Are facial expressions common across cultures?
- yes, they are common across cultures
What occurs in facial expressions of blind children?
- children born blind are similar to children who can see. They can express facially just like children who can see.
The recognition of facial expression is what?
- automatic, rapid, and generally accurate?
- we are good at recognizing emotions and do not need a lot of detail in order to recognize these emotions
What is the function of the right hemisphere in recognizing emotions?
- plays a more fundamental role than the left.
- It utilizes emotional cues directly
What is the role of the left hemisphere in recognizing emotions?
- tends to rely on the meaning of words.
What is prosody?
- when we speak, there is a flow that we have.
- the RH is very sensitive to that
What occurs with an aphasia?
- damage to the left hemisphere
- issues with recognizing words, but can recognize emotions
What occurs with right hemisphere damage?
- damage impairs recognition of emotions from facial expression and voice tone
What is bilateral prefrontal activation?
- when identifying emotion from word meaning
What is right prefrontal activation?
- when identifying emotion from tone of voice
- if we have damage in the right ear, then we would have a hard time recognizing emotion
What is Affective blindsight?
- people with unilateral visual cortex lesions are shown faces in their visual field, but do not recognize the face or emotion. However, the person with the lesion will still make a facial expression
What explains why affective blindsight occurs?
- explained by the amygdala’s reliance on the magnocellular system, which provides rapid input bypassing the visual cortex
What is an implication for normal emotional recognition?
- we rely on a “gut reaction” for understanding facial expression before actually seeing the face.
What area of the brain is critically involved in the recognition of facial expressions?
- right somatosensory cortex
What is the simulationist hypothesis?
- we understand emotional expressions by imitating them; the resulting somatosensory perception allows identification, understanding, and empathy
True or False: Recognition is accomplished to a great extent by the mirror neuron system
True
What is an implication for normal emotional recognition?
- we rely on a “gut reaction” for understanding facial expression before actually seeing the face.
What area of the brain is critically involved in the recognition of facial expressions?
- right somatosensory cortex
What is the simulationist hypothesis?
- we understand emotional expressions by imitating them; the resulting somatosensory perception allows identification, understanding, and empathy
True or False: Recognition is accomplished to a great extent by the mirror neuron system
True
Where are mirror neurons located?
- ventral premotor cortex
- posterior parietal cortex (reciprocally connected)
What is Volitional facial paralysis?
- damage to the face region of the primary motor cortex
- people cannot control the left half of their face
- Can involuntarily respond, but cannot voluntarily respond to emotion
What is Moebius syndrome?
- caused by the defective development of the 6th and 7th cranial nerves
- results in facial paralysis and inability to make lateral eye movements
- people who have this syndrome cannot make facial expressions & have difficulty recognizing facial expressions of others
True or False: Facial expressions are automatic and involuntary
True
What is emotional facial paresis?
- damage to the insular region of the prefrontal cortex. white matter of the frontal lobe or parts of the thalamus
- partial facial paralysis
- cannot express emotions involuntarily, but can do so voluntarily
What do emotional facial paresis and volational facial paresis tell us about the brain mechanisms underlying facial expression of emotion?
- ## It tells us that the frontal lobe is a localized are for facial expressions
What are Kimeric faces?
- composites of the face are on the same side
- basically determines that the left side is more expressive
- Right hemisphere is in charge of expression on the left side of the face
What is the James-Lange theory of emotion?
- emotional stimuli evoke physiological reactions including muscle contraction
- sensory feedback from reactions perceived by the brain to generate feelings
True or False: High spinal cord transections produced smaller reductions in emotional intensity
FALSE: greater reductions
What is the case of H.M.?
- hippocampus was removed
medial temporal bisected due to epilepsy
What is learning?
- process by which experiences change our nervous system
- acquisition of knowledge
What is the neural model of classical conditioning?
- Unconditioned stimulus (US) is paired with a conditioned stimulus (CS)
- neuron in somatosensroy (US) and in the auditory system (CS) are activated
- Synapse P - strong (US) and Synapse T - weak (CS) connect to create the action
- (blink) occurs with the unconditioned response (UR) and the conditioned response (CR)
- the key is that the stimulus is repeatedly paired together in order to create the response
What are the different types of learning?
- perceptual, stimulus-response, classical conditioning, instrumental conditioning, motor, relational
What occurs in the perceptual , stimulus response, and motor learning?
