A low-awareness closed-loop emotional intervention method and system based on high-frequency steady-state visual evoked potentials

Abstract

The application discloses a low-awareness closed-loop emotional intervention method and system based on high-frequency steady-state visual evoked potentials, and the method comprises the following steps: simultaneously inducing steady-state visual evoked potentials by using high-frequency visual carriers to realize real-time neural monitoring, adjusting the neural oscillation background by low-frequency envelope modulation of the embedded carrier, executing multi-dimensional unconscious intervention in combination with subthreshold emotional stimulation of phase locking, and adaptively adjusting the stimulation strategy based on real-time feedback parameters. The application can complete closed-loop emotional regulation under the condition of low subjective awareness, improve neural feedback consistency and intervention stability, and optimize user experience.

Description

Technical Field

[0001] This invention belongs to the technical fields of brain-computer interface, emotion computing and neurofeedback, and specifically relates to a low-awareness closed-loop emotion intervention method and system based on high-frequency steady-state visual evoked potentials. Background Technology

[0002] Objective monitoring and precise regulation of emotional states are core research directions in the fields of emotion computing and mental health. Currently, related technologies have the following shortcomings in practical applications:

[0003] Emotion assessment relies on subjective reports: Traditional emotion assessment often uses scales, interviews and other methods, which are limited by subjective cognitive bias, social expectation effect and symptom insight. The reliability and validity of the assessment results are unstable and cannot continuously obtain neurophysiological response characteristics related to emotions under the condition of low subjective awareness of users.

[0004] Intervention processes can easily trigger subjective discomfort: Emotional intervention methods, such as exposure therapy, can easily trigger negative reactions such as anxiety and resistance because users can clearly perceive the stimuli, leading to decreased user compliance and limiting clinical application scenarios.

[0005] Neuromodulation lacks individualized closed-loop feedback: Existing neuromodulation techniques such as transcranial electrical stimulation and magnetic stimulation mostly adopt open-loop fixed parameter modes, which cannot dynamically adjust the stimulation strategy based on real-time neurophysiological feedback. The intervention effect varies greatly from person to person, and it is difficult to ensure the comfort of the intervention process.

[0006] The effectiveness of subliminal priming techniques is limited: While existing subliminal visual priming techniques can reduce user awareness, they generally suffer from weak intervention efficacy, short duration of action, and large individual variability in response. The core reason lies in the lack of an active optimization process for the background state of brain neural oscillations, resulting in insufficient consistency of neural responses induced by subliminal stimuli, thus limiting the stability and sustainability of the intervention process.

[0007] In addition, existing research has confirmed that high-frequency steady-state visual evoked potential (SSVEP) signals contain decodeable emotion-related neural response features, but they are currently only applied to passive emotion monitoring scenarios and have not yet formed a complete technical solution integrating real-time monitoring, neural optimization, subthreshold intervention and closed-loop feedback. Summary of the Invention

[0008] The main objective of this invention is to overcome the shortcomings and deficiencies of the prior art and provide a low-awareness closed-loop emotion intervention method and system based on high-frequency steady-state visual evoked potentials. Under conditions of low user subjective awareness, it can achieve real-time monitoring of emotion-related neural states, dynamic optimization of neural oscillation background, and closed-loop regulation of subthreshold cognitive stimulation, thereby improving the stability, effectiveness, and user comfort of emotion intervention.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] In a first aspect, the present invention provides a low-awareness closed-loop emotion intervention method based on high-frequency steady-state visual evoked potentials, comprising the following steps:

[0011] Collect users' resting-state EEG data to establish individual real-time baseline, target accommodation range, and individual alpha peak frequency parameters;

[0012] A high refresh rate display system presents users with periodically flashing visual stimuli, induces steady-state visual evoked potentials, collects EEG signals in real time and extracts characteristic parameters of steady-state visual evoked potentials, and assesses the user's emotion-related neural response status.

[0013] Closed-loop regulation is initiated when the deviation of the neural response state from the individual's immediate baseline or target adjustment range continuously meets the preset threshold condition.

[0014] While maintaining a high-frequency visual carrier, the carrier amplitude is envelope-modulated at a low-frequency Alpha band based on the individual Alpha peak frequency to adjust the user's neural oscillation background state.

[0015] Real-time tracking of the phase information of low-frequency envelopes, implanting subthreshold emotional intervention stimuli at preset target phase points, and adding masking stimuli after the stimuli are presented;

[0016] Based on real-time collected EEG signal feedback, the envelope modulation parameters and subthreshold stimulation parameters are dynamically adjusted until the user's neural response state is stably maintained within the target regulation range, thus completing closed-loop regulation.

