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Graphic mind interface


Final goal : Graphic interface to mind based on subconsciousnes generated visul data showed in visual field ( mind eye ).


Hypangogic state


Ganzfeld-induced hallucinatory experience, its phenomenology and cerebral electrophysiology

  • The term ganzfeld originally denoted a homogeneous visual

field. By analogy, unstructured or de-structured stimulation can be applied to other sensory systems, e.g., auditory or tactile. Studies aiming at induction of ASC have been using ‘multi-modal ganzfeld’ (MMGF), i.e., simultaneous exposure to unstructured visual and auditory input.

  • Further research focused mainly on the conditions of figure-

ground differentiation in the ganzfeld and colour perception (see Avant, 1965, for a review, cf. also Tsuji et al., 2004).

  • In our earlier experimental studies (Wackermann et al.,

2002; Pu¨ tz et al., 2006) a red-coloured incandescent 60-W lamp, placed at a distancew120 cm from the eye-shields, was used as the light source; in recent studies, where a precise control of the ganzfeld colour is important, a computerdriven, xenon lamp based D-ILA projector has been used (Pu¨ tz and Wackermann, 2007). The choice of red colour reportedly (Cohen, 1958) facilitates the observers’ ‘immersion’ in the ganzfeld.

  • Elementary changes of sensory qualities are usually observed

already after a relatively short exposure to the visual or MMGF (a few minutes). The visual field’s luminance diminishes and the field shows diffuse inhomogeneities, often described as a ‘cloudy fog’. In case of a colour ganzfeld, the field’s colour gradually bleaches, up to the point of a loss of the sensation of colour: the field is of indefinite grey, sometimes with an undertone of the complementary colour, e.g., greyish-green if red light is used. In addition, more distinct structures may appear against the diffuse ‘foggy’ background: dots, zig-zag lines, or more complex patterns. Generally, these elementary perceptual phenomena can be accounted for by adaptive retinal processes: saturation of the receptive elements and their mutually inhibitory interactions

  • After a prolonged exposure (a few minutes up to tens of

minutes) to the ganzfeld, some subjects report complex percepts

  • Another phenomenon occasionally reported from the

ganzfeld are episodes of ‘‘complete disappearance of the sense of vision for short periods of time’’, also called ‘blankouts’ (Cohen, 1960), occurring after prolonged exposure (10– 20 min) to the ganzfeld. Subjects also report that during these periods they were uncertain whether their eyes were open or closed, or even unable to control their eye movements. In the ‘luminous fog’ of the ganzfeld the subjects do not see anything; in the ‘blank-out’ periods, they may experience presence of ‘nothingness’ (Gibson, 1979).

  • Interestingly, the very first hallucinatory percept of the

three reported above emerged after a ‘blank-out’ period. Herrmann (2001) in an electroencephalographic (EEG) study of the visual cortex’s response to a flickering visual field observed the appearance of subjective colours and forms. Herrmann and Elliott (2001) described the variety of these perceptual phenomena as a function of flicker frequency (1– 40 Hz). Recently, Becker and Elliott (2006) reported cooccurrences of forms and colours in a flickering ganzfeld being dependent on flicker frequency, and phase relationship between the subject’s response and the flicker period.

  • Immobilised retinal images

The image created by the eye’s optical system can be fixed on the retina by special techniques (Heckenmueller, 1965). The structure of the visual field thus remains preserved but the scanning motion due to eye movements is inhibited. Under these conditions, partial or total ‘fade-outs’ of the visual field may occur (Yarbus, 1967), indicating that a regular refreshing is necessary for maintaining the visual structure. We may hypothesise a relationship between these ‘fade-outs’ and the ‘blank-out’ periods in ganzfeld, where eye movements are reportedly reduced.

  • However, later studies

revealed functional differences between sub-bands within the alpha frequency range: low-frequency alpha, reflecting rather attentional processes, and high-frequency alpha reflecting cognitive processes (Klimesch, 1997, 1999; cf. also Shaw, 2003).

  • Cohen and Cadwallader (1958) reported correlation between

higher alpha activity in the resting EEG and individual susceptibility to ‘blank-outs’. Cohen (1960) interpreted occurrence of alpha activity during the ‘blank-outs’ as alpha rebounddthis is a well-known phenomenon where, after a transitory suppression e.g., due to an external stimulus, eyes opening, etc., alpha activity attains the original level, or even increases. Tepas (1962) found an increase of alpha amplitude during the ‘blank-outs’, which was intermediate to ‘eyes closed’ and ‘eyes open’ conditions, but could not confirm the hypothesised relation between high alpha activity and blank-out susceptibility. These findings are in line with early observations by Adrian and Matthews (1934), who had previously reported alpha rebound after eyes opening in a uniform visual field. Later, Lehtonen and Lehtinen (1972) also reported re-occurrence of alpha activity in the ganzfeld, comparable to the ‘eyes closed’ condition. Increase of alpha activity was also observed during the ‘fade-out’ periods in perception of stabilised retinal images (Lehmann et al., 1967); this supports the relation to ganzfeld ‘blank-outs’ hypothesised above. As shown in the preceding sections, the variety of ganzfeld- induced phenomena is fairly rich and suggests relations to several different classes of perceptual phenomena and/or states of consciousness. Objective characterisation of the brain’s functional states under ganzfeld stimulation by means of EEG measures may help to elucidate these relations. This was the objective of our two major ganzfeld studies, results of which are summarised below.

  • There is recent experimental evidence

that eyes-open and eyes-closed conditions are not equivalent even in the absence of any visual input (Marx et al., 2003).

