Seeking advice from experts is an everyday occurrence.   People predominantly resort to experts’ advice during the times of heightened uncertainty, such as an economic downturn. During such times, people may find themselves incapable of predicting the consequences of their choices and may resort to expert’s advice in an attempt to reduce the heightened perception of risk.  For instance, during times of economic contraction, individuals often tend to turn to an expert, or a well-informed colleague or friend, for advice before making their investment decisions.  A research study was conducted to shed a light on the neural impact of such advice or opinion. In this study, neurobiological basis of the expert advice was scrutinized using functional magnetic resonance imaging (fMRI), while participants made financial decisions under uncertainty and left free to choose whether to follow or ignore advice provided by a financial expert. Individuals were put through an fMRI scanning while making their financial decisions between a certain payment or lottery.  Such decisions were made under two different conditions. Under the first condition, a financial expert’s advice was stated, under the second condition, no advice was available.  Expert advice included an opinion of an expert economist on the choice to be made.  In an attempt to increase the expert advice’s probability of influencing the decisions, competency of the advice was tried to be maximized.  An expert advice can affect individuals’ decision-making process through a few potential mechanisms.  The research study sought answers to the following questions.


1) Does expert’s advice influence individuals’ decisions?


2) What is the pattern of brain activations connected to the expert advice?


3) Is there a difference between observed brain activations of the individuals when they choose to follow the expert’s advice and when they ignore it?


4) Does receiving the message change activation patterns in the brain regions associated with evaluations when a decision is made?


Conclusions:


Behavior:


Behavioral results indicate that the expert’s advice meaningfully influence behavior.  For measuring the effects of following the expert’s advice, participants’ brain blood flow oxygenation levels (only for main effect of conformity to the message) were evaluated, when they follow or ignore the expert’s advice.  Significant increase in activations was observed in the left anterior insula and right globus pallidusta, when participants acted independently and chose to ignore the expert’s advice.  


This shows that in the absence of an expert’s advice the participants extensively employed valuation mechanisms, and in the presence of expert’s advice, abandoned the burden of decision-making.  


Discussion:


In this study, a simple financial decision-making mechanism involving risk was used to explore the behavioral and neural mechanisms of the effect of financial advice offered by an expert economist, on making decisions under risk. Behavioral results show a meaningful effect of expert’s advice on probability weighting, for it changed probability weighting functions in the direction of the expert advice.  Behavioral effect of the expert’s views corresponds to the changes in neural activation patterns. These findings support the hypothesis that one effect of an expert advice is to leave the calculations for assessing alternative behavioral options, underlying decision-making mechanisms in the individual’s brain, to the expert’s opinion.  Reduced activation of evaluation mechanisms corresponds to the behavioral results.


Meaningful behavioral effects of an expert advice on probability weighting were also supported by the   fMRI findings. At the behavioral level, a meaningful effect of the expert advice on probability weighting function was observed.  Specifically, our results showed that participants, in the absence of an expert advice, used two fundamentally separate networks. These Networks are made up of brain regions that display correlations with two types of value.   Such values are; a) gains on an assured profit and b) weighted value of a lottery.  These correlations are reduced, if an expert advice is available. These results identify specific networks that play a role in evaluating different behavioral options and their substance in the financial decision-making process.  In this study, regions that were proved to be sensitive to the amount of the gain, namely the parietal cortex, precuneus and intraparietal sulcus (IPS), have previously been associated with decision-making under uncertainty.  Specifically, responses in this area are proportionate with the size and predictability of the reward and PCC is an integrating focal point of the brain’s network involved in processing self-referential conditions and part of a network that facilitates assigning subjective values to rewards.  A valuable finding reveals that the expert advice caused reduction in these regions’ responses, suggesting that the expert advice replaced the process of assigning value to choices.  Accordingly, it may be concluded that a neurobiological equivalent of possibility weighting is affected by the expert’s advice.  


