GB2393786A

GB2393786A - Visual stimulation in synchronisation with heartbeat

Info

Publication number: GB2393786A
Application number: GB0223057A
Authority: GB
Inventors: Ernesto Marcelo Dario Korenman
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-10-04
Filing date: 2002-10-04
Publication date: 2004-04-07
Also published as: GB0223057D0

Abstract

A method and apparatus where the eyes of a user are alternately occluded and exposed in synchronisation with the user's heartbeat to enhance bilateral brain activity. The pulse rate is detected (5, figure 2) and liquid crystal shutters (LCS) 1, 2 positioned in front of the eyes (as lenses 1, 2 on a pair of spectacles) are successively activated in synchronisation with heart beat to alternatively expose each eye to it's visual field for the whole heart interbeat period. An audio click may be provided in the same ear as the exposed eye using a set of headphones to provide multi-sensory stimulation. The heart beat may be measured using a pulse sensor (5, figure 2) or an ECG. Uses include the improvement of mood and increase of alertness, and improvement of slow inter-hemispheric switching.

Description

Title: Method and apparatus for improving mood and I.. Vlgl ance.

1. Introduction

1.1 Lefc/right hemisphere cognitive differences Research has shown that each brain hemisphere appears to specialize in a particular set of activities. The left hemisphere of the brain is considered to be our "logic" side; it is the centre of speech, reasoning and the written language. The right hemisphere of the brain is instead the "art " side and is generally associated with emotion, imagination and spatial awareness. There is no total monopoly of any given function; and man's highest achievements obviously require the complementary working of both sides. There are in the market various types of special music that claims to promote bilateral brain activity such as the "Biolateral Sound Recordings" (http://www.biolateral.com) and "Hemi Sync" music from the Monroe Institute (http://www.hemi-sync.com). The hemispheres also appear to have complementary cognitive styles and modes of encoding information. In case of lateral impairment, (leading to contra-lateral dominance), the situation can result in very different results depending of the side involved. For instance, stroke patients with right-sided parietal lesions sometimes deny their disease ("anosognosia") (McGlynn & Schacter, 1989) but patients with similar left-sided lesions rarely exhibit this type of denial and are usually fully aware of their deficit. The left hemisphere's cognitive style appears to be goal-directed with a coherent plan of action that denies or smoothes over discrepancies, whereas the right hemisphere's style is that of a 'devil's advocate' that monitors and seeks to raise discrepancies (Ramachandran VS, 1994).

Therefore, according to the intensity and duration of hemisphere activation, the left dominant hemisphere will induce a progression through confidence, elation, and mania while the right dominant hemisphere will proceed through caution, apprehension and depression.

1.2 Bilateral hemispheric ultradian rhythms There are naturally occurring rhythmic shifts in patterns of brain hemispheric efficiency, which follow an ultradian, (more than I a day), cycle (Shannahoff-Khalsa, 1993). For instance, the shift of performance on verbal and spatial tasks (Klein and Armitage, 1979), the asymmetry of bilateral electro-dermal responses from hands and feet (Conesa, 1995), and the "nasal airflow cycle" of nostril dominance (Werntz et al, 1983). Most of these cycles have a near 90 minutes period and have been experimentally used to assess hemispheric dominance.

The complementary viewpoints of each brain hemisphere described in the section 1.1 appear to be adopted successively rather than simultaneously. This "hemispheric switching" constitutes a much faster ultradian rhythm, which switches in seconds rather than in minutes.

1.3 Bipolar disorder and inter-hemispheric switching Bipolar disorder (manic depression) is a mood disorder classically considered to have a strong biological basis. During manic/depressive cycles patients show dramatic fluctuations of mood, energy, activity, infommation processing and behaviors (Carroll B.J., 1994). This is a common condition with a lifetime prevalence of 1.2-1.6% (Weissman MM et al, 1988). Despite years of research on this disorder, its underlying pa/ho-physiology remains elusive.

A number of recent neuro-imaging studies have suggested that patients with mood disorders have inter-hemispheric asymmetries in brain activity with the left hemisphere being hypoactive and showing lower excitability (Baxter et al, 1984) and (Maeda et al, 2000).

When a different image is presented to each one of the two eyes, they compete for perceptual dominance, such that one image is visible and the other is suppressed (binocular rivalry). There is evidence that the resolution of the conflicting visual information in binocular rivalry might be resolved by alternating hemispheric activation. Binocular rivalry is itself an inter-hemispheric switching phenomenon (Pettigrew, J. D. et al, 1998).

