JP7757641B2 - Memory fixation control device and memory fixation method - Google Patents

Description

The present invention relates to a memory fixation control device and a memory fixation method.

Technology is known that enhances the cognitive domain of a sleeping subject by providing sensory stimulation to the subject (see, for example, Patent Document 1).

Special Publication No. 2021-503339

The technology described in Patent Document 1 provides sensory stimuli regardless of whether the subject's memory has been consolidated, making it difficult to efficiently consolidate memories in the subject. Therefore, there is a need for technology that can efficiently consolidate memories in the subject.

The present invention was made in consideration of the above, and aims to provide a memory consolidation control device and memory consolidation method that can efficiently consolidate memories in subjects.

The memory consolidation control device according to the present invention comprises an acquisition unit that acquires brain activity information indicating the activity state of the subject's brain; a state determination unit that determines the activity state of a specific part of the subject's brain based on the acquired brain activity information; a playback control unit that causes a playback device to play content that stimulates the subject's hearing in accordance with the determination result of the state determination unit; and a memory consolidation determination unit that determines whether the content has been consolidated as a memory.

The memory consolidation method of the present invention includes acquiring brain activity information indicating the activity state of a subject's brain, determining the activity state of a specific region of the subject's brain based on the acquired brain activity information, causing a playback device to play content that stimulates the subject's hearing in accordance with the activity state determination result, and determining whether the content has been consolidated as a memory.

The present invention makes it possible to efficiently consolidate memories in subjects.

FIG. 1 is a schematic diagram showing an example of a memory fixing device according to the present embodiment. FIG. 2 is a functional block diagram showing an example of the memory fixing device according to the present embodiment. FIG. 3 is a diagram showing an example of sleep levels. FIG. 4 is a diagram showing an example of the change over time in the deoxyhemoglobin concentration of a subject. FIG. 5 is a diagram showing an example of the change over time in the sleep level of a subject. FIG. 6 is a flowchart showing an example of the operation of the control device. FIG. 7 is a diagram showing an example of the change over time in the sleep level of a subject. FIG. 8 is a flowchart showing an example of the operation of the control device.

Embodiments of a memory fixation control device and a memory fixation method according to the present invention will be described below with reference to the drawings. Note that the present invention is not limited to these embodiments. Furthermore, the components in the following embodiments include those that are easily replaceable by those skilled in the art, or those that are substantially identical.

FIG. 1 is a schematic diagram showing an example of a memory fixation device 100 according to this embodiment. As shown in FIG. 1, the memory fixation device 100 includes a detection device 10, a setting device 20, a control device (memory fixation control device) 30, a playback device 40, and a stimulus providing device 50.

The detection device 10 detects brain activity information indicating the activity state of the subject's brain. The detection device 10 may be, for example, a measurement device that measures cerebral blood flow based on the principles of fNIRS (functional near-infrared spectroscopy). Note that the detection device 10 is not limited to measurement devices based on the principles of fNIRS; for example, a measurement device that measures brain activity based on the principles of fMRI (functional magnetic resonance imaging), which measures brain activity as brain activity information, may also be used.

The detection device 10 includes, for example, a head-mounted unit 11, multiple optical fiber channels 12, and an information generation unit 13. The head-mounted unit 11 is attached to the subject's head. The optical fiber channel 12 includes an emission optical fiber 12a that emits near-infrared light from a light source (not shown) toward the subject's head, and a light-receiving optical fiber 12b that receives near-infrared light reflected or scattered inside the subject's head and sends it to the information generation unit 13. The optical fibers 12a and 12b are positioned at locations that allow measurement of the Wernicke's area of the subject's brain. Note that the optical fibers 12a and 12b may be positioned at locations that allow measurement of Broca's area in addition to or instead of the Wernicke's area of the subject's brain.

The information generation unit 13 calculates the oxygenated hemoglobin concentration as brain activity information based on the near-infrared light transmitted from the light-receiving optical fiber 12b. The information generation unit 13 may calculate at least one of the deoxygenated hemoglobin concentration and the total hemoglobin concentration as brain activity information, in addition to or instead of the oxygenated hemoglobin concentration. In this embodiment, the brain activity information calculated by the information generation unit 13 is activity information about the Wernicke's area of the subject's brain. The optical fiber 12b and the information generation unit 13 may be connected by wire or wirelessly. The information generation unit 13 may also be built into the head-mounted unit 11.

