短间刺激间隔 (ISI) 的N1促进发生在400ms以下,并且依赖于先前声音的ISI:使用不可预测的听觉刺激序列的证据
F López-Caballero1, B A Coffman1, D Seebold1
1Clinical Neurophysiology Research Laboratory, Western Psychiatric Hospital, Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
概括
N1 听觉唤起的潜在促进发生在 400 ms 以下的刺激间隔 (ISI),特别是当前的 ISI 短时. 这挑战了以前关于上下文独立的神经反应动态的假设.
科学领域:
- 神经科学是一个神经科学.
- 听觉神经科学 听觉神经科学
- 认知神经科学 认知神经科学
背景情况:
- N1的听觉唤起潜能 (AEP) 振幅对刺激间隔 (ISI) 很敏感.
- 通常,N1振幅随着ISI的缩短而下降,这表明在呈现率更高时神经反应减少.
- 在非常短的ISIs (150-500 ms) 中增加N1振幅的N1促进,是这一规则的例外.
研究的目的:
- 通过检查ISI的连续分布,精确地描述N1便利化.
- 为了确定N1促进发生的特定ISI范围.
- 调查ISI历史对N1促进的影响及其与认知表现的关系.
主要方法:
- 从29名参与者中记录了EEG,他们被动地听到听觉点击.
- 使用ISI连续分布 (0.25到8秒) 和不同强度 (65,75,85dB) 的方法.
- 特别注意的是0.25到0.5秒的ISI范围,收集了多达1800次扫描.
主要成果:
- 在ISI低于400ms时证实了N1便利化,幅度恢复到较长的ISI (约. 1.7 个小时).
- 这种便利性取决于ISI历史,特别是当前的ISI小于1.5秒 (p=0.001) 时发生.
- 当之前的ISI超过1.5秒 (p=0.37) 时,没有观察到显著的便利性.
结论:
- 在特定的短时间ISI条件下 (低于400 ms) 进行N1便利化,并且取决于最近的ISI历史.
- 这些发现完善了我们对N1 AEPs时间动态的理解.
- 结果挑战了一个简单的,独立于背景的潜在抑制机制的概念,这是N1促进的基础.
相关概念视频
Long-term Potentiation
54.8K
Long-term potentiation, or LTP, is one of the ways by which synaptic plasticity—changes in the strength of chemical synapses—can occur in the brain. LTP is the process of synaptic strengthening that occurs over time between pre- and postsynaptic neuronal connections. The synaptic strengthening of LTP works in opposition to the synaptic weakening of long-term depression (LTD) and together are the main mechanisms that underlie learning and memory.
54.8K
Muscle Stimulation Frequency
2.0K
The contraction strength of muscles is regulated by motor neurons, which modulate the frequency of action potentials dispatched to the motor units based on the body's requirements. This process of varying the muscle stimulation frequency allows muscles to contract with a force that is precisely tailored to the needs of the moment, whether lifting a feather or a heavy box.
Wave summation
At low firing rates, motor neurons induce individual twitch contractions in muscle fibers. These twitches...
Wave summation
At low firing rates, motor neurons induce individual twitch contractions in muscle fibers. These twitches...
2.0K
Interference: Path Lengths
1.3K
Consider two sources of sound, that may or may not be in phase, emitting waves at a single frequency, and consider the frequencies to be the same.
Two special sources may be considered when they are in phase. This can be easily achieved by feeding the two sources from the same source. An example would be synchronizing the two speakers by feeding them with the same source, such as the sound waves produced by a tuning fork. This setup ensures that the two sources have the same frequency and are...
Two special sources may be considered when they are in phase. This can be easily achieved by feeding the two sources from the same source. An example would be synchronizing the two speakers by feeding them with the same source, such as the sound waves produced by a tuning fork. This setup ensures that the two sources have the same frequency and are...
1.3K
Integration of Synaptic Events
1.4K
Synaptic integration mainly includes the summation of graded potentials. Graded potentials, regardless of their type, cause subtle alterations in membrane voltage, resulting in either depolarization or hyperpolarization. These incremental changes, when combined or summed, can propel the neuron toward its threshold. Consider, for example, a membrane experiencing a +15 mV shift, causing it to depolarize from -70 mV to -55 mV. In this scenario, graded potentials govern the membrane's ability...
1.4K
NMR Spectrometers: Radiofrequency Pulses and Pulse Sequences
742
A pulse is a short burst of radio waves distributed over a range of frequencies that simultaneously excites all the nuclei in the sample. Upon passing a radio frequency pulse along the x-axis, the nuclei absorb energy corresponding to their Larmor frequencies and achieve resonance. This shifts the net magnetization vector from the z-axis toward the transverse plane. This angle of rotation of the magnetization vector, or the flip angle, is proportional to the duration and intensity of the pulse.
742
Sound Waves: Interference
3.7K
Sound waves can be modeled either as longitudinal waves, wherein the molecules of the medium oscillate around an equilibrium position, or as pressure waves. When two identical waves from the same source superimpose on each other, the combination of two crests or two troughs results in amplitude reinforcement known as constructive interference. If two identical waves, that are initially in phase, become out of phase because of different path lengths, the combination of crests with troughs...
3.7K


