Social Interactions, Neural Systems and Health Outcomes

Dates: :	February 6th and February 13th at 9:00 – 11:30am
Location:	February 6th at ISERP room 270B February 13th at MSPH 14th FL conference room
Facilitator:	Kim Montgomery and Peter Bearman

Framing Questions

What is the relationship between health benefits of social interactions and the brain systems involved in social interactions?

To address that main question, the seminar will focus on the following questions.

 

• What are the benefits of social interactions on health outcomes?
• Is all social support positive for health outcomes?
• What neural systems are involved with social interactions?
• Are these neural systems modulated by different social interaction abilities?
• What are the connections between neural systems used in social interactions and health outcomes?

During week 1, we will begin with the introduction that humans are social beings and that the brain may have evolved because of the need to deal with complex social environments (“the social brain hypothesis”).  After this background, we will review two articles that address the question of health benefits for social interactions. 

During week 2, we will connect the previous week’s readings and discussions with the neural systems involved with social interactions. This discussion will focus on the mirror neuron system, regions in the brain that are involved during the observation and execution of actions.  We will discuss what mirror neurons are and the likelihood that there are other mirror neuron mechanisms in the brain.  Finally, we will focus on the possible role of the mirror neuron system in social interactions and connect activity in this brain system to social interaction abilities.

 

Readings

 

• Week One: February 6th
• Dunbar, R.I.M. (1998).  The Social Brain Hypothesis.  Evolutionary Anthropology, 6, 178-190.                                      

This article addresses the question of why did the brain evolve.  Many had suggested that the brain had evolved to deal with processing information and focused on things like the need for better pattern recognition.  In this paper, Dunbar reviews the evidence for an alternative hypothesis by Byrne and Whiten that suggested that the brain evolved due to the need for more complex computations when the size of social groups increased.                                  

• Cacioppo, J.T., Hawkley, L.C. (2003).  Social isolation and health, with an emphasis on underlying mechanisms.  Perspectives in Biology and Medicine, 46, S39-S52.

In this article, Cacioppo and Hawkley review the different mechanisms-attractiveness, health behavior, stress and repair and maintenance, for how social isolation may impact health.  They provide strong evidence that suggests stress and repair and maintenance may be the mechanisms for how social isolation leads to worse health outcomes.

• Bolger, N., Zuckerman, A., Kessler, R.C. (2000).  Invisible support and adjustment to stress.  Journal of Personality and Social Psychology, 79, 953-961.

Bolger and colleagues report a study showing that invisible, not visible support is associated with better health outcomes.  This experiment involved couples with one of the partners in the couple studying and taking the New York state bar exam.  Using daily diary methods, they measured visible support as when the partner reported giving support and the other partner reported receiving support and invisible support as when the partner reported giving support, but the other partner reported not receiving support.

 

• Week Two: February 13th
• Rizzolatti, G., Craighero, L. (2004).  The mirror neuron system.  Annual Reviews of Neuroscience, 27, 169-92.

This article is a review of the evidence for mirror neurons in the monkey and the mirror neuron system in the human.  Rizzolatti and Craighero argue that mirror neurons play an important role in action understanding and imitation.  Finally, they discuss the role of mirror neurons in language. 

• Gallese, V. (2003).  The manifold of interpersonal relations: the quest for a common mechanism.  Philosophical Transactions of the Royal Society of London.  Series B: Biological Sciences, 358, 517-528.

In this article, Gallese discusses how a “like me” understanding between the self and other is a basic building block for social cognition.  He discusses how this “like me” understanding may be mediated by mirror neurons.  Finally, he discusses how imitation, empathy, and theory of mind is possible because of embodied simulation, which is the understanding another’s intentions and actions by modeling their behavior using the same mechanisms needed to perform those actions by yourself.

• Pfeifer, J.H., Iacoboni, M., Mazziotta, J.C., Dapretto, M. Mirroring others’ emotions relates to empathy and interpersonal competence in children.  NeuroImage, in press

In this paper, Pfeifer and colleagues report a study where they found a significant relationship between activity in the mirror neuron system and empathy in children.  In the experiment, they measure the activity in the mirror neuron system during the observation and imitation of emotional facial expressions.  They found that activity in the mirror neuron system was significantly correlated with measures of empathy including personal distress, empathic concern, and fantasy.