The setting device 20 inputs setting information for the memory fixing device 100. The setting information includes, for example, information regarding the content to be played back by the playback device 40. The setting device 20 may be an input device such as a keyboard or mouse, or may be a smartphone or tablet with a touch panel.

The control device 30 comprehensively controls the operation of the memory fixing device 100. The control device 30 has a processing device such as a CPU (Central Processing Unit) and a storage device such as RAM (Random Access Memory) or ROM (Read Only Memory).

The playback device 40 plays the first content and the second content under the control of the playback control unit 33. The playback device 40 has, for example, a speaker that outputs sound. The speaker may be, for example, mounted on headphones that can be worn on the subject's head.

The stimulus application device 50 is a device that stimulates a sense other than the subject's hearing. The stimulus application device 50 has, for example, a visual stimulus unit 51 that stimulates the subject's vision, a tactile stimulus unit 52 that stimulates the subject's sense of touch, and an olfactory stimulus unit 53 that stimulates the subject's sense of smell. The visual stimulus unit 51 can be, for example, an eye mask with a light irradiation function. The tactile stimulus unit 52 can be, for example, a glove-type tactile device. The olfactory stimulus unit 53 can be, for example, a device that can spray fragrance components such as air fresheners. The stimulus application device 50 can apply multimodal stimuli to the subject by applying stimuli corresponding to words in the content played on the playback device 40 as stimuli for the vision, touch, and smell.

Next, the configuration of the control device 30 according to this embodiment will be described. Figure 2 is a functional block diagram showing an example of a memory consolidation device 100 according to this embodiment. As shown in Figure 2, the control device 30 has an acquisition unit 31, a state determination unit 32, a playback control unit 33, a stimulation control unit 34, a memory consolidation determination unit 35, and a memory unit 36.

The acquisition unit 31 acquires brain activity information generated by the information generation unit 13 of the detection device 10. The acquisition unit 31 may be configured to have the functions of the information generation unit 13 described above. In other words, the acquisition unit 31 may be configured to directly acquire signals sent from the optical fiber 12b of the detection device 10 and calculate brain activity information. The acquisition unit 31 acquires brain activity information at predetermined intervals.

The state determination unit 32 determines the activity state of a specific region of the subject's brain based on the brain activity information acquired by the acquisition unit 31. The timing at which the state determination unit 32 determines the activity information can be, for example, the same as or corresponding to the timing at which the acquisition unit 31 acquires the brain activity information. In this embodiment, the specific region of the brain is, for example, Wernicke's area. The activity state can be set to two stages: an adaptive state (predetermined state) that is suitable for memory consolidation, or a non-adaptive state that is not suitable for memory consolidation.

Figure 3 shows an example of the change in a subject's oxyhemoglobin concentration over time. When brain cells are active, oxygen molecules are released from the oxyhemoglobin in the blood (deoxidation), converting it to deoxyhemoglobin, and the oxygen molecules produced by deoxidation are transported to brain cells. In other words, a state in which the oxyhemoglobin concentration is low and the deoxyhemoglobin concentration is high can be recognized as a state in which brain cells are actively active and deoxygenation is occurring actively. On the other hand, a state in which the oxyhemoglobin concentration is high and the deoxyhemoglobin concentration is low can be recognized as a state in which deoxygenation is not occurring as actively and brain cells have ample room for activity.

Therefore, as shown in FIG. 3, for example, the state determination unit 32 can determine an adaptive state when the oxyhemoglobin concentration in the Wernicke's area of the brain is equal to or greater than a predetermined threshold A1, and can determine an adaptive state when the oxyhemoglobin concentration in the Wernicke's area of the brain is less than the threshold A1.

The state determination unit 32 may determine the sleep level of the subject. The timing at which the state determination unit 32 determines the sleep level may be the same as or correspond to the timing at which the acquisition unit 31 acquires brain activity information, or may be different from or not correspond to the timing at which the acquisition unit 31 acquires brain activity information.

