... the brain regions implicated in bipolar disorder, specifically the anterior cingulate...
http://www.mayo.edu/research/discoverys-edge/genomics-bipolar-disorder
The
anterior cingulate cortex (ACC) is the frontal part of the
cingulate cortex, which resembles a "collar" surrounding the frontal part of the
corpus callosum.
It appears to play a role in a wide variety of autonomic functions, such as regulating blood pressure and heart rate... It is also involved in rational cognitive functions, such as reward anticipation, decision-making, empathy, impulse control,
and emotion.
A typical task that activates the ACC involves eliciting some form of
conflict within the participant that can potentially result in an error.
One such task is called the Eriksen flanker task
and consists of an arrow pointing to the left or right, which is
flanked by two distractor arrows creating either compatible
(<<<<<) or incompatible (<<<>>) trials. Another very common conflict-inducing stimulus is the Stroop task (Pardo et al., 1990), which involves naming the color ink of words that are either congruent (
RED written in red) or incongruent (
RED
written in blue). Conflict occurs because people’s reading abilities
interfere with their attempt to correctly name the word’s ink color. A
variation of this task is the
Counting-Stroop, during which
people count either neutral stimuli (‘dog’ presented four times) or
interfering stimuli (‘three’ presented four times) by pressing a button...
Many studies attribute specific functions such as error detection, anticipation of tasks, attention,
motivation, and modulation of emotional responses to the ACC.
http://en.wikipedia.org/wiki/Anterior_cingulate_cortex
A... study suggests that people’s ability to distinguish between what
really happened and what was imagined may be determined by the presence
of a fold at the front of the brain that develops late in pregnancy, and
is missing entirely in 27% of people.
The key brain structure identified by the study is called the
paracingulate sulcus (PCS), a fold in part of the prefrontal cortex, the
region that is involved with planning, thought and judgment. The size
of the PCS varies greatly in normal people, and some people have a PCS only
on one side of their brain, while others have one on both.
... studies like this cannot determine whether having a small or absent PCS
causes difficulties with reality recognition memories, or whether the
effect works the other way around.
http://books.google.se/books?id=WQVviYqU-IcC&pg=PA70&lpg=PA70&dq=anterior+cingulate+psychosis&source=bl&ots=3Qu_QIraPk&sig=aR95bFI_OgN9J6H6TiqF7uwz4OM&hl=en&sa=X&ei=DW3EUou8IarJ4gTR14HIBQ&ved=0CGgQ6AEwBw#v=onepage&q=anterior%20cingulate%20psychosis&f=false