ABSTRACT
Cognition impairment caused by space motion sickness often is a risk of spaceflight. So the dynamic changes of pattern of brain cognitive processing under varied vestibular stimuli was explored using event-related potentials. Vestibular stimulation was produced by rotary chair and varied linearly, i.e. control, constant 10 degrees/s rotation and constant 0.6 degrees/s, 0.8 degrees/s, 1.0 degrees/s, 1.2 degrees/s acceleration. Thirty-three subjects participated in the study and performed same auditory selective attention task in which the odd numbers in a randomly mixed series of odd and even numbers (go/no-go) presented acoustically in Chinese pronunciation were assigned as target signal during the rotation stimuli. The results showed that the P3 latency induced by target signal and the N1P2, P2N2 and N2P3 peak-to-peak amplitudes decreased significantly during constant 10 degrees/s rotation in contrast to control and constant angular acceleration. The P3 latency induced by target signal was shorter during constant 0.6 degrees/s and 1.2 degrees/s acceleration rotations than that during constant 0.8 degrees/s and 1.0 degrees/s acceleration rotations. It was suggested that constant angular velocity rotation had a promotion effect on brain cognitive processing. The constant angular acceleration inhibited the cognitive processing and its action had at least two different levels.
Subject(s)
Brain/physiology , Cognition/physiology , Evoked Potentials/physiology , Vestibule, Labyrinth/physiology , Acceleration , Acoustic Stimulation/methods , Adolescent , Adult , Analysis of Variance , Attention/physiology , Electrodes , Electroencephalography/methods , Female , Humans , Male , Reaction Time/physiology , RotationABSTRACT
OBJECTIVE: To explore the dynamic change of the late attentional selection process under linearly varied vestibular stimuli using event-related potentials (ERPs) technique. METHOD: Thirty-three subjects participated in the experiment. They were exposed to vestibular stimulation of constant angular velocity rotation (10 degrees/s) and four levels of constant angular acceleration rotation, the acceleration was 0.6 degrees/s2, 0.8 degrees/s2, 1.0 degrees/s2, 1.2 degrees/s2 respectively. The same auditory go/no-go cognitive task was done during the stimulation. The task involved verbally given Chinese digit number from two to nine with 1000 ms random interval. Subjects were asked to push the button for the odd numbers (target) and withhold to the even numbers (non-target). RESULT: Compared with control and different level of constant angular acceleration rotation, the N2 amplitude of non-target ERPs (NT-ERPs) decreased significantly over anterior-central scalp during 10 degrees/s constant rotation, but the N2 amplitude of target ERPs (T-ERPs) reduced significantly only at F4, F(Z) and T4 sites. The P3 latency of T-ERPs decreased significantly in 10 degrees/s constant rotation in contrast with control. Under four different acceleration level, the P3 latency of T-ERPs was relatively longer in 0.8 degrees/s2 and 1.0 degrees/s2, but shorter in 0.6 degrees/s2 and 1.2 degrees/s2. CONCLUSION: Constant angular velocity rotation had an activating effect on late attentional selection process. In contrast to the activation effect of constant angular velocity rotation, constant angular acceleration had an inhibition effect on the cognitive processes and this inhibition effect may have several levels.
Subject(s)
Acceleration , Attention/physiology , Cognition/physiology , Evoked Potentials/physiology , Vestibule, Labyrinth/physiology , Acoustic Stimulation , Adolescent , Adult , Brain/physiology , Electroencephalography/methods , Female , Humans , Male , Reaction Time/physiology , Rotation , Space Motion Sickness/physiopathologyABSTRACT
OBJECTIVE: To examine the effect of extremely low frequency magnetic field (ELMF) on the brain trauma in rats. METHOD: Using the focal left-brain cortex contusion model, rats were divided into two groups, ELMF group (3 d and 8 d) and control group (3 d and 8 d), ELMF stimulations were given after the brain trauma provided by a coil (phi 10 cm) which was driven by 15 Hz sinusoidal signals so that ELMF strength of 18 mT at the midpoint was obtained. The morphologic changes were observed in these groups. RESULT: As compared with the control group, the extent of the inflammatory reaction and the neuronal damage was apparently lighter in magnetic field group, especially in 8 d group. At the far away region from the injured brain area, the neuronal shape was changed, and the amount of this special neurocyte was larger in magnetic field group than that in control group, especially in 8 d group. CONCLUSION: ELMF stimulation in the present study may alleviate the brain injury reaction. Attention should be paid to the role of the special neurocyte during the brain injury.
Subject(s)
Brain Injuries/pathology , Brain Injuries/prevention & control , Magnetics/therapeutic use , Animals , Electromagnetic Fields , Inflammation/pathology , Inflammation/prevention & control , Neurons/pathology , Rats , Rats, WistarABSTRACT
OBJECTIVE: To study non-target stimuli processing in the brain. METHOD: Features of the event-related potentials (ERPs) from non-target stimuli during selective response task (SR) was compared with that during visual selective discrimination (DR) task in 26 normal subjects. The stimuli consisted of two color LED flashes (red and green) appeared randomly in left (LVF) or right (RVF) visual field with same probability. ERPs were derived at 9 electrode sites on the scalp under 2 task conditions: a) SR, making switch response to the target (NT) stimuli from LVF or RVF in one direction and making no response to the non-target (NT) ones; b) DR, making switching response to T stimuli differentially, i.e., to the left for T from LVF and to the right for T from RVF. RESULT: 1) the non-target stimuli in DR conditions, compared with that in SR condition, elicited smaller P2 and P3 components and larger N2 component at the frontal brain areas; 2) a significant negative component, named as WMN (working memory negativity), appeared in the non-target ERPs during DR in the period of 100 to 700 ms post stimulation which was predominant at the frontal brain areas. CONCLUSION: According to the major difference between brain activities for non-target stimuli during SR and DR, the predominant appearance of WMN at the frontal brain areas demonstrated that the non-target stimulus processing was an active process and was related to working memory, i.e., the temporary elimination and the retrieval of the response mode which was stored in working memory.
