PT  - JOURNAL ARTICLE
AU  - Campanhã, Camila
AU  - Minati, Ludovico
AU  - Fregni, Felipe
AU  - Boggio, Paulo S.
TI  - Responding to Unfair Offers Made by a Friend: Neuroelectrical Activity Changes in the Anterior Medial Prefrontal Cortex
AID  - 10.1523/JNEUROSCI.1253-11.2011
DP  - 2011 Oct 26
TA  - The Journal of Neuroscience
PG  - 15569--15574
VI  - 31
IP  - 43
4099  - http://www.jneurosci.org/content/31/43/15569.short
4100  - http://www.jneurosci.org/content/31/43/15569.full
SO  - J. Neurosci.2011 Oct 26; 31
AB  - When receiving unfair monetary offers from another person, the most common response is punishment. Existing literature on the Ultimatum Game indicates that individuals frequently refuse unfair offers even when this results in a loss for themselves. Here, we present behavioral and neurophysiological evidence demonstrating that friendship substantially modifies this response. When the proposer was a friend rather than an unknown person, unfair offers were less frequently rejected and the medial frontal negativity (MFN) typically associated with unfair offers was reversed to positive polarity. The underlying generators were located in inferior-mesial and right inferior- and medial-lateral frontal regions (BA10 and BA11). These findings highlight the fundamental role of the anterior prefrontal cortex in interpersonal economic interaction and, particularly, present new evidence on the effects of social distance on the MFN.