Visual stimulus pattern presentation paradigm, device, medium, product and adapted system

Abstract

The invention discloses a visual stimulation pattern display normal form, equipment, a medium, a product and an adaptive system, and belongs to the field of brain-computer interfaces. The normal form comprises the steps that at least two stimulation areas are displayed in a display interface, each stimulation area in the at least two stimulation areas at least comprises a peripheral view pattern displayed at a preset frequency, the peripheral view patterns are used for inducing steady-state visual evoked potentials, and different stimulation areas correspond to different stimulation time windows; a silence time window is arranged between every two adjacent stimulation time windows; for each stimulation time window under the current stimulation round, determining a display time period distributed in the current stimulation time window, when the display time period arrives, displaying a central view pattern in the center of the corresponding stimulation area, the display time period being randomly distributed in the current stimulation time window, and displaying the central view pattern in the center of the corresponding stimulation area; the duration of the display period is determined based on the response time of the predetermined component of the subject event-related potential. According to the embodiment of the invention, the number of targets corresponding to the classifiable central view pattern can be increased.

Description

Technical Field

[0001] The present invention relates to the technical field of brain-computer interfaces, and in particular, to a visual stimulus pattern display paradigm, device, medium, product, and adapted system. Background Art

[0002] A steady-state visual evoked potential (SSVEP) brain-computer interface (BCI) is a technology that enables interaction between the brain and external devices based on brain electrical signals evoked by visual stimuli. Specifically, it refers to the stable, frequency-related brain electrical signals generated by the visual cortex of the brain in response to periodic visual stimuli (such as flashing lights), whose frequencies are highly correlated with the stimulus frequencies and have good stability and repeatability.

[0003] Existing steady-state visual evoked potential brain-computer interfaces usually use visual stimulators to generate periodic visual stimuli, such as flashing lights, moving images, etc. However, these visual stimulus paradigms generally have the problem of less encoded content. Summary of the Invention

[0004] The present invention provides a visual stimulus pattern display paradigm, device, medium, product, and adapted system to solve the problem of less encoded content in existing visual stimulus methods.

[0005] According to one aspect of the present invention, there is provided a visual stimulus pattern display paradigm, including:

[0006] Displaying at least two stimulus regions in a display interface, each of the at least two stimulus regions including at least a peripheral visual field pattern displayed at a predetermined frequency, the peripheral visual field pattern being used to evoke steady-state visual evoked potentials, different stimulus regions corresponding to different stimulus time windows, and a silent time window being set between adjacent stimulus time windows;

[0007] For each of the stimulus time windows in the current stimulus round, determining a display period distributed within the current stimulus time window, and when the display period arrives, displaying a central visual field pattern at the center of the corresponding stimulus region, the display period being randomly distributed within the current stimulus time window, the duration of the display period being determined based on the response time of a predetermined component of the subject's event-related potential, and the brightness of the central visual field pattern being greater than the brightness of the peripheral visual field pattern.

[0008] According to another aspect of the present invention, there is provided a steady-state visual potential brain-computer interface system, including a processor, a display device, and an electroencephalogram acquisition device, the processor being configured to perform the following steps:

[0009] At least two stimulation regions are displayed in the display interface, and each of the at least two stimulation regions includes at least a peripheral visual field pattern displayed at a predetermined frequency, the peripheral visual field pattern being used to evoke steady-state visual evoked potentials. Different stimulation regions correspond to different stimulation time windows, and a silent time window is set between adjacent stimulation time windows;

[0010] For each of the stimulation time windows in the current stimulation round, determine the display periods distributed within the current stimulation time window. When the display period arrives, display a central visual field pattern at the center of the corresponding stimulation region. The display periods are randomly distributed within the current stimulation time window, and the duration of the display period is determined based on the response time of a predetermined component of the subject's event-related potential. The brightness of the central visual field pattern is greater than that of the peripheral visual field pattern.

[0011] Obtain the electroencephalogram signals collected by the electroencephalogram acquisition device and determine the visual stimulation recognition result corresponding to the electroencephalogram signals.

[0012] According to another aspect of the present invention, there is provided a visual stimulation pattern display device, the device comprising:

[0013] A first module for displaying at least two stimulation regions in the display interface, and each of the at least two stimulation regions includes at least a peripheral visual field pattern displayed at a predetermined frequency, the peripheral visual field pattern being used to evoke steady-state visual evoked potentials. Different stimulation regions correspond to different stimulation time windows, and a silent time window is set between adjacent stimulation time windows;

[0014] A second module for, for each of the stimulation time windows in the current stimulation round, determining the display periods distributed within the current stimulation time window, and when the display period arrives, displaying a central visual field pattern at the center of the corresponding stimulation region. The display periods are randomly distributed within the current stimulation time window, and the duration of the display period is determined based on the response time of a predetermined component of the subject's event-related potential. The brightness of the central visual field pattern is greater than that of the peripheral visual field pattern.