Subject(s)
Brain/physiology , Discrimination, Psychological/physiology , Evoked Potentials, Visual/physiology , Memory/physiology , Visual Fields/physiology , Adolescent , Adult , Electroencephalography , Frontal Lobe/physiology , Humans , Photic Stimulation , Psychomotor Performance/physiologyABSTRACT
OBJECTIVE: To make the manned space flight more efficient and safer, a concept of human-artificial (AI) system is proposed in the present paper. METHOD: The task of future manned space flight and the technique requirement with respect to the human-AI system development were analyzed. RESULT: The main points are as follows: 1)Astronaut and AI are complementary to each other functionally; 2) Both symbol AI and connectionist AI should be included in the human-AI system, but expert system and Soar-like system are used mainly inside the cabin, the COG-like robots are mainly assigned for EVA either in LEO flight or on the surface of Moon or Mars; 3) The human-AI system is hierarchical in nature with astronaut at the top level; 4) The complex interfaces between astronaut and AI are the key points for running the system reliably and efficiently. CONCLUSION: As the importance of human-AI system in future manned space flight and the complexity of related technology, it is suggested that the R/D should be planned as early as possible.
Subject(s)
Artificial Intelligence , Man-Machine Systems , Space Flight/instrumentation , User-Computer Interface , Weightlessness , Astronauts , Ergonomics , Extravehicular Activity , Humans , Research , Robotics , Space Flight/trendsABSTRACT
Objective. To study the difference between two types of event-related brain potentials (ERPs) in auditory location discrimination task. Method. Event-related potentials (ERPs) in auditory location discrimination task were recorded in 14 normal subjects and were compared with head-down tilt (HDT) and head-up tilt (HUT) conditions. Result. 1) The subjects could be divided into group I (n=7) and group II (n =7) according to the feature of the target ERPs component (P3). The difference between the two groups was mainly that there was a negative slow wave after 150 ms in the ERPs of group II subjects, and that the reaction time and error rate in II group was higher than in I group. These data indicated that the psychological load on group II was larger than that on group I. 2) The reduction of mean slow potential amplitude during HDT was more significant in group II than in group I. Conclusion. The slow potential amplitude of ERPs may reflect the psychological load and the brain function state. Attention should be paid to the feature of auditory ERPs in space medical practice.
Subject(s)
Discrimination, Psychological/physiology , Evoked Potentials, Auditory/physiology , Head-Down Tilt , Sound Localization/physiology , Weightlessness Simulation , Acoustic Stimulation , Adult , Auditory Perception , Electroencephalography , Ergonomics , Humans , Reaction TimeABSTRACT
Objective. To study N2 effect and its feature on non-target event-related brain potentials during auditory selective attention. Method. The subjects were 16 healthy right-handed male volunteers aged 23.2 +/- 2.1 years. The stimuli were male voice of one-digit numbers (2 to 7), which were single syllable pronunciated in Chinese, and appeared randomly with equal probability. The subjects were asked to press a switch as soon as the target signal (odd or even number) was heard but make no response to the non-target signal. EEG signals at 9 locations were recorded. Result. 1) A negative component N280 (N2 effect) was found after non-target stimuli as compared to target stimuli, which was significant in the frontal brain locations; 2) P3 was smaller and its peak appeared later in non-target ERPs than in target ERPs. Conclusion. N2 effect was also elicited by non-target stimuli during auditory modality. We assume that N2 effect might reflect the readjusting of model stored in working memory at the frontal brain.
Subject(s)
Attention/drug effects , Evoked Potentials, Auditory/drug effects , Memory/drug effects , Nitrogen/pharmacology , Reaction Time/drug effects , Adult , Electroencephalography , Ergonomics , Humans , MaleABSTRACT
OBJECTIVE: To study the effects of task load on early and late components of auditory event-related potentials. METHOD: The subjects were 12 healthy right-handed volunteers aged 20-23 years. The stimuli were auditory signals of two kinds of tones and appeared randomly from four speakers located on the left-front, left-rear, right-front and right-rear over the head of the subject. Tasks included: a) pressing the button in response to all signals (AR); b) making location discrimination to tones from left or right (DR); c) making location discrimination to target signals (T, high-tone or low-tone) from the four sides, and make no response to non-target signals (NT). The event-related potentials (ERPs) of three tasks were compared with each other. RESULT: 1) The early components include P1, N1 and P2, and the late components include N2 (N2a/N2b), P3 and SW (slow wave). 2) P1 wave amplitude increased with the increase of the task load. N1 wave amplitude of SR(T)-ERPs decreased markedly compared with that of AR-ERPs and DR-ERPs, and P2 wave amplitude of AR-ERPs increased significantly compared with that of DR-ERPs and SR(T)-ERPs. P2 wave latency shortened with increase of the task load. 3) N2 (N2a/N2b), P3 and SW wave amplitudes increased with the increase of the task load. CONCLUSION: These data indicate that not only the late components but also the early components of auditory event-related potentials were affected by task load. The effects on the late components may be related to the change of the early component (P1) which may reflect the early activity process of the brain.