  • Within the waking states, the ganzfeld and ‘normal’

waking states were best distinguished by the band power ratio a2/a1 (frequency ranges 10–12 Hz and 8–10 Hz, respectively), which was increased in the ganzfeld EEG, indicating an acceleration of the alpha activity. Visual inspection of the spectra reveals a power drop along the lower flank of the alpha peak in the ganzfeld EEG, leading to an increase of the peak frequency

  • to ganzfeld imagery, with the maximum alpha acceleration in

the time segment 20–10 sec before the report. A time–frequency analysis of the data gave additional evidence for alpha acceleration (Wackermann et al., 2003).

  • GFI–EEG spectra and revealed various forms of ‘correlation

profiles’ over the analysed 30 sec time window. The most stable correlation over this time window was a global (i.e., involving all 19 channels) negative correlation between a2 power, measured relative to individual GFB baselines, and subject-reported vividness of imagery.

  • The relation between fast a2 activity and imagery formation

was interpreted by Pu¨ tz et al. (2006) as an indicator of activation of thalamo-cortical feedback loops involved in retrieval, activation and embedding of memory content in the ganzfeld-induced imagery. The observed a1 attenuation during the analysis epoch may reflect a shift of attention towards the visual percept and, later, preparation of the required motor action (button press signalling occurrence of imagery). The unspecific alpha-inducing effect of the ganzfeld-induced steady-state (no imagery) is in line with the inhibition hypothesis (i.e., alpha synchronisation due to inhibition of cortical areas related to external sensory information processing), and with earlier findings of other authors mentioned above

Gamma /theta synchrony

Tetris effect - Cognitive overload

Hypocampal buffer



  • cholinergic
  • dopaminergic

Subjective measuring

Siganl priority - P

  • Preception priority of signal 0-5 , 3 is border of consciousnes preception .

Signal Intensity - I

  • 0-100

Use of system resources - R

  • 1R = 1/100 of resources aviable in normal state of wakefullnes

Image properties

  • Phase


  • Brightnes


  • Size % of visual field


  • Time
    • 0,5 flash - image unrocgnizable
    • 1 flash - image rocognizible
    • 2 image
    • 2,5 series of image
    • 3 scene
    • 4 micro dream
    • 5 dream
  • Theme stability

Objective measuring



  • mainly subjective data from automatic drawing , greaphs drawn in PC was simplified
  • First i notice this in teris effect tests .When i blink i notice very short “flash” of image .First idea was that is becouse closed eyes but when i closed eyes for longer time i not see any new images or see only much weaker images than on blink (depends os strenght of tetris effect).
  • base priority NV around 3,83
  • duration 20-150ms depend of blink time
  • NV in peak 3,1 - 3,2
  • after blink 0,01 - 0,03 lower than base


  • time in s , priority
  • + try to get beter temporal resolution


  • time in s , priority ,green physical vision
  • normal intensity 0,058
  • longer blink higher intensity increase by similar rate
  • back to normal 12-15ms
  • TO DO : longer eye closed , synchornization with priority changes



  • blue line eye closed/open
  • change of priority not depend on duration of blink


Slow eyes closing and opening

  • test various closing and opening rates


  • one “box” = 0,1s
  • priority of NV
  • why NV priority decerase when eyes close, what presisly cause this effect ? Slower closing better and priority? + TEST even longer closing ,P-FV,R-FV,R-NV,I-FV,I-NV


  • reason find : decrease is caused by focus on FV behaind eylids blacknes
  • no focus on NV because no precevable NV , increase NV by disinhibition ?

Pasive relaxation


  • N- nonpysical
  • F- physical
  • T- touch+termo
  • P- proprioreception
  • V- vision
  • in end strong hypnagogic halucination but low lucidity

Pasive vs progresive relaxation - test on hands

  • deapnes of hand relaxation was very similar but interesting is second images witch show changes in preceprion priority
  • senory intereaction and turning on and off of senses, many intresting things to research
  • 3 is a limit of consciousnes preception when signl break this barier down to higher priority is consciously precieve, when signal move above 3 is not longer precived

this chnage is noticable in relaxation but is hard to describe it its like change from 2D to 3D balacknes diffent preception of space .This change have different levels i suspect it depends how much senses is turn off (vision , proprioreception..) pasiv-porogresiv-ruce.jpg


Pasive relaxation - red behaind the eylids

  • intreaction of thoughts , NV and FV priorities


Pasive relaxation - change of position , hypnagogic state, sleeap signals , dream

  • about 30 mins of pasive relaxation before recording “image” , i try to sleeap and change position minimal 3 times (left,right,left)
  • i notice some hypnagogic imaginery before recording
  • recording start few second before chnge position to laing on left side (red dots - eyes open)
  • brown time line is changing position forehed against wall of the bed - notice blue line - physical touch in priority
  • greean line -physical vision
  • light blue time line - stable hypnagogic satate constatnt flow of images and short scenes ,hyp phase about 0,5-1,5 (depend of NV priority),orange line in P
  • yelow time line + blue line - Sleep signals ,touch based dream , somthing else? This need more data
  • Blakc time line in R - Probalby lost of consciousnes or very weak
  • Indigo time line - dream , notice also increase in R
  • Unfortunetly i recording only NV,FV,FT and R and large part of intresting data is lost, experinc continue about next 20min dream,hypnagogic stability control , 2x false awakening .Without data from other senses is FV,NV almoust meaningless


Visualisation : Visual attention focus problem


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