Brain wave activation device for improving cognitive ability in elderly

Abstract

Provided is a brain wave activation device enabling the improving of cognitive ability in the elderly by using flickering light stimulation (FLS) of visible light. The brain wave activation device modulates the luminance intensity, color, or flicker frequency of FLS according to user so that the greatest change in the power of brain waves is exhibited in response to the FLS, wherein the flicker frequency of the FLS is outputted so as to be reduced as the age of the user increases.

Description

A brainwave activation device that improves cognitive abilities in the elderly

[0001] The present invention relates to a brain wave activation device, and more particularly, to a brain wave activation device that improves cognitive ability of the elderly by using flash light stimulation (FLS) of visible light.

[0002] Brain waves in the human brain are classified into delta rhythm (0.5-4 Hz), theta rhythm (4-8 Hz), alpha rhythm (8-13 Hz), beta rhythm (13-30 Hz), and gamma rhythm (30-100 Hz) according to their frequency bands. Brain waves with each of these unique vibrational frequencies affect different cognitive and behavioral functions. In particular, much research is being conducted on the functional role of brain waves in the gamma rhythm band. It is known that brain waves in the gamma rhythm band are involved in attention, memory, and object recognition, and are involved in both bottom-up and top-down neural regulation.

[0003] However, specific studies using brain waves in the gamma rhythm band to improve cognitive function have not been reported. In Alzheimer's disease (AD), the most prevalent cognitive disorder, reduced gamma rhythm brain waves are observed in patients compared to the general population. However, current treatments for AD are limited to medications, magnetic fields (rTMS), or electrical currents (tDCS). Even these treatments are difficult to control for side effects, are expensive, and have not yet been proven effective, hindering their development.

[0004] The problem to be solved by the present invention is to provide a brain wave activation device that can improve the cognitive ability of the elderly by using flash light stimulation (FLS) of visible light.

[0005] The problems to be solved by the present invention are not limited to the problems mentioned above, and other problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present invention belongs from the description below.

[0006] According to one embodiment of the present invention for achieving the above object, a brain wave activation device is a brain wave activation device for improving cognitive ability, wherein a flickering light stimulus (FLS) that modulates the flickering of visible light is irradiated on a user to activate brain waves in the gamma rhythm band in the human brain through visual stimulation, and the luminance intensity, color, or flickering frequency of the flickering light stimulus (FLS) is modulated according to the user so that the power change of the brain waves is the greatest in response to the flickering light stimulus (FLS), and the flickering frequency of the flickering light stimulus (FLS) is reduced and output as the age of the user increases.

[0007] If the user is a young person aged between 19 and 35, a flashing light stimulus (FLS) with a flashing frequency of 36 to 38 Hz may be output so that the power change of the brain waves is greatest. If the user is an elderly person aged between 60 and 60, a flashing light stimulus (FLS) with a flashing frequency of 32 to 34 Hz ​​may be output so that the power change of the brain waves is greatest.

[0008] In order to make the power change of the brain waves appear the greatest in response to the above-mentioned flashing light stimulus (FLS), the flashing frequency of the flashing light stimulus (FLS) can be output by decreasing as the luminance intensity of the flashing light stimulus (FLS) increases.

[0009] The luminance intensity of the above flashing light stimulus (FLS) is 400 to 700 cd / m 2The color of the flashing light stimulus (FLS) may be red or white, and the flashing frequency of the flashing light stimulus (FLS) may be 32 to 40 Hz.

[0010] Specific details of other embodiments are included in the specific contents and drawings.

[0011] As described above, according to the brain wave activation device of the present invention, brain waves in the gamma rhythm band can be induced efficiently at low cost using a safe visible light band flashing light stimulus (FLS).

[0012] Furthermore, it is expected that induced gamma rhythm-band EEG could be used to prevent Alzheimer's disease by delaying the accumulation of amyloid beta. Furthermore, induced gamma rhythm-band EEG could be used to improve cognitive function in patients with mild cognitive impairment or Alzheimer's disease.

[0013] Additionally, by synchronizing gamma rhythm band brain waves in the brain as a way to enhance entrainment of optimal gamma band brain waves and functional connectivity between brain regions, it can be used to improve perceptual and cognitive functions related to gamma activity, and to prevent and treat Alzheimer's disease.

