Perception & Cognition Psychology Flashcards
1
Q
Stimulus
A
- Any passing source of physical energy that produces a response in a sense organ
2
Q
Sensation
A
- Activation of the sense organs by a source of physical energy
3
Q
Perception
A
- Sorting out, interpretation, analysis and integration of stimuli carried out by the sense organs and brain
4
Q
Sensation & Perception process
A
- Stimulus energy: Light, sound, smell etc
- Sensory receptors: Eyes, ears, nose etc
- Neural impulses
- Brain: Visual, auditory, olfactory areas
5
Q
How many senses
A
- 8
6
Q
Brain & Perception
A
- Different areas of the brain are responsible for processing different senses
- Even within one area (visual cortex) different subareas function for different purposes
7
Q
Visual Perception
A
- Human visual system can only process a certain range of wavelengths
8
Q
Structure of the eye
A
- Retina: a layer of photoreceptor cells
- Fovea (fovea centralis): a small pit in the retina; provides the most accuracy in vision
9
Q
Structure of Retina
A
- Cones: sensitive to colours; used under light
- Rods: used in dim light; black-and-white perception
10
Q
How many cones types are there in homo sapiens
A
- 3
11
Q
Cones colpurs
A
- Blue: short-wavelengths cones
- Green: medium-wavelength cones
- Red: long-wavelength cones
12
Q
Cones
A
- Activity of a single cone (type) is not sufficient to identify colour
- Colour perception involved comparison in activity between the three cone types
13
Q
From Cones to Brain: Convergence
A
- Comparison between cone types require some way of monitoring and comparing activity of more than one cell at a time
- So there is some cells that receive input from more than one cone
14
Q
From Cones to Brain: Convergence: take place
A
- Occurs in retina and in visual cortex
15
Q
Colour constancy
A
- Perceiving objects as having consistent colour, even if changing illumination alters the wavelengths
reflected by the objects
16
Q
Gestalt
A
- Organised whole
- Gestalt psychologists (early 20th century) emphasised our tendency to integrate pieces of information into meaningful wholes.
- Perception is not just the sum of all parts.
17
Q
Gestalt Principles
A
- Similarity
- Proximity
- Closure
- Continuity
18
Q
Perception
A
- Processing information from senses
19
Q
Cognition
A
- Elaboration of information
20
Q
Perception & Cognition stage
A
- Sensation > perception > cognition
sensation > perception: bottom-up (stimulus-driven)
perception > cognition
top-down (knowledge-driven)
21
Q
Perceiving depth
A
- We need to construct a 3D world from a 2D retinal image
- Intrinsically difficult, complex task
22
Q
Depth Perception
A
- Recovering size and depth from a 2D retinal image cannot be explained by sensation alone.
- Requires internal cognitive processing to recover perception.
- Based on knowledge and assumptions about the world.
23
Q
Size Constancy
A
- Knowledge/understanding of world to aid perception.
- Things don’t tend to change in physical size.
- Size cues for depth perception
24
Q
Visual Illusions
A
- Ponzo illusion: Depth cues (size constancy) can cause (physical) size illusions
25
Ames Room Illusion
- Using false cues for depth to alter perception of size
| - Different size people in same room
26
Illusory Contours
- Cut shapes making it look like there is another shape
27
Cultural Effects on Perception
- Gregory & Gombrich (1973)
> Object Recognition:
Europeans: indoor + object above woman’s head
= window
East Africans: outdoor under tree + object = basket / box
- Hudson (1960)
> Depth Perception:
Tribal Africans: hunter to kill 'baby elephant'
28
Our preferences for faces
- Humans have a tendency to pay attention to human faces > animal faces…
> objects that could look like a face
29
Face preferences from Birth
Valenza
- Valenza et al. (1996)
> 36 infants (mean age 73 hours)
> Showed face-like patterns (vs inversed patterns)
> Face-like patterns were looked at longer (=preferred).