[0015] According to another aspect of the present invention, there is provided an electronic device, the electronic device comprising:

[0016] At least one processor; and

[0017] A memory communicatively connected to the at least one processor; wherein,

[0018] The memory stores a computer program executable by the at least one processor, and when the computer program is executed by the at least one processor, the at least one processor is enabled to execute the visual stimulus pattern display paradigm according to any embodiment of the present invention.

[0019] According to another aspect of the present invention, there is provided a computer-readable storage medium storing computer instructions for implementing the visual stimulus pattern display paradigm according to any embodiment of the present invention when executed by a processor.

[0020] The technical solution provided by the embodiments of the present invention simultaneously displays at least two stimulation regions on a display interface. Each stimulation region corresponds to a different stimulation time window, and a silent time window is set between adjacent stimulation time windows. A central visual field pattern is used to induce event-related potentials, and a peripheral visual field pattern that flashes at a predetermined frequency is used to induce steady-state visual evoked potentials. In each stimulation time window of the current stimulation round, a display period randomly distributed in the current stimulation time window is determined, and within the display period, the central visual field pattern is highlighted at the center of the corresponding stimulation region. The duration of the display period is determined based on the response time of a predetermined component of the subject's event-related potential. In this way, frequency encoding is completed through the peripheral visual field pattern, and time-domain encoding of different targets is completed by highlighting the central visual field pattern at the center of the corresponding stimulation region within the display periods randomly distributed in each stimulation time window, significantly improving the efficiency of time-domain encoding at a single frequency domain frequency, and at the same time ensuring the accuracy of each target time-domain encoding and visual recognition. The subject only needs to continuously track the central visual field pattern located at the center of different stimulation regions under steady-state visual evoked potentials. For the subject, compared with the existing test process, the test complexity is not increased.

[0021] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present invention, nor is it used to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0023] Figure 1 is a flowchart of the visual stimulus pattern display paradigm according to an embodiment of the present invention;

[0024] Figure 2It is another flowchart of the visual stimulus pattern display paradigm provided by the embodiments of the present invention;

[0025] Figure 3 It is a schematic diagram of the visual stimulus pattern display paradigm provided by the embodiments of the present invention;

[0026] Figure 4 It is another schematic diagram of the visual stimulus pattern display paradigm provided by the embodiments of the present invention;

[0027] Figure 5 It is a schematic structural diagram of a steady-state visual evoked potential brain-computer interface system provided by the embodiments of the present invention;

[0028] Figure 6 It is a schematic structural diagram of a visual stimulus pattern display device provided by the embodiments of the present invention;

[0029] Figure 7 It is a schematic structural diagram of an electronic device for implementing the visual stimulus pattern display paradigm of the embodiments of the present invention. Detailed implementation manners

[0030] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0031] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and do not have to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present invention described here can be implemented in an order different from those illustrated or described here. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0032] Figure 1The flowchart of the visual stimulus pattern display paradigm provided by the embodiments of the present invention is applicable to the situation of automatically generating visual stimulus patterns. This method can be executed by a visual stimulus pattern determination device, which can be implemented in the form of hardware and / or software and can be configured in the processor of an electronic device. As Figure 1 shown, the method includes:

[0033] S110. Display at least two stimulus regions in the display interface. Each stimulus region in the at least two stimulus regions includes at least a peripheral visual field pattern displayed at a predetermined frequency. The peripheral visual field pattern is used to evoke steady-state visual evoked potentials. Different stimulus regions correspond to different stimulus time windows, and a silent time window is set between adjacent stimulus time windows.

[0034] The display interface is provided with at least two stimulus regions. Different stimulus regions correspond to different stimulus time windows. The peripheral visual field patterns of each stimulus region are arranged around the center of the stimulus region, and their predetermined frequencies are used to evoke steady-state visual evoked potentials.

[0035] Each stimulus time window corresponds to a predetermined component. The silent time window should ensure that there is no overlap in the response time ranges of the predetermined components corresponding to adjacent stimulus time windows. Specifically, it is used to isolate the display periods under adjacent two stimulus time windows and separate the neural responses of the central visual field patterns of the stimulus regions corresponding to adjacent two stimulus time windows, so as to avoid the overlap of the predetermined components corresponding to the display periods of adjacent stimulus time windows in the electroencephalogram signal.

[0036] The stimulus time window can be understood as a time range. Therefore, in this embodiment, the start time of the silent time window is the end time of its previous stimulus time window; the end time of the silent time window is the start time of its subsequent stimulus time window.

