permanent storage or immediate response from short-term memory

Wundt's model of apperception?

Looks at how we transfer sensations, organize them, perceive them, and integrate them with already stored info

When was the cognitive revolution?

1960s

3 ways to tackle knowledge

1. Acquired (perception, categorize)

2. Retained (memory, retrieval)

3. Used (judgement, inference)

how did brodmann determine the cytoarchitectural areas of the brain?

Classified diff brain regions via Nissl and Golgi stains

What are the two direct measures of brain electrical activity? High or low temporal/spatial resolution?

EEG and ERP, high temporal, low spatial

What are the two indirect (blood-flow) measures of brain electrical activity? High or low temporal/spatial resolution?

PET and fMRI, high spatial, low temporal

VISUAL PERCEPTION

Sensation

energy coming in, what actual info comes into vision

Perception

how we interpret and organize info

Bistable figrue

has 2 possible interpretations

3 components of visual perception

1. Form perception

2. Depth perception

3. Motion perception

Lateral

things are at the same level

Parallel processing

things close together are processed together, info is passed onto separate systems which are parallel and passed at same time

2 streams of vision

Dorsal and ventral stream

Dorsal stream

where system --> info goes upwards into brain

ventral stream

what system --> info goes downward into brain

Binding problem

after info is separated into two streams it's difficult to associate the info back together

2 ways to associate information back together (solution to binding problem)

1. Spatial position

2. Rhythm

1. Spatial position

if two things are in the same place of the brain then they are probably the same info

2. Rhythm

if neural signals are coordinated and occurring at same time then its likely the same info being processed by these neurons

3 main ideas of perception

1. Perceptual constancy

2. Perceptual organization of forms

3. Depth perception

Perceptual constancy

Features of objects are perceived as constant despite continual changes in retinal images of objects

1) Size constancy

Allows to perceive an object as same physical size even when distance changes and image on eye shrinks or grows

2) Shape constancy

Objects perceived as same shape when viewed from diff angles despite diff retinal images of same object

3) Brightness constancy

Brightness of object is perceived relative to background, and perceive an object as having a constant level of brightness even when amount of light shining on it changes

4) Colour Constancy

Colour of object perceived same despite diff illuminations

2 steps of form perception (perceptual organization of forms)

1. Figure-ground

2. Grouping (gestalt)

1. Figure-ground

Separating what's figure from background

2. Grouping

how we tend to group objects based on gestalt principles

1. Similarity (gestalt)

We group things based on similar shape, orientation and colour

2. Closure (gestalt)

we have bias to assume incomplete figures are closed

3. Proximity (gestalt)

Things are grouped together due to being in close proximity; spaced together = grouped together

4. Good continuation (gestalt)

Will assume something is made of two things which overlap for continuing an object for simple grouping

5. Common fate (gestalt)

Things that move together are grouped together

Is muller-lyer illusion culturally dependent?

NO --> all cultures perceive the same

Principle of simplicity

Brain will want to think something is formed and grouped in simplest possible way

2 sources of depth

1. Oculomotor sources

2. Visual sources

Oculomotor sources

What's mechanically happening in your eyes

Are eyes separately dominant from each other?

Yes

2 oculomotor sources

1) convergence

2) accomodation

1) Convergence

The more you converge your eyes the closer the object must be

2) Accommodation

Brain picks up amount the lens moves to accommodate an object to determine the object's distance

Binocular disparity (binocular visual sources)

Can determine if one object is infront of another based on diff angles the objects hit either eye at --> disparity of angles

Monocular visual sources

1) Interposition

2) Linear perspective

3) Reduced clarity

4) Height in the visual field

5) Relative size

6) Shading

7) Textural gradient

8) Structure through motion

9) Movement gradient, motion parallax

1) Interposition

closer objects block view of further objects

2) Linear perspective

closer together two converging lines, the greater the perceived distance

3) Reduced clarity

greater distances have less clarity

4) Height in the visual field

objects further in distance are usually higher in visual field than closer objects