[0014] In addition, by providing the FLS with different brightness intensity, color, or flickering frequency depending on the user, the entrainment effect and the change in brain wave power in response to the FLS can be maximized. Specifically, in order for the change in brain wave power to be large and for gamma brain wave entrainment to occur well, it is desirable to present the FLS with a reduced flickering frequency in the range of 32 to 40 Hz as the user's age increases. For example, if the user is over 60 years old and belongs to the elderly, white, 700 cd / m 2 It was confirmed that gamma brainwave entrainment occurred best when a flashing light stimulus (FLS) was presented under conditions of 32 Hz.

[0015] In addition, in order for the power change of the brain waves to be large and for gamma brainwave synchronization to occur well, it is desirable to present the flickering frequency of the flickering light stimulus (FLS) by decreasing it within the range of 32 to 40 Hz as the brightness intensity of the flickering light stimulus (FLS) increases.

[0016] In this way, by controlling the modulation conditions of the flashing light stimulus (FLS) to maximize the accompanying effect for the elderly, it can be usefully used for the prevention and treatment of Alzheimer's disease.

[0017] Figure 1 is a schematic diagram showing a brain wave activation device according to one embodiment of the present invention.

[0018] Fig. 2 is a photograph showing an actual implementation example of the brain wave activation device of Fig. 1.

[0019] Fig. 3 is a diagram showing the layout of brain electrodes used as an example in the brain wave measurement unit of Fig. 2.

[0020] FIG. 4 illustrates a method of presenting a flash light stimulus (FLS) of visible light that activates brain waves in the gamma rhythm band according to one embodiment of the present invention.

[0021] Figure 5 shows SSVEP measured by an EEG activation device according to one embodiment of the present invention.

[0022] Figure 6 is a graph measuring the average ERS of SSVEP induced by FLS according to a time window.

[0023] Figure 7 is a graph measuring ERS according to changes in FLS parameters (luminance intensity, color, and extinction frequency).

[0024] Figure 8a is a graph measuring changes in gamma rhythm connectivity after FLS.

[0025] Figure 8b shows the main effect of luminance intensity on the average strength of the parietal-frontotemporal gamma rhythm connection in Figure 8a. Figure 8c shows the main effect of flicker frequency on the average strength of the parietal-frontotemporal gamma rhythm connection in Figure 8a.

[0026] Figure 9a is a graph measuring the center frequency according to the change in the user's age.

[0027] Figure 9b is a graph measuring the center frequency according to changes in luminance intensity.

[0028] The advantages and features of the present invention, and the methods for achieving them, will become clearer with reference to the embodiments described in detail below together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms. These embodiments are provided only to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims. Like reference numerals designate like elements throughout the specification.

[0029] Gamma rhythms (30-100 Hz) play an important role in object perception, visual attention control, word encoding, maintenance of relevant items in working memory, crossmodal semantic matching, and short-term memory retention. In patients with Alzheimer's disease (AD), gamma rhythm responses are delayed and their power is reduced compared to cognitively healthy older adults. Gamma rhythms entrained by flash light stimulation (FLS) increase amyloid endocytosis in microglia in the visual cortex, thereby reducing amyloid burden. Gamma rhythms entrained by FLS reduce amyloid-β protein, a dementia-causing substance, and improve cognitive behavior.

[0030] In the present invention, flickering light stimulation (FLS) induces steady-state oscillations in humans in the frequency range of 1 to 90 Hz. Gamma entrainment using FLS in this frequency range may be a noninvasive method for reducing symptoms of or preventing the onset of Alzheimer's disease (AD) in humans.

[0031] Fig. 1 is a schematic diagram of a brain wave activation device according to one embodiment of the present invention. Fig. 2 is a photograph showing an actual implementation example of the brain wave activation device of Fig. 1. Fig. 3 is a layout diagram of brain electrodes used as an example for the brain wave measurement unit of Fig. 2.

[0032] Referring to FIGS. 1 and 2, the brain wave activation device (100) is a cognitive ability improvement device using light neuromodulation technology, and includes a light source providing unit (10), a brain wave measuring unit (20), and a control unit (30) that controls them.