Pettigrew has proposed that bipolar disorder is the result of a propensity for slow inter-hemispheric switching mechanisms that become 'stuck' in one or the other state (Pettigrew J. D. and Steven M. Miller, 1998). Because slow switches are also 'sticky' when compared with fast switches, the clinical manifestations of bipolar disorder may be explained by hemispheric activation being 'stuck' on the left (mania) or on the right (depression) hemisphere. Support for this 'sticky' inter- hemispheric switching hypothesis in depression stems from the experimental observation that the rate of perceptual alternation in binocular rivalry is significantly slower in subjects with bipolar disorder (median 0.27Hz) compared with normal controls (median 0.60Hz).

1.4 "Light & sound machines" Brain wave entrainment through optical and acoustic stimulation has been successfully used for many behavioural and clinical applications. There are in the market various devices, which use flickers of pulsating light and sound to "entrain" the BEG to a particular specific brain wave pattern. This is possible because, when they are stimulated, the neural infommation from each eye and ear is carried out through their neural pathway generating an associated evoked response at the brain cortex level, which follows the frequency of the stimulation ("frequency following response"). Light pulses and images are delivered by emitting diodes and liquid crystal displays assembled on goggles & glasses; and sound stimuli are delivered by earphones. The audiovisual stimuli are then presented to the user following special patterns designed to enhance a specific brain frequency and/or to promote a specific type of brain lateral dominance. An example of the "state of the art" application of the above principle is disclosed in the patent by Jaillet (Jaillet, 2002).

The successful use of light and sound machines requires a good degree of introspection. It entrains the subjects by isolating them from the environment while imposing an artificial LED driven light pulsation and/or a sound stimulus schedule.

1.5 Eye movement desensitization and reprocessing ("EMDR") "EMDR" is a well-researched psychotherapeutic methodology for the treatment of disturbing experiences as in post-traumatic stress disorder ("PTSD") (Francine Shapiro, 2001).

EMDR is driven by bilateral brain stimulation, which results from a client tracking the therapist's fingers from side to side (or by sound moving from ear to ear or by tapping the hands left and right). Simultaneously, the client reactivates an image, with its accompanying sensory experiences, of a profound traumatic event, along with the associated distorted negative self-beliefs. This procedure helps the neuro-

physiological system, (the basis of the mind/body connection), to free itself from blockages and reconnect itself bringing recovery and healing.

Successful EMDR treatment requires various sessions with a therapist. Extended training sessions of bilateral brain stimulation in the domestic environment could enhance the treatment and be much welcomed by patients and therapists.

1.6 Heart-Brain Pacemakers Coherence A repetitive beat in music, ideally ranging from 45 to 72 beats per minute (a rhythm close to the beat of the human heart), can be very hypnotic and generate an eyes-open altered state of consciousness in a very large percentage of people.

In the last few years it has been proposed a relationship between psychophysiological coherence and positive emotions (Heart Math InstituteFreeze Frame). Increased heart-brain synchronization (between the heartbeat and the EEG) is claimed to be

positive to improve psycho-behavioural status. In patents like the one by the present writer (Korenman E. M. D., 1998) a special breathing manipulation is used to enhance neural-mediated respiratory sinus arrhythmia and promote such coherence.

2. Purpose and Principles This invention is based on the realization that, by the provision of appropriate hardware and the design of a suitable methodological procedure, it is possible to integrate the background experimental knowledge described in sections 1.1, 1.2 & 1.3

above plus the added extra features disclosed below to provide a novel and effective technology for the treatment of brain lateral deficiencies easily, at home, unobtrusively and without drugs.

This invention relates to a method and apparatus to help people to entrain into a desirable and natural heart-brain coherent light/sound schedule while they can continue to fully interact with the environment.

The use of this method and apparatus results in enhanced bilateral brain activation in sync with the heart pacemaker. It is expected that through this technology people with a slow hemispheric switch can be entrained into the faster endogenous rhythm of their own heart, people with hypoactive lateral brain deficiencies can be stimulated into bilateral brain equilibrium and people suffering the effects of traumatic or negative emotional events can improve and expand the bilateral-brain based self-exploratory process leading to psychological healing.

3. Implementation All the above is done mainly by providing the means for the user to alternatively see the environment with each single eye for the length of a whole heartbeat period.

Briefly, the heartbeat of the user is detected. This signal serves as a time cue to trigger an electronic processing circuit, which alternates the activation of a pair of liquid

crystal shutters (LCS), positioned one in front of each eye. Accordingly, the arrival of a heartbeat switches the LCS in front of one of the eyes into open (translucent) mode exposing it to its visual field for the whole inter-beat period until the next heartbeat

arrives and opens the contra-lateral LCS and expose the contra lateral eye to its visual field and so forth.

A possible addition to the above arrangement is to pulsate an audio click to each ear alternatively in sync with the opening of the LCS on the same side. This is in order to increase the effects of the stimulation by making it multi-censorial, hence activating a larger part of the brain.