[0037] In one embodiment, the peripheral visual field pattern is an annular segment, and the center of the circle corresponding to the annular segment is located at the center of the central visual field pattern or the center of the stimulus region; both the width of the annular segment and the corresponding angular range are configurable items. Setting the peripheral visual field pattern as an annular segment can not only ensure the stimulation effect of its steady-state visual evoked potential but also highlight the central visual field pattern.

[0038] Specifically, the peripheral visual field pattern is an annular segment filled with a predetermined color, and the center of the central visual field pattern is at the center of the circle corresponding to the annular segment. The user can adjust the width of the annular segment and the corresponding angular range according to actual needs. Here, the width of the annular segment refers to the distance between the inner and outer arc segments, and the angular range corresponding to the annular segment refers to the central angle of the inner or outer arc segment of the annular segment. The peripheral visual field pattern is used to induce steady-state visual evoked potential signals, and the central visual field pattern is used to induce event-related potential signals, providing a more comfortable user experience on the basis of ensuring that the brain electrical signals can be reliably induced. Because the flicker of the peripheral visual field pattern distributed on the periphery of the central visual field pattern can reduce the flicker feeling of the display interface, helping to relieve the visual fatigue of the subject and thus enhancing the user experience.

[0039] S120. For each stimulation time window in the current stimulation round, determine the display period distributed within the current stimulation time window. When the display period arrives, display the central visual field pattern at the center of the corresponding stimulation area. The display period is randomly distributed within the current stimulation time window, and the duration of the display period is determined based on the response time of the predetermined component of the subject's event-related potential. The brightness of the central visual field pattern is greater than that of the peripheral visual field pattern.

[0040] The peripheral visual field pattern is a fixed pattern, and the presence or absence of the display period has no effect on it. The brightness of the central visual field pattern is greater than that of the peripheral visual field pattern, which can enable the subject to better focus on the central visual field pattern.

[0041] Within the display period randomly distributed in the current stimulation time window, display the central visual field pattern at the center of the corresponding stimulation area. By fixing the stimulation time window corresponding to each stimulation area but not fixing the specific timing of the display period within the stimulation time window, the time coding effect of the central visual field pattern is improved.

[0042] The duration of the display period is determined based on the predetermined component of the subject's event-related unit. Specifically, the duration of the display period is not less than the shortest response time required to induce the predetermined component (such as P1 component, N1 component, etc.) of the subject's event-related potential (ERP), and the durations of all display periods are the same. Specifically, for each predetermined component, determine the corresponding visual response time range by means of multiple attempts, determine the maximum value among all the visual response time ranges corresponding to all predetermined components, and determine the duration of the display period based on this maximum value.

[0043] In one embodiment, the display period is greater than or equal to 150 milliseconds and less than or equal to 250 milliseconds; the window width of the silent time window is greater than 200 ms.

[0044] The display periods in each stimulation time window are randomly distributed within each stimulation time window, but overall follow a uniform distribution. This implementation can ensure that the display of the central visual field pattern in each stimulation area has no fixed period.

[0045] In one embodiment, a trigger signal is randomly generated in the first half of the current stimulation time window, and a mutation pulse signal is generated according to the trigger signal; during the period when the mutation pulse signal is in effect, the central visual field pattern is displayed at the center of the corresponding stimulation area.

[0046] Specifically, the start time of the display period in the current stimulation time window is located in the first half of the current stimulation time window, and the entire display period is within the current stimulation time window. This can ensure the integrity of the display period, thereby ensuring the display duration of the central visual field pattern.

[0047] It can be understood that if the user's visual response is rapid, they can track the central visual field patterns under all stimulation areas in each stimulation round; conversely, they may only track the central visual field patterns under some stimulation areas in each stimulation round.

[0048] In this embodiment, each stimulation area completes frequency encoding through the peripheral visual field pattern, and each stimulation area displays the central visual field pattern within the randomly distributed display period in the corresponding stimulation time window to complete the time encoding of the corresponding central visual field pattern; thus, in one stimulation round, as the display periods in different stimulation time windows arrive, the corresponding stimulation areas display the central visual field pattern; during the process of the subject visually tracking the central visual field patterns in different stimulation areas, corresponding electroencephalogram signals are generated; by processing the electroencephalogram signals, the time window corresponding to the central visual field pattern tracked by the subject can be identified, that is, the number of targets corresponding to the distinguishable central visual field pattern can be identified.