30
Face preferences from Birth
Mondloch
- Mondloch et al. (1999)
> Tested 3 different age groups
> Normal (positive) vs. negative faces
> Newborns & 6 weeks: no preference between normal and negative
> By 12 weeks: strong preference for normal
> Initially crude representation of face refines over time?
31
Importance of Face
```
- Faces are very important in our lives, especially for communication:
> Expressions – indicating emotions
> Eye contact
> Eye directions / following
> idicates the identity of the person.
```
32
Facial Expressions
- Field et al (1982)
> 74 babies (mean age 36 hours) saw a live model with 3 facial expressions.
> Babies’ expressions were recorded.
> Observers able to guess the expression from facial responses of babies.
> Newborns can discriminate and imitate those expressions
33
Eye Contact
- Eye contact for 30% of the time in conversation
- Timing matters - e.g., duration
- Turn taking - 75% look at other when listening, 40% when talking.
34
Eye directions
- We use eye directions as a communicative signal.
| - We have tendency to follow another’s gaze
35
Recognising Famous Faces
- We are experts
- Even without peripheral features (hair, ears etc)
- Even with slight visual distortions
36
Inversion Effect
- Upside down faces
- Yin (1969)
> Faces are affected by inversion much more than other types of objects.
> Face processing is different from other object processing.
37
Featural Processing
Thatcher Effect
- Thompson (1980)
> Detection of inversion of eyes and mouth is difficult when the whole face is inverted.
> i.e., We can still recognise the picture as of Thatcher, and don’t notice the oddity.
38
Featural Processing
Thatcher Effect: How does this happen
- When an entire face is inverted, processing the configuration (=holistic processing) is difficult.
- Then featural processing becomes dominant.
- Although inverted, each feature is processed locally, and the oddity is not noticed.
39
Face Recognition
- Bruce & Young (1986)
| > Recognition process of familiar faces
40
Face Recognition
Bruce & Young (1986): Process
- Structural encoding
- Face recognition units (FRUs)
- Person identity nodes (PINs)
- Name generation
41
Face Recognition
Bruce & Young (1986): Structural encoding
- Produce various representations of the face;
| > Recognise the face as a face
42
Face Recognition
Bruce & Young (1986): Face recognition units (FRUs)
- Contain (fairly abstract) structural information about known faces;
> Recognise the face as familiar
43
Face Recognition
Bruce & Young (1986): Person identity nodes (PINs)
- Provide information about individuals (e.g., occupations, interests)
44
Face Recognition
Bruce & Young (1986): Name generation
- Provide the name for the face (names are stored separately)
45
Prosopagnosia
- A condition in which there is a severe impairment in face recognition, but much less in object recognition.
- Also known as ‘face blindness’
- Could occur with brain damage (‘acquired prosopagnosia’) or without (‘developmental prosopagnosia’).
- Precise symptoms and degrees vary across patients.
46
Prosopagnosia
MS (Newcombe et al. 1989)
```
- Found that not having a functional structural encoding meant:
>Face/non-face
>Familiarity
>Information
>Name
```
Did not work
47
Prosopagnosia
NR (DeHaan et al., 1992)
- Found that not having a functional face recognition units (FRUs) meant:
>Familiarity
>Information
>Name
did not work
48
Prosopagnosia
PH (Young & DeHaan,1992)
- Found that not having a functional personal identity nodes (PINs) meant:
>Information
>Name
did not work
49
Prosopagnosia
MH (Carney & Temple, 1993)
- Found that not having a functional name generation meant:
>Name
did not work
50
Misidentification Delusions
- Some of common misidentification delusions could be explained by deficits in units in Bruce & Young’s model (Ellis & Young, 1990).
- These delusions often occur in psychiatric settings (e.g., paranoid schizophrenia).
- But could occur as a result of neurological conditions.
51
Fregoli Syndrome
- aka Fregoli Delusion
- Delusional belief that a single person can assume different physical appearances.
