Mirror Neurons

Question 1

What are mirror neurons?

Answer 1

• A class of neurons that become active when individuals perform a specific motor function and when they observe a similar one done by others

Question 2

What is a single-unit recording?

Answer 2

• Requires surgical opeping of the skull then implanting of recording microelectrodes

Question 3

Who is this technique used on?

Answer 3

Animals usually, people with Parkinsons and epilepsy

Question 4

What did Rizzolati find?

Answer 4

• Neurons in macaque monkey’s premotor cortex called F5 that fired when monkeys did things like reach or bite a peanut
• Found that individual neurons would only respond to very specific actions

Question 4

What role does the premotor cortex have?

Answer 4

Believed to have direct control over the movements of voluntary muscles

Question 5

How were Rizzolati’s experiments carried out?

Answer 5

• 3 awake monkeys, 497 neurons
• E1 - peanut breaking, paper ripping, plastic crumpling and dry food manipulation etc presented in and out of sight
• Non-action related sounds: white noise, pure tones, clicks, animal noises
• E2 - neurons capacity to differentiate between 2 different actions based on vision and sound

Question 6

What did neuron 1 respond to?

Answer 6

Vision and sound of tearing action
- Non-action sounds didn’t provoke a response

Question 7

What did neuron 2 respond to?

Answer 7

Vision and sound of a dropped stick - and when it hit the floor

Question 8

What did neuron 4 respond to?

Answer 8

Responded vigorously when monkey broke peanut

Question 8

What did neuron 3 respond to?

Answer 8

When monkey observed experimenter break peanut ans when they heard it
- Also when they made same action

Question 9

What were the overall findings of Rizzolati’s study?

Answer 9

• Area F5 contains a population of neurons - audio-visual mirror neurons that discharge not just to execution of a specific action but also when this action can only be heard

Question 10

What did Mukamel report (2010)?

Answer 10

On experiments using single-units recordings in humans

Question 11

What was Mukamel’s Experimental procedure (2010)?

Answer 11

• Extracellular activity from 21 pateints with pharmacologically intractable epilepsy recorded
• Grasp, facial expressions and control

Question 12

What happened in the conditions of Mukamel’s study?

Answer 12

• Grasp - action observation and action-execution (conditions)
• 3s video clip observed
• In action-execution, ‘finger’ appeared on the screen
• Facials - same 2 conditions - ‘smile’ on screen in execution

Question 13

What were the results of Mukamel’s study?

Answer 13

• 653 neurons - supplementary motor area and cingulate cortex
• 525 - medial temporal lobe
• 229 - amygdala, hippocampus, parahippocampal gyrus (PHG) and entorhinal cortex (EC)

Question 14

How were electrode locations verified and displayed in the study?

Answer 14

Post-op CT scans were co-registered with pre-op MRIs, transformed into MNI space, and shown on the MNI 305 brain for medial frontal and temporal lobes (e.g., SMA, ACC, amygdala, hippocampus)

Question 15

What was Lacoboni (2005) experimental procedure?

Answer 15

• 23 right handed Ps
• 11 received implicit instructions whilst 12 recieved explicit instructions
• Implicit - told to watch clips
• Explicit - told to pay attention to objects displyed in context clips, type of grip in action clip and figure out intention motivating grasping action in context clips

Question 16

What were the results of Iacobani (2005) study?

Answer 16

• Significant signal increase/increased neural activity for action, context and intention
• Neural activity increase in occipital, posterior temporal, parietal and frontal areas for action and intention

Question 17

What area had no noticeable signal increases in Iacobani (2005) study?

Answer 17

STS - superior temporal sulcus

Question 18

What was the main question of Iocobani (2005) study?

Answer 18

Whether there are signif. differences between the intention condition and action and context conditions in areas known to have mirror properties in the human brain

Question 19

What was the answer to the main question of Iocobani (2005) study?

Answer 19

Intention condition yielded significant signal increases compard to the action condition

Question 20

What were the main findings of Iacobani (2005) study?

Answer 20

• Increased activity of the right inferioir frontal cortex for the Intention condition sugges that this mirror neuron area actively participates in understanding the intentions behind the observed actions
• If this area were only involved in action understanding, a similar response should have been observed in the inferior frontal cortex while observing a grasping action, regardless of whether a context surrounding the observed grasping action was present or not