Characteristics of saccadic intrusions
Characteristics of saccadic intrusions
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DOI：
10.1016/j.visres.2004.05.009
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发表时间：
2004-10-01
期刊：
影响因子：
1.8
通讯作者：
Gowen, E
中科院分区：
文献类型：
--
作者：
Abadi, R;Gowen, E
初级注视从来不是完全稳定的，而是经常被缓慢漂移、微扫视和扫视侵入（SI）打断。SI是无意识的共轭运动，其采取远离期望的眼睛位置的初始快速运动的形式，并且在短持续时间之后跟随有返回的次级扫视或漂移。本研究的目的是在50名健康受试者中检查SI的患病率和指标。使用一维和二维记录，我们发现，所有50名成员的主题组表现出SI。SI为双侧、共轭和水平。没有纯粹的垂直SI检测时，在三个主题。SI振幅平均值和范围为0.6度± 0.5度，0.1度-4.1度，SI频率平均值和范围为18.0 ± 14.3次/min，1.0 - 54.8次/min; SI持续时间平均值和范围为225 ± 150，去除SI <0.5 °时，SI平均振幅为0.97 ° ~ 0.56 °，频率为7.0 ± 11.4次/min。年龄与SI振幅呈正相关（p < 0.01），而与SI频率无相关性。四种类型的S1单相方波侵入（MSWI），双相方波侵入（BSWI）和双扫视脉冲（DSP）被发现是专门扫视，而第四种类型，单扫视脉冲（SSP），被证实表现出缓慢的次要成分。MSWI是50例受试者中47例（94%）最常观察到的SI，平均振幅、频率和持续时间分别为0.7度± 0.5度、11.5 ± 11.6次/min和255 ± 147 ms。BSWI（n = 20）、SSP（n = 11）和DSP（n = 34）的平均振幅和频率分别为0.50度± 0.2度、1.2 ± 2.5次/min;分别为0.40度± 0.20度，0.4 ± 1.0/min和0.3度± 0.4度，5.0 ± 8.7/min。双眼和单眼观察之间的MSWI特性没有差异。SI发生的可能解释包括实验观察条件、受试者疲劳和注意力的内隐转移。(C)2004 Elsevier Ltd.保留所有权利。
Primary fixation is never perfectly stable, but is frequently interrupted by slow drifts, microsaccades and saccadic intrusions (SI). SI are involuntary, conjugate movements which take the form of an initial fast movement away from the desired eye position and followed after a short duration, by either a return secondary saccade or a drift. The purpose of this study was to examine the prevalence and metrics of SI in a population of 50 healthy subjects. Using both one and two dimensional recordings we find that all 50 members of the subject group exhibited SI. The SI were bilateral, conjugate and horizontal. No purely vertical SI were detected when examined in three subjects. SI amplitude mean and range was 0.6degrees +/- 0.5degrees, 0.1degrees - 4.1degrees; SI frequency mean and range was 18.0 +/- 14.3 per min, 1.0 - 54.8 per min; SI duration mean and range was 225 +/- 150, 20 - 870 ms. The mean SI amplitude and frequency when SI < 0.5degrees were removed was 0.97degrees - 0.56degrees and 7.0 +/- 11.4 per min respectively. Age was positively correlated with SI amplitude (p < 0.01), but there was no correlation between age and SI frequency. Three of four types of SI monophasic square wave intrusions (MSWI), biphasic square wave intrusions (BSWI) and double saccadic pulses (DSP) were found to be exclusively saccadic, whilst the fourth type, the single saccadic pulses (SSP), were confirmed to exhibit a slow secondary component. MSWI were the most frequently observed SI occurring in 47 out of 50 (94%) of the subjects with a mean amplitude, frequency and duration of 0.7degrees +/- 0.5degrees, 11.5 +/- 11.6 per min, and 255 +/- 147 ms respectively. Mean amplitudes and frequencies for BSWI (n = 20), SSP (n = 11) and DSP (n = 34) were found to be 0.50degrees +/- 0.2degrees, 1.2 +/- 2.5 per min; 0.40degrees +/- 0.20degrees, 0.4 +/- 1.0 per min and 0.3degrees +/- 0.4degrees, 5.0 +/- 8.7 per min respectively. No differences in MSWI characteristics were found between binocular and monocular viewing. Possible explanations for SI occurrence include experimental viewing conditions, subject fatigue and covert shifts in attention. (C) 2004 Elsevier Ltd. All rights reserved.