ANALYZING BRAIN FUNCTIONING USING BEHAVIORAL EVENT MARKERS FROM PORTABLE ELECTRONIC DEVICE
20220230757 · 2022-07-21
Assignee
Inventors
Cpc classification
A61B5/6898
HUMAN NECESSITIES
A61B5/1123
HUMAN NECESSITIES
G16H50/30
PHYSICS
International classification
Abstract
A method of monitoring a user's neuronal activity (10) includes recording a user's behavioural output with a portable electronic device, such as a mobile cellphone. The user's behavioural output (14) is compared (18) with predefined behavioural outputs associated with known event-related neuronal activations (20). The user's event-related neuronal activation (22) is determined based upon the comparison so as to provide an indication of the user's neuronal activity.
Claims
1. A method of monitoring a user's neuronal activity, the method comprising recording a user's behavioural output with a portable electronic device, such as a mobile cellphone, comparing the user's behavioural output with predefined behavioural outputs associated with known event-related neuronal activations; and determining the user's event-related neuronal activation based upon the comparison so as to provide an indication of the user's neuronal activity.
2. The method of claim 1, comprising recording a plurality of behavioural outputs of the user; and using the plurality of behavioural outputs to determine the neuronal activity of the user.
3. The method of claim 1, comprising determining the user's neuronal activity over a period of time, sequentially, to identify a development in the user's neuronal activity.
4. The method of claim 1, comprising associating the user's neuronal activity with one or more of: physical wellbeing; mental wellbeing; physical development/s; mental development/s; treatment; disease; diagnosis.
5. The method of claim 1, comprising comparing the user's behavioural output with an event-related neuronal activation matching a pattern associated with a behavioural output recorder with known patterns to identify an event-related neuronal activation; and the known patterns are previously established using a neuronal recorder.
6. The method of claim 1, wherein the method comprises compiling a database of a plurality of neuronal activities and corresponding behavioural outputs.
7. The method of claim 6, wherein the method comprises compiling the database in advance of performing the monitoring of the user's neuronal activity.
8. The method of claim 6, wherein the method comprises pattern matching of behavioural output with neuronal activity to enable identification of one of behavioural output or neuronal activity based on only one of the other of neuronal activity or behavioural output.
9. The method of claim 6, wherein the database enables the identification of neuronal activity based solely on recording or observing behavioural output, without requiring direct neuronal recording.
10. The method of claim 1, wherein the method does not comprise synchronising the behavioural output recorder and the neuronal activity recorder.
11. The method of claim 1, wherein the method comprises the asynchronous recording of behavioural output and neuronal activity.
12. The method of claim 1, wherein the event-related neuronal activation is associated with a provision of an input towards the portable electronic device.
13. The method of claim 12, wherein the input comprises one or more of: a gesture; a touch; a sound input, such as voice command; a sequence; a series.
14. The method of claim 1, wherein the method comprises a method of diagnosis, the user comprising a patient.
15. The method of claim 1, wherein the monitoring comprises assessing the user's cognitive function.
16. A non-transitory computer readable carrier medium carrying computer readable code to carry out the method of claim 1.