[0049] The technical solution provided by the embodiment of the present invention displays at least two stimulation regions on the display interface. Each stimulation region corresponds to a different stimulation time window, and a silent time window is set between adjacent stimulation time windows. The central visual field pattern is used to evoke event-related potentials, and the peripheral visual field pattern that flashes at a predetermined frequency is used to evoke steady-state visual evoked potentials. In each stimulation time window of the current stimulation round, a display period randomly distributed in the current stimulation time window is determined, and within the display period, the central visual field pattern is highlighted at the center of the corresponding stimulation region. The duration of the display period is determined based on the response time of the predetermined component of the subject's event-related potential. In this way, frequency encoding is completed through the peripheral visual field pattern, and time-domain encoding of different targets is completed by highlighting the central visual field pattern at the center of the corresponding stimulation region within the display periods randomly distributed in each stimulation time window, significantly improving the efficiency of time-domain encoding at a single frequency domain frequency, and at the same time ensuring the accuracy of each target time-domain encoding and visual recognition. The subject only needs to continuously track the central visual field pattern located at the center of different stimulation regions under steady-state visual evoked potentials, and compared with the existing test process, the test complexity is not increased.

[0050] Figure 2 It is a flowchart of the visual stimulus pattern display paradigm provided by the embodiment of the present invention. This embodiment is used to refine the corresponding relationship between the stimulation time window and the stimulation region in the above embodiment. As Figure 2 shown, the method includes:

[0051] S210. Display a first stimulation region and a second stimulation region on the display interface. Both the first stimulation region and the second stimulation region at least include a peripheral visual field pattern displayed at a predetermined frequency. The peripheral visual field pattern is used to evoke steady-state visual evoked potentials. The first stimulation region corresponds to a first stimulation time window, the second stimulation region corresponds to a second stimulation time window, and a silent time window is set between the first stimulation time window and the second stimulation time window.

[0052] In this embodiment, the display interface is provided with two stimulation regions, which are the first stimulation region and the second stimulation region respectively. Among them, the first stimulation region corresponds to the first stimulation time window, and the second stimulation region corresponds to the second stimulation time window. A silent time window is set between the first stimulation time window and the second stimulation time window.

[0053] Exemplarily, the duration of each stimulation round is 3 seconds. The first stimulation time window corresponds to the time range of 0 - 1.2 seconds; the second stimulation time window corresponds to the time range of 1.8 - 3 seconds, and the silent time window is 1.2 - 1.8 seconds.

[0054] S220. For each stimulation time window in the current stimulation round, determine the display time period distributed in the current stimulation time window. When the display time period arrives, display the central visual field pattern at the center of the corresponding stimulation area. The display time period is randomly distributed in the current stimulation time window. The length of the display time period is determined based on the response time of a predetermined component of the subject's event-related potential. The brightness of the central visual field pattern is greater than the brightness of the peripheral visual field pattern.

[0055] When the display period of the first stimulation time window arrives, the central visual field pattern is displayed in the center of the first stimulation area, and in the other periods of the entire stimulation round, the first stimulation area only displays the peripheral visual field pattern; when the display period of the second stimulation time window arrives, the central visual field pattern is displayed in the center of the second stimulation area, and in the other periods of the entire stimulation round, the second stimulation area only displays the peripheral visual field pattern.

[0056] In one embodiment, the display period is implemented in the form of a mutation signal pulse. Specifically, the width of the first mutation signal pulse randomly distributed in the first stimulation time window is used as the display period in the first stimulation time window; the width of the second mutation signal pulse randomly distributed in the second stimulation time window is used as the display period in the second stimulation time window.

[0057] For example, the duration of each stimulation round is 3 seconds. The first stimulation time window corresponds to a time range of 0-1.2 seconds; the second stimulation time window corresponds to a time range of 1.8-3 seconds, and the silent time window is 1.2-1.8 seconds to avoid the time overlap of P1-N1 and other components in the EEG signal. Figure 3 As shown, the horizontal axis is the time axis, the unit is 1 second; the vertical axis is the normalized value of the brightness of the central visual field pattern and the peripheral visual field pattern; the time range of the first mutation signal pulse in the first stimulation time window is 0.25-0.45 seconds, and the time range of the second mutation signal pulse in the second stimulation time window is 1.8-2 seconds. During the effective period of the first mutation signal pulse, the central visual field pattern is displayed in the center of the first stimulation area; during the effective period of the second mutation signal pulse, the central visual field pattern is displayed in the center of the second stimulation area. The brightness of the central visual field pattern remains unchanged during the effective period of the corresponding mutation signal pulse signal; the peripheral visual field pattern flickers at a frequency of 6Hz, and its maximum brightness is half of the central visual field pattern.

[0058] like Figure 4As shown, the first stimulation area is located above the second stimulation area. The corresponding time range of the first mutant signal pulse is 0.3 - 0.5 seconds. Therefore, the first stimulation area displays the central visual field pattern (a white-highlighted circular pattern) and the peripheral visual field pattern (a gray ring segment) during the effective period of the first mutant signal pulse, and only displays the peripheral visual field pattern at other times during the entire stimulation round; the corresponding time range of the second mutant signal pulse is approximately 1.92 - 2.12 seconds. Therefore, the second stimulation area displays the central visual field pattern and the peripheral visual field pattern during the effective period of the second mutant signal pulse, and only displays the peripheral visual field pattern at other times during the entire stimulation round. Moreover, as can be seen from this figure, the brightness of the central visual field pattern is higher than that of the peripheral visual field pattern. The brightness of the central visual field pattern can be set to twice the brightness of the peripheral visual field pattern. The position of the "cross" in this figure is the center of the corresponding stimulation area.

