ABSTRACT
ObjectiveTo investigate the effects of eyes-closed (EC) and eyes-open (EO) EEG field powers on the auditory P300 evoke potentials.MethodsThe EEG was recorded in 12 healthy male college students (20 ～24 years) respectively in their eyes-closed and eyes-open states,and then the auditory P300 paradigm was performed.Results① Alpha band was distributed at the posterior-occipital area,while Alpha-1 (7.5～9.5 Hz) field power were EC as (2.62 ±0.81 ) μV2 and EO as ( 1.80 ±0.56) μV2,with statistical significance (P ＜ 0.01 ) ; Alpha-2 ( 10 ～ 12 Hz) field power were EC as ( 8.55 ± 1.85 ) μV2 and EO as (4.95 ± 1.59 )μV2,also with statistical significance (P＜0.05).②In P300,the Common stimulus elicited clear component N1 (90ms)and P2 (180ms) in the ERPs after stimulus,while there were no significant differences between EC and EO states.Correspondingly,the rare stimulus elicited clear component N2 (207 ms) and P3 (313 ms) in the ERPs after stimulus on-set.Comparing the differences of field potentials of the rare stimulus between the two states,N2field potential in EC ( (0.01 ± 0.71 ) μV) was smaller than that in EO ( ( - 2.13 ± 0.80 ) μV ),with statistical significance (P ＜ 0.05 ) ; while P3 field potential in the EC ( ( 4.16 ± 1.08 ) μV ) was smaller than that in EO ( (4.78 ± 1.20) μV),but without statistical significance (P ＞ 0.05 ).ConclusionThe alpha field power is higher in eyes-closed than in eyes-open state,while performing the same auditory P300 paradigm,significant reduction of field potential in the N2 component are observed in eyes-closed than in eyes-open state.
ABSTRACT
Objective To investigate the gender differences and the effect of three factors(the angle of rotation, left/right,palm/back) on hand mental rotation. Methods 40 healthy adults (20 males and 20 females, age; 18～26 years) were enrolled in this study. By simulation of human hand as picture stimuli,participants were instructed to decide as quickly as possible whether the stimulus was a left or right hand. The accuracy rate and reaction time of the behavior task were quantified. Results ① the subjects' reaction speed was far slower at 180° than 0°(P＜0.01). ②On judgment of 0° back picture,females were faster than males(left back: males( 1033. 16 ±245.85) ms,females( 853.15 ± 142.79) ms,P=0.014; right back; males( 973.07 ±217.11) ms;,females (796.28 ±146.67 )ms, P = 0.016). And,the right hand was responded faster than left hand,with statistical significance (males; P = 0.028, females; P=0.038). ③The time of females in judging the 0° hand back ( left (853. 15 ± 142.79) ms,right (796. 27 ± 146. 67 ms) ) was shorter than palm(left ( 1002. 72 ± 227. 91) ms,right ( 986.06 ± 230. 03) ms), reached statistical significance ( both at P ＜ 0. 001). In contrast, males in judging the 180° pictures, the speed of reaction to back(left ( 1252. 70 ±269. 35) ms,right ( 1216. 68 ±293. 54 )ms) was slower than palm with statistical significance (left: P ＜ 0. 01, right: P = 0. 015). Conclusion The three factors (angle of rotation,left/right,and palm/back) all exert effect on the behavior of hand mental rotation. It really has gender difference on hand mental rotation. Females response faster than males.