Biopsychology of Emotion
Ch. 17
Outline
(1) Early Research on the Biopsychology of
Emotion
(2) Emotions and the Autonomic Nervous
System
(3) Human Facial Expressions of Emotion
(4) Fear Conditioning
(5) Brain Mechanisms of Human Emotion
Early Research
• Darwin’s The Expression of Emotions in Man and
Animals was the first major event in the study of
the biological bases of emotion
• Darwin believed emotions evolved from behaviors
that indicated what an animal would do next in a
given situation; that when these behaviors were
advantageous to the animal
Early Research
• The James-Lange Theory was the first
attempt to explain the physiological bases
of emotion; suggests that emotion-inducing
stimuli are received and interpreted by the
brain, which triggers visceral changes (
organ changes in the abdomen or thorax)
that subsequently trigger the experience of
emotion
Early Research
• Canon-Bard Theory is alternative theory
based on the idea that emotional stimuli
evoke visceral and emotional responses that
are independent of one another
Early Research
• Neither theory is entirely correct; emotions can be
induced by stimuli that cannot elicit a peripheral,
visceral response (e.g., patients suffering from a
spinal cord transection), but visceral responses can
often induce an emotional state in the absence of
any obvious eliciting stimuli (e.g., a racing
heartbeat and increased respiration can produce a
feeling of fear in the absence of an eliciting
stimuli)
Early Research
• Bard reported that decorticate cats (without
cortex) responded with unusual aggression to the
slightest provocation; often this behavior was not
directed at any specific topic.
• Bard concluded that the hypothalamus is critical
for the performance of these aggressive behaviors,
which he called sham rage; he also believed that
the cortex normally inhibited and directed these
aggressive displays
Early Research
• This theory of hypothalamic function was
followed by Papez’s proposal of a limbic system
that controlled the expression of emotions by
connections with the hypothalamus and mediated
the perception of emotions by connections with
the cortex
• This was supported by Kluver-Bucy syndrome damage to the amygdala (part of the limbic
system) resulting patients who are fearless,
hypersexual, and inclined to explore objects with
mouth
Emotions and the ANS
• A large body of research has focused on the
degree to which specific patterns of ANS
activity are associated with specific
emotions; both the J-L (multitude of activity
patterns, each generating a unique emotion
and C-B (single general pattern of
activation) theories are partially correct
Emotions and the ANS
• In addition, the effectiveness of ANS
measures in polgraphy has been studied;
these tests examine changes in emotions as
indexed by ANS activity to assess
truthfulness
Emotions and the ANS
• Many of these studies employ a controlquestion technique -ANS responses to
answers to innocuous questions (Is your
mother’s name Betty?) are compared to
those of target questions (Did you steal the
money?)
Emotions and the ANS
• However, most normal people will react
strongly to the target question, even if they
are not guilty, which makes it difficult for
investigators to tell if they are lying
• To circumvent this possibility, guiltyknowledge technique is used
Emotions and the ANS
• Guilty knowledge technique - polygrapher
asks a series of questions that contain
possible details of the crime
• Only some details are true; a subject’s
responses to true details (only a guilty
suspect would know) are compared to false
details (that would make innocent parties
equally uneasy)
Human Facial
Expressions of Emotion
The Primary Facial Expressions
• Ekman and Friesen analyzed hundreds of
films and photos of people experiencing
various emotions
• They concluded that there are six primary
facial expressions of emotions and all
others are mixtures of these
The Primary Facial Expressions
• The six primary facial expressions are:
–
–
–
–
–
–
anger
fear
happiness
surprise
sadness
disgust
The Primary Facial Expressions
• Facial expressions are universal:
– when asked to view photos of people who were
asked to contract specific facial muscles, the 12
different cultures that were tested linked the
same emotions to the facial expressions
– isolated New Guinea tribe members could
correctly identify facial expressions and vice
versa
Deceptive Facial Expressions
• It is difficult to fool an expert because
microexpressions of genuine emotion often break
through the false one
• For example, genuine smiles(Duchenne smiles)
involve contraction of both the zygomaticus
major and the orbicularis oculi, whereas false
only involve the zygomaticus major
• EMG recordings can also detect emotional
changes even when the motor output to the facial
muscles is too slight to change them
Fear Conditioning
• Fear conditioning is the establishment of
fear in response to a previously neutral
stimulus like a tone (CS) by pairing it with
the presentation of an aversive stimulus like
a footshock (US)
• There are neural substrates for this form of
auditory fear conditioning
The Amygdala and Fear
Conditioning
• Lesions to the medial geniculate nucleus
of the thalamus block fear conditioning, but
lesions to the primary auditory cortex did
not
• Suggested that MGN projected to an
alternate neural structure that was involved
in fear - amygdala, which, when lesioned,
also blocks fear conditioning
The Hippocampus and
Contextual Fear Conditioning
• The context or environment in which fearinducing stimuli are encountered can also
come to elicit fear; this is called contextual
fear conditioning
The Hippocampus and
Contextual Fear Conditioning
• Given the role of the hippocampus in spatial
memory, it is not surprising that this brain
structure is involved; lesioning the
hippocampus blocks the development of
contextual fear conditioning without
blocking conditioning to CS
Brain Mechanisms of
Human Emotion
Specific Brain Regions
Have Specific Roles
• This research focuses on brain-damaged
patients and functional imaging studies of
healthy patients
• Have confirmed the role of the amygdala
and prefrontal cortex in human emotion and
failed to support the limbic theory
Specific Brain Regions
Have Specific Roles
• Researchers have found that brain regions
involved with one emotion are not
necessarily involved in another… and that
brain region might be involved in one
aspect of an emotion but not another aspect
of the same emotion
Specific Brain Regions
Have Specific Roles
• Example: the amygdala appears to be very
involved in the perception (as opposed to
the expression) of fear… lesioning the
amygdala leaves a person unable to
perceive fearful emotions from others,
although these patients have no problems
matching the appropriate emotion with a
sentence or in expressing various emotions
using facial expression upon request
Specific Brain Regions
Have Specific Roles
• A similar deficit is seen in patients with UrbackWiethe disease, in which the tissue forming the
amygdala and medial temporal lobes is calcified
and destroyed
• fMRI has revealed the lateral aspects of the
frontal lobes as most associated with positive
emotions, whereas the medial aspects of the
frontal lobes are most associated with negative
emotion
The Right Hemisphere is More
Involved in Human Emotion
• Studies involving brain damaged patients
and functional imaging techniques have
both revealed that, in general, the right
hemisphere tends to play a greater role in
emotional behaviors; however, this depends
on the structure under consideration and the
particular aspect of emotion under study
The Right Hemisphere is More
Involved in Human Emotion
• The RH is more involved in perception of
emotion, specifically facial expression and
prosody (melody of speech that conveys
sincerity, sarcasm, etc.)
The Right Hemisphere is More
Involved in Human Emotion
• Although lesions of the right and left frontal
lobes equally disrupt perception of emotion
from facial features, lesions of the right, but
not left, temporal lobe disrupt it
The Right Hemisphere is More
Involved in Human Emotion
• By contrast, PET studies indicated that the
right amygdala and prefrontal cortex are
more active in prosody, whereas the right
temporal lobe is less responsive than the left