| EEG is an important electrophysiological signal of the human body,which reflects the law of bioelectrical rhythm activity in the brain and contains a large amount of cognitive function information such as sense/perception,emotion and memory.So,it have become the main technical means in the fields of disease diagnosis and brain computer interface.Taste,as the basic sensory system,it was conducted by nerves after the odor was dissolved in saliva and neuro-activated in the brain,while taste-induced EEG signals can,to some extent,show changes in the body's taste function.Therefore,by designing the induced EEG experimental paradigm to obtain the signal response caused by single taste stimulation in the human brain and quantitative analysis of taste induced power generation level,this paper aims to truly reflect the difference between the human brain's perception of taste during the tasting process,and provide theoretical basis for human feeding choice.In order to meet the control requirements of the amount and length of time of liquid stimulation in the study of EEG experiments,an automatic taste stimulation transfer device was designed independently,which was mainly composed of PC,lower control device and liquid delivery path,which can provide quantitative liquid stimulation for the subjects studied in the experiment.First of all,the use of Lab VIEW according to the block-related experimental paradigm written by the upper machine interface,and achieve control of the stimulus sequence in each block,complete the liquid at 0.3 ml/s rate of timed,quantitative delivery.In addition,pure water was designed as the control group of taste experiment to avoid the influence of odor or body sensation in human mouth on taste perception in natural state,and salty taste was taken as an example to study the response of taste stimulation in brain.Therefore,compared with resting state EEG,this paper constructs a taste transmission device,which provides technical support for the study of taste evoked EEG.In order to obtain the high temporal resolution EEG response of subjects to taste stimulation,the raw data were collected by EEG instrument with the parameters of sampling frequency of256Hz;the EEG data of 0.5-35 hz were retained with band-pass filter,and independent component analysis(ICA)was performed to remove the signal artifacts and reject invalid experimental data.Then,wavelet analysis is used to extract the main frequency band features,the characteristics were classified using a support vector machine.The following classification results show that the classification accuracy of water and salt under 200 m M was 81% compared with the low concentrations of 80 m M,90 Mm,100m M and 150 m M.Similarly,in the case of different concentrations of the same taste stimulant,the discrimination degree of EEG signals for taste was 47.42% and 81.34%,respectively.The results showed that the contrast concentration gradients were 10 and 50,and the higher the concentration change value,the higher the degree of taste sensitivity.In addition,due to individual differences,whether different taste differences or different concentrations of the same taste distinction,individuals show a high sensitivity to high concentrations of Na Cl solution;and with the increase of salty intensity,the overall taste response showed concentration dependence,which was consistent with the results of artificial sensory evaluation.Therefore,taste induced power generation provides a relatively fair,reliable and simple method for the objective evaluation of human taste function.In summary,EEG technology was applied to taste recognition in human beings,and the real-time dynamic response of the brain in the resting state and stimulating state was analyzed to arrive at a general paradigm suitable for taste study in order to quantify different concentrations of salty taste,and to study the response of the brain under different concentrations of taste stimuli. |
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