[0059] In the technical solution provided by the embodiment of the present invention, the first stimulation area is bound to the first stimulation time window, and the second stimulation area is bound to the second stimulation time window; the first mutant signal pulse corresponds to the first stimulation time window, and the second mutant signal pulse corresponds to the second stimulation time window; the first stimulation area displays the central visual field pattern and the peripheral visual field pattern during the effective period of the first mutant signal pulse, and only displays the peripheral visual field pattern at other times during the entire stimulation round; the second stimulation area displays the central visual field pattern and the peripheral visual field pattern during the effective period of the second mutant signal pulse, and only displays the peripheral visual field pattern at other times during the entire stimulation round; the technical effect of showing two different time encoding results of the central visual field pattern to the subject through two stimulation areas corresponding to two stimulation time windows respectively is achieved.

[0060] Figure 5 It is a schematic structural diagram of the steady-state visual evoked potential brain-computer interface system provided by the embodiment of the present invention. The system includes a processor 21, a display device 22, and an electroencephalogram acquisition device 23. The processor 21 is configured to perform the following steps:

[0061] S310. Display at least two stimulation areas in the display interface. Each of the stimulation areas in the at least two stimulation areas at least includes a peripheral visual field pattern displayed at a predetermined frequency. The peripheral visual field pattern is used to induce steady-state visual evoked potentials. Different stimulation areas correspond to different stimulation time windows, and a silent time window is set between adjacent stimulation time windows.

[0062] S320. For each of the stimulation time windows in the current stimulation round, determine the display periods distributed within the current stimulation time window. When the display period arrives, display the central visual field pattern at the center of the corresponding stimulation area. The display periods are randomly distributed within the current stimulation time window, and the duration of the display period is determined based on the response time of the predetermined component of the subject's event-related potential. The brightness of the central visual field pattern is greater than the brightness of the peripheral visual field pattern.

[0063] The display device 22 is connected to the processor 21. Under the control of the processor, the display device displays the display interface and the stimulation information in the display interface, such as the stimulation area, the peripheral visual field pattern in the stimulation area, and the central visual field pattern during the effective period of the mutation signal pulse. For the determination methods of the peripheral visual field pattern in the stimulation area and the central visual field pattern during the effective period of the mutation signal pulse, refer to the foregoing embodiments, and this embodiment does not make specific limitations here.

[0064] S330. Obtain the electroencephalogram (EEG) signals collected by the EEG acquisition device, and determine the visual stimulation recognition result corresponding to the EEG signals.

[0065] The EEG acquisition device 23 is used to collect EEG signals and is placed in the visual area of the brain. The EEG acquisition device 23 includes multiple electrodes, such as 9 electrodes, or more electrodes. Taking 9 electrodes as an example, the 9 electrodes are respectively the electrode labeled O1, the electrode labeled O2, the electrode labeled Oz, the electrode labeled Pz, the electrode labeled Poz, the electrode labeled PO3, the electrode labeled PO4, the electrode labeled PO5, and the electrode labeled PO6. The electrodes of the EEG acquisition device can be placed in the visual area of the brain using the existing electrode placement method, and this embodiment does not make specific descriptions here.

[0066] The processor preprocesses the collected EEG signals to obtain the preprocessed EEG signals. The preprocessing includes operations such as time-domain alignment, artifact removal, and feature extraction to enhance the visual evoked signal. A pre-trained recognition model is used to analyze the preprocessed EEG signals to obtain the visual stimulation recognition result. Optionally, the recognition module is a one-dimensional convolutional neural network classification model, which uses independent component analysis to remove eye movement artifacts and extracts frequency band features of 1 - 30 Hz through wavelet transform.

[0067] Specifically, determine the set of EEG signals corresponding to each mutation signal pulse; then preprocess each set of EEG signals to obtain the preprocessed set of EEG signals; then use the pre-trained recognition model to analyze each preprocessed set of EEG signals to obtain the visual stimulation recognition result of each set of EEG signals. The visual stimulation recognition result is used to indicate whether the subject sees the central visual field pattern corresponding to the corresponding mutation signal pulse.