[0017] As a preferred technical solution, the initial value of the modulation depth of the envelope modulation is 1%, and the dynamic adjustment upper limit is no more than 5%.

[0018] As a preferred technical solution, the subthreshold emotion intervention stimulus is divided into a non-targeted priming mode and a targeted extinction mode:

[0019] In the non-directional initiation mode, a positive induction symbol is presented;

[0020] In the targeted extinction mode, user-defined conditional stimulus cues are presented;

[0021] The presentation duration of the subthreshold emotion intervention stimulus is 4ms to 33ms, and the masking stimulus is a high spatial frequency masking map with a presentation duration of not less than 100ms.

[0022] As a preferred technical solution, once the neural response state is stably maintained within the target regulation range, the envelope modulation depth and the subthreshold stimulation presentation frequency are gradually reduced according to a preset step size, smoothly fading out to pure monitoring mode.

[0023] Secondly, the present invention also provides a low-awareness closed-loop emotion intervention system based on high-frequency steady-state visual evoked potentials, which is applied to the aforementioned low-awareness closed-loop emotion intervention method based on high-frequency steady-state visual evoked potentials, including a visual stimulus presentation module, an EEG signal acquisition module, and a processing and control module.

[0024] The visual stimulus presentation module is used to present visual stimulus signals to the user; the electroencephalogram (EEG) signal acquisition module is used to acquire the user's EEG signals in real time; the processing and control module is communicatively connected to the visual stimulus presentation module and the EEG signal acquisition module respectively.

[0025] The processing and control module controls the visual stimulus presentation module to output a high-frequency visual carrier wave higher than the visual perception threshold to induce the user to generate steady-state visual evoked potentials; the processing and control module extracts the characteristic parameters of steady-state visual evoked potentials from the collected EEG signals and evaluates the user's emotion-related neural response status by combining the individual's instantaneous baseline and target accommodation interval.

[0026] When the neural response state deviates from the preset conditions, the processing and control module, while maintaining the high-frequency visual carrier, performs low-frequency Alpha band envelope modulation on the carrier amplitude to adjust the user's neural oscillation background state; and according to the phase information of the low-frequency envelope, triggers the visual stimulus presentation module to implant subthreshold emotional intervention stimulation at the preset target phase point.

[0027] The processing and control module dynamically adjusts the envelope modulation parameters and subthreshold stimulation parameters based on the real-time acquired EEG signals until the user's neural response state returns to the target regulation range, forming a closed-loop emotion regulation.

[0028] As a preferred technical solution, the characteristic parameters of the steady-state visual evoked potential include at least one of signal-to-noise ratio, power spectral density, and time-frequency characteristics.

[0029] As a preferred technical solution, the frequency range of the low-frequency Alpha band is 8-13Hz, the initial value of the modulation depth of the envelope modulation is 1%, and the upper limit of dynamic adjustment does not exceed 5%.

[0030] As a preferred technical solution, the subthreshold emotion intervention stimulus includes two modes: non-targeted priming stimulus and targeted extinction stimulus;

[0031] The non-targeted priming stimulus is a positive induction symbol with standardized valence; the targeted extinction stimulus is a user-defined conditioned stimulus cue image.

[0032] As a preferred technical solution, the presentation duration of the subthreshold emotional intervention stimulus is 4ms-33ms; the visual stimulus presentation module immediately presents a high spatial frequency masking map with a duration of not less than 100ms after the presentation of the subthreshold emotional intervention stimulus.

[0033] As a preferred technical solution, the processing and control module is preset with individual offset threshold and target offset threshold, and adopts a continuous time window consistency judgment mechanism. The closed-loop adjustment program is triggered only when the offset condition of the neural response state is continuously met within a continuous preset number of time windows.

[0034] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0035] (1) This invention utilizes the same high-frequency visual carrier to simultaneously realize SSVEP neural monitoring and low-frequency neural oscillation modulation. Compared with traditional systems where monitoring and stimulation modules are independent, this reduces timing errors and additional stimulation interference caused by module switching, and improves the consistency and real-time performance of closed-loop neural feedback.

[0036] (2) The present invention embeds low-frequency Alpha envelope modulation into high-frequency steady-state visual carrier, which reduces the subjective perception significance of low-frequency brightness fluctuations while maintaining SSVEP induction capability, reduces the interference of neural modulation process on user visual experience, and improves the comfort of the system during long-term operation.

