微跳是基本的动眼现象和复杂的认知功能过程之间的接口,对于微妙的实验和充分的统计分析,它们也是一个挑战。在特殊主题问题的第二部分(第一部分见4),作者提出了一系列文章,这些文章表明,微跳仍然是科学研究的一个有趣和有益的领域,在许多领域的感官研究的前沿,感性的,和认知过程。.在他们的文章“复杂决策过程中对认知努力和情绪唤醒的瞳孔和微跳反应”中,44%urawska,Duchowski,&Wichary(1)研究了情感启动下多属性决策过程中瞳孔和微跳对信息处理的反应。参与者被随机分配到三个情感启动条件(中性,令人厌恶的,和色情),并指示做出歧视性决定。正如作者所假设的那样,结果表明,微小扫视速率抑制和瞳孔扩张,取决于决策前的认知努力,并通过情感启动来调节。逆向启动增加了瞳孔和微跳对信息处理工作的反应。结果表明,瞳孔反应受情感启动的影响比微扫视率更大。根据瞳孔和微视行为的神经心理学机制讨论了结果。在文章“在单眼和双眼刺激条件下的微跳速率特征相关”中,Leube,Rifai,&Wahl(2020)研究了微跳在单眼和双眼条件下的定向分布和速率。在两种刺激条件下,参与者都固定了一个Gabor贴片,该贴片在很宽的空间频率范围内以45°或135°的方向随机呈现。微扫视大多是水平取向的,而与光栅的空间频率无关。该结果在两种刺激条件之间是一致的。这项研究发现,微跳跳速率特征曲线在两种刺激条件之间相关,因此,将微跳的使用扩展到临床应用,由于参数为对比敏感度,在临床研究中经常进行单眼测量。马丁的这项研究“高速连续视觉搜索过程中的微跳”,戴维斯,Riesenhuber,&Thorpe(3)提供了对视觉搜索过程中发生的微跳的分析,针对小脸粘贴到杂乱的背景照片或简单的灰色背景。指示参与者在变化的场景中瞄准奇异的3度直立或倒置的面孔。一旦参与者的目光到达目标面部,在不同的随机位置显示了一张新的面孔。无论实验背景如何(例如背景场景,没有背景场景),或目标偏心(从4到20度的视角),作者发现,微视速率在12毫秒内降至接近零的水平。在刺激发作后和第一次扫视之前,几乎没有任何微跳。在大约20%的试验中,有一个单一的微扫视,几乎立即发生在前一个扫视的偏移。作者认为,需要通过处理刺激的视觉层次结构进行一次前馈才能实现长时间的连续视觉搜索,并提供证据证明微扫视可以发挥感知功能,例如在连续视觉搜索过程中纠正扫视或实现面向任务的目标。虽然许多研究已经描述了视觉注视过程中的眼球运动,包括微跳,在大多数情况下,只有水平和垂直分量被记录和分析。关于微跳的扭转成分知之甚少。在这项研究中,“在固定和视动刺激期间快速阶段的微跳的扭转成分”Sadeghpour&Otero-Millan(5)记录了在固定和扭转视动刺激期间围绕三个旋转轴的眼球运动。作者发现,固定过程中微扫视的扭转分量的平均幅度为0.34±0.07度,速度遵循主序列,其斜率与水平和垂直分量相当。微扫视过程中扭转位移的大小与水平分量相关,而与垂直分量无关。与固定刺激固定过程中产生的微跳相比,在存在视动刺激的情况下,诱导眼球震颤产生更频繁和更大的扭转快速阶段。快速相的扭转分量和垂直聚散分量随速度的增加而增加。在以前的研究中,微跳被解释为任务负荷的心理生理指标。到目前为止,不同类型的任务需求如何影响微扫视率仍在争论中。Schneider等人在他们的文章“任务难度与微视速率之间的相互作用:视觉负荷的关键作用的证据”中。(6)检查了视觉负荷之间的关系,心理负荷和微视速率。参与者执行了一个连续的绩效任务(n-back),其中视觉任务负载(字母与抽象数字)和心理任务负荷(1-back到4-back)作为受试者内部变量进行操纵。眼动追踪数据,记录了绩效数据和主观工作量。数据分析显示,对于高视觉需求的刺激(即抽象数字),微扫视速率增加,而精神需求(n-back-level)并不调节微视速率。作者得出结论,微小扫视率反映了任务的视觉负荷,而不是其心理负荷。这一结论符合克鲁格等人的命题。(2)“微跳区分看和看”,将感官与认知现象联系起来。当前的特殊主题为围绕微跳的研究景观增加了几个新的有趣方面。它们仍然是跨学科研究和跨学科应用的有吸引力的焦点。因此,正如在本期特别专题的第一部分中已经指出的那样,对微跳的研究不仅会持续下去,但随着知识库的扩展而不断发展。
Microsaccades are at the interface between basic oculomotor phenomena and complex processes of cognitive functioning, and they also have been a challenge for subtle experimentation and adequate statistical analysis. In the second part of the special thematic issue (for the first part see 4) the authors present a series of articles which demonstrate that microsaccades are still an interesting and rewarding area of scientific research the forefront of research in many areas of
sensory, perceptual, and cognitive processes.. In their article \"Pupillary and microsaccadic responses to cognitive effort and emotional arousal during complex decision making\" Krejtz, Żurawska, Duchowski, & Wichary (1) investigate pupillary and microsaccadic responses to information processing during multi-attribute decision making under affective priming. The participants were randomly assigned into three affective priming conditions (neutral, aversive, and erotic) and instructed to make discriminative decisions. As hypothesized by the authors, the results showed microsaccadic rate inhibition and pupillary dilation, depending on cognitive effort prior to decision and moderated by affective priming. Aversive priming increased pupillary and microsaccadic responses to information processing effort. The results indicate that pupillary response is more influenced by affective priming than microsaccadic rate. The results are discussed in the light of neuropsychological mechanisms of pupillary and microsaccadic behavior. In the article \"Microsaccadic rate signatures correlate under monocular and binocular stimulation conditions\" Essig, Leube, Rifai, & Wahl (2020) investigate microsaccades with respect to their directional distribution and rate under monocular and binocular conditions. In both stimulation conditions participants fixated a Gabor patch presented randomly in orientation of 45° or 135° over a wide range of spatial frequencies. Microsaccades were mostly horizontally oriented regardless of the spatial frequency of the grating. This outcome was consistent between both stimulation conditions. This study found that the microsaccadic rate signature curve correlates between both stimulation conditions, therefore extending the use of microsaccades to clinical applications, since parameters as contrast sensitivity, have frequently been