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ПрÐμзÐμнÑ"ацР̧я (1,3 Mб)

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    • Dorokhov V. B.
    • Institute of Higher Nervous Activity and Neurophysiology RAS, Moscow, Russia
    • e - mail : vbdorokhov@ mail.ru
  • 2. Drowsiness
    • Drowsiness is the cause of an accident on transport and industry.
    • Drowsy subject is not to be aware the danger of his own state.
    • Drowsiness is a change of a state of consciousness at which the attention is switched from external environment to internal information processes that rather frequently is accompanied by occurrence of hypnagogic images .
  • 3. Presence URL http:// www.presence-connect.com
    • Presence is defined as the subjective experience of being in one place or environment, even when one is physically situated in another
  • 4. Evolution and presence
    • Sense of presence allows the nervous system to solve a key problem for its survival: how to differentiate between internal and external states . ( Waterworth 2003 ).
    • Two kinds of information, the concrete and the abstract .
    • Concrete information -via the perceptual-motor systems from the world around us.
    • Abstract information must be realised mentally.
  • 5. Internal mental world
    • Sense of presence could appear in three cases : in a real world in a virtual world and in an internal mental world (Int) .
    • We do not always feel present in physical environments. T he daydreamer feels present ”here” in the mental imagery of the simulation occurring in their head. This I have called the ” reality problem ,“ the need to explain how one might not feel present even when exposed to high fidelity sensory stimuli. ( F . Biocca. 2002 )
  • 6. Consciousness and presence/absence
    • Presence – is as attending to an external world - real or virtual
    • Absence – is as attending to a world that is created internally .
    • ( Waterworth 2003 ).
    • If we are “…lost in thought" we are not present (in the real or a virtual world), but we are conscious
    • To feel presence or absence both require consciousness .
  • 7. Measuring presence - Break In Presence ( BIP )
    • Presence is a product of an unconscious continuous reality-check to fit what we perceive with our senses (see, hear, touch, smell, taste). The issues of presence is only interesting when there are competing signals from at least two environments.
    • Slater & Steed (2000) propose a mechanism for measuring presence, the Break In Presence (BIP ). Model, based on the idea that at any instant "t" of time one either is present 100% or not, in one environment, being this virtual or real.
    • This view is different to those of others that actually proposes presence as a continuously changing feeling with a shift of attentive resources (Ijsselsteijn & de Ridder, 1998). The difference in view does not lie in the idea of continuous against discrete ".. a break in presence may be conceived of as an attentional shift away from the mediated environment and towards the physical environment, but with the possibility to still feel a sense of presence in the mediated environment, albeit to a lesser extent ." (Ijsselsteijn, 2002)
  • 8. Two experimental models for investigation of performance error during falling asleep Driving simulator and polygraphic recording
    • Psychomotorical test
    • with the closed eyes in sitting or lying position.
    • 1) counting of external stimulus (sound clicks).
    • 2) self pacing counting without external stimulation,
  • 9. Electrodermal indices of the subjective perception of performance errors (BIP) Р sychomotoric test, self-pacing button pressing (right hand, sitting position)
    • S kin conductance response ( SCR ), EEG, EOG, and button pressings were recorded.
    • E rror onset was shown to be preceded by the decreased in the rate of spontaneous SCR. Performance reappearance after the self-detected error was accompanied by phasic SCR and alpha-burst of EEG .
    • When participants spontaneously self-activated and renewal of proper performance, he/she reported about
    • "... lost in thought " Mean interval between the error and the last preceding SCR = 69.8 s Mean interval between the error and the first following SCR = 10.1 s
    • . .
  • 10. ALPHA-BURSTS AND K-COMPLEX ACTIVATION PATTERN AFTER ERRORS (BIP) Р sychomotoric test, self-pacing button pressing (two hand, lying position) Alpha activation Theta error Performance reappearance KC+alpha
  • 11. ALPHA – RHYTHM AND PERFORMANCE Psychomotorical test (closed eyes, counting of external stimulus - sound clicks). (two hand, lying position) Correct performance alpha – rhythm Performance error alpha blocking Correct performance reappearance alpha reappearance
  • 12.
    • It is known that during the transition from waking to sleeping when the ability to respond to external stimuli ceases, alpha power decreases, whereas theta increases. It is suggested that the encoding of new information is reflected by theta oscillations in hippocampo-cortical feedback loops, whereas search and retrieval processes in semantic long-term memory are reflected by alpha oscillations in thalamo-cortical feedback loops . W . Klimesch . 1999
    Hypothesis EEG correlates of a presence/absence switch is a alpha /theta interaction
  • 13. DREAMING and the BRAIN: Toward a Cognitive Neuroscience of Conscious States J. A. Hobson, E. Pace-Schott, R. Stickgold (2000)
  • 14. A State Space Model of the Brain-Mind From : J. A. Hobson, E. Pace-Schott, R. Stickgold (2000) DREAMING and the BRAIN:Toward a Cognitive Neuroscience of Conscious States
    • A - ( A ctivation)-уровень активации мозга. К ак много информации может быть обработано мозгом
    • I - ( I nformation flow) -откуда приходит информация (внешний мир или внутрення среда). Какая информация обрабатывается мозгом
    • M - M ode of information processing
    • -каким способом информация обрабатывается (основной тип нейромодулятора). Как эта информация обрабатывается мозгом