[0037] (3) The present invention combines high-frequency steady-state stimulation, low-depth envelope modulation and subthreshold visual stimulation presentation mechanism, so that neural regulation and emotional intervention can be performed under low subjective awareness conditions. Compared with explicit exposure intervention, it significantly reduces the user's subjective sensitivity and resistance to the intervention process.

[0038] (4) The present invention controls the timing of the presentation of subthreshold stimuli based on the phase information of the low-frequency envelope, so that the visual intervention material can be accurately presented in the preset neural oscillation stage, which improves the consistency and repeatability of closed-loop stimulation timing control and enhances the stability of the intervention effect.

[0039] (5) Based on real-time neural feedback parameters, individual instantaneous baseline and target adjustment range, the present invention dynamically adjusts the envelope modulation depth, stimulus presentation frequency and subthreshold stimulus density, so that the closed-loop adjustment process has individualized adaptation and dynamic self-optimization characteristics. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 This is a flowchart of a low-awareness closed-loop emotion intervention method based on high-frequency steady-state visual evoked potentials, as described in an embodiment of the present invention.

[0042] Figure 2 This is a schematic diagram of high-frequency steady-state stimulation and low-depth envelope modulation in an embodiment of the present invention;

[0043] Figure 3 This is a time-series diagram illustrating non-directional unconscious intervention in an embodiment of the present invention;

[0044] Figure 4 This is a schematic diagram of targeted unconscious intervention according to an embodiment of the present invention;

[0045] Figure 5 This is a schematic diagram of the structure of a low-awareness closed-loop emotion intervention system based on high-frequency steady-state visual evoked potentials, according to an embodiment of the present invention. Detailed Implementation

[0046] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative effort are within the scope of protection of the present application.

[0047] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0048] Please see Figure 1 This embodiment provides a low-awareness closed-loop emotion intervention method based on high-frequency steady-state visual evoked potentials, including the following steps:

[0049] Individual baseline calibration: Collect users' resting-state EEG data to establish individual real-time baselines, target accommodation intervals, and individual alpha peak frequency parameters;

[0050] S1. Real-time neural monitoring: The system presents periodically flashing visual stimuli to the user through a high refresh rate display system, induces steady-state visual evoked potentials, collects EEG signals in real time and extracts characteristic parameters of steady-state visual evoked potentials, and assesses the user's emotion-related neural response status.

[0051] The system first performs individualized calibration. High-frequency carrier stimulation is presented on a high refresh rate display terminal (e.g., 120 to 240 Hz), while the EEG acquisition module records the user's resting-state EEG for 2 minutes. The EEG acquisition module preferably uses a multi-channel EEG device with a sampling rate of at least 500 Hz, with acquisition electrodes placed in the occipital visual cortex region, including leads O2, O1, and O2.

[0052] This can be explained by the system displaying a 60Hz constant-amplitude high-frequency carrier wave on a 240Hz refresh rate display terminal. The user's individual alpha peak frequency (IAPF, e.g., 10.5Hz) is determined through the EEG acquisition module.

[0053] At this point, the feature extraction basis is as follows: the algorithm calculates the signal-to-noise ratio (SNR) or power spectral density (PSD) of the 60Hz SSVEP in real time using FFT or convolutional neural networks, and constructs an individualized neural state assessment parameter V to characterize SSVEP response changes related to emotional state. Timing alignment between the display module and the EEG acquisition module is achieved via TTL trigger signals.

[0054] Statistical analysis: The system begins calculating the mean V value μ every 30 seconds. base and standard deviation σ base .

[0055] In addition to the immediate individual baseline, the system can further establish a target regulation interval. The target regulation interval is used to represent the target neural response range corresponding to the expected emotion regulation direction, and it can be generated based on user historical data, standardized group neural response templates, public emotion EEG databases, or pre-trained models.

[0056] Determine the optimal resonance point: Extract the alpha peak frequency (IAPF, e.g., 10.5 Hz) of the individual user and set it as the "optimal resonance point" for subsequent envelope modulation.

[0057] S2, Closed-loop regulation trigger: When the deviation of the neural response state from the individual's immediate baseline or target regulation range continuously meets the preset threshold condition, closed-loop regulation is initiated.

[0058] The system calculates the degree of deviation of the real-time neural feedback parameters relative to the individual's immediate baseline and target adjustment range.

[0059] In the specific implementation process, the real-time neural feedback parameter is set to V. real Individual instantaneous baseline is μ base The center value of the target adjustment interval is μ target The corresponding standard deviations are σ base With σ target Then the system can calculate separately:

[0060] Individual offset:

[0061]

[0062] Target offset:

[0063]

[0064] The system dynamically calculates the closed-loop triggering conditions based on the magnitude, duration, and trend of the offset.