Under the MES Condition (in the presence of the expert’s advice) activation of regions associated with mentalization:  Under the MES condition valuation processes reflecting the reward’s size and probability weighting are significantly subdued.  When combined with behavioral results, these findings reveal that the presence of the expert’s advice meaningfully changed the decision –making process. In the presence of the expert’s advice, a network becomes activated that include areas, such as TPJ and DMPFC, associated with visualizing other individuals’ purposes. Other regions showing increased activity during the presence of expert advice include caudate nucleus, a region involved in learning social rewards, anterior insula, a region involved in risk and negative emotional stimulation and lateral inferior frontal gyrus, a region involved in inhibitory control and task switching.   Except for the anterior insula, these regions do not overlap with areas involved in financial decision-making.  This activation pattern is consistent with the hypothesis that in the presence of an expert’s advice differential assessment processes are utilized. Combining all results together, it may be concluded that regions associated with TOM reasoning were activated as activation patterns observed in the presence of the expert’s advice were suppressed in utilization of valuation mechanisms.   Especially in the right hemisphere, TPJ has previously been shown to have a role in passing judgments on true and false beliefs may be held by other people, as well as making attributions to mental states and assessments of beliefs when making moral judgments.  On the other hand, medial prefrontal cortex becomes activated in a series of scenarios that have to do with mentalizing. Especially, when one visualizes about a different being,   the dorsomedial prefrontal cortex becomes activated.  As a valuable piece of information, which holds a particular importance for our findings; the caudate nucleus can be said to have an important role in learning about the trustworthiness of the trading partners in the presence of economic games.  Such studies have shown that as participants learn to make predictions about their partners’ actions, signals in that region reflective of the error in the social reward predictions decrease.  Furthermore, responses in the caudate nucleus have been shown to be affected by moral character descriptions of the trading partners.  The caudate nucleus responds to the financial feedback when making risk involved choices about trusting a trading partner, especially when information about the partner’s character is poorly provided (neutral status), and suppresses such responses when good or bad, a satisfactory information about the trading partner’s actions is obtained.  In light of above findings, it may be concluded that results from the current study are consistent with the hypothesis that the caudate nucleus is involved in social reward learning. We may think that activations in the caudate nucleus observed in the presence of expert advice in our study are associated with the learning process of whether to trust the expert or not.


 


Ignoring the expert’s advice:  Activations in brain regions when following or ignoring the expert advice have been compared.  Especially anterior insula and globus pallidus show increased activity when ignoring the expert’s advice. This finding may conclude that these regions play a role in when making decisions that ignore the expert’s advice.   Interestingly,   it was observed that the responses of a subset of globus pallidus neurons are associated with the negative reward-related signals, and this finding may be consistent with the hypothesis that activity in this region may reflect a negative review of the expert’s advice.   Our findings suggest that the anterior insula is an integrative region that assesses the risk involved in choosing the lottery and ignoring the advice provided by the expert economist.  


To summarize, our findings demonstrate that a financial advice provided by an expert economist during decision-making under conditions of uncertainty, had a meaningful impact on both behavior and brain responses.   The change in probability weighting functions in the direction of expert advice may be shown as an example of behavioral response.   Behavioral responses correspond to the neural activation patterns.  Specifically,


1) Meaningful correlations with the value of choice alternatives were obtained only in the absence of the expert’s advice.  This may indicate that utilization of valuation processes are suppressed in the presence of the expert’s advice.


2) Under the MES condition, DMPFC and bilateral TPJ, areas associated with mentalizing, are enabled.


3) Under the MES condition, neurobiological probability response rates (NPRR) revealed a pronounced flattening. This finding also further supports the hypothesis that in the presence of an expert advice, utilization of valuation mechanisms is suppressed.  Combining all the results together, it can be concluded that one significant effect of the expert’s advice is to relieve the individual’s brain from the burden of the responsibility of expected utility calculations.   


Engelman J.B,Capra CM,Noussair C,Berns GS (March 2009)


A translated summary from www.plosone.org .

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