Figure 4 is a diagram showing an example of sleep levels. As shown in Figure 4, in this embodiment, sleep levels can be set to six levels: level 0 for an awake state (a state that is not asleep), level 1 for REM sleep, level 2 for stage 1 of non-REM sleep, level 3 for stage 2 of non-REM sleep, level 4 for stage 3 of non-REM sleep, and level 5 for stage 4 of non-REM sleep. Note that the sleep level settings are not limited to the above and may be set to, for example, five levels or less or seven levels or more. The state determination unit 32 may determine the sleep level using brain activity information acquired by the acquisition unit 31, or may determine the sleep level using brain waves and heart rate detected by an electroencephalograph or heart rate monitor, or the person's movements and vibrations during sleep detected by a three-axis acceleration sensor or the like.

Based on the determination result of the state determination unit 32, the playback control unit 33 causes the playback device 40 to play content that stimulates the subject's hearing. In this embodiment, the content is, for example, audio set by the subject using the setting device 20, and includes first content containing content to be memorized by the subject, and second content that is different from the first content. Examples of the second content include music related to the content of the first content, music that calms the subject, and advertising audio that appeals to the subject about products and services.

When the state determination unit 32 determines that the sleep level is the first level and that the activity state is an adaptive state, the playback control unit 33 causes the playback device 40 to play the first content as the content. In this embodiment, the first level can be, for example, level 1, when the subject is in REM sleep. During period L (see Figure 4) in the non-adaptive state, the playback control unit 33 controls so that the first content does not play even if the subject's sleep level is the first level. This avoids placing more strain than necessary on brain cells, allowing for efficient memory consolidation in a state where brain cells have room for activity.

When the state determination unit 32 determines that the sleep level is a second level different from the first level, the playback control unit 33 causes the playback device 40 to play the second content as the content. The second level can be a level of sleep that is deeper than the first level. In this embodiment, the second level can be, for example, a level corresponding to stage 1 or stage 2 of non-REM sleep in the subject, i.e., level 2 or level 3. Note that the playback control unit 33 does not need to cause the playback of the second content. For example, when causing the playback device 40 to play audio from an advertisement as the second content, the playback control unit 33 can start playback, for example, a predetermined time after it is determined that the subject's sleep level is at the second level, so as not to hinder the memory retention of the contents of the first content.

After causing the playback device 40 to play the first content, the playback control unit 33 stops the first content if the state determination unit 32 determines that the sleep level is different from the first level or that the subject's brain activity state is not in an adaptive state. Furthermore, after causing the playback device 40 to play the second content, the playback control unit 33 stops the second content if the state determination unit 32 determines that the sleep level is different from the second level.

The playback control unit 33 adjusts the playback mode of the content on the playback device 40 according to the determination result of the memory consolidation determination unit 35, which will be described later. For example, if the determination result of the memory consolidation determination unit 35 is a consolidation state (a state in which memory is consolidated; described later), the playback control unit 33 may switch the content to be played on the playback device 40 from the currently played content (first content for memory) to another content. In this case, the content to be switched to may be another first content previously set by the subject, or the second content. When selecting the content to be switched from multiple types of first content, if the playback order is set by the setting device 20, the playback control unit 33 selects the first content based on the playback order setting. Furthermore, the playback control unit 33 may calculate the comprehension difficulty level based on the amount of language, field, etc. contained in the first content, and select the first content based on the calculated comprehension difficulty level. In this case, the playback control unit 33 may select the first content, for example, in ascending or descending order of comprehension difficulty level. Furthermore, when the determination result of the memory settlement determination unit 35 is an unsettled state (a state in which memory is not settled: described below), the playback control unit 33 may cause the playback device 40 to repeatedly play the currently played content (first content for storage). Furthermore, when the determination result of the memory settlement determination unit 35 is an unsettled state (a state in which memory is not settled: described below), the playback control unit 33 may cause the playback device 40 to repeatedly play the currently played content.

When content is played on the playback device 40, the stimulus control unit 34 causes the stimulus providing device 50 to provide a stimulus to a sense other than the subject's hearing. For example, when first content is played on the playback device 40, the stimulus control unit 34 can cause the stimulus providing device 50 to provide the subject with a stimulus corresponding to a word played on the playback device 40.