[0065] Furthermore, to reduce the impact of blinking, motion artifacts, and environmental noise on real-time neural feedback parameters, the system employs a continuous time window consistency determination mechanism. Only when the offset condition is continuously met within a preset number of continuous time windows does the system confirm the existence of a persistent neural response offset and send a trigger signal to the control module, automatically switching to closed-loop adjustment mode.

[0066] When D base When the value remains consistently above a first preset threshold, the system determines that the user's current neural response state fluctuates significantly relative to the immediate baseline; when D target When the value remains above the second preset threshold, the system determines that the current state deviates from the target adjustment range.

[0067] The first preset threshold and the second preset threshold are closed-loop control parameters set based on the statistical fluctuation range:

[0068] In some embodiments, a first preset threshold is used to characterize the degree of abnormal deviation of the real-time neural feedback parameters relative to the individual instantaneous baseline, and its preferred range is 1–3 times the standardized fluctuation unit; a second preset threshold is used to characterize the degree of deviation of the real-time neural feedback parameters relative to the target adjustment range, and its preferred range is 0.5–2 times the standardized fluctuation unit.

[0069] The threshold can be dynamically adjusted based on individual user differences, historical neural feedback data, system sensitivity requirements, or closed-loop adjustment stages.

[0070] S3. Neural Background Optimization: While maintaining a high-frequency visual carrier, the carrier amplitude is envelope-modulated at a low-frequency Alpha band based on the individual Alpha peak frequency to adjust the user's neural oscillation background state.

[0071] Based on the user's individualized neurophysiological characteristics, the system automatically extracts the user's individual alpha peak frequency (IAPF) from the EEG.

[0072] Specifically, while maintaining a high-frequency monitoring carrier (e.g., 60Hz), the system initiates a low-frequency envelope modulation process, such as... Figure 2 As shown:

[0073] Synthesizing composite stimulus signals using amplitude modulation techniques:

[0074]

[0075] Where C(t) is the high-frequency monitoring carrier, f m To determine the individualized optimal resonant frequency, the modulation depth m is initially set to 1% and dynamically adjusted based on the deviation of the real-time neural feedback parameters from the individual instantaneous baseline and target adjustment range, with the upper limit preferably not exceeding 5%. Due to the low modulation depth m and high carrier frequency, the brightness fluctuations generated by low-frequency envelope modulation are, in most cases, below the level of subjective and significant perception by the user, thereby reducing the interference of the low-frequency neural adjustment process on the user's visual experience.

[0076] During envelope modulation, the system continuously collects high-frequency SSVEP response changes and returns real-time neural feedback parameters to the control module for dynamic adjustment of the timing and intensity of subsequent subthreshold stimulation presentation.

[0077] S4. Phase Locking Intervention: Real-time tracking of the phase information of the low-frequency envelope, implanting subthreshold emotional intervention stimuli at the preset target phase point, and adding masking stimuli after the stimulus is presented.

[0078] In summary, step S4 can be performed as follows:

[0079] S41. Before the system enters the closed-loop control procedure, first execute the configuration steps:

[0080] (1) Non-targeted intervention model (universal emotion regulation):

[0081] Applicable scenarios: Users aiming to relieve daily psychological stress or optimize their overall mood.

[0082] Technical Implementation: The system automatically loads a pre-set positive material library. The material library contains a set of positive induction symbols (such as pleasant faces, positive natural landscapes, etc.) that have been standardized and valence-rated, used to regulate the user's overall emotional neural response state by utilizing the emotional priming effect.

[0083] (2) Targeted Extinction Intervention Model:

[0084] Applicable scenarios: Users aim to overcome specific fears (such as snakes, spiders) or negative emotional reactions related to bed.

[0085] Technical implementation: such as Figure 4 As shown, users can actively upload conditioned stimulus (CS+) image cues associated with their specific negative emotions (the cues include, but are not limited to, specific feared objects, associated scenes, or symbols) through the configuration interface. The system loads this custom material into the targeted extinction unit, preparing to perform targeted desensitization.

[0086] S42. Intervention Implementation:

[0087] (1) Phase locking: The algorithm tracks the phase of the low-frequency envelope modulation signal generated in step S3 in real time. When the envelope waveform is at a preset target phase, the visual material is triggered to be presented; the target phase can be set according to the individualized calibration results. In some embodiments, the target phase is preferably the phase near the peak of the envelope waveform.