5) Relative size

if 2 objects assumed to be same size, one producing larger retinal image is closer

6) Shading

light and shadow contribute to perception of dimensions --> the crater/dome illusion (circles w/ shadows) --> since we perceive sunlight coming from above

7) Textural gradient

texture appears smaller and less detailed as distance increases

8) Structure through motion

motion provides cues to 3D properties of objects

9) Movement gradient, motion parallax

Closer distance objects move faster, further distance objects move slower

Reification

perceived spatial info is more explicit than sensory stimulus itself; what we perceive is stronger than what we actually see therefore info comes from higher level processes of perception and not sensory stimulus input --> generative aspect --> perceived image contains more explicit info than physical stimulus so brain constructively fills in missing visual data to get whole object perceived

Unstable figure

both interpretations cannot be true at same time from figure therefore impossible figure

"The Educated Eye"

Some experts are able to see better --> ex. artists can see and perceive better --> can be taught to become better educated

OBJECT RECOGNITION

Is perception a higher or lower step of object recognition?

lower

Is recognition a higher or lower step of object recognition?

higher

Template matching

Assumes exact match between stimulus and internal construct (template) of the object to recognize it

- calculates correlation between inout and template to see which degree they fit together

Feature analysis

all objects are composed of separable distinct parts which can be looked at through a "visual alphabet" to understand an object's assembly and recognize it

3 evidence for features

1. Physiological

2. Cognitive visual search

3. Search asymmetries

1. Physiological?

Neurons have specific receptive fields which they preferentially respond to certain features in

How is physiological evidence determined? What tool?

Neuronal/cell recordings

What are V1 neurons specialized for?

Edges and lines

What are V2 neurons specialized for?

Shapes -- made from V1 features combined

What are V4 neurons specialized for?

Objects -- from V2 shapes put together

What are IT neurons specialized for?

Faces -- puts all info from V1, V2, and V4 together for facial recognition

2. Cognitive visual search?

Searching for features of a specific object against array of other similar, but different objects

2 types of cognitive searches?

1) Conjunction

2) Single feature

Conjunction search

When looking for multiple features of a target object to find it amongst other objects with similar features --> much slower search

Large visual array

A very visually cluttered image with lots of similar, scattered objects, making a search difficult --> ex. Where's Waldo?

In a graph, how does Reaction Time (RT) compare to display size for a conjunction search?

RT increases as function of display size --> as number of items in search field increases, RT of search increases (increasing linear positive sloped line)

Single feature search

Look for only one feature which differs the target object from the rest

In a graph, how does Reaction Time (RT) compare to display size for a single feature search?

RT is independent of display size --> no matter how many more items are added to an image, RT remains roughly the same (horizontal line)

Pop-out effect

When the object of a visual search is easily found, regardless of set size --> no matter how many items are added, the reaction time is the same

3. Search asymmetries

visual systems have an easier time looking for asymmetry surrounded by normal visual input than the other way around --> visual systems like to look for asymmetrical features

Componential/Structural approach

Uses information about components and spatial relations (how parts connect) of simpler geometric building blocks to organize them together to get 3D, complex objects --> Recognition by components theory

FACIAL and WORD RECOGNITION

Recognition-By-Components (RBC) theory (Beiderman)

Everyone has mental models of objects which are made of components called geons --> objects created by combining geons by edges and considering relations of different geons

Number of geons

36 different geons

Is RBC theory viewpoint independent?

Yes --> since geons are already 3D, when combined you can recognize the object from any angle already via an automatic viewpoint in all directions

Are geons hierarchically specific?

Yes

Is facial recognition featurely processed or holistically processed?

Holistically --> look at whole via features put together

Face Inversion effect

It is easier to process upright faces than it is inverted/upside down faces due to holistic processing --> when upright = holistic, when inverted = forced to consider the face feature by feature to recognize it

Are houses or faces lower in number of errors when viewing upright?

Faces