The piecing together of the data from numerous lesion studies and visual experiments led to a break down in the conventional view that the brain constructs a single view of space. Rather, it seems to construct more specific versions of space that optimize the simultaneous execution of various categories of behaviors. And according to Previc, it has constructed four spatial realms: the peripersonal (PrP); the ambient extrapersonal (AeP) ; the focal extrapersonal (FcE); and the action extrapersonal (AcE). (See Previc's The Neuropsychology of 3-D Space, 1998, Psychological Bulletin, Vol 124.)
Previc's four realms of space are depicted in the diagram below (excerpted from Fred Previc's The role of extrapersonal brain systems in religious activity, 2006, Conciousness and Cognition 15).
Diagram 1: Previc's Four Spatial Realms
Peripersonal Space: a Liberal Connection?
The yellow field in the above diagram represents the well-known concept of peripersonal (PrP) space, which is the space within our grasp. The neurology surrounding peripersonal space is interesting, as it supports the control of the upper limbs. In primates, these limbs are positioned in the lower visual field. There is a distinctive downward bias of the peripersonal visual field, as can be easily be seen in the disproportionate time we spend manipulating objects that are beneath eye level.
The peripersonal system also has a distinctive neuroanatomy and neurochemistry, one that runs right into our theory of political orientation. Previc describes the neuroanatomy of the peripersonal system as "mainly housed in the dorsal cortical networks extending from the dorsal visual pathways through the lateral and medial portions of the parietal lobe and finally into the superior-lateral portions of the frontal lobe".
Interestingly, the right hemisphere has a greater role in the management of the peripersonal system. The PrP system is also associated with the greater role of both noradrenaline and serotonin in its neurochemical management. Noradrenaline and serotonin are distributed asymmetrically in the right hemisphere, and the regular readers of this web site will immediately see the connection to political-religious disposition.
We have previously proposed an elevated influence of the right hemisphere and both the noradrenergic and serotonergic systems in liberal cognitive styles and behavior. Does this mean that liberalism is more oriented towards the peripersonal system than conservatism? This is probable. But this isn't the only space that seems to be favored by liberals, as we also suspect a stronger orientation towards ambient extrapersonal space.
"Hyperreligiosity is a major feature of mania, obsessive-compulsive disorder, schizophrenia, temporal-lobe epilepsy and related disorders, in which the ventromedial dopaminergic systems are highly activated and exaggerated attentional or goal-directed behavior toward extrapersonal space occurs....the evolution of religion is linked to an expansion of dopaminergic systems in humans, brought about by changes in diet and other psychological influences."
Previc cites a genetic study regarding dopamine and religion: "it is consistent with the finding...that 'spiritual acceptance' is by far the most highly correlated (p < .001) personality trait with the number of repeat alleles of the dopamine D4 receptor gene (DRD4)". The higher reproductive output of the religious may indeed be advancing the occurrence of the DRD4 gene in the human gene pool.