[0033] The light source providing unit (10) modulates the flickering of visible light that is harmless to the human body to generate a flickering light stimulus (FLS), and irradiates this to the user to activate brain waves in the gamma rhythm band in the human brain through visual stimulation. This flickering light stimulus (FLS) can induce brain waves having a frequency similar to that of the irradiated flickering light stimulus (FLS) by entraining the intrinsic oscillator associated with the human body's behavioral cognitive function. The brain waves having a frequency induced in this way ultimately bring about functional changes. The light source providing unit (10) can induce brain waves in the gamma rhythm band without using a magnetic field or current through the flickering light stimulus (FLS) using visible light. The light source providing unit (10) can provide effective light neurotherapy by utilizing stimulation conditions that maximize entrainment, which is the core of gamma rhythm induction.

[0034] For example, the light source providing unit (10) may be formed of a light-emitting diode (LED), an organic light-emitting diode (OLED), a quantum dot light-emitting device (QD-LED), etc. For example, the light source providing unit (10) may be formed of a pair of OLED panels attached to glasses, and an optical filter may be disposed on the OLED panels to generate a white or red flashing light stimulus (FLS). The OLED panels may be driven by a function generator controlled by a 'LabVIEW' program based on a light stimulus parameter control system. The flashing light stimulus (FLS) may be implemented in the OLED panel as a square wave at 100% modulation depth and 50% duty cycle. The red flash light stimulus (FLS) can have a spectral emission range of 590 to 700 nm, and the white flash light stimulus (FLS) can have a spectral emission range of 440 to 700 nm.

[0035] The light source providing unit (10) modulates at least one of luminance intensity, color, flickering frequency, and stimulation time according to the user so that the power change of the brain waves is the greatest in response to the flickering light stimulus (FLS). Here, the luminance intensity of the flickering light stimulus (FLS) is 400 to 700 cd / m 2 , the color of the flashing light stimulus (FLS) is red or white, and the flashing frequency of the flashing light stimulus (FLS) is 32 to 40 Hz.

[0036] In addition, the light source providing unit (10) can maximize the power change of the brain wave by reducing the flickering frequency of the flickering light stimulus (FLS) and outputting it as the user's age increases. If the user is a young person between 19 and 35 years old, the light source providing unit (10) can output a flickering light stimulus (FLS) with a flickering frequency of 36 to 38 Hz so that the power change of the brain wave appears the greatest. If the user is an elderly person over 60 years old, the light source providing unit (10) can output a flickering light stimulus (FLS) with a flickering frequency of 32 to 34 Hz ​​so that the power change of the brain wave appears the greatest.

[0037] In order to cause the greatest change in brain wave power in response to the flashing light stimulus (FLS), the light source providing unit (10) can output the flashing light stimulus (FLS) by decreasing the flashing frequency of the flashing light stimulus (FLS) as the luminance intensity of the flashing light stimulus (FLS) increases.

[0038] The brainwave measurement unit (20) measures the brainwaves of a human who has been provided with a flashing light stimulus (FLS). For example, the brainwave measurement unit (20) may be formed of an elastic cap having 64 Ag-AgCl electrodes attached according to the international 10-20 system (Easycap, EASYCAP GmbH, Munich, Germany). Fig. 3 is an exemplary diagram showing the arrangement of brain electrodes for brainwave measurement. The brainwave measurement unit (20) measures a human brainwave, i.e., an electroencephalogram (EEG) and a steady-state visual evoked potential (SSVEP), to analyze the effect of the flashing light stimulus (FLS) on a human. The SSVEP is used as an involuntary brainwave characteristic induced by an external stimulus, and is a characteristic of a brain signal induced when a user gazes at a light source emitting at a specific frequency and the corresponding frequency is projected onto the brain.