17. A computer program product executable on a processor so as to implement the method of claim 1.
18. A non-transitory computer readable medium loaded with the computer program product of claim 17.
19. A processor arranged to implement the method of claim 1.
20. A system comprising the portable electronic device of claim 1 any and a computer program product executable on a processor.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0035]
[0036]
[0037]
[0038]
[0039]
DETAILED DESCRIPTION
[0040]
[0041]
[0042] In at least some examples, the method comprises recording a plurality of behavioural outputs of the user; and using the plurality of behavioural outputs to determine the neuronal activity of the user. The method comprises determining the user's neuronal activity over a period of time, sequentially, to identify a development in the user's neuronal activity. The method comprises associating the user's neuronal activity with one or more of: physical wellbeing; mental wellbeing; physical development/s; mental development/s; treatment; disease; diagnosis. The method comprises comparing the user's behavioural output with an event-related neuronal activation matching a pattern associated with a behavioural output recorder with known patterns to identify an event-related neuronal activation; and the known patterns are previously established using a neuronal recorder. The method comprises compiling a database of a plurality of neuronal activities and corresponding behavioural outputs. It will be appreciated that the method comprises compiling the database in advance of performing the monitoring of the user's neuronal activity, such as with the method as shown in
[0043] As will be described in more detail below, the event-related neuronal activation is associated with a provision of an input towards the portable electronic device. The input comprises one or more of: a gesture; a touch; a sound input, such as voice command; a sequence; a series. In at least some examples, the method comprises a method of diagnosis, the user comprising a patient. Similarly, in at least some examples (potentially overlapping examples), the monitoring comprises assessing the user's cognitive function. For example, cognitive tasks may involve the processing of salient information regardless of the modality used for the inputs. The MP of an individual may be depressed by an increased cognitive load with no overt motor impact. Emotionally laden stimuli may depress MP related signals. Accordingly, assessment of the behavioural output (via the input to the device) may provide indications of the user's cognitive function.
[0044]
[0045] As used herein, the term “smartphone related potential” or SmRP preferably means one or more, preferably all, of the following: the readiness potential (“RP”), the motor potential (“MP”), the reafferent potential (“RAP”) of the brain of an individual, the consecutive post movement sensory processing involving the tactile, visual, frontal & parietal electrodes.
[0046] The method involves comparing the smartphone related potential (“SmRP”) of an individual's touchscreen events with the rapid engagement of distinct cortical processes of the individual surrounding the events.
[0047] Initially, SmRP is measured prior to and following any touchscreen event by the individual. For this purpose, EEG signals of the individual are measured while the individual is engaged in spontaneous right-handed (thumb) touchscreen touches on his/her own smartphone to reveal the neuronal activity surrounding the touchscreen event. The population median of inter-touch intervals of the analyzed events can be 2 s (a 700 ms inter-touch interval cutoff can be used to eliminate the fast touchscreen events). It is estimated that the EEG signal population average to capture the statistically significant deviations from a 1 s long baseline starting at 4 s prior to the touch. A flat recording can persist for up to 704 ms prior to the touch and the earliest signal can be detected at the right parietal and occipital electrodes (
[0048] Then, SmRP is measured after a touchscreen event by the individual. With the touchscreen event, the signals over the sensorimotor cortex can begin to reverse from the negativity. The bilateral negative components over the parietal and occipital electrodes, which can develop prior to the touch, can peak in the first 100 ms after the touch (
[0049] The variations in the amplitude of the negative sensorimotor signal detected before the touch between different individuals shows that the pre-touch negativity can be correlated with the post-touch activity. The pre-touch activity can be correlated almost exclusively over the parietal & occipital electrodes. The higher the amplitude of pre-touch activity the larger is the positive component over the parietal and occipital electrodes between 200-600 ms.
[0050] The effect on pre-touch neuronal activity of an individual between social and non-social Apps is also measured. Apart from measuring the brain signals of the individual, the thumb flexion and the extension of the thumb of the individual are also preferably measured, preferably by using bend sensor recordings (see e.g. “a” of
[0051] The effects of ‘air touches’ on SmRP is also measured. In this regard, while individuals are using their smartphone, their thumbs generally are at times flexed towards the screen without resulting in any touchscreen event (
[0052] The SmRP prior to an “air touch” is also compared to the SmRP prior to an actual touch, starting from 680 ms prior to the touch (
[0053] It has been found, by this method, that touchscreen movements by an individual are rapidly prepared and that the crucial decision by the individual to touch or not to touch the screen of a smartphone can occur with movement initiation. The first consistently visible signals before the touchscreen event are detected over the frontal and parietal (and occipital) electrodes about 700 ms before the touchscreen event, while the thumb was already extended to descend towards the screen at .sup.˜600 ms before the touch. Such frontal-parietal signals seen prior to dominant negativity over the sensorimotor cortex are associated with visuomotor attention and response selection. This suggests that neuronal activity precedes the movements by only 100 ms-20× faster than the 2 s preparatory time observed in slow laboratory finger tapping tasks. However, an extended thumb does not always lead to a touchscreen event and such an event is accompanied with a distinct positive component over the sensorimotor cortex starting at .sup.˜700 ms prior to the ‘air touch’. Therefore, the decision process underlying a touchscreen event and the motor control processes can be highly compressed in time on the smartphone. Although screen touches separated by 2 s are common, more rapid are frequent, separated by less than 500 ms (median).
