W7: Pain and Sensorimotor Emapthy Flashcards
(20 cards)
What do current scientific models of empathy postulate?
Current neuroscientific models of empathy postulate that a given motor, perceptual or emotional state of an individual activates corresponding representations in another individual observing that state
What do single cell recording studies in monkeys show? e.g. Rizzolati et al 2001
That premotor neurons become active both during execution of a given action and during observation of the same action performed by another monkey or human
What did Wicker et al (2010) demonstrate when looking at the observations of other individuals acting?
Observation of others individuals acting, being touched or showing facial emotions induces activity in neural networks that are also activated when observers act, are touched or display the same emotions
What can TMS be used for?
TMS can be used to interfere with cognitive and motor performance. By stimulating a targeted brain area, it is possible to study its involvement in specific function
What are MEPs?
Motor evoked potentials- electrical signals that are produced when the motor regions of the brain or spinal cord are naturally stimulated- when the motor cortex is stimulated, it makes an electrical signal
What practical applications can TMS have?
It can be developed for various therapeutic purposes e.g. for depression
Describe the process of TMS
A non invasive stimulation technique of the human brain. Stimulation is produced by generating a brief, high intensity magnetic field by passing a brief electric current through a magnetic coil- field can excite or inhibit a small area of the brain below the coil. Brain neurons use tiny amounts of electricity to send and relay information throughout the brain and body- bringing a magnet close to the brain can influence electrical activity
When a strong magnetic pulse is applied over the motor cortex, what is evoked?
MEPS- measures corticospinal activity
When a participant is experiencing pain, what do MEPs elicited by TMS indicate?
A marked reduction of corticospinal excitability
What did Avenanti et al (2005) measure and find in relation to MEPs and TMS in experiment 1?
Used TMS to measure the sensitivity of different pathways- strength of the TMS signal required to elicit MEPs is a measure of corticospinal activity. Ppts saw sets of videos, either control or pain- measured muscle responses on specific parts of the hand that was also getting penetrated by the needle (in the video)
The control was the same hand but had different areas and/or used a Q tip instead of the needle
They found a similar REDUCTION of corticospinal excitability when ppts saw someone else receiving a painful stimulus- by contrast there was NO modulation of MEPs recorded from the ADM muscle which was not involved in the pain or touch stimulation
What did Avenanti et al (2005) further investigate and find in their second experiment on MEPs and TMS?
Same procedure as experiment 1 except ppts watched video clips of a needle penetrating a FOOT or a q tip penetrating the foot but their hand response was measured
They found NO significant modulation of MEP amplitude recorded from FDI or ADM muscles when the observer viewed foot stimulations, suggesting the phenomenon is specific to the body area you are measuring
What did Avenanti et al (2005) investigate and find in their third experiment on MEPs and TMS?
Video clips showed a static view of the ADM region of the right hand, view of right foot, needle in ADM, or needle in right foot
Results were consistent with the topographic selectivity seen in exp 1 and 2- MEPs recorded from the ADM muscle during observation of needle in ADM were significantly LOWER with respect to corresponding baseline needle in foot
What is VAS and how was it used by Avenanti et al (2005) in their three part experiment?
Visual Angle Scale- one of the pain rating scales to measure the intensity or frequency of various symptoms from 0-10
Subjective ratings of pain unpleasantness and pain intensity showed that the painfulness of the observed stimuli did not differ between the hand and foot stimulations so the selectivity of motor inhibition cannot reflect differences in the perceived painfulness of observed events
What were the overall findings of evidence of sensorimotor empathy by Avenanti et al (2005) ? (Four key findings)
Highlights the sensorimotor side of empathy for pain by showing a consistent reduction of excitability of hand muscles during mere observation
- Specific for the observation of a needle entering the hand and absent during the observation of a needle entering the feet
- Confined to the observation of pain and absent during the observation of harmless tactile stimulation
- Selective for MEPs recorded from the hand muscle underlying the skin region penetrated by the needle and absent for MEPs recorded from a nearby hand muscle
- Effect was clearly related to the observer’s subjective empathetic rating of the sensory but not affective qualities of the pain ascribed to the model
What did Avenanti et al (2010) investigate in relation to racial bias and TMS?
Sought to determine whether neurophysiological and autonomic indices of reactivity to others’ pain are modulated by racial membership and racial bias- focused on sensorimotor contagion, automatic reduction of corticospinal excitability
They explored changes in excitability of corticospinal body representations in White and black ppts who were asked to watch and pay attention to: needles penetrating the FDI and a q tip gently touching the same hand muscle of black or white models
What did Avenanti et al (2010) find when they investigated racial bias and TMS?
Watching painful stimuli administered to the ingroup but not the outgroup models brought about a reduction of MEP amplitude that was specific for the muscle ppts observed being stimulated. There was no main effect or interaction showing black and white ppts showed the same MEP modulation.
NO signif difference in control muscle but MEP amplitude reduced for white ppts compared to all other three stimuli
How did Avenanti et al (2010) expand their additional investigations into race and TMS using purple coloured hands and what did they find?
Authors tested a subgroup of ppts with TMS in two additional conditions with the same stimuli but on a purple coloured hand , which defined no racial group, judged as the most dissimilar
MEPs analysis suggests an empathic sensorimotor response to this model
Absence of pain resonant mapping cannot therefore be fully explained by a reduction of observers’ familiarity or by somatic similarity with outgroup members- instead this lack of embodied resonance is likely due to racial stereotype and prejudice effects
What were the overall take aways from Avenanti et al’s (2010) research into sensorimotor empathy and race?
Clear sensorimotor contagion was found not only in response to pain of stranger individuals belonging to the same racial group but also in response to pain of violet hands. Reported lack of empathic brain response to pain of outgroup members seems to provide a neural foundation for the notion that race related prejudices can shape social categorisation and lead to dehumanised perception
What did Minio-Paluello et al (2008) investigate regarding autism and TMS/MEPs?
Using TMS to explore sensorimotor contagion elicited in neurotypical ppts when they observe a painful stimuli applied to the body of another person (needle in hand), or a tomato
MEPs were induced by focal single pulse TMS from hand muscles- ppts FDI muscles were vicariously involved by painful stimulation
Asked whether autistic individuals embody others’ pain as if they were vicariously feeling it and whether their proposed empathic difficulties may extend from higher-order to more basic levels of neural processing
What did Minio-Paluello et al (2008) find when investigating autism and TMS/MEPs?
There was a specific decrease in MEPs for control ppts when painful region was shown (FDI)- this reduction was significantly different from reduction shown by other gorup (ADM area)
When observing pain affecting another person, ppts with autism did not show any neurophysiological modulation of their corticospinal system - idicates that embodied empathic pain resonance effects are absent in autistic people