[0088] like Figure 3 As shown, the same modulated visual signal performs two functions simultaneously: the 60Hz high-frequency component is responsible for inducing SSVEP and achieving real-time neural monitoring; the 10Hz low-frequency envelope is responsible for modulating alpha neural oscillations and optimizing the neural background. This design eliminates the need for two separate stimulation channels, achieving multi-frequency information superposition within a single visual presentation channel. This reduces the time synchronization requirements between multiple stimulation channels, improving the consistency of stimulus presentation and system efficiency. The low-frequency sine wave in the figure has clear phase characteristics (peak, trough, rising edge, falling edge). Subthreshold stimulation is precisely delivered at the preset target phase (usually the peak, corresponding to the rhythmic window of highest neural excitability), ensuring that each stimulus acts on the optimal phase of the neural oscillation, improving the consistency and repeatability of the intervention effect.

[0089] It's worth explaining that, to illustrate the principle of the "low-perception" characteristic, this embodiment magnifies the modulation depth in the diagram. Because the flickering of the high-frequency carrier itself is extremely weak, the brightness fluctuations resulting from the low-depth envelope are minimal, typically below the subjective perception threshold of the human eye. The combination of these two factors achieves the effect of "hiding neural modulation signals within the high-frequency carrier," thus presenting a brightness change that is almost imperceptible to the user.

[0090] (2) Instantaneous presentation of materials: If it is a non-directional priming mode: present instantaneous visual materials (such as happy faces) with a duration not exceeding the user's individual perception threshold, preferably 4ms–33ms. Utilize the priming effect to regulate the user's current emotion-related neural response state. Adopt a low-density triggering mode, and perform a small number (e.g., no more than 5 times) of discrete pulse interventions in a single intervention.

[0091] For targeted extinction: For users with specific phobias, a pre-defined phobia cue map (CS+) is presented, and the intensity of the conditioned negative association response is reduced through "low-perceived salience repetitive exposure." Specifically, multiple "stimulus-mask" units are triggered consecutively within the intervention period. Each unit contains a CS+ material flash (preferably 4ms–33ms) not exceeding the user's individual perception threshold, followed by masking. A single intervention task typically includes 30 to over 100 repetitive flashes.

[0092] (3) Weak Perception State Protection Mechanism: After the intervention material is presented, the system immediately follows with a high spatial frequency masking image (such as a high-frequency noise image, a Mondrian image, or a complex mosaic masking texture) with a presentation duration of more than 100ms. The visual post-masking effect is used to physically block the intervention material from entering the user's subjective consciousness, thereby reducing the user's subjective perception of the intervention stimulus.

[0093] S5. Dynamic Adaptive Adjustment: Based on real-time collected EEG signal feedback, the envelope modulation parameters and subthreshold stimulation parameters are dynamically adjusted until the user's neural response state is stably maintained within the target adjustment range, thus completing closed-loop adjustment.

[0094] The system continuously monitors the real-time neurofeedback parameter V during the intervention. real Furthermore, the closed-loop adjustment strategy is dynamically optimized by combining individual real-time baseline and target adjustment range.

[0095] (1) Steady-state determination mechanism: When V is detected real When the system continuously moves closer to the target adjustment range or returns to the preset steady-state range, it determines that the current neural response state is stabilizing. In practical applications, the following criteria can be used for this determination:

[0096]

[0097] in: Adjust the center value of the target interval; The target adjustment range is the fluctuation range; These are the preset sensitivity parameters.

[0098] (2) Dynamic adjustment mechanism: If the real-time neural feedback parameters do not continuously change towards the target adjustment range, the system will dynamically adjust the closed-loop adjustment parameters, including but not limited to:

[0099] Increase the presentation density of low-awareness priming (e.g., reduce the presentation cycle from once every 10 seconds to once every 3 seconds).

[0100] Adjust the envelope modulation depth m;

[0101] (3) Fade-out mechanism: When the system confirms that the real-time neural feedback parameters are stably maintained within the target adjustment range, the system gradually reduces the envelope modulation intensity m and the subthreshold stimulation presentation frequency according to the preset step size, and finally returns to the pure monitoring mode, thereby completing a closed-loop adjustment process.

[0102] It should be noted that, for the sake of simplicity, the aforementioned method embodiments are all described as a series of actions. However, those skilled in the art should understand that the present invention is not limited to the described order of actions, because according to the present invention, some steps can be performed in other orders or simultaneously.