[0054] It has also been found that the pre-touch negativity over the sensorimotor cortex is depressed when engaged in social Apps compared to the non-social Apps. This difference is apparent from .sup.˜500 ms prior to the touch up to .sup.˜100 ms after the touch, even when any contribution of motor amplitude fluctuations are regressed out at the level of individual trials. This suggests that the sensorimotor computations remain connected to the behavioural context through much of the ongoing action.
[0055] The SmRP potentials, measured by this method, suggest the following. Firstly, a touch is followed by continued negativity over the contralateral sensorimotor cortex and enlargement of the negativity bilaterally to occupy the parietal and occipital electrodes. These signals most likely reflect action monitoring and tactile-visual confirmation of the touchscreen event. Secondly, there is a positive component that sequentially recruited the anterior to the posterior electrodes. This pattern of activity and the signal latency is consistent with the P3 (P300) component which reflects the attention and memory-related brain. This wave is commonly observed in cognitive tasks involving the processing of salient information regardless of the modality used for the inputs. The neuronal generators underlying this signal likely inhibit extraneous information flow and thus enhance the flow of information from an attention-grabbing input from the frontal to the parietal cortical structures to ‘sharpen memory. The post-touch cognitive processing may, in fact, be shaped by the pre-touch sensorimotor activity, as the amplitude of the sensorimotor signals recorded prior to the touch was correlated to the post-touch activity over the parietal and occipital electrodes.
[0056] Accordingly, it can be seen that patterns matching behavioural output with neuronal activity can be identified. Such patterns can be stored in a database. For example, particular touches associated with particular smartphone functions can be matched to particular neuronal activities. These patterns can then be used, such as in the method of
[0057] The measured SmRP of the brain of an individual can be compared with standard measured values of SmRPs of brains of other individuals when the other individuals use, particularly with the other individual's thumbs, touch screens of smartphones. From this comparison, one can readily analyse one or more of the individual's wellbeing, health, preferences, predilections, fears, biases, loyalties and the like.
[0058] It will be appreciated that the method can be we can include estimates of ‘accuracy’ of alignment, and optionally distinguish outcomes in healthy and diseased individuals. It will also be appreciated that the exact detailed shape of the SmRP may be refined. For example, further peaks and valleys may be revealed or identified as the database 20 grows. In at least some examples, the coarse features as shown here may remain stable but the finer features may be altered.
[0059] With over 20% of the global population on smartphones, the touchscreen movements are one of the most common actions and yet one of the simplest in appearance. Understanding how these actions are generated can not only reveal fundamental insights into how the brain engages in complex behavior but also offers a new avenue to measure brain functions relevant to the real world.
[0060] Also in accordance with this invention, a system is provided for analyzing a functioning of neuronal circuits of a brain of an individual, which circuits are engaged in the individual's voluntary, self-paced motor control of a button press with a finger, the system comprising: a smartphone with a touch screen; an apparatus for scanning the brain of the individual to measure the SmRP of the brain of the individual when the individual uses, particularly with the individual's thumb, the touch screen of the smartphone; and means for comparing the measured SmRP of the brain of the individual with standard measured values of SmRP of brains of other individuals when the other individuals use, particularly with the other individuals's thumbs, touch screens of smartphones.