4. Embodiment The invention is illustrated, by way of example, with reference to the following description of preferred embodiment of apparatus and methodological use:

4.1 Liquid Crystal Shutter (LCS) glasses (Figure 1) This consists of a pair of glasses made with ferro-electric liquid crystal lenses (1).

When a voltage is applied across the lenses they become circularly polarised and if the polarity of the applied field is changed, the sense of circular polarization changes.

Circularly polarised lenses are translucent (2) and enable the eye behind it to receive the images present in their respective visual field. These LCS can be switched on in

less than 100 microseconds.

The LCS of each eye is activated separately by a voltage ramp output coming from the LCS activation module (3).

4.2 The heartbeat trigger hardware module (Figure 2) (4) This module consists of a biosensor (5) for the detection of a time cue signal related to heart periodicity; for instance, the detection of the peripheral pulse wave through photo-plethysmography from the fingers or from the ear; or, (if required), the detection of the R wave from the electro-cardiogram (ECG).

Further hardware circuitry produces a TTX logic signal (6) each time the heartbeat is detected by the biosensor.

4.3 LCS bilateral activation module (Figure 2) (7) This consists of an electronic circuit, which outputs the voltage ramps (8) needed to activate each one of the bilateral shutters in the LCS glasses in succession. It consists of an alternating logic circuit which switches between two states: i) right LCS channel activated and left channel off (RLCSon) or ii) left LEC channel activated and right channel of (LLCSon). The RLCSon - LLCSon - RLCSon - LLCSon.... resulting sequence is caused by the arrival of the TTX logic signal generated by the heartbeat trigger hardware module.

4.4 Visual tracking movement correction arrangement (Figure 3) After each shift in the activation of LCSs from one side to the opposite, the person wearing the device is expected to produce a correcting lateral eye tracking movement (9) in order to maintain continuous focus on the same part of the visual field.

Sometimes, (especially when the observed objects are too near or when they move fast in front of the subject), the required tracking movements are larger and training with the device demands an extra effort from the user.

From time to time it may be desirable to reduce the length of the lateral tracking movements. This can be achieved by placing an adjustable correcting prism lens (10) in front of each LCSn, which changes the angular axis of vision for that eye.

The user can then re-position the correcting prism lenses adapting the device to his required inter-ocular angle of visual axis disparity.

4.4 Alternating earphones (Figure 1) (Figure 2) A pair of headphones (11) can be added to the above modules. Each ear of the headphone will be alternatively stimulated by a pulsed click sound in sync with the opening of the LCS of the same side. RLCS will then be accompanied by a click sound delivered to the right ear, (right click on RCLKon), and LLCS will be accompanied by a click sound delivered to the left ear, (left click on LCLKon).

As with the LCS glasses, the click to each ear is delivered by a voltage ramp output coming from the stimulation module.

As in the example of optical stimulation, the same bilateral activation module outputs the voltage ramps needed to generate the click for ach ear in succession with a sequence: RCLKSon - LCLKon - RCLKon - LCLKon caused by the arrival of the m logic signal generated by the heartbeat trigger hardware module. (Figure 1) 5. Device operation and effects When the user wears the device switched on, he/she will keep sensing the images in front of the LCS glasses and the clicks sounds delivered to the earphones jumping from the eye and ear of one side to the eye and ear of the contralateral side. The user will then be forced to perform correcting lateral movements of the eye in order to maintain focus to the same point of reference. These bilateral alternations of optical and auditory activations together with the required visual tracking correction task produce powerful bilateral brain activation.

The synchronicity of the above activation with the heartbeat induces higher levels of heart-brain coherence. After some practice, the user becomes accustomed himself to wear the device for increasingly longer periods hence self-inducing fuller brain entrainment to the eye-toeye/ear- to-ear shifting schedule. All this can be done while interacting with the environment and performing normal domestic activities.

6. Uses of this technology The system disclosed here can be used for general self-improvement and/or, (in the case of certain affective disorders) to complement and enhance behavioural and cognitive therapeutic strategies.

It can be used by the general public as a non-invasive, drugless way to improve mood, increase alertness, enhance cognitive-behavioural balance and encourage the application of whole-brain, (logic-intuitive), solving strategies to normal domestic situations. In the case of subjects with bipolar disorder and other types of depression this technology may provide a totally natural way to "unstuck" the inter-hemispheric switch oscillator.

By means of the use of this technology, subjects with PTSD may continue the process of analysis and "re-programming" of traumatic events at home.

In subjects with other affective disorders with brain lateral deficiency component, (such as some types of ADD and aggressive and compulsive behaviours), this technology may provide a simple way to achieve the healing effects of higher heart-

brain coherence.

7. Brief description of the drawings

Figure I is a schematic representation of the apparatus as described in the preferred embodiment. Figure 2 is a flow diagram of the process steps involved in this invention.