[0039] Referring to Figure 3, multiple electrodes are evenly placed over the entire scalp using the 10-20 electrode arrangement to measure EEG in response to flashing light stimulation (FLS). The reference electrode is placed at FCz, and the ground electrode is placed on the forehead. Among the multiple electrodes placed, EEG measured at the parietal electrode (Pz) and the frontal electrode (Fz) were used in the experiments. An additional pair of electrodes is attached above and below the left eye to record electromyogram (EMG), and all electrodes are maintained with an impedance of less than 10 kΩ. The recorded EEG signals are amplified and stored using a 24-bit ActiCHamp DC amplifier and a BrainVision Recorder (Brain Products GmbH, Gliching, Germany). The sampling rate is set to 1000 Hz. No online filtering was applied during EEG recording, and stimulus markers were provided by the FLS control system and synchronized with the recording.

[0040] The control unit (30) controls the light source providing unit (10) and the brain wave measuring unit (20).

[0041]

[0042] Hereinafter, an experimental example is described to obtain a causal relationship between a user's age and the optimal parameters (luminance intensity, color, and flicker frequency) of a flashing light stimulus (FLS) for gamma entrainment using an EEG activation device according to one embodiment of the present invention.

[0043]

[0044] <1. Experimental participants>

[0045] Thirty-five subjects (17 men, 18 women, age 70.0 ± 2.4 years) aged 60 years or older without any psychiatric or neurological disorders participated in the experiment. All participants had normal vision and hearing. None had a history of major psychiatric or neurological disorders, including epilepsy. This experiment was approved by the Institutional Review Board (IRB) of Seoul National University Bundang Hospital (IRB No.: B-1809-493-004) and was conducted in accordance with relevant guidelines and regulations.

[0046]

[0047] <2. Presentation method of flashing light stimulus (FLS)>

[0048] Figure 4 illustrates a method for presenting a flash light stimulus (FLS) of visible light that activates brain waves in the gamma rhythm band according to one embodiment of the present invention. Referring to Figure 4, this experiment consists of a 5-minute resting period (rsEEG) for recording resting-state EEG and 4 sessions for recording SSVEP. To control the potential confounding effects of the experimental design, the order of the FLS parameters was randomized, and all intervals between the resting period (rsEEG) and the 4 sessions were set to 3 minutes. Each session was provided with 4 visible light sources (400 cd / m 2 White light, 700cd / m 2 White light, 400cd / m 2 Red light and 700cd / m 2 One randomly selected red light was assigned. Each session consisted of 10 blocks, with a 10-second rest period between each block.

[0049] One block lasts 65 seconds (s). One block consists of 10 trials. One trial consists of one flash light stimulus (FLS) period and one inter-stimulus interval (ISI, hereinafter abbreviated as 'ISI'). The ISI period is a rest period without the flash light stimulus (FLS). At this time, the flash light stimulus (FLS) period is set to 2 seconds (s), and the ISI period can be set to 3-6 seconds (s). That is, the process of providing the flash light stimulus (FLS) for 2 seconds (s), stopping the flash light stimulus (FLS) for 3-6 seconds (s), and then providing the flash light stimulus (FLS) again for 2 seconds (s) can be repeated. Here, the reason for having a resting interval (ISI interval) is to prevent suppression of optic nerve activity due to visual adaptation when multiple flashing light stimuli (FLS) are presented in succession.

[0050] Within a block, the flashing light stimulus (FLS) segments have the same flashing frequency. When changing blocks, the flashing frequency of the FLS segments can be changed. The flashing frequency of the FLS can be selected from one of five frequencies (32 Hz, 34 Hz, 36 Hz, 38 Hz, and 40 Hz). Since each session consists of 10 blocks, each flashing frequency was assigned to two blocks within one session.

[0051]

[0052] <3. Preprocessing and Analysis of Brain Waves>

[0053] In this experimental example, the EEG data measured after providing various conditions of flashing light stimulation (FLS) were preprocessed. All preprocessing procedures were performed using MATLAB (The MathWorks Inc., Natick, MA, USA), EEGLAB, and the BSMART toolbox. The EEG data were filtered using a 1-Hz high-pass finite impulse response (FIR) filter and a 60-Hz notch filter, and then a common mean criterion could be applied. By passing the EEG data through the FIR and notch filters, noise other than the EEG signal is removed. The EEG data can be analyzed using independent component analysis to remove ocular artifacts such as eye blinks.