measured monocularly in the clinical studies. The study \"Microsaccades during high speed continuous visual search\" by Martin, Davis, Riesenhuber, & Thorpe (3) provides an analysis of the microsaccades occurring during visual search, targeting to small faces pasted either into cluttered background photos or into a simple gray background. Participants were instructed to target singular 3-degree upright or inverted faces in changing scenes. As soon as the participant\'s gaze reached the target face, a new face was displayed in a different random location. Regardless of the experimental context (e.g. background scene, no background scene), or target eccentricity (from 4 to 20 degrees of visual angle), The authors found that the microsaccade rate dropped to near zero levels within 12 milliseconds. There were almost never any microsaccades after stimulus onset and before the first saccade to the face. In about 20% of the trials, there was a single microsaccade that occurred almost immediately after the preceding saccade\'s offset. The authors argue that a single feedforward pass through the visual hierarchy of processing a stimulus is needed to effectuate prolonged continuous visual search and provide evidence that microsaccades can serve perceptual functions like correcting saccades or effectuating task-oriented goals during continuous visual search. While many studies have characterized the eye movements during visual fixation, including microsaccades, in most cases only horizontal and vertical components have been recorded and analyzed. Little is known about the torsional component of microsaccades. In the study \"Torsional component of microsaccades during fixation and quick phases during optokinetic stimulation\" Sadeghpour & Otero-Millan (5) recorded eye movements around the three axes of rotation during fixation and torsional optokinetic stimulus. The authors found that the average amplitude of the torsional component of microsaccades during fixation was 0.34 ± 0.07 degrees with velocities following a main sequence with a slope comparable to the horizontal and vertical components. The size of the torsional displacement during microsaccades was correlated with the horizontal but not the vertical component. In the presence of an optokinetic stimulus a nystagmus was induced producing more frequent and larger torsional quick phases compared to microsaccades produced during fixation of a stationary stimulus. The torsional component and the vertical vergence component of quick phases increased with higher velocities. In previous research, microsaccades have been interpreted as psychophysiological indicators of task load. So far, it is still under debate how different types of task demands are influencing microsaccade rate. In their article \"The interplay between task difficulty and microsaccade rate: Evidence for the critical role of visual load\" Schneider et al. (6) examined the relation between visual load, mental load and microsaccade rate. The participants carried out a continuous performance task (n-back) in which visual task load (letters vs. abstract figures) and mental task load (1-back to 4-back) were manipulated as within-subjects variables. Eye tracking data, performance data as well as subjective workload were recorded. Data analysis revealed an increased level of microsaccade rate for stimuli of high visual demand (i.e. abstract figures), while mental demand (n-back-level) did not modulate microsaccade rate. The authors concluded that microsaccade rate reflects visual load of a task rather than its mental load. This conclusion is in accordance with the proposition of Krueger et al. (2) \"Microsaccades distinguish looking from seeing\", linking
sensory with cognitive phenomena. The present special thematic issue adds several new interesting facets to the research landscape around microsaccades. They still remain an attractive focus of interdisciplinary research and transdisciplinary applications. Thus, as already noted in the first part of this special thematic issue, research on microsaccades will not only endure, but keep evolving as the knowledge base expands.