[0061] Also in accordance with this invention, a use of a smartphone for analyzing a functioning of neuronal circuits of a brain of an individual, which circuits are engaged in the individual's voluntary, self-paced motor control of a button press with a finger, the use comprising; determining the SmRP of the brain of the individual when the individual uses, particularly with the individual's thumb, a touch screen of a smartphone; and comparing the determined SmRP of the brain of the individual with standard determined values of SmRP of brains of other individuals when the other individuals use, particularly with the other individuals's thumbs, touch screens of smartphones.
Example
[0062] A total of 45 people were recruited. The sample age ranged from 18 to 45 (median age, 23).
[0063] Smartphone Activity Recordings
[0064] The timestamps of the touchscreen interactions and the corresponding Apps in use were recorded by using a background App attached to a cloud-based data collection platform (TapCounter, QuantActions Ltd, Lausanne, Switzerland). The background App was installed for a period of 3-5 weeks prior to the laboratory-based EEG recordings. This data were downloaded from the cloud in a compressed form and further processed using MATLAB (Mathworks, Natick, USA) by using the data unpacking processes made available by QuantActions.
[0065] Categorization of Social and Non-Social Apps
[0066] The classification of social and non-social Apps was primarily based on the definitions used in a previous report. To elaborate, an app label captured on the phone was categorized as social if the main purpose was to allow users to communicate with others (friends or strangers). The app had to also contain the tools to enable these interactions such as direct messaging, public posts or voice chat, personalized profiles and being able to rate or follow the profile. The apps that did not fit the main purpose and have the tools were labeled as non-social. A slightly altered definition was applied when categorizing gaming apps—they were categorized as social only if they engaged other users during the game rather than sharing the results after playing the game solo.
[0067] Movement Sensor Recordings
[0068] During the laboratory measurements of smartphone behavior, the thumb flexions were tracked using a bend sensor (Flex Sensor, 4.5″, Spectra Symbol, Salt Lake City, USA). The sensor was attached to the thumb (dorsum) using a custom-built jacket that allowed the sensor to bend within the jacket without the sensor being pulled. The thumb was further covered with a conductive surface (aluminum foil) ensuring that all the touches were translated to touchscreen events and that the same part of the thumb was used to target the screen. The analog signals from the sensor were digitized at 1 kHz using Labview via the USB 6008 DAQ (National Instruments, Austin, USA). The same DAQ was also used to power the sensor. The thumb was all able to freely move on the touchscreen under this configuration. The movements were recorded along with synchronizing triggers emitting from the EEG recording set-up.
[0069] EEG Recordings
[0070] The EEG recordings were conducted in a faraday shielded room (Holland Shielding Systems BV, Dordrecht, The Netherlands) with optic fiber transmitted internet connectivity. The users used their own smartphone while comfortably reclined on a chair. White noise was presented through the experiment using earphones. Sixty-four channel EEG caps with equidistant electrodes were used (Easycap GmbH, Worthsee, Germany) in conjunction with ABRALYT HiCl electrode gel. Prior to recording the EEG signals, the contact impedances were reduced to less than 10 kΩ by rubbing the gel on the skin. The capsizes were matched using head circumference measurements. The EEG recordings were conducted using BrainAmp DC amplifiers (Brainproducts, Gilching, Germany). The data sample rate was set at 1 kHz and no online filters were applied during the recordings. As the EEG, the smartphone and the movement sensors operated on different clocks they were synchronized using common TTL pulse bursts generated by using an IBM T 42 motherboard running MATLAB.