[0068] In one embodiment, for each mutation signal pulse, the EEG signal combination corresponding to the M1 period before the current mutation signal pulse, the EEG signal combination corresponding to the current mutation signal pulse, and the EEG signal combination corresponding to the M2 period after the current mutation signal pulse are taken as the EEG signal set corresponding to the current pulse signal. Among them, M2 is greater than M1. For example, M1 is 200 milliseconds, M2 is 400 milliseconds, and the width of the pulse signal is 200 milliseconds. An averaging processor is used to perform coherent averaging on the EEG signal set corresponding to each mutation signal pulse to enhance the time domain features and extract the joint features of the event-related potential and the problem visual evoked potential.

[0069] The technical solution provided by the embodiment of the present invention is to simultaneously display at least two stimulation areas on the display interface, each stimulation area corresponds to a different stimulation time window, a silent time window is set between adjacent stimulation time windows, a central visual field pattern is used to induce event-related potentials, and a peripheral visual field pattern flashing at a predetermined frequency is used to induce steady-state evoked potentials; in each stimulation time window under the current stimulation round, a display period randomly distributed in the current stimulation time window is determined, and within the display period, the central visual field pattern is highlighted in the center of the corresponding stimulation area, and the duration of the display period is determined based on the response time of the predetermined component of the subject's event-related potential; in this way, frequency encoding is completed through the peripheral visual field pattern, and time domain encoding of different targets is completed by highlighting the central visual field pattern in the center of the corresponding stimulation area within the display period randomly distributed in each stimulation time window, which significantly improves the efficiency of time domain encoding under a single frequency domain frequency, and at the same time can ensure the accuracy of time domain encoding and visual recognition of each target; the subject can continue to track the central visual field pattern located in the center of different stimulation areas under steady-state visual evoked potentials, and for the subject, compared with the existing test process, the complexity of the test is not increased.

[0070] Figure 6 Schematic diagram of the structure of the visual stimulation pattern display device provided by the embodiment of the present invention. Figure 6 As shown, the device comprises:

[0071] The first module 31 is used to display at least two stimulation areas in the display interface, each of the at least two stimulation areas at least includes a peripheral visual field pattern displayed at a predetermined frequency, the peripheral visual field pattern is used to induce steady-state visual evoked potentials, different stimulation areas correspond to different stimulation time windows, and a silent time window is set between adjacent stimulation time windows;

[0072] The second module 32 is configured to determine, for each of the stimulation time windows in the current stimulation round, a display period distributed within the current stimulation time window. When the display period arrives, a central visual field pattern is displayed at the center of the corresponding stimulation area. The display period is randomly distributed within the current stimulation time window, and the duration of the display period is determined based on the response time of a predetermined component of the subject's event-related potential. The brightness of the central visual field pattern is greater than the brightness of the peripheral visual field pattern.

[0073] In one embodiment, the second module 31 is configured to:

[0074] Randomly generate a trigger signal in the first half of the current stimulation time window, and generate a mutation pulse signal according to the trigger signal;

[0075] During the period when the mutation pulse signal is in effect, display a central visual field pattern at the center of the corresponding stimulation area.

[0076] In one embodiment, the display interface displays a first stimulation area and a second stimulation area; the first stimulation area corresponds to a first stimulation time window, and the second stimulation area corresponds to a second stimulation time window; a silent time window is provided between the first stimulation time window and the second stimulation time window.

[0077] In one embodiment, the peripheral visual field pattern is an annular segment, and the center of the circle corresponding to the annular segment is located at the center of the central visual field pattern and the second pattern; both the width of the annular segment and the corresponding angular range are configurable items.

[0078] In one embodiment, the display period is greater than or equal to 150 milliseconds and less than or equal to 250 milliseconds; the window width of the silent time window is greater than 200 ms.

[0079] The technical solution provided by the embodiment of the present invention simultaneously displays at least two stimulation regions on the display interface. Each stimulation region corresponds to a different stimulation time window, and a silent time window is set between adjacent stimulation time windows. The central visual field pattern is used to evoke event-related potentials, and the peripheral visual field pattern that flashes at a predetermined frequency is used to evoke steady-state evoked potentials. In each stimulation time window of the current stimulation round, a display period randomly distributed in the current stimulation time window is determined, and within the display period, the central visual field pattern is highlighted at the center of the corresponding stimulation region. The duration of the display period is determined based on the response time of the predetermined component of the subject's event-related potential. In this way, frequency encoding is completed through the peripheral visual field pattern, and time-domain encoding of different targets is completed by highlighting the central visual field pattern at the center of the corresponding stimulation region within the display period randomly distributed in each stimulation time window, significantly improving the efficiency of time-domain encoding at a single frequency domain frequency, and at the same time ensuring the accuracy of each target time-domain encoding and visual recognition. The subject only needs to continuously track the central visual field pattern located at the center of different stimulation regions under steady-state visual evoked potentials. For the subject, compared with the existing test process, the test complexity is not increased.