[0054] After preprocessing, 5-min rsEEG recordings were segmented into 1500-ms epochs, and then 20 aptitude-free epochs were randomly selected. A 4000-ms epoch was acquired from 1000 ms before the onset of each flash light stimulus (FLS) to 1000 ms after the FLS cessation, resulting in 20 4000-ms epochs for each frequency. For spectral Granger causality (sGC) analysis, 1500 ms from 501 to 2000 ms was acquired from each 4000-ms epoch.

[0055] To find the optimal luminance intensity, color, and flicker frequency of FLS for gamma rhythm entrainment with aging, we analyzed the spectral power changes of the EEG induced by FLS using the Event-Related Spectral Perturbation (ERSP) method in each block. The time-frequency spectrum was calculated for each epoch and normalized by dividing it by the mean power of the pre-stimulus interval. For each FLS, the ratio of the 'EEG spectral power' during the FLS to the 'EEG spectral power' during the pre-FLS interval was generated. To obtain the normalized mean spectral power changes induced by the color, luminance intensity, and frequency of a given FLS, the spectral power ratios of the EEG from 20 FLS trials at a given FLS frequency in one session were averaged to generate an event-related desynchronization (ERD) / event-related synchronization (ERSP) value.

[0056] In addition, the time-related changes in the wave spectrum were calculated by averaging the ERSP of 11 consecutive and non-overlapping 250-ms time windows from 250 ms before FLS onset to 2500 ms after FLS onset in each block (T0-T10). The presentation time of the FLS is 2 seconds. This time (2 seconds) is divided into 250-ms units, and the baseline (-250 ms to 0 ms) before the presentation of the FLS is set as T0. In other words, T0 represents the time window before the FLS. Then, the first 250-ms section from the time of presentation of the FLS (0 ms) is set as T1, and the next 250-ms section is set as T2. In this way, the entire time window T1 to T8 during which the FLS is presented is set. The flashing light stimulus was presented continuously between 0 ms and 2000 ms (T1–T8). T9 and T10 represent the time window following the flashing light stimulus (FLS) offset.

[0057] Subsequently, by comparing the ERS between 11 blocks (T0-T10), repeated measures analysis of variance (rmANOVA) with Greenhouse-Geisser non-sphericity correction and Bonferroni post hoc comparisons was used to confirm that FLS entrains the gamma rhythm. The average ERS during FLS (T1-T8) was used in the analysis of the effects of luminance intensity, color, and flash frequency on gamma entrainment. The parietal electrode (Pz) was chosen because the SSVEP of visual stimuli was dominantly observed in the parietal lobe, and the frontal electrode (Fz) was chosen because it is one of the electrodes farthest from the occipital lobe to demonstrate that the gamma rhythm contained in the occipital lobe spreads well throughout the brain. 2 (Luminance: 400 cd / m 2, 700 cd / m 2 ) × 2 (color: white, red) × 5 (flicker frequency: 32 Hz, 34 Hz, 36 Hz, 38 Hz, 40 Hz) design rmANOVA was used to examine the effects of luminance intensity, color, and flicker frequency of FLS on gamma rhythm changes. In addition, the optimal FLS frequency was tested using Student's t-test, and the optimal FLS luminance (400 cd / m) was tested using Mann-Whitney U test between the young elderly group (12 males, 10 females; age 67.9 ± 1.0 years) and the old elderly group (5 males, 8 females; age 71.6 ± 1.8 years). 2 , 700 cd / m 2 ) and colors (white, red) were compared.

[0058]

