Jordi, there is a substantial body of experimental support for the retinoid model of egocentric space. Some of this confirming evidence is described in these two publications:

Space, self, and the theater of consciousness. *Consciousness and Cognition*, 2007.

Where Am I? Redux. *Journal of Consciousness Studies*, 2013.

You can read these papers on my Research Gate page. I would be very much interested in your thoughts about the evidence in support of egocentric space and its realization in the brain's retinoid system.

Jordi: "Because we might ask ourselves, what we consider as the psychic space? .... is there really a self-centered or is just a fragment of the mind process?"

Jordi, can you explain more about what you mean when you say "just a fragment of the mind process" as opposed to a self-centered (egocentric) space? I think this is an important point in trying to understand the underlying mechanism of hemispatial neglect.

Jordi, in my SMTT experiments a vivid hallucination of a triangle appears to be moving back and forth, left and right, out there in front of each subject. if I understand your meaning, from a *denotative* perspective (objective?) this hallucination is the neuronal activity in the brain's putative retinoid space, whereas from a *connotative* perspective (subjective) the hallucination is the vivid conscious experience of the subject. Does this connect with the point you are making?

Jordi, your mind is what is happening inside of your brain. So your mind is locatable. The mind that is happening inside of your brain can only be denoted as a theoretical model of the mind mechanisms inside of your brain. The theoretical model of your mind can be observed by you and others, and it can be tested to see if it can successfully predict mental phenomena that we couldn't predict before. This is how science makes theories and tests theories.

Jodi: "The mind has no ipseity".

If your mind has no ipseity -- no individual identity -- then how can you think of yourself as the same person from day to day and from year to year? What does "I" mean when you say "I think the mind has no ipseity"? For more about the ipseity of mind, see Where Am I ? Redux.

Jordi, you conflate the core self (identity) with the self image, what Metzinger calls the phenomenal self-model. You cannot develop or assume a self image without having an innate core self (I!). For a discussion of this see here:

http://www.theassc.org/files/assc/Commentary_on_Praetorius.pdf

Jordi: "The mental process is a subjective information flow in constant construction, the image of necessity remains subjective memory process ... "

So you do agree that that the conscious image (what I call retinoid space) is subjectively organized. According to retinoid theory, there can be no subjectivity without a fixed locus of perspectival origin. The cluster of autaptic neurons that constitute this perspectival origin in retinoid space are what I call the *core self* (I!). When we use the line-bisection method to test for hemispatial neglect, the distal part of the line in the neglected field vanishes for the brain-damaged subject and the heuristic self-locus (I!*) shifts in a direction away from "shortened" field to mark the *apparent* center of the distorted phenomenal line. For an explanation of the heuristic self-locus (I!*) see "Where Am I? Redux" on my Research Gate page.

This recent paper on hemi-spatial neglect assumes that neglect is mainly an attentional disorder:

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Integr. Neurosci., 29 January 2014 | doi: 10.3389/fnint.2014.00004

Galvanic vestibular stimulation in hemi-spatial neglect

David Wilkinson1*, Olga Zubko1, Mohamed Sakel2, Simon Coulton3, Tracy Higgins3 and Patrick Pullicino2

1School of Psychology, University of Kent, Canterbury, UK

2East Kent Neuro-Rehabilitation Service, East Kent Hospitals University NHS Foundation Trust, Canterbury, UK

3Centre for Health Services Studies, University of Kent, Canterbury, UK

Hemi-spatial neglect is an attentional disorder in which the sufferer fails to acknowledge or respond to stimuli appearing in contralesional space. In recent years, it has become clear that a measurable reduction in contralesional neglect can occur during galvanic vestibular stimulation, a technique by which transmastoid, small amplitude current induces lateral, attentional shifts via asymmetric modulation of the left and right vestibular nerves. …….

Near complete, but transient, relief from neglect has been observed during artificial stimulation of the vestibular nerves (Rubens, 1985; Cappa et al., 1987). These nerves send information from the semi-circular canals and otoliths of the inner ear to, among other brain regions, parts of the peri-sylvia involved in spatial attention and awareness (Suzuki et al., 2001; Balaban et al., 2011). The conventional method, caloric vestibular stimulation, involves the injection of thermal current (usually via cold water) into the ear canal. This alters the density of endolymph within the nearby balance organs and in turn modulates their afferent firing patterns (see Miller and Ngo, 2007). Unfortunately, the therapeutic benefit of CVS is offset by severe vertigo, nausea and the more general impracticality of ear irrigation, all of which hinder repeated use.

Recent studies suggest that a related technique, known as galvanic vestibular stimulation may provide a more tolerable and simpler way of harnessing this beneficial effect (see Utz et al., 2010). GVS involves the delivery of tiny electrical currents via two small electrodes to the mastoid processes which overlie the vestibular nerves (Coats, 1972).

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This report has interesting implications for the retinoid explanation of hemi-spatial neglect because in the retinoid model vestibular stimulation would activate shift-control cells to drive the heuristic self-locus (selective attention) into peripheral regions of egocentric space. These, presumably, would be the regions of attentional neglect. For more about the heuristic self-locus see "Where Am? Redux" on my RG page.