Emotions 2

Front 1

Facial Expressions

Back 1

Darwin - innate expressions of emotion, using facial muscles, these are common across cultures.
Ekman & Friesen - universality of emotions, studies PNG tribe, 1971, had no trouble recognising and producing western emotions.

Front 2

Culture & Expression of Emotion

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Display rules - unique to culture of what emotion is appropriate to display when. Ekman showed scary film to US and Jap students, when alone showed same facial expressions, when together Jap students were less likely to show negative emotion & more likely to mask with positive emotions

Front 3

Recognition of Emotion

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Recognition depends on audition and vision, two way process, right hemisphere specialised for emotion recognition. Localisation of function to RH means that patients with discrete lesions can:
- fail to recognise a face, while correctly identifying an emotional expression
- fail to visually identify an emotion, while recognising the face
- fail to visually identify an emotion, while identifying the emotion by audition.
Example -
This man appears to be expressing disgust in the original photo here; the middle photo shows the original right side of his face plus a mirror image of the right side; and the last photo shows the left side of his face plus its mirror image. The left side is more expressive, and because motor control is contra-lateral this suggests that the right hemisphere is more important in expressing emotions.

Front 4

Laterality of emotion recognition

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right hemisphere has a more important role than the left in comprehension of emotion
Experiment
- 1 condition: listen to meaning of the words and state whether they described a sad, happy situation
- 1 condition: judge the emotional content of the tone of voice
Comprehension of emotion derived from word meaning: activated prefrontal cortex bilaterally, left more than right
Comprehension of emotion from tone of voice: only increased activity of right prefrontal cortex

Front 5

Amygdala

Back 5

Plays a role not only in emotional response but also recognition of emotions. Imaging studies show increased activation of amgydala when viewing facial expressions of fear but not happiness, Damage to the amydala impairs peoples ability to recognise facial expressions of emotion. Role of amygdala appears to be limited to recognition of the visual component of emotion

Front 6

Recognition Pathways in Visual System

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Magnocellular system
- Relays visual information from the eye to the visual cortex
- Movement, depth, contrast, low frequency
- Early in evolution, rapid
- Monochromatic, fuzzy images

Parvocellular system – visual cortex
- Colour vision, high frequency, slow transition
- Recent evolutionary development, humans and some primates
- Provides information to the Fusiform Face Area, the part of visual association cortex responsible for recognition of faces

Front 7

Visual Input to AmygVdala

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Two pathways:
Sub-cortical input from superior colliculus and pulvinar (nucleus in thalamus). It is the primary source of emotional information to the amygdala. Magnocellular system.

Cortical input from visual association cortex. Provides face recognition information, but is less important to the amygdala.

Front 8

Vuilleumier Study

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The more primitive magnocellular system is sensitive to low spatial frequency (SF) & more recently evolved parvocellular is sensitive high SF.
Results - Fusiform face area was better at recognizing faces (as indicated by greater activity on functional scans) and used high spatial frequency (parvocellular) information (as indicated by better performance with high SF pictures). But the amygdala (and areas that provide it with visual information including superior colliculus and pulvinar of thalamus) recognised expression of fear (as indicated by greater activity on scans ) and used low spatial frequency (magnocellular) information (as indicated by better performance

Front 9

Visual Recognition & Emotion: Different Pathways

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Another research group found that fearful faces produce the largest responses in the visual system and that the amygdala receives the information before the visual cortex – this supports the idea that amygdala gets information from the magnocellular system which processes information rapidly and this is what allows rapid recognition of fear

Front 10

Gaze-Direction Cell

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Researchers found that neurons in monkey’s superior temporal sulcus are involved in recognition of direction of gaze, and individual neurons are sensitive to gazes oriented in particular directions.
Gaze direction is important because it’s good to know whether an emotion is directed toward you or not!
Research also suggests that connections between neurons in the superior temporal sulcus and the parietal cortex allow orientation of another person’s gaze to direct your gaze to a specific location in space (recalling that the dorsal visual stream, “where,” terminates in the parietal lobe)

Front 11

Somatosensory Cues

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We use somatosensory cues to understand other’s facial expressions. When we see a facial expression of an emotion, we understand the meaning of it by either unconsciously imagining ourselves making the expression or by actually doing it. The worst recognition of facial expressions of emotions occurred in patients with lesions in the right hemisphere, specifically in the region just posterior to the central sulcus – the postcentral gyrus, or the primary somatosensory cortex
Mirror neurons, which are located in the ventral premotor area of the frontal lobe receive input from the superior temporal sulcus & are activated by performing or observing another animal perform a certain goal-directed action (i.e. grasping) – thought to be important for imitation of movements; this circuit is thought to help us understand the intentions of the movements of others because the same neurons responsible for us doing that action are activated; in the same way,

Front 12

Expression of Emotion

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Not all muscles of the face responsible for emotional expressions are under voluntary control
- volitional facial paresis
- emotional facial paresis
Examp

Front 13

James Lange Theory of Emotion

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Suggests that behaviours and physiological responses are directly elicited by situations and that feelings of emotions are produced by feedback from these behaviours and responses. Thus feelings are the result, not cause of emotional responses
An emotion-provoking stimulus directly produces physiological changes and behavior, and then these events produce the feeling of an emotion, e.g. dog, run away, fear. Lots of data to support it. Emotional experience is a function of emotional behaviour

Front 14

Cannon-Bard Theory of Emotion (You are afraid because the situation demands it)

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Opposed the James-Lange view by stating that the initial component is a cognitive appraisal of the situation, which then simultaneously leads to the emotional feeling, visceral changes and appropriate behaviour
i.e., you run and are afraid because the situation is judged to demand it. An emotion-provoking stimulus activates the “thalamus,” which simultaneously sends messages to the cortex, producing the feeling of an emotion, to the viscera, producing arousal, and to the skeletal muscles, producing behavior

Front 15

Cannon's Argument

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The same visceral changes occur in very different emotional states and in non-emotional states (“fight or flight” response). The viscera are relatively insensitive structures
Sympathectomized cats
- Still responded as though they were feeling emotion in every observable way except those that their surgeries prevented ( i.e., piloerection)

But, important to distinguish between emotional feelings and emotional behaviour