[0080] The visual stimulus pattern display device provided by the embodiment of the present invention can execute the visual stimulus pattern display paradigm provided by any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the execution method.

[0081] Figure 7 FIG. shows a schematic structural diagram of an electronic device 10 that can be used to implement the embodiments of the present invention. The electronic device is intended to represent various forms of digital computers, such as, laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the present invention described and / or claimed herein.

[0082] As Figure 7 shown, the electronic device 10 includes at least one processor 11, and a memory communicatively connected to at least one processor 11, such as a read-only memory (ROM) 12, a random access memory (RAM) 13, etc. The memory stores a computer program executable by at least one processor. The processor 11 can execute various appropriate actions and processes according to the computer program stored in the read-only memory (ROM) 12 or the computer program loaded from the storage unit 18 into the random access memory (RAM) 13. In the RAM 13, various programs and data required for the operation of the electronic device 10 can also be stored. The processor 11, the ROM 12, and the RAM 13 are connected to each other through a bus 14. The input / output (I / O) interface 15 is also connected to the bus 14.

[0083] Multiple components in the electronic device 10 are connected to the I / O interface 15, including: an input unit 16, such as a keyboard, a mouse, etc.; an output unit 17, such as various types of displays, speakers, etc.; a storage unit 18, such as a disk, an optical disc, etc.; and a communication unit 19, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 19 allows the electronic device 10 to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0084] The processor 11 can be various general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of the processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. The processor 11 executes the various methods and processes described above, such as the visual stimulus pattern display paradigm.

[0085] In some embodiments, the visual stimulus pattern display paradigm can be implemented as a computer program, which is tangibly contained in a computer-readable storage medium, such as the storage unit 18. In some embodiments, part or all of the computer program can be loaded and / or installed onto the electronic device 10 via the ROM 12 and / or the communication unit 19. When the computer program is loaded into the RAM 13 and executed by the processor 11, one or more steps of the visual stimulus pattern display paradigm described above can be executed. Alternatively, in other embodiments, the processor 11 can be configured to execute the visual stimulus pattern display paradigm in any other suitable manner (e.g., by means of firmware).

[0086] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on a chip (SOCs), complex programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments can include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special or general programmable processor, and can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit the data and instructions to the storage system, the at least one input device, and the at least one output device.

[0087] A computer program for implementing the method of the present invention can be written in any combination of one or more programming languages. These computer programs can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when executed by the processor, the computer programs cause the functions / operations specified in the flowchart and / or block diagram to be implemented. The computer programs can be executed entirely on the machine, partially on the machine, executed partially on the machine and partially on a remote machine as an independent software package, or executed entirely on a remote machine or server.

[0088] In the context of the present invention, a computer-readable storage medium can be a tangible medium that can contain or store a computer program for use by or in connection with an instruction execution system, apparatus, or device. The computer-readable storage medium can include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. Alternatively, the computer-readable storage medium can be a machine-readable signal medium. More specific examples of the machine-readable storage medium would include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination of the foregoing.

[0089] To provide interaction with a user, the systems and techniques described herein can be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and a pointing device (e.g., a mouse or a trackball) through which the user can provide input to the electronic device. Other kinds of devices can also be used to provide interaction with the user; for example, the feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including acoustic input, voice input, or tactile input).

[0090] The systems and techniques described herein can be implemented in a computing system that includes backend components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes frontend components (e.g., a user computer having a graphical user interface or a web browser through which a user can interact with an implementation of the systems and techniques described herein), or a computing system that includes any combination of such backend components, middleware components, or frontend components. The components of the system can be interconnected to each other by digital data communication in any form or medium (e.g., a communication network). Examples of communication networks include: local area network (LAN), wide area network (WAN), blockchain network, and the Internet.

[0091] A computing system can include a client and a server. The client and the server are generally remote from each other and typically interact through a communication network. The client-server relationship is created by computer programs that run on respective computers and have a client-server relationship with each other. The server can be a cloud server, also known as a cloud computing server or a cloud host, which is a host product in the cloud computing service system, solving the defects of difficult management and weak business scalability existing in traditional physical hosts and VPS services.

[0092] An embodiment of the present invention also provides a computer program product, including a computer program which, when executed by a processor, implements the visual stimulus pattern display paradigm provided in any embodiment of the present application.

[0093] In the process of implementing the computer program product, computer program code for performing the operations of the present invention can be written in one or more programming languages or combinations thereof. The programming languages include object-oriented programming languages such as Java, Smalltalk, C++, and also include conventional procedural programming languages such as the "C" language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, executed as a stand-alone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer can be connected to the user's computer through any type of network - including a local area network (LAN) or a wide area network (WAN) - or can be connected to an external computer (e.g., by connecting through the Internet using an Internet service provider).