[0071] To measure the EEG signals surrounding the smartphone behavior, the users were provided with a list of their own top 4 apps-top 2 social and non-social ranked based on the number of touches generated over the previous weeks. Video Apps such as youtube were eliminated prior to the ranking. The users were given 12 minutes to use each App, and the usage was separated by 2 minute short breaks where the subsequent App was launched and ready to be used. The order of the Apps was randomized. Social interactions were anticipated to be dominated by higher levels of text messaging compared to the non-social interactions. To enable comparison between the social and non-social interactions we instructed the participants to ‘not engage in extensive text messaging’—and this was further monitored by the experimenter by using the thumb flexion bend sensor measures online. However, users were permitted .sup.˜50 characters of typing in situations where they judged that typing was essential for continued engagement (for instance when writing a short reaction to a posted picture). According to debriefing interviews, users mainly browsed older posts, read and liked the posts, and responded with brief comments using emojis and a few characters.
[0072] EEG Analysis and Statistics
[0073] The temporal alignment between the smartphone touchscreen events and the bend sensor recordings was confirmed using cross-correlation analysis (Signal processing toolbox, MATLAB). In 8 of the 45 participants the alignment could not be confirmed (R2<0.8) due to recording gaps or trigger alignment failures and they were disregarded from further analysis in social vs. non-social comparisons (kinematically adjusted), and in air touches vs. real touchscreen event categories. For further analysis, a threshold of 700 acceptable trials had to be met for the establishment of the SmRP and 350 trials (per category) in the cross-category comparisons. A key focus of our analysis was to compare social vs. non-social interactions. In addition to the instructions to diminish typing interactions we also determined that in the real world the typing interactions were dominated by intervals of 200 ms (median) and towards our analysis interactions separated by less than 3.5× threshold (700 ms) gap were excluded. The population median of median separations was 2 s (for both social and non-social interactions) during the laboratory testing. After these layers of exclusions, we were left with 34 participants for the establishment of SmRPs, 20 participants for the comparison between social vs. non-social interactions (without kinematic adjustments), and 24 participants for the comparison between air touches vs. real touchscreen events.
[0074] The EEG recordings were band-pass filtered between 0.1 to 70 Hz, and independent component analysis was run for subtracting blink artifacts from the EEG signals (Icablinkmetrics implemented in MATLAB). This was followed by another band-pass filter between 0.1 to 30 Hz (and a parallel set was created with 0.1 to 3 Hz focused on the slower signals). Trials above 1 mV were eliminated. The epoch durations were −4 s to 4 s from the touchscreen event, and signals were baseline corrected between −4 to −3 s from the touchscreen event. The signals were then processed using the hierarchical linear modelling toolbox LIMO EEG using ordinary least squares regression. The SmRP was tested using one sample t-test at the population level. For comparison of social and non-social touches, the trial-to-trial motor amplitudes were used towards an ANCOVA model at the single subject level and the resultant β values for the social and no-social categories were used towards the paired t-test at the population level. For comparison of air touches vs. real touchscreen events paired t-test was used at the population level. The statistics were for corrected for multiple comparison correction (MCC) using bootstrapped signals and 2-D spatiotemporal clustering implemented in LIMO EEG (α=0.05). The statistical masks of the main and parallel streams were merged using the logical ‘or’ operator. For the simple behavioural regression analysis robust (bi-square) linear regression was used.
[0075] Subsequent Monitoring
[0076] Accordingly, it can be seen that patterns matching behavioural output with neuronal activity can be identified, along the lines above and illustrated as an example in
[0077] The applicant hereby discloses in isolation each individual feature described herein and any combination of two or more such features, to the extent that such features or combinations are capable of being carried out based on the present specification as a whole in the light of the common general knowledge of a person skilled in the art, irrespective of whether such features or combinations of features solve any problems disclosed herein, and without limitation to the scope of the claims.
[0078] The applicant indicates that aspects of the present invention may consist of any such individual feature or combination of features. It should be understood that the embodiments described herein are merely exemplary and that various modifications may be made thereto without departing from the scope or spirit of the invention. For example, it will be appreciated that although shown here relating to a smartphone touch, in other examples other events, behaviours and associated neuronal activities are included.