Electroencephalogram interface system, electroencephalogram interface providing apparatus, method of operating electroencephalogram interface, and program

1. An electroencephalogram interface system comprising:

a presentation section for presenting a plurality of options to a user, the plurality of options being manipulable items concerning manipulations of a device;

a selection flicker control section for flickering each of the plurality of options;

a biological signal detection section for measuring an electroencephalogram signal from the user;

an inference section for inferring one option corresponding to a desired manipulation of the user by utilizing an event-related potential of an electroencephalogram contained in the electroencephalogram signal, the event-related potential being based on the flickering of each of the plurality of options as a starting point;

a confirmation flicker control section for effecting confirmation flickering of the one option inferred;

a determination section for determining whether the inferred option corresponds to the desired manipulation of the user by utilizing an event-related potential of an electroencephalogram contained in the electroencephalogram signal, the event-related potential being based on the confirmation flickering of the one option as a starting point; and

an output section for executing a process which is in accordance with a result of determination by the determination section.

2. The electroencephalogram interface system of claim 1 , wherein at least one of the inference section and the confirmation flicker control section adjusts the number of times of flickering each of the plurality of options and/or the number of confirmation flickers, by using event-related potentials having been acquired up to a given point in time.

3. The electroencephalogram interface system of claim 2 , wherein,

at least the confirmation flicker control section adjusts the number of confirmation flickers; and

by using the event-related potentials having been acquired up to the given point in time, the confirmation flicker control section calculates a certainty level, the certainty level being an index indicating how certain the option inferred by the inference section is to the user, and decreases the number of confirmation flickers if the certainty level is high, or increases the number of confirmation flickers if the certainty level is low.

4. The electroencephalogram interface system of claim 3 , wherein the determination section calculates a certainty level concerning presence or absence of a request for changing the inferred option by using a similarity level, the similarity level being calculated based on a waveform of an event-related potential for the confirmation flickering and a prestored template waveform for use when a request of a retrial is made.

5. The electroencephalogram interface system of claim 2 , wherein,

at least the confirmation flicker control section adjusts the number of confirmation flickers;

the determination section calculates a certainty level concerning presence or absence of a request for changing the inferred option by using an event-related potential concerning the confirmation flickering;

when the certainty level is equal to or greater than a predetermined threshold value, the determination section categorizes the certainty level to be high, and the confirmation flicker control section decreases the number of confirmation flickers; and

when the certainty level is smaller than the predetermined threshold value, the determination section categorizes the certainty level to be low, and the confirmation flicker control section increases the number of confirmation flickers.

6. The electroencephalogram interface system of claim 2 , wherein the determination section calculates a certainty level concerning presence or absence of a request for changing the inferred option by using a similarity level, the similarity level being calculated based on a waveform of an event-related potential for the confirmation flickering and a prestored template waveform for use when a request of a retrial is made.

7. The electroencephalogram interface system of claim 6 , wherein,

when a result of inference by the inference section is determined by the determination section as incorrect,

the selection flicker control section increases the number of flickers for each option if a proportion with which the result or results of inference are determined as incorrect is equal to or greater than a predetermined value, and the selection flicker control section decreases the number of flickers for each option if the proportion with which the result or results of inference are determined as incorrect is smaller than the predetermined value.

8. The electroencephalogram interface system of claim 1 , wherein, by utilizing a proportion with which a result or results of inference by the inference section are determined by the determination section as incorrect, the selection flicker control section adjusts the number of flickers for each option.

9. The electroencephalogram interface system of claim 1 , wherein the number of confirmation flickers controlled by the confirmation flicker control section is larger than the number of selection flickers controlled by the selection flicker control section.

10. The electroencephalogram interface system of claim 1 , wherein,

the inference section infers an option for which a predetermined component of the event-related potential takes a largest amplitude to be the option corresponding to the desired manipulation of the user; and

when the inferred option is determined by the determination section as incorrect, the inference section re-infers an option for which the predetermined component takes a second largest amplitude to be the option corresponding to the desired manipulation of the user.

