W3L1 - Face processing and emotion Flashcards
Facial Emotional Recognition: What is the hypothesis to suggest innateness. Evidence from animals (1 evidence) and humans (3 evidences)
Universal facial expression hypothesis
- Evolved to recognise emotions for survival
Evidences: Animals
- Similar expressions in closely related species in animals
Evidences: Humans
- Expression evident in deaf and blind people
- But blind are less proficient at posing
- Babies
- Innate or learned early
- Though different emotions have different timings in learning
- Cross-cultural studies
- High cross-cultural agreement in judgments of emotions in faces
- Both literate and preliterate cultures
What is the role of the amygdala in facial processing
Guide attention to emotionally relevant information
Anger Superiority Effect.
Study
Innate mechanism for detecting anger
Finding the face in the crowd
Target Absent
- Longer RT than Target Present
In both Target Present/Absent
- Angry faces identified consistently faster (Processed first)
Anger Superiority Effect Study’s Caveat.
Some people find an advantage for happy faces
Caveat
- May depend on stimulus set
- Larger set size take longer
- May depend on feature strength
- Whiteness of teeth
What are evidences to support non-holistic processing of facial emotions
Non-holistic processing
1.) Facial Action Coding (FAC)
- Code emotion by looking at the muscle activity that gives rise to these changes in the features
- Recording movement of muscles and decode
- ) Emotion perception of morphed faces reveals categorical perception
- ) Calder et al. (2000)
- Top half of the face: Anger, fear and sadness
- Bottom half of face: Happiness and disgust
- Equally: Surprise
What are the evidence suggesting facial expressions are processed holistically?
Holistic Evidences:
Composite effects
- Mismatching emotions aligned and misaligned. Aligned poorer.
- (1) Upper Expression
- Aligned vs. misaligned (happy faces): slower
- Aligned vs. misaligned (angry face): faster
- Effects disappear with inversion
- (2) Expression judgements for composities unaffected by identity, vice versa.
- Evidence for holistic processing in recognition and identificaiton but some independence between emotion and identity
Can developmental prosopagnosics decode expressions of emotion?
Mixed
Yes
- Can label basic facial expression
- Can decode difficult to categorise emotions
No
- Deficits in facial expression recognition
- Suggest using individual features to decode
Evidence for holistic processing in emotions in prosopagnosics
Study and Results
Composite Task for Prosopagnosics: Weaker holistic processing in Emotions
Match identity and emotions
Results
- Controls shows drop in performance in aligned compared to unaligned
- Increased RT in aligned
- Prosopagosics smaller drop in aligned compared to unaligned
- Less increase in RT in aligned
- Bigger effect for control suggest prosopagnosics have impaired holistic processing
- For both identity and expression
What do models of face recognition suggest for expression and identity
Independence - Expression and Identity are separate
Bruce and Young:
- Dedicated route for Expression
Haxby
- Superior Temporal Sulcus (STS) = Expression
- Ventral Temporal Route (include FFA) = Identity
Do we have different locations for different emotions. Compare emotion and identity
Yes (unlike faces, emotions have a more dynamic network)
Behavioural Evidence to suggest different locations for different emotions
- Dynamic changes in muscle activity over time for different facial expressions suggest decoding over time
- Disgust, anger, fear move more quickly.
Physiological Evidence to suggest different locations for different emotions. Amydala Routes
Activation of Amygdala
- 120ms - Fast (low-dirty road)
- 170ms - Detailed perception
- 300ms - Conceptual knowledge of emotions
- Unlike FFA, processing emotions involve a much larger network
Physiological Evidence to suggest different locations for different emotions. MEG Speed study
MEG - Response to happy/fear/neutral in identity/emotion task
- 90ms
- Orbito-frontal response to emotion without attention
- 170ms
- Right-insula response to emotion with attention
- 220ms
- Identity processing
Thus, emotions are processed subconsciously before identity or even attention
To what degree does is amygdala fear responses specific for faces?
Faces vs non-face (gun) threatening stimuli in matching task
- Preferential right amygdala response to faces
- Implying amygdala playing a role in decoding fearful information in faces
What else does the Amygdala mediate other than fear
- Anger, Disgust, Sadness, Happiness
- May be responsive to all emotional-relevant information, not just fear
- Always activated in tasks requiring emotional decision-making
Are all facial features important for encoding fear? Amygdala
- Amygdala responsive to large eye whites in fear (and surprise) expressions
- Black eye no difference, implicate whiteness of eyes are important
- Responds more to whole faces
- i.e. responds to eyes, but holistic processing leads to larger responses
Who is SM. What can he do/ cannot
Bilateral amygdala lesion. Loss of visual information for danger.
Can
- Perceive fearful tones in voice
- Perceive body positions
- Normal startle
- Neural pathway independent of the amygdala
Cannot
- Recognize facial emotion in others (whiteness eyes). Look at mouth instead
- Lack of natural fear to snakes and spiders
- Lack of loss aversion (gambling)
Eye tracking in SM. What happens when he’s told to look
- Absence of fixations on the eyes across emotions
- When instructed
- SM decoding moves up to normal
- Suggests that the amygdala is important for initiating eye movements for emotional decision-making (recognizing fear)