- Deficit in PINs?: Wrong nodes activated?
52
Intermetamorphosis
- Delusional belief that people change appearance to that of someone else familiar.
- Deficit in FRUs?: activating FRUs with abnormally low thresholds?
53
Capgras Syndrome
- aka Capgras Delusion
- Delusional belief that someone who looks familiar is actually an impostor
- Preserved face recognition but impaired emotional response to the faces?
- Familiar person replaced by physically similar double
54
Our interactions with the world
- Stimulus
- Sensation > perception > cognition
- Response
55
Traditional Cognition
- Thinking about, looking at and interacting with an object all result in DIFFERENT activations in the brain.
- Representations are stored (somewhere) away from sensory and motor regions of the brain.
56
Embodied Cognition (alternative approach)
- Our cognitive systems are grounded in our sensory and motor systems.
- No need for a separate mental representation.
- Representations are distributed across motor and sensory areas.
57
Embodied Cognition
- Thinking about, looking at and interacting with an object all result in (more or less) the SAME activations in the brain.
- Representations are distributed across (and stored within) sensory and motor systems.
- Cognition involves 'mental simulation'
> of perceptual and motor experience
58
Priming and Activating Representations
Embodied cognition: If activate one part of representation of an object then this will activate other components of that representation.
> e.g., Reading word ‘CAT’ activating the feeling of touching a cat?
59
Predictions
- If we activate motor aspects of representations then this should prime memories of objects that involve this action.
> body-mind effects (body affecting mind)
- If we activate sensory aspects of representations of an object then this should prime actions associated with that object.
> mind-body effects (mind affecting body)
60
Body-mind effects: Witt & Brockmore (2012)
- Witt & Brockmore (2012)
> subjects holding either gun or ball; Asked to move it up (if saw gun) or down (if saw neutral obj)
> action affecting object detection
61
Checking the effects
- Witt & Brockmore (2012)
> Ex1 & 2: response –raise object (gun or ball) for gun present, lower for absent
> Ex3: response - lower object for gun present, raise for absent
> Ex4: presence of gun in room but not for response = no bias
> Ex5: hold shoe = bias for reporting shoes - so effect is NOT GUN-SPECIFIC
>Overall, evidence for body-mind effects: holding object for response: affecting difficulty of perceiving stimulus object
62
Mind-body Effects: Tucker & Ellis (2004)
- Subjects saw pictures of either small or large objects.
- Task: judge whether the object is natural or man-made, by moving a response switch with either a precision or power grip.
63
Mind-body Effects: Tucker & Ellis (2004): conditions
- Conditions:
> stimulus-response compatible:
nut (natural/small – precision) vs. bottle (man-made/large – power)
> stimulus-response incompatible:
nut (natural/small – power) vs. bottle (man-made/large – precision)
64
Mind-body Effects: Tucker & Ellis (2004): results
- Stimulus-response compatibility effects
- Evidence for mind-body effects: perceiving stimulus object : activating information about handling it manually: affecting difficulty of response action
65
Action Observation
Helbig et al. (2009)
- Subjects saw movie of hand action (prime): picture of object: word
- Task: judge whether name matches object.
- Conditions: Congruent vs. Incongruent
66
Action Observation: results
Helbig et al. (2009)
- Priming effect of action on object recognition
- Observing someone else’s action
> activating perceptual/motor representation related to action > making it easier to recognise object that involves the action.
67
Adaptive Advantage
Studies showing perception/ cognition influenced by body:
- Steepness of hills with a backpack (Bhalla & Proffitt, 1999)
> judging a hill steeper
- Steepness of hills after a sugary drink (Schnall et al., 2010)
> Judging a hull less steep
- Size of hole in golf with performance (Witt et al., 2008)
> judging a hole bigger
- Width of doors with arms outstretched (Stefanucci & Geuss, 2009)
> Judging a door smaller