• Montgomery, K.J., Seeherman, K.R., Haxby, J.V. Well-tempered social brain.  Almost submitted

In this paper, we report a study that found a significant relationship with perspective taking and activity in the mirror neuron system when participants viewed socially relevant facial expressions, but not during the observation of socially irrelevant facial movements.  These results suggest that there is modulation of activity in the mirror neuron system due to perspective taking abilities, but only for socially informative movements.

• Daily diary methods involve having participants answer several questions each day or several times during a day.  This method is employed by many social psychologists to investigate how participants are feeling and thinking as well as measuring what kind of interactions the participants have during their day.  Many times these experiments involve beeping participants using palm pilots to get data on who the participants are with, what they are doing and thinking at different moments during the day for several days or weeks.  In the Bolger study, they use paper methods that involve asking participants different questions once a day for several weeks.
• Empathy is measured both in the Pfeifer and my study by using the Interpersonal Reactivity Index (IRI) by Davis (1983).  The IRI is a 28 question questionnaire where people answer questions like “I sometimes find it difficult to see things from the ‘other guy’s’ point of view” using a 5 point Likert scale going from does not describe me well to describes me very well.  The IRI has 4 subscales of empathy-perspective taking, empathic concern, personal distress and fantasy.  Perspective taking measures the ability to take the point of view of another, empathic concern measures feelings of sympathy and concern for unfortunate others, personal distress measures feelings of personal anxiety and unease in tense interpersonal situations and fantasy measures the ability to put oneself imaginatively into the feelings and actions of fictitious characters in books and movies.
• Functional MRI (fMRI) is based on the fact that there is an increase of blood flow to active brain regions.  In fMRI, imaging is focused on the magnetic properties of hemoglobin, which carries oxygen in the bloodstream.  When oxygen is absorbed, the hemoglobin becomes deoxygenated.  Since deoxygenated hemoglobin is paramagnetic, it is the signal for fMRI.  The blood-oxygen-level-dependent (BOLD) fMRI signal measures the ratio of oxygenated to deoxygenated hemoglobin.  Active regions of the brain have a higher ratio of oxygenated to deoxygenated hemoglobin.  Due to this, fMRI can produce a map of changes in regional blood flow that are associated with neuronal activity.  Logothetis (2002) investigated the source of the BOLD signal by measuring the BOLD signal and signal unit recording measures at the same time in the monkey.  He found that the BOLD signal measures the input and processing of neuronal information within a brain region.  As a note, the physics behind imaging are incredibly complex- two scientists won the Nobel Prize in Medicine in 2003 for discoveries pertaining to MRI.  This was meant only to give a brief, basic explanation on fMRI.
• Mirror neurons were an accidental discovery by Rizzolatti and colleagues studying premotor neurons in the monkey.  They were conducting single-unit experiments measuring the firing rate of premotor neurons when the monkey performed actions like grasping an object.  One day while they were recording from the neuron, the experimenter grasped an object and the neuron fired!  This neuron fired both when the monkey grasped the object and when the experimenter did.  This was the first time that the same neuron fired both for perception and action.  These cells first were termed “monkey see, monkey do” neurons, but the name was changed to mirror neurons.  To study mirror neurons in the human, researchers have used either Positron Emission Tomography (PET) or fMRI to measure which brain regions are active during the observation and execution of actions.  The human homologue for area F5 in the monkey is the frontal operculum (a region in premotor cortex).  Studies have found (as indicated in the figure below) that the frontal operculum, inferior parietal lobe (IPL) and the superior temporal sulcus (STS) are activated during the observation and execution of actions. 

N.K. Logothetis (2002).  The neural basis of the blood-oxygen-level-dependent functional magnetic resonance imaging signal. Philosophical Transactions of the Royal Society of London.  Series B: Biological Sciences, 357, 1003-1037.

Figure of the monkey brain.                                            Figure of the human brain

 

F5 and PF/PFG, the two places in the                           Activity in the frontal operculum (F5),

monkey brain where mirror neurons                 IPL, and STS, during the observation

were discovered are circled.                                              and execution of actions.