Figure 5 shows an example of the correspondence between the types of stimuli provided to the subject and the words played back by the playback device 40. As shown in Figure 5, for example, when the playback device 40 plays back words describing visual conditions such as dazzling, flickering, strong sunlight, afternoon sun, and oncoming vehicle headlights, the stimulus control unit 34 can provide the subject with a visual stimulus via the visual stimulus unit 51. Also, for example, when the playback device 40 plays back words describing tactile conditions such as painful, hot, rough, smooth, and soft, the stimulus control unit 34 can provide the subject with a tactile stimulus via the tactile stimulus unit 52. Also, for example, when the playback device 40 plays back words describing olfactory conditions such as the scent of roses, the scent of Kikuno, the smell of rotten fish, and the smell of soy sauce, the stimulus control unit 34 can provide the subject with an olfactory stimulus via the olfactory stimulus unit 53.

The memory fixation determination unit 35 determines whether the content has been fixed as a memory. In this embodiment, the memory fixation determination unit 35 determines whether the content of the first content for storage set by the setting device 20 has been fixed as a memory. Note that the memory fixation determination unit 35 may also determine whether the content of the second content has been fixed as a memory.

Figure 6 shows an example of the change in oxyhemoglobin concentration over time in a subject's Wernicke's area. It is known that when Wernicke's area can understand the meaning of language, the language can be processed without increased activity in Wernicke's area, resulting in reduced deoxygenation and an increase in oxyhemoglobin concentration. On the other hand, when Wernicke's area cannot understand the meaning of language, deoxygenation is not reduced and oxyhemoglobin concentration does not increase. In other words, a high oxyhemoglobin concentration indicates that Wernicke's area understands the meaning of language and memory has been consolidated. On the other hand, a low oxyhemoglobin concentration indicates that Wernicke's area does not understand the meaning of language and memory has not been consolidated. Therefore, the memory consolidation assessment unit 35 determines that a memory has been consolidated (hereinafter referred to as a "consolidated state") when the oxyhemoglobin concentration in the brain's Wernicke's area is equal to or greater than a predetermined threshold A2, and determines that a memory has not been consolidated (hereinafter referred to as a "non-consolidated state") when the oxyhemoglobin concentration is less than threshold A2. Note that the threshold A2 for the oxygenated hemoglobin concentration in the Wernicke's area of the brain of the subject is assumed to be an adaptive state, so A1 < A2 can be satisfied. In the example shown in FIG. 6 , the memory consolidation assessment unit 35 makes a assessment for each predetermined unit period and determines that the memory is consolidated when the oxygenated hemoglobin concentration is equal to or greater than threshold A2 for at least a portion of the unit period, but this is not limiting. Here, the memory consolidation assessment unit 35 may determine that the memory is consolidated when the deoxygenated hemoglobin concentration in the Wernicke's area of the brain is less than the predetermined threshold, and may determine that the memory is not consolidated when the deoxygenated hemoglobin concentration is equal to or greater than the predetermined threshold.

The memory unit 36 stores various types of information. The memory unit 36 has storage such as a hard disk drive or solid state drive. Note that an external storage medium such as a removable disk may also be used as the memory unit 36. The memory unit 36 stores programs, data, etc. for executing various processes of the acquisition unit 31, state determination unit 32, and playback control unit 33 in the control device 30. The memory unit 36 also stores first content and second content. The memory unit 36 also stores the settings set by the setting device 20.

The storage unit 36 stores a program that causes a computer to execute the following processes: acquire brain activity information indicating the activity state of the subject's brain; determine the activity state of a specific part of the subject's brain based on the acquired brain activity information; play content that stimulates the subject's hearing on the playback device 40 based on the activity state determination results; and determine whether the content has been retained in memory.

Next, we will explain a memory consolidation method using the memory consolidation device 100 configured as described above. The subject wears the head-mounted unit 11 of the detection device 10 on their head and adjusts the position so that the optical fiber channel 12 corresponds to Wernicke's area of the brain. The subject sleeps in this state. Figure 7 is a diagram showing an example of changes in the subject's sleep level over time. In the example shown in Figure 7, the subject's sleep level gradually changes from level 0, which is an awake state, to a deeper sleep state (e.g., level 5), and then repeatedly rises and falls over time.