[0103] Based on the same idea as the low-awareness closed-loop emotion intervention method based on high-frequency steady-state visual evoked potentials in the above embodiments, the present invention also provides a low-awareness closed-loop emotion intervention system based on high-frequency steady-state visual evoked potentials. This system can be used to execute the above-described low-awareness closed-loop emotion intervention method based on high-frequency steady-state visual evoked potentials. For ease of explanation, the structural schematic diagram of the embodiment of the low-awareness closed-loop emotion intervention system based on high-frequency steady-state visual evoked potentials only shows the parts related to the embodiments of the present invention. Those skilled in the art will understand that the illustrated structure does not constitute a limitation on the device, and may include more or fewer components than illustrated, or combine certain components, or have different component arrangements.

[0104] Please see Figure 5 In another embodiment of this application, a low-awareness closed-loop emotion intervention system 10 based on high-frequency steady-state visual evoked potentials is provided. The system includes a visual stimulus presentation module 11, an electroencephalogram (EEG) signal acquisition module 12, and a processing and control module 13.

[0105] The visual stimulus presentation module 11 is used to present visual stimulus signals to the user; the EEG signal acquisition module 12 is used to acquire the user's EEG signals in real time; the processing and control module 13 is communicatively connected to the visual stimulus presentation module 11 and the EEG signal acquisition module 12 respectively.

[0106] The visual stimulus presentation module 11 uses a display terminal with a refresh rate of no less than 240Hz to present periodically flashing visual stimulus signals, envelope modulation signals, and subthreshold intervention stimuli to the user through a high refresh rate display system. The display terminal is placed directly in front of the user, with the viewing distance controlled within the range of 50-70cm.

[0107] The EEG signal acquisition module 12 employs a multi-channel EEG acquisition device with a sampling rate of no less than 500Hz. Electrodes are positioned in the occipital visual cortex region, including at least three leads: Oz, O1, and O2. Reference electrodes are placed on both earlobes, and grounding electrodes are placed at the FPz position on the forehead. This module is used to acquire the user's EEG signals in real time and transmit the raw signals to the processing and control module.

[0108] The processing and control module 13 adopts an embedded processor or a host computer computing unit, and has built-in signal preprocessing algorithm, feature extraction algorithm, closed-loop control logic and stimulus generation unit. It is used to perform core functions such as EEG signal analysis, neural state assessment, closed-loop trigger determination, stimulus parameter generation and dynamic adjustment.

[0109] The processing and control module 13 controls the visual stimulus presentation module to output a high-frequency visual carrier wave higher than the visual perception threshold to induce the user to generate steady-state visual evoked potentials; the processing and control module 13 extracts the characteristic parameters of steady-state visual evoked potentials from the collected EEG signals and evaluates the user's emotion-related neural response status by combining the individual's instantaneous baseline and target adjustment range.

[0110] When the neural response state deviates from the preset conditions, the processing and control module 13, while maintaining the high-frequency visual carrier, performs low-frequency Alpha band envelope modulation on the carrier amplitude to adjust the user's neural oscillation background state; and according to the phase information of the low-frequency envelope, triggers the visual stimulus presentation module to implant subthreshold emotional intervention stimulation at the preset target phase point.

[0111] The processing and control module 13 dynamically adjusts the envelope modulation parameters and subthreshold stimulation parameters based on the real-time collected EEG signals until the user's neural response state returns to the target regulation range, forming a closed-loop emotion regulation.

[0112] The core working principle of this system is as follows:

[0113] The processing and control module generates a high-frequency visual carrier signal to control the visual stimulus presentation module for display, thereby inducing steady-state visual evoked potentials (SSVEPs) in the user's visual cortex. In this embodiment, the high-frequency visual carrier frequency is set to 60Hz, which is higher than the subjectively sensitive frequency band of the human eye to flickering stimuli. This can effectively induce SSVEP while reducing the subjective salience of visual flicker.

[0114] The EEG signal acquisition module acquires the user's EEG signals in real time and transmits them to the processing and control module. After filtering and artifact removal preprocessing the raw EEG signals, the processing and control module extracts characteristic parameters such as the signal-to-noise ratio (SNR) and power spectral density (PSD) of the SSVEP signal through Fast Fourier Transform (FFT) or time-frequency analysis algorithms to construct an emotion-related neural response assessment index V.

[0115] The processing and control module pre-stores the user's individual instantaneous baseline parameters and target adjustment range. The system calculates the offset of the current neural response evaluation index V relative to the individual instantaneous baseline and target adjustment range in real time, and uses a continuous time window consistency judgment mechanism for trigger determination. Only when the offset exceeds the preset threshold for three consecutive time windows (each window lasting 1 second) does the system determine that the neural state has a persistent offset, and automatically start the closed-loop adjustment program, which can effectively avoid false triggers caused by instantaneous interference such as blinking and motion artifacts.