Figure 3 is a schematic representation of the optional arrangement to decrease eye tracking movement amplitude.

8. References Baxter et al (1984) "Reduction of prefrontal cortex glucose metabolism common to three types of depression". Archives of General Psychiatry 46, 243-250.

Carroll B.J. (1994). "Brain mechanisms in manic depression." Clin. Chem. 40(2), 303-308.

Conesa (1995) "Electrodermal palmer asymmetry and nostril dominance. Perceptual and Motor Skills 80, 211-216.

Francine Shapiro (2001): "Eye Movement Desensitisation and Reprocessing" Second Edition. The Guilford Press, NY.

Jaillet (2002) "Apparatus and method for changing critical brain activity using light and sound" US 6,443,977.

Kessler et al (1994) "Sex and depression in the National Co-morbidity Survey. II: Cohort effects". J Affect Disord. 1994 Jan;30(1):15-26.

Klein and Armitage (1979) "Rhythms in human performance". Science 204, 1326-

1328. Korenman E. M. D. (1998) "Assisting breathing in synchronism with the heart".

GB2315332.

Maeda et al (2000) "Inter-hemispheric asymmetry of motor cortical excitability in major depression as measured by trans-cranial magnetic stimulation". British Journal of Psychiatry 177, 169-173.

McGlynn & Schacter (1989) "Unawareness of deficits in neuropsychological syndromes". J Clin Exp Neuropsychol. 1989 Mar; 11(2): 143-205. Review Pettigrew J. D. and Steven M. Miller (1998) "A sticky' inter-hemispheric switch in bipolar disorder?" Proc. Australian Neuroscience Society, 9, 71.

Pettigrew, J. D., Miller, S. M., Liu, G. B. & Hooper, G. (1998) "A hemispheric switch in binocular rivalry?" Proc. Aust. Neurosci. Soc. 9, 71.

Ramachandran VS (1994) "Phantom limbs, neglect syndromes, repressed memories, and Freudian psychology". Int. Rev. Neurobiol. 1994; 37:291-333; discussion 369-72.

Shannahoff-Khalsa (1993) "The ultradian rhythm of alternating cerebral hemispheric activity". Int J Neurosci. 1993 Jun;70(3-4):285-98.

Weissman MM et al (1988) "The epidemiology of anxiety disorders: rates, risks and familial patterns."J Psychiatry Res 1988;22 Suppl 1:99-114 Werntz et al (1983, "Alternating cerebral hemispheric activity and the lateralization of autonomic nervous function. Human Neurobiology 2, 39-43.

Claims

Claims Claim 1: A method and apparatus that when the heartbeat of the user

is detected, it occludes the visual field of one of the user's eyes leaving the other eye exposed to its

own visual field keeping this condition for the whole heart inter-beat period until the

next heartbeat is detected, when the previously occluded visual field becomes exposed

and the previously exposed visual field becomes occluded for the following heart

inter-beat period; and so forth, imposing a pattern of alternating bilateral visual stimulation of the brain in sync with the heart pacemaker while the user remains visually connected with the environment.

Claim 2: A method and apparatus as claimed in Claim 1 that, when the heartbeat of the user is detected, it delivers a single click sound in sync with the heart beat to the ear of the same lateral side of the eye which became exposed to its visual field; hence,

imposing a pattern of alternating bilateral audiovisual stimulation of the brain.

Claim 3: An apparatus as claimed in Claim 1 where the bilateral alternative occlusion and exposure of the eyes to their respective visual fields is achieved by a pair of

glasses worn by the user where lenses are made of liquid crystal shutters that remain opaque when not activated and become translucent when a suitable voltage is applied through them.

Claim 4: An apparatus as claimed in Claim 2 where the bilateral alternative exposure of ears to a clicking sound is achieved by a pair of headphones that deliver the sound into the ear of each channel accordingly.

Claim 5: An apparatus as claimed in Claim 1 and Claim 2 where the heartbeat of the user is detected by means of a peripheral pulse sensor such as a photo-

plethysmographic sensor positioned on a peripheral part of the user's body such as a finger or an ear, or alternately by a suitable pair of electrodes detecting the R wave of the ECG (electrocardiograph) preceding the heartbeat; and where a conventional digital trigger pulse is generated in sync with each heartbeat which is delivered to a processing electronic circuit.

Claim 6: A processing electronic circuit as claimed in Claim 5 with multimodular electronic circuitry, which processes the inputted heartbeat trigger signal into suitable signals to activate the bilateral liquid crystal shutters and the headphone.

Claim 7: A pair of liquid crystal shutter glasses as claimed in Claim 3 with adjustable correcting prism lenses added in front of the shutters to alter the focal angle of each lens in order to allow the user to modify the eye tracking movement necessary to maintain focus after each alternation of visual stimulation.