Detection device 10 irradiates near-infrared light onto the subject's head from optical fiber 12a and sends the near-infrared light received by optical fiber 12b to information generation unit 13. Based on the near-infrared light sent from optical fiber 12b, information generation unit 13 calculates the oxygenated hemoglobin concentration in the Wernicke's area of the subject's brain as brain activity information.

In the control device 30, the acquisition unit 31 acquires the brain activity information generated by the information generation unit 13. The state determination unit 32 determines the subject's sleep level and determines the activity state of specific parts of the subject's brain based on the brain activity information acquired by the acquisition unit 31.

In the example shown in FIG. 7 , at time t1, the state determination unit 32 determines that the subject's sleep level is level 3. In this case, the playback control unit 33 causes the playback device 40 to play the second content C2 as the content. A subject in a level 3 sleep state has their hearing stimulated by the second content played from the playback device 40. For example, if the hearing is stimulated by music related to the content of the first content, memory can be consolidated even in a level 3 or level 4 sleep state. Furthermore, if the hearing is stimulated by music that calms the subject, the subject is put into a calm state, thereby suppressing the accumulation of fatigue. Furthermore, if the hearing is stimulated by advertising audio, the content of a product or service can be efficiently promoted to a subject in a level 3 or level 4 sleep state. After time t1, the determination result of the subject's sleep level remains at level 3 for a certain period of time, and then changes to level 2. During this period, the playback control unit 33 continues playing the second content C2.

Also, at time t2, the state determination unit 32 determines that the subject's sleep level has changed to level 1. In this case, the playback control unit 33 checks whether the state determination unit 32 determines that the subject's activity state is an adaptive state. If the state determination unit 32 determines that the subject's activity state is an adaptive state, playback of the second content C2 is stopped and the playback device 40 plays the first content C1. A subject in REM sleep (level 1 sleep state) has their hearing stimulated by the first content C1 played from the playback device 40. This stimulation causes the content contained in the first content C1 to be memorized in the brain. Note that when the first content C1 is being played, the stimulation control unit 34 may also cause the stimulation device 50 to stimulate a sense other than hearing.

When the first content C1 is played back by the playback device 40, the memory consolidation determination unit 35 determines whether the content of the first content C1 has been consolidated as memory by the subject (whether it is consolidated or not). If the memory consolidation determination unit 35 determines that the content is consolidated, the playback control unit 33 can stop the playback of the first content C1 or change the content of the first content C1 and play it back from the playback device 40. If the memory consolidation determination unit 35 determines that the content is not consolidated, the playback control unit 33 can repeatedly play back the content of the first content C1 on the playback device 40.

Furthermore, during the period L from time t3 to time t4, the state determination unit 32 determines that the subject's activity state is in a non-adaptive state. In this case, the playback control unit 33 stops playback of the first content C1. At time t4, the determination again determines that the subject's activity state is in an adaptive state. In this case, the playback control unit 33 resumes playback of the first content C1.

After playback of the first content C1 is resumed, at time t5, the judgment result of the subject's sleep level changes to level 2. In this case, the playback control unit 33 stops playback of the first content C1 and starts playback of the second content C2. After time t5, the judgment result of the subject's sleep level remains at level 2 for a certain period of time, and then changes to level 3. During this period, the playback control unit 33 continues playback of the second content C2. Furthermore, at time t6, the judgment result of the subject's sleep level changes to level 4. In this case, the playback control unit 33 stops playback of the second content C2.

In this way, the memory consolidation determination unit 35 determines whether the state is consolidated or not, making it easy to determine whether the contents of the first content C1 have been consolidated as memory by the subject. Furthermore, the playback control unit 33 adjusts the playback mode of the content on the playback device 40 according to the determination result of the memory consolidation determination unit 35, so that content can be played according to the consolidation state of the subject's memory. Furthermore, the stimulus control unit 34 causes the stimulus imparting device 50 to impart stimuli to a sense other than the subject's hearing when content is played back from the playback device 40, thereby promoting memory consolidation in the subject.

Figure 8 is a flowchart showing an example of the operation of the control device 30. As shown in Figure 8, the acquisition unit 31 acquires the brain activity information generated by the information generation unit 13 (step S10). The state determination unit 32 determines the subject's sleep level and determines the activity state of a specific part of the subject's brain based on the brain activity information acquired by the acquisition unit 31 (step S20).

