People find it easier and faster to pick up information about themselves than about something else, for example, identifying their own name in a list or spotting their own face in a group picture. Working memory refers to the ability to actively think about and manipulate information, and self-bias is reflected in this, i.e., people are better at remembering and recalling things about themselves.
Investigators measured participants' brain activity while they were asked to remember locations of different colored dots that represented a friend, stranger or themselves, using an fMRI. The fastest response time recorded was for recalling the dot representing themselves. Greater activity in the ventromedial prefrontal cortex (VMPFC) -- an area involved in processing self-relevant information, was observed when people focused on the dot that represented themselves.
The VMPFC and working memory regions showed high synchrony corresponding to faster response times. When VMPFC activity was interfered with the help of transcranial direct current stimulation, the bias for information about self, disappeared, which indicated that activity in the region drives the bias.