Discomfort with space and motion: A possible marker of vestibular dysfunction assessed by the situational characteristics questionnaire

Space and motion discomfort (SMD) refers to the situational specificity of symptoms occurring in some patients with vestibular dysfunction, such as those with balance disorders and some with panic disorder. SMD occurs in situations characterized by inadequate visual or kinesthetic information for normal spatial orientation. We report the results of two studies of the construct validity of the Situational Characteristics