[0059] <4-1. Experimental Results: Gamma Rhythm Entrainment>

[0060] Figure 5 shows SSVEP measured by an EEG activation device according to one embodiment of the present invention. Specifically, Figure 5(a) shows white, 400 cd / m 2 The SSVEP measured at the parietal electrode (Pz) over time after presentation of a flash light stimulus (FLS) is shown in Figure 5(b) in white, 400 cd / m 2 The SSVEP measured at the prefrontal electrode (Fz) over time after presentation of a flash light stimulus (FLS) is shown in Figure 5(c) in white, 700 cd / m 2 The SSVEP measured at the parietal electrode (Pz) over time after presentation of a flash light stimulus (FLS) is shown in Figure 5(d) under white light, 700 cd / m 2 The SSVEP measured at the prefrontal electrode (Fz) over time after presentation of a flash light stimulus (FLS) is shown in Fig. 5(e) at red, 400 cd / m 2The SSVEP measured at the parietal electrode (Pz) over time after presentation of a flash light stimulus (FLS) is shown in Fig. 5(f) at red, 400 cd / m 2 The SSVEP measured at the prefrontal electrode (Fz) over time after presentation of a flash light stimulus (FLS) of red, 700 cd / m is shown in Fig. 5(g). 2 The SSVEP measured at the parietal electrode (Pz) over time after presentation of a flash light stimulus (FLS) is shown in Fig. 5(h) at red, 700 cd / m 2 The SSVEP measured at the prefrontal electrode (Fz) over time after presentation of a flash light stimulus (FLS) is shown. Figure 6 is a graph measuring the average ERS of the SSVEP induced by the FLS over a time window.

[0061] As shown, the spectral power of steady-state visual evoked potentials (SSVEPs) began to increase at the fundamental and harmonic frequencies of FLS after FLS onset, persisted during FLS, and decreased after FLS offset at both Pz and Fz. The ERD / ERS mean in each time window after FLS onset was positive (ERS), indicating that the spectral power of SSVEPs increased after FLS. The main effect of time window on ERS was significant at both Pz and Fz (F 10, 340 = 170.699, p < 0.001, ηp 2 = 0.834, at Pz; F 10, 340 = 96.205, p < 0.001, ηp 2 = 0.739 at Fz). In both Pz and Fz, ERS during FLS (T1-T9) was higher than ERS before FLS (T0) and after FLS (T10).

[0062]

[0063] <4-2. Experimental Results: The Effect of FLS Luminance Intensity and Color on Gamma Entrainment>

[0064] Figure 7 is a graph measuring ERS according to changes in the parameters (luminance intensity, color, and extinction frequency) of FLS. Specifically, Figure 7(a) shows changes in the luminance intensity of FLS (400 cd / m 2 , 700cd / m 2 ) shows the ERS measured at the parietal electrode (Pz), and Fig. 7(b) shows the change in luminance intensity of FLS (400 cd / m 2 , 700cd / m 2 ) shows the ERS measured at the frontal electrode (Fz) according to the change in the color of the FLS (white, red), and Fig. 7(c) shows the ERS measured at the parietal electrode (Pz) according to the change in the color of the FLS (white, red), and Fig. 7(d) shows the ERS measured at the frontal electrode (Fz) according to the change in the color of the FLS (white, red). Fig. 7(d) shows the ERS measured at the parietal electrode (Pz) according to the change in the blinking frequency of the FLS (32 Hz, 34 Hz, 36 Hz, 38 Hz, 40 Hz), and Fig. 7(f) shows the ERS measured at the frontal electrode (Fz) according to the change in the blinking frequency of the FLS (32 Hz, 34 Hz, 36 Hz, 38 Hz, 40 Hz).

[0065] As shown, the main effect of the luminance intensity of FLS on ERS is Pz(F 1, 34 = 10.536, p = 0.003, ηp 2 = 0.237, Fig. 7a), but was significant in Fz (p = 0.385, ηp 2 = 0.022, was not significant in Fig. 7b). At Pz, 700 cd / m 2 FLS is 400 cd / m 2 It accompanied a stronger SSVEP than FLS (p = 0.003). In contrast, the main effect of FLS color on ERS was Pz (p = 0.955, ηp 2< 0.001, Fig. 7c) and Fz (p = 0.261, ηp 2 = 0.037, Fig. 7d) was not significant in all. The main effect of the flashing frequency of FLS on ERS was Pz(F 4, 136 = 9.584, p < 0.001, ηp 2 = 0.220, Fig. 7e) and Fz (F 4, 136 = 17.453, p < 0.001, ηp 2 = 0.339, Fig. 7f) were significant in both cases. As the flicker frequency of the FLS decreased from 40 Hz to 32 Hz at both Pz and Fz, the fundamental and harmonic responses became stronger. Post hoc comparisons showed that 32 Hz or 34 Hz ​​FLS evoked stronger ERS than 38 Hz or 40 Hz at both Pz (p < 0.05) and Fz (p < 0.01).