- Stimulus occurs
- Next is perceptual learning (Changes in neural circuit that detects a particular stimulus)
- Stimulus response learning occurs
- Then motor learning (changes in neural circuit that controls particular behavior)
- Response is created
How does instrumental conditioning work?
- we see something, and then detect a stimulus
- This is another name for operant conditioning
- Relationship between stimulus and response that was not there before.
What i the Hebb Rule?
- synapse that is repeatedly active at about the same the time the postsynaptic neuron fires will be come stronger
What does the Hebb rule imply?
- implies that repeated neural activity will produce physical changes in the neurons system
Synaptic plasticity?
- LTP: Long-term (lasting) increase excitability of neuron to particular synaptic input caused by repeated high-
frequency activity of that input - Hippocampal Formation: Forebrain structure of temporal lobe, constituting important part of limbic system; includes hippocampus proper, dedrate gyrus, and subiculum
- Population EPSP: Evoked potential that represents EPSPs of population neurons
What is the stimulation and recording of LTP?
- input arrives at the interinal cortex
- From there it goes to the dendrate gyrus
- if we want to produce LTP, then we can apply a strong electrical current to the neuron and then measure it
What are the components of the hippocampal formation?
- Entorhinal cortex, dendrate gyrus, CA1 field
What is the entorhinal cortex?
- provides major source of input to the hippocampal formation through the preforant path
What is the dentatate gyrus?
- receives input from the entorhinal cortex and projects to the CA3 field
What is the CA1 field?
- receives input form the CA3 field, and projects outward toward the subiculum
What is the relationship between associative long-term potentiation and the induction of LTP?
- LTP in which concurrent stimulation of weak and strong synapses to a given neuron STRENGTHENS WEAK ONES
- induction occurs through repetition
What is the relationship between induction of LTP and non-associative LTP requires an addictive effect?
- Series of pulses delivered at high rate all in one burst will produce LTP, but same number of pulses given at slow rate will not
The role of summation in LTP?
- Low rate of stimulation does not deporlarize membrane membrane sufficiently
- Threshold for establishment of LTP
- EPSPS produced by a high rate of stimulation summate and reach the threshold
Continuation of induction of LTP
- Rapid rate of stimulation causes excitatory postsynaptic potentials to summate, because each successive EPSP occurs before previous one has dissipated
- Rapid stimulation depolarizes postsynaptic membrane much more than slow stimulation does
Process of LTP?
- strengthening of a synapse occurs when it is stimulated while he postsynaptic neuron is depolarized
- LTP requires both activation of a synapse and depolarization of postsynaptic neuron
What is the function of the NMDA function?
- NDMA receptors in the hippocampal formation, particularly in CA1
- CA++ channel controlled by NDMA receptor is NT and voltage-dependent
Process of the NMDA receptor?
- Magnesium is always there
- Ca++ cannot rush in because magnesium is still sitting there
- Depolarization needs to occur so the channel is opened and the calcium can enter
- Neurotransmitters need to bind to the receptor of glutamate AND depolarization needs to occur at the same time!!!
True or False: action potential can occur in dendrites as well
True
How are dendritic spikes triggered?
- They are triggered when an action potential occurs along the axon.
- There is a backwash of depolarization across the cell body and up the dendritic trunk that causes the spike
- the spike evicts the magnesium ion in the NMDA receptors
- What occurs with weak synapses with LTP?
- If a weak synapses activates simultaneously with dendritic spike, Mg in the NDMA receptor is dislodged and calcium can rush in
What strengthens the synapse?
- insertion of additional AMPA receptors
- Calcium floods into the receptor after depolarization occurs
- The more AMPA receptors, the more influx Na+, the stronger the EPSP
- The calcium enters and ectivates the enzyme CaM-KII and stimulates the AMPA
- When that happens the stronger there is more influx of sodium and the stronger of the EPSP
True or False: Does the dendritic spine change shape during
LTP?
True
What is the role of PKM-zeta in long-term potentiation?
- protein will generate constantly and get into the postsynaptic membrane via mRNA
- Does not get produced because of the enzyme Pin1, but CAM-KII supresses the Pin 1
- Without early LTP, Pin1 blocks mRNA PKM-zeta transcription; with early LTP Pin1 is deactivated by CAM-KII and PKM-zeta is produced
- Once the PKM-zeta is activated , then it will always suprsses Pin1
- The final is the PKM synthesis, and this becomes self-sustaining. Late LTP requires an additional step of the PKM-zeta being produced and self-sustaining and also keeping the AMPA produced.