If the state determination unit 32 determines that the sleep level is the first level and the activity state is the adaptive state (Yes in step S30), the playback control unit 33 determines whether the second content is being played (step S40). If the playback control unit 33 determines that the second content is being played (Yes in step S40), it stops the playback of the second content (step S50). If the playback control unit 33 determines that the second content is not being played (No in step S40) or has stopped the playback of the second content, it determines whether the first content is being played (step S60). If the playback control unit 33 determines that the first content is not being played (No in step S60), it causes the playback device 40 to play the first content (step S70). If the playback control unit 33 determines that the first content is being played (Yes in step S60), it skips step S70 and performs the processing from step S150 onwards, which will be described later.

If it is determined in step S30 that the sleep level is not at the first level or the activity state is not an adaptive state (No in step S30), the playback control unit 33 determines whether the first content is currently being played (step S80). If it is determined that the first content is currently being played (Yes in step S80), the playback control unit 33 stops the playback of the first content (step S90).

If the playback control unit 33 determines that the first content is not being played (No in step S80) or if playback of the first content has stopped, it determines whether the sleep level determination result is the second level. If the playback control unit 33 determines that the sleep level determination result is the second level (Yes in step S100), it determines whether the second content is being played (step S110). If the playback control unit 33 determines that the second content is not being played (No in step S110), it causes the playback device 40 to play the second content (step S120). If the playback control unit 33 determines that the second content is being played (Yes in step S110), it skips step S120 and ends the process.

If the playback control unit 33 determines that the sleep level is not the second level (No in step S100), it determines whether the second content is currently being played (step S130). If the playback control unit 33 determines that the second content is currently being played (Yes in step S130), it stops the playback of the second content (step S140). If the playback control unit 33 determines that the second content is not currently being played (No in step S130), it skips step S140 and ends the process.

If step S70 has been performed, or if step S60 has been processed as No, the stimulus control unit 34 determines whether the first content played from the playback device 40 contains a predetermined word (step S150). If the stimulus control unit 34 determines that the first content contains a predetermined word (step S150: Yes), it causes the stimulus application device 50 to apply a sensory stimulus corresponding to the word to the subject (step S160). If the stimulus control unit 34 determines that the first content does not contain a predetermined word (step S150: No), it skips the processing of step S160.

If step S160 is performed, or if step S150 returns No, the memory consolidation determination unit 35 determines whether the content of the first content has been consolidated in the subject's memory (consolidated or unconsolidated) (step S170). Depending on the determination result of the memory consolidation determination unit 35, the playback control unit 33 changes at least one of the content being played on the playback device 40 and the playback mode of the content on the playback device 40 (step S180).

If the memory fixation determination unit 35 determines in step S180 that the memory fixation state is established, the playback control unit 33 can perform processing such as stopping playback of the first content, or, if multiple first contents have been set in the setting device 20, playing the next first content.

Furthermore, if the memory fixation determination unit 35 determines in step S180 that the memory fixation state is not fixed, the playback control unit 33 can perform processing such as causing the repeat playback device 40 to play the contents of the first content, or causing the playback of second content that helps understand the contents of the first content. When causing the repeat playback device 40 to play the contents of the first content, the playback speed may be changed, for example, by slowing down the playback speed.

As described above, the control device 30 according to this embodiment includes an acquisition unit 31 that acquires brain activity information indicating the activity state of the subject's brain, a state determination unit 32 that determines the activity state of a specific part of the subject's brain based on the acquired brain activity information, a playback control unit 33 that causes the playback device 40 to play content that stimulates the subject's hearing in accordance with the determination result of the state determination unit 32, and a memory consolidation determination unit 35 that determines whether the content has been consolidated as memory.

The memory consolidation method according to this embodiment also includes acquiring brain activity information indicating the activity state of the subject's brain, determining the activity state of a specific part of the subject's brain based on the acquired brain activity information, causing the playback device 40 to play content that stimulates the subject's hearing in accordance with the activity state determination result, and determining whether the content has been consolidated as a memory.

With this configuration, a determination is made as to whether the content played back from the playback device 40 has been retained in the subject's memory, making it easy to determine whether the content has been retained in the subject's memory, thereby efficiently retaining the memory in the subject.