[0094] It should be understood that the various forms of processes shown above can be used, with steps reordered, added or deleted. For example, the steps recited in the present invention can be executed in parallel, sequentially or in a different order, as long as the desired results of the technical solution of the present invention can be achieved, and no limitation is imposed herein.

[0095] The above specific embodiments do not constitute a limitation on the protection scope of the present invention. Those skilled in the art should understand that various modifications, combinations, sub - combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A visual stimulus pattern display paradigm, characterized in that, Comprising: Displaying at least two stimulation regions in a display interface, each of the at least two stimulation regions at least including a peripheral visual field pattern displayed at a predetermined frequency, the peripheral visual field pattern being used to evoke steady-state visual evoked potentials, different stimulation regions corresponding to different stimulation time windows, and a silent time window being provided between adjacent stimulation time windows; For each of the stimulation time windows in the current stimulation round, determining a display period distributed within the current stimulation time window, and when the display period arrives, displaying a central visual field pattern at the center of the corresponding stimulation region, the display period being randomly distributed within the current stimulation time window, the duration of the display period being determined based on the response time of a predetermined component of the subject's event-related potential, and the brightness of the central visual field pattern being greater than the brightness of the peripheral visual field pattern.

2. The paradigm according to claim 1, wherein The determining the display period distributed within the current stimulation time window and, when the display period arrives, displaying a central visual field pattern at the center of the corresponding stimulation region includes: Randomly generating a trigger signal in the first half of the current stimulation time window, and generating a mutant pulse signal according to the trigger signal; During the period when the mutant pulse signal is in effect, displaying a central visual field pattern at the center of the corresponding stimulation region.

3. The paradigm according to claim 1, wherein The display interface displays a first stimulation region and a second stimulation region; The first stimulation region corresponds to a first stimulation time window, and the second stimulation region corresponds to a second stimulation time window; A silent time window is provided between the first stimulation time window and the second stimulation time window.

4. The paradigm according to claim 1, wherein The peripheral visual field pattern is an annular segment, and the center of the circle corresponding to the annular segment is located at the center of the central visual field pattern or the center of the stimulation region; Both the width of the annular segment and the corresponding angular range are configurable items.

5. The paradigm according to claim 2, wherein The display period is greater than or equal to 150 milliseconds and less than or equal to 250 milliseconds; The window width of the silent time window is greater than 200 ms.

6. A steady-state visually evoked potential brain-computer interface system, comprising a processor, a display device, and an electroencephalogram acquisition device, characterized in that, The processor is configured to perform the following steps: Displaying at least two stimulation regions in a display interface, each of the at least two stimulation regions at least including a peripheral visual field pattern displayed at a predetermined frequency, the peripheral visual field pattern being used to evoke steady-state visual evoked potentials, different stimulation regions corresponding to different stimulation time windows, and a silent time window being provided between adjacent stimulation time windows; For each of the stimulation time windows in the current stimulation round, determining a display period distributed within the current stimulation time window, and when the display period arrives, displaying a central visual field pattern at the center of the corresponding stimulation region, the display period being randomly distributed within the current stimulation time window, the duration of the display period being determined based on the response time of a predetermined component of the subject's event-related potential, and the brightness of the central visual field pattern being greater than the brightness of the peripheral visual field pattern; Obtain the electroencephalogram signal collected by the electroencephalogram acquisition device, and determine the visual stimulus recognition result corresponding to the electroencephalogram signal.

7. A visual stimulus pattern display device, characterized in that, The device includes: A pulse signal module, configured to display at least two stimulus regions in a display interface, each of the at least two stimulus regions includes at least a peripheral visual field pattern displayed at a predetermined frequency, the peripheral visual field pattern is used to induce steady-state visual evoked potentials, different stimulus regions correspond to different stimulus time windows, and a silent time window is set between adjacent stimulus time windows; A display module, configured to, for each of the stimulus time windows in the current stimulus round, determine a display period distributed within the current stimulus time window, and when the display period arrives, display a central visual field pattern at the center of the corresponding stimulus region, the display period is randomly distributed within the current stimulus time window, the duration of the display period is determined based on the response time of the predetermined component of the subject's event-related potential, and the brightness of the central visual field pattern is greater than the brightness of the peripheral visual field pattern.

8. An electronic device, characterized in that, The electronic device includes: At least one processor; and A memory communicatively connected to the at least one processor; wherein, The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the visual stimulus pattern display paradigm according to any one of claims 1-5.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions, and the computer instructions are used to implement the visual stimulus pattern display paradigm according to any one of claims 1-5 when executed by a processor.

10. A computer program product, characterized in that, The computer program product includes a computer program, and the computer program implements the visual stimulus pattern display paradigm according to any one of claims 1-5 when executed by a processor.

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