[0116] After initiating closed-loop regulation, the processing and control module, while maintaining a 60Hz high-frequency carrier, performs sinusoidal envelope modulation of the carrier's brightness amplitude in the low-frequency alpha band. The reference frequency for envelope modulation is the user-individualized Alpha Peak Frequency (IAPF), ranging from 8-13Hz, extracted during the initial calibration phase. The initial modulation depth of the envelope modulation is set to 1%, meaning the brightness fluctuation amplitude is 1% of the base brightness; subsequent adjustments are made dynamically based on neural feedback effects, with an upper limit of 5%. Due to the low modulation depth and high carrier frequency, this brightness fluctuation is below the user's subjective perception threshold in most cases. This allows for the regulation of the brain's low-frequency neural oscillation background without interfering with the user's visual experience, optimizing neural excitability and improving the consistency of subsequent subthreshold stimulus-induced responses.

[0117] During envelope modulation, the processing and control module tracks the phase information of the low-frequency envelope waveform in real time. When the waveform reaches the preset target phase (preferably the peak phase in this embodiment), the visual stimulus presentation module is triggered to implant subthreshold emotional intervention stimulation.

[0118] This system supports two intervention modes:

[0119] (1) Non-directional priming mode: suitable for daily mood relief and stress regulation. The system loads a library of positive induction symbols with standardized valence assessment, including materials such as pleasant faces and positive natural landscapes. The stimulus presentation duration is set to 16.7ms (corresponding to the single frame duration of a 240Hz display), which is below the subjective awareness threshold of most users. Immediately after the stimulus presentation, a 120ms high spatial frequency masking image (such as Mondrian pattern, high-frequency noise texture) is displayed to block the stimulus from entering subjective consciousness through the post-masking effect, further reducing awareness. This mode adopts a low-density triggering strategy, presenting no more than 5 discrete stimuli in a single intervention cycle.

[0120] (2) Targeted Extinction Mode: Suitable for targeted desensitization of specific fears or negative emotions. Users can upload custom conditioned stimulus cues (CS+) images in advance, such as specific fear objects, associated scenes, etc. The system executes high-density repetitive pulse sequences during the intervention period. Each intervention contains 30-100 "stimulus-mask" units. Through repeated exposure with low perceived salience, the intensity of the conditioned negative response associated with the target stimulus is gradually reduced.

[0121] During the intervention, the system continuously monitors changes in SSVEP characteristic parameters and dynamically optimizes the envelope modulation depth and subthreshold stimulus presentation density based on the adjustment progress of the neural response. Once the neural response assessment index V remains stable within the target adjustment range for a preset duration, the system gradually reduces the envelope modulation depth and stimulus presentation frequency according to a preset step size, smoothly transitioning back to the pure high-frequency carrier monitoring mode, thus completing a full closed-loop emotion regulation cycle.

[0122] It should be noted that the low-awareness closed-loop emotion intervention system based on high-frequency steady-state visual evoked potentials of the present invention corresponds one-to-one with the low-awareness closed-loop emotion intervention method based on high-frequency steady-state visual evoked potentials of the present invention. The technical features and beneficial effects described in the embodiments of the low-awareness closed-loop emotion intervention method based on high-frequency steady-state visual evoked potentials are all applicable to the embodiments of the low-awareness closed-loop emotion intervention method based on high-frequency steady-state visual evoked potentials. For details, please refer to the description in the embodiments of the method of the present invention, which will not be repeated here. This is hereby declared.

[0123] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0124] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A low-awareness closed-loop emotion intervention method based on high-frequency steady-state visual evoked potentials, characterized in that, Includes the following steps: Collect users' resting-state EEG data to establish individual real-time baseline, target accommodation range, and individual alpha peak frequency parameters; A high refresh rate display system presents users with periodically flashing visual stimuli, induces steady-state visual evoked potentials, collects EEG signals in real time and extracts characteristic parameters of steady-state visual evoked potentials, and assesses the user's emotion-related neural response status. Closed-loop regulation is initiated when the deviation of the neural response state from the individual's immediate baseline or target adjustment range continuously meets the preset threshold condition. While maintaining a high-frequency visual carrier, the carrier amplitude is envelope-modulated at a low-frequency Alpha band based on the individual Alpha peak frequency to adjust the user's neural oscillation background state. Real-time tracking of the phase information of low-frequency envelopes, implanting subthreshold emotional intervention stimuli at preset target phase points, and adding masking stimuli after the stimuli are presented; Based on real-time collected EEG signal feedback, the envelope modulation parameters and subthreshold stimulation parameters are dynamically adjusted until the user's neural response state is stably maintained within the target regulation range, thus completing closed-loop regulation.