In the control device 30 according to this embodiment, the playback control unit 33 changes at least one of the content played on the playback device 40 and the playback mode of the content on the playback device 40, depending on the determination result of the memory consolidation determination unit 35. With this configuration, by changing at least one of the content and the playback mode depending on the subject's memory consolidation status, it is possible to allow the subject to efficiently consolidate their memory.

In the control device 30 according to this embodiment, the predetermined state is a state in which the oxygenated hemoglobin concentration in the Wernicke's area of the subject's brain is equal to or greater than the first threshold A1. This configuration allows for efficient memory consolidation according to the activity state of the subject's language center.

In the control device 30 according to this embodiment, the memory consolidation determination unit 35 determines that the content has been consolidated as a memory when the oxyhemoglobin concentration in the Wernicke's area of the subject's brain is equal to or greater than the second threshold A2. With this configuration, it is easy to determine whether the content has been consolidated as a memory in the subject based on the activity state of the subject's language center.

The control device 30 according to this embodiment further includes a stimulus control unit 34 that causes a stimulus application device to apply stimuli to a sense other than the subject's hearing when content is played. This configuration allows the subject to receive multimodal stimuli to senses other than hearing, thereby efficiently solidifying the memory.

The technical scope of the present invention is not limited to the above-described embodiments, and modifications may be made as appropriate without departing from the spirit of the present invention. For example, in the above-described embodiments, level 1 (a state in REM sleep) was used as an example of the first sleep level, but this is not limiting. Note that the first level may be, for example, in addition to or instead of level 1, a level corresponding to stage 1 or stage 2 of non-REM sleep in which the subject is asleep, i.e., level 2 or level 3.

<Modification 1>
Furthermore, when the state determination unit 32 determines the activity state of a predetermined region of the subject's brain, the threshold value of the oxyhemoglobin concentration may be changed depending on the sleep level. For example, when the sleep level corresponding to the first level is high (low alertness), the threshold value of the oxyhemoglobin concentration may be increased, and when the sleep level corresponding to the first level is low (high alertness), the threshold value of the oxyhemoglobin concentration may be decreased. In this way, auditory stimuli can be applied to the subject more easily when the alertness level is high and more carefully when the alertness level is low, thereby reducing the impact on the subject's health.

<Modification 2>
Although the state determination unit 32 can determine whether the subject is in an adaptive state or an unadaptable state based on whether the oxyhemoglobin concentration in the Wernicke's area is greater than or equal to a predetermined value, the difference between the oxyhemoglobin concentration and the deoxyhemoglobin concentration in the Wernicke's area may be used instead of the oxyhemoglobin concentration in the Wernicke's area. That is, the state determination unit 32 determines the subject to be in an adaptive state when the difference between the oxyhemoglobin concentration and the deoxyhemoglobin concentration in the Wernicke's area is greater than or equal to a predetermined value B1, and determines the subject to be in an unadaptable state when the difference between the oxyhemoglobin concentration and the deoxyhemoglobin concentration in the Wernicke's area is less than the predetermined value B1. In this manner, when both the oxyhemoglobin concentration and the deoxyhemoglobin concentration are high, providing an auditory stimulus to the subject effectively reduces the impact on the subject's health without forcing the subject to further supply oxyhemoglobin. Furthermore, by using the difference between the oxygenated hemoglobin concentration and the deoxygenated hemoglobin concentration, a relative value can be obtained, which makes it easier to tolerate individual differences.

<Modification 3>
Although the memory consolidation determination unit 35 determines whether the memory is consolidated or not based on whether the oxyhemoglobin concentration in the Wernicke's area of the brain is equal to or greater than a predetermined threshold, the difference between the oxyhemoglobin concentration and the deoxyhemoglobin concentration in the Wernicke's area of the brain may be used instead of the oxyhemoglobin concentration in the Wernicke's area of the brain. That is, the memory consolidation determination unit 35 may determine that the memory is consolidated when the difference between the oxyhemoglobin concentration and the deoxyhemoglobin concentration in the Wernicke's area of the brain is equal to or greater than a predetermined value B2, and may determine that the memory is not consolidated when the difference is less than the predetermined value B2.