11. The electroencephalogram interface system of claim 1 , wherein the inference section infers the option corresponding to the desired manipulation of the user by using a positive local maximum of an event-related potential from 200 milliseconds to 400 milliseconds based on the flickering of each option as a starting point, or a negative local minimum of an event-related potential from 100 milliseconds to 300 milliseconds based on the flickering of each option as a starting point.

12. The electroencephalogram interface system of claim 1 , wherein, in determining whether the inferred option corresponds to the desired manipulation of the user, the determination section uses P300 or N200, where P300 is a positive local maximum of an event-related potential from 200 milliseconds to 400 milliseconds based on the confirmation flickering of the inferred option as a starting point, and N200 is a negative local minimum of an event-related potential from 100 milliseconds to 300 milliseconds based on the confirmation flickering of the inferred option as a starting point.

13. The electroencephalogram interface system of claim 1 , wherein the inference section infers an option that corresponds to, among event-related potentials based on the flickering of the plurality of options as starting points, an event-related potential having a predetermined characteristic component to be the one option corresponding to the desired manipulation of the user.

14. The electroencephalogram interface system of claim 1 , wherein,

when an event-related potential based on the flickering of the one option as a starting point contains a predetermined characteristic component, the determination section determines that the one option corresponds to the desired manipulation of the user; and

when an event-related potential based on the flickering of the one option as a starting point does not contain the predetermined characteristic component, the determination section determines that the one option does not correspond to the desired manipulation of the user.

15. An electroencephalogram interface providing apparatus comprising:

a selection flicker control section for flickering each of a plurality of options on a presentation section, the plurality of options being manipulable items concerning manipulations of a device;

an inference section for inferring one option corresponding to a desired manipulation of the user by utilizing an event-related potential of an electroencephalogram contained in an electroencephalogram signal from the user measured by a biological signal detection section, the event-related potential being based on the flickering of each of the plurality of options as a starting point;

a confirmation flicker control section for effecting confirmation flickering of the one option inferred; and

a determination section for determining whether the inferred option corresponds to the desired manipulation of the user by utilizing an event-related potential of an electroencephalogram contained in the electroencephalogram signal, the event-related potential being based on the confirmation flickering of the one option as a starting point, wherein

the electroencephalogram interface providing apparatus causes an output section to execute a process which is in accordance with a result of determination by the determination section.

16. A method of operating an electroencephalogram interface system, comprising the steps of:

presenting a plurality of options to a user, the plurality of options being manipulable items concerning manipulations of a device;

flickering each of the plurality of options;

measuring an electroencephalogram signal from the user;

inferring one option corresponding to a desired manipulation of the user by utilizing an event-related potential of an electroencephalogram contained in the electroencephalogram signal, the event-related potential being based on the flickering of each of the plurality of options as a starting point;

effecting confirmation flickering of the one option inferred;

determining whether the inferred option is an option corresponding to the desired manipulation of the user by utilizing an event-related potential of an electroencephalogram contained in the electroencephalogram signal, the event-related potential being based on the confirmation flickering of the one option as a starting point; and

executing a process which is in accordance with a result of determination by the determination step.

17. A computer program, stored on a non-transitory computer-readable medium, to be executed by a computer mounted in an electroencephalogram interface providing apparatus, wherein

the computer program causes the computer to execute the steps of:

causing a presentation section to present a plurality of options, the plurality of options being manipulable items concerning manipulations of a device;

flickering each of the plurality of options;

receiving an electroencephalogram signal from the user measured by a biological signal detection section;

inferring one option corresponding to a desired manipulation of the user by utilizing an event-related potential of an electroencephalogram contained in the electroencephalogram signal, the event-related potential being based on the flickering of each of the plurality of options as a starting point;

effecting confirmation flickering of the one option inferred;

determining whether the inferred option is an option corresponding to the desired manipulation of the user by utilizing an event-related potential of an electroencephalogram contained in the electroencephalogram signal, the event-related potential being based on the confirmation flickering of the one option as a starting point; and

causing an output section to execute a process which is in accordance with a result of determination by the determination step.