2. The low-awareness closed-loop emotion intervention method based on high-frequency steady-state visual evoked potentials according to claim 1, characterized in that, The initial value of the envelope modulation modulation depth is 1%, and the dynamic adjustment upper limit is no more than 5%.

3. The low-awareness closed-loop emotion intervention method based on high-frequency steady-state visual evoked potentials according to claim 1, characterized in that, The subthreshold emotion intervention stimuli are divided into non-targeted priming mode and targeted extinction mode: In the non-directional initiation mode, a positive induction symbol is presented; In the targeted extinction mode, user-defined conditional stimulus cues are presented; The presentation duration of the subthreshold emotion intervention stimulus is 4ms to 33ms, and the masking stimulus is a high spatial frequency masking map with a presentation duration of not less than 100ms.

4. The low-awareness closed-loop emotion intervention method based on high-frequency steady-state visual evoked potentials according to claim 1, characterized in that, Once the neural response state is stabilized within the target regulation range, the envelope modulation depth and subthreshold stimulus presentation frequency are gradually reduced according to a preset step size, smoothly fading out to pure monitoring mode.

5. A low-awareness closed-loop emotion intervention system based on high-frequency steady-state visual evoked potentials, characterized in that, The low-awareness closed-loop emotion intervention method based on high-frequency steady-state visual evoked potentials, as described in any one of claims 1-4, includes a visual stimulus presentation module, an EEG signal acquisition module, and a processing and control module. The visual stimulus presentation module is used to present visual stimulus signals to the user; the electroencephalogram (EEG) signal acquisition module is used to acquire the user's EEG signals in real time; the processing and control module is communicatively connected to the visual stimulus presentation module and the EEG signal acquisition module respectively. The processing and control module controls the visual stimulus presentation module to output a high-frequency visual carrier wave higher than the visual perception threshold to induce the user to generate steady-state visual evoked potentials; the processing and control module extracts the characteristic parameters of steady-state visual evoked potentials from the collected EEG signals and evaluates the user's emotion-related neural response status by combining the individual's instantaneous baseline and target accommodation interval. When the neural response state deviates from the preset conditions, the processing and control module, while maintaining the high-frequency visual carrier, performs low-frequency Alpha band envelope modulation on the carrier amplitude to adjust the user's neural oscillation background state. Based on the phase information of the low-frequency envelope, the visual stimulus presentation module is triggered to implant subthreshold emotional intervention stimuli at a preset target phase point. The processing and control module dynamically adjusts the envelope modulation parameters and subthreshold stimulation parameters based on the real-time collected EEG signals until the user's neural response state returns to the target regulation range, forming a closed-loop emotion regulation.

6. The low-awareness closed-loop emotion intervention system based on high-frequency steady-state visual evoked potentials according to claim 5, characterized in that, The characteristic parameters of the steady-state visual evoked potential include at least one of the following: signal-to-noise ratio, power spectral density, and time-frequency characteristics.

7. The low-awareness closed-loop emotion intervention system based on high-frequency steady-state visual evoked potentials according to claim 5, characterized in that, The frequency range of the low-frequency Alpha band is 8-13Hz, and the initial value of the modulation depth of the envelope modulation is 1%, with a dynamic adjustment upper limit not exceeding 5%.

8. The low-awareness closed-loop emotion intervention system based on high-frequency steady-state visual evoked potentials according to claim 5, characterized in that, The subthreshold emotion intervention stimuli include two modes: non-targeted priming stimuli and targeted extinction stimuli. The non-targeted priming stimulus is a positive induction symbol with standardized valence; the targeted extinction stimulus is a user-defined conditioned stimulus cue image.

9. The low-awareness closed-loop emotion intervention system based on high-frequency steady-state visual evoked potentials according to claim 8, characterized in that, The presentation duration of the subthreshold emotional intervention stimulus is 4ms-33ms; the visual stimulus presentation module immediately presents a high spatial frequency masking map with a duration of not less than 100ms after the presentation of the subthreshold emotional intervention stimulus.

10. The low-awareness closed-loop emotion intervention system based on high-frequency steady-state visual evoked potentials according to claim 8, characterized in that, The processing and control module is preset with individual offset threshold and target offset threshold, and adopts a continuous time window consistency judgment mechanism. The closed-loop adjustment program is triggered only when the offset condition of the neural response state is continuously met within a continuous preset number of time windows.

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