<Modification 4>
Furthermore, although the state determination unit 32 has been exemplified as determining the activity state of Wernicke's area as a predetermined region of the subject's brain, Broca's area may also be included as a predetermined region of the brain. That is, the state determination unit 32 may determine an adaptive state when the oxyhemoglobin concentrations in both Wernicke's area and Broca's area of the brain are equal to or greater than predetermined values (thresholds A1 and C1, respectively), and may determine a non-adaptive state when the oxyhemoglobin concentration in at least one of Wernicke's area and Broca's area of the brain is less than the thresholds A1 and C1, respectively. In this case, the memory consolidation determination unit 35 may determine a memory consolidation state when the oxyhemoglobin concentrations in both Wernicke's area and Broca's area of the brain are equal to or greater than predetermined values (thresholds A2 and C2, respectively), and may determine a memory non-consolidation state when the oxyhemoglobin concentration in at least one of Wernicke's area and Broca's area of the brain is less than the thresholds A2 and C2, respectively.

Note that each of the above modifications can be combined with other modifications.

10...Detection device, 11...Head-mounted unit, 12...Optical fiber channel, 12a, 12b...Optical fiber, 13...Information generation unit, 20...Setting device, 30...Control device, 31...Acquisition unit, 32...Status determination unit, 33...Playback control unit, 34...Stimulation control unit, 35...Memory consolidation determination unit, 36...Memory unit, 40...Playback device, 50...Stimulation device, 51...Visual stimulation unit, 52...Tactile stimulation unit, 53...Olfactory stimulation unit, 100...Memory consolidation device

Claims (6)

an acquisition unit that acquires brain activity information indicating the oxyhemoglobin concentration or the deoxyhemoglobin concentration in the Wernicke's area and the Broca's area of the brain of the subject;
a state determination unit that determines whether an activity state of a predetermined region of the subject's brain is in a predetermined state based on the acquired brain activity information;
a playback control unit that causes a playback device to play content that stimulates the auditory sense of the subject in accordance with a determination result of the state determination unit;
a memory consolidation determination unit that determines whether the content has been consolidated as a memory based on the acquired brain activity information ,
The predetermined state is a state in which the oxygenated hemoglobin concentration in the Wernicke's area of the brain of the subject is equal to or higher than a first threshold.
Memory consolidation control device. The memory fixation control device according to claim 1 , wherein the playback control unit changes at least one of the content played back by the playback device and the playback mode of the content in the playback device, depending on the determination result of the memory fixation determination unit. 3. The memory consolidation control device according to claim 1 , wherein the memory consolidation determination unit determines that the content has been consolidated as a memory when the oxyhemoglobin concentration in the Wernicke's area of the subject's brain is equal to or higher than a second threshold. The memory consolidation control device according to claim 1 , further comprising a stimulus control unit that causes a stimulus applying device to apply a stimulus to a sense other than the sense of hearing of the subject when the content is played back. acquiring brain activity information indicating oxyhemoglobin concentration or deoxyhemoglobin concentration in Wernicke's area and Broca's area of the brain of the subject;
determining whether an activity state of a predetermined region of the subject's brain is in a predetermined state based on the acquired brain activity information;
causing a playback device to play content that stimulates the subject's hearing in accordance with the determination result of the active state;
determining whether the content has been retained as a memory based on the acquired brain activity information ;
The predetermined state is a state in which the oxygenated hemoglobin concentration in the Wernicke's area of the brain of the subject is equal to or higher than a first threshold.
Memory consolidation method. an acquisition unit that acquires brain activity information indicating the oxyhemoglobin concentration or the deoxyhemoglobin concentration in the Wernicke's area and the Broca's area of the brain of the subject;
a state determination unit that determines whether an activity state of a predetermined region of the subject's brain is in a predetermined state based on the acquired brain activity information;
a playback control unit that causes a playback device to play content that stimulates the auditory sense of the subject in accordance with a determination result of the state determination unit;
a memory consolidation determination unit that determines whether the content has been consolidated as a memory based on the acquired brain activity information;
Equipped with
The memory consolidation determination unit determines that the content has been consolidated as a memory when the oxyhemoglobin concentration in the Wernicke's area of the brain of the subject is equal to or greater than a second threshold.
Memory consolidation control device.