[0066] The interaction between the flicker frequency of FLS and the luminance intensity of FLS was Pz (p = 0.781, ηp 2 = 0.012) and Fz (p = 0.907, ηp 2 = 0.007) was not significant in all, whereas the color of FLS was Pz(F 4, 136 = 3.383, p = 0.028, ηp 2 = 0.090) was statistically significant. In red FLS, ERS entrained by 32 Hz FLS was stronger than ERS entrained by 36 Hz or higher FLS (p < 0.05). However, in white FLS, ERS was equally entrained at all flicker frequencies (p > 0.05).

[0067]

[0068] <4-3. Experimental Results: The Effect of FLS Luminance Intensity and Color on the Propagation of Entrained Gamma Rhythm>

[0069] Figure 8a is a graph measuring changes in gamma rhythm connectivity after FLS. The spectral Granger causality (sGC) of this experiment was analyzed from 1953 connections between 63 electrodes, and the t-value of the spectral Granger causality of the occipitoparietal-frontotemporal gamma rhythm connection is presented. The upper left corner of each matrix represents the parietal-frontotemporal connection. Figure 8b shows the main effect of luminance intensity on the mean strength of the parietal-frontotemporal gamma rhythm connection in Figure 8a. Figure 8c shows the main effect of flash frequency on the mean strength of the parietal-frontotemporal gamma rhythm connection in Figure 8a.

[0070] As shown in Figure 8a, the connectivity of gamma rhythm after FLS was significantly increased in both the parieto-occipital-frontotemporal and frontotemporal-parieto-occipital connection edges (p < 0.05).

[0071] In addition, the main effects of the luminance intensity and flicker frequency of the FLS on the parieto-occipital-frontotemporal connection strength were significant (in the case of luminance intensity, F 1, 34 = 15.903, p < 0.001, ηp 2 = 0.319, Fig. 8b; For the blinking frequency, F 4, 136 = 58.469, p < 0.001, ηp 2 = 0.632, Fig. 8c). 700 cd / m 2 The connection accompanied by FLS is 400 cd / m 2 Connections entrained by FLS were stronger than those entrained by FLS (p < 0.001). Connections entrained by 32 Hz FLS or 34 Hz ​​FLS were also stronger than those entrained by FLS above 36 Hz (p < 0.001). However, the main effect of FLS color on connectivity strength was not significant (F 1, 34 = 0.163, p = 0.689, ηp 2= 0.005). All interactions between luminance intensity, color, and flash frequency of FLS on connection strength were not significant (p > 0.185, ηp 2 = 0.030).

[0072]

[0073] <4-4. Experimental Results: Optimal FLS Frequency for Gamma Entrainment Associated with Age>

[0074] When the optimal FLS frequency was compared between younger participants (12 males, 10 females, age 67.9 ± 1.0 years) and older participants (5 males, 8 females, age 71.6 ± 1.8 years) aged 70 years or older, the blink frequency that entrained the strongest gamma rhythm was higher in younger participants than in older participants (33.7 ± 2.8 Hz vs. 32.2 ± 0.6 Hz; t = 2.569, p = 0.017, Cohen's d = 0.533). However, the luminance intensity and color that entrained the strongest gamma rhythm did not significantly differ between young and old participants (for luminance intensity, U = 118.5, p = 0.408, r = 0.209; for color, U = 146.5, p = 0.906, r = 0.024).

[0075] This experiment confirmed that the optimal blink frequency for gamma rhythm entrainment in older adults (hereinafter referred to as “elderly”) was lower than that in younger adults (hereinafter referred to as “young adults”) aged 19 to 35 years. The blink frequency that entrained the strongest and most widespread gamma rhythm was 32 or 34 Hz ​​in older adults, but 36 or 38 Hz in young adults. In older adults, 32 or 34 Hz ​​FLS entrained gamma rhythm about 1.2 times stronger at Pz and about 1.4 times stronger at Fz than 40 Hz FLS. In addition, 32 and 34 Hz ​​FLS entrained gamma rhythm in about 1.3 times more nodes with about twice the intensity as 40 Hz FLS. In contrast, in young adults, 32 Hz FLS entrained gamma rhythms equally well as 40 Hz FLS. These results confirm that the optimal blink frequency for entraining gamma rhythms decreases with age.

[0076] Furthermore, the age-related decrease in the optimal blink frequency for gamma entrainment is attributed to the age-related decrease in the center frequency of the human gamma rhythm. Here, the <center frequency> is the frequency at which the change in brain wave power in response to an external visual stimulus (FLS) is greatest. Here, the change in brain wave power due to an external visual stimulus is defined as the ERS value of the brain wave for 2 seconds during the stimulus presentation, with the brain wave 1 second before the stimulus presentation as the baseline, as in [Mathematical Equation 1].

[0077]

[0078] [Mathematical Formula 1]

[0079] ERS = [(Power during stimulus) - (Power before stimulus presentation)] / (Power before stimulus presentation)

[0080]

[0081] Using data (age, center frequency, luminance intensity) on 35 elderly participants aged 60 years or older and data (age, center frequency, luminance intensity) on 17 young participants aged 19 to 35, we examined the causal relationship between the center frequency of the flashing light stimulus (FLS) and the user's age (the FLS color was limited to white). Figure 9a is a graph measuring the center frequency according to the change in the user's age, and Figure 9b is a graph measuring the center frequency according to the change in luminance intensity. Table 1 below shows the results of a linear regression analysis on age (or luminance intensity) and center frequency.

[0082]

[0083] As shown in Fig. 9a, Fig. 9b and Table 1, it was confirmed that the center frequency decreases as the age of the user (participant) increases. Therefore, in order to show the largest change in brain wave power in response to the flickering light stimulus (FLS), it is desirable to output the flickering frequency of the flickering light stimulus (FLS) by decreasing it as the age of the user increases. In addition, it was confirmed that the center frequency decreases as the luminance intensity increases. Therefore, in order to show the largest change in brain wave power in response to the flickering light stimulus (FLS), it is desirable to output the flickering frequency of the flickering light stimulus (FLS) by decreasing it as the luminance intensity of the flickering light stimulus (FLS) increases.

[0084]

[0085] The aforementioned control unit, system, function unit, module, etc. may be configured as a computer program, for example, by a plurality of program modules implemented by one or more processors stored or loaded on a computer-readable storage medium. In addition, each step mentioned in the flowchart may be implemented as a computer program, a program module, or a computer-executable instruction.

[0086] Although the embodiments of the present invention have been described with reference to the attached drawings, those skilled in the art will appreciate that the present invention can be implemented in other specific forms without altering the technical concept or essential features thereof. Therefore, the embodiments described above should be understood to be illustrative in all respects and not restrictive.

Claims

1. As a brain wave activation device that improves cognitive ability, By irradiating the user with a flickering light stimulus (FLS) that modulates the flashing of visible light, the brain activates the gamma rhythm band brain waves in the human brain through visual stimulation. A brainwave activation device characterized in that the luminance intensity, color, or flickering frequency of the flickering light stimulus (FLS) is modulated according to the user so that the power change of the brainwave is greatest in response to the flickering light stimulus (FLS), and the flickering frequency of the flickering light stimulus (FLS) is reduced and output as the age of the user increases.

2. In paragraph 1, If the user is a young person aged 19 to 35, a flashing light stimulus (FLS) with a flashing frequency of 36 to 38 Hz is output so that the power change of the brain waves is greatest. A brainwave activation device characterized in that it outputs a flashing light stimulus (FLS) having a flashing frequency of 32 to 34 Hz ​​so that the power change of the brainwave is the greatest when the user is 60 years of age or older.

3. In paragraph 1, A brainwave activation device characterized in that the blinking frequency of the blinking light stimulus (FLS) is reduced and outputted as the brightness intensity of the blinking light stimulus (FLS) increases, so that the power change of the brainwave is greatest in response to the blinking light stimulus (FLS).

4. In paragraph 1, The luminance intensity of the above flashing light stimulus (FLS) is 400 to 700 cd / m 2 And, The color of the above flashing light stimulus (FLS) is red or white, A brainwave activation device characterized in that the flickering frequency of the above-mentioned flashing light stimulus (FLS) is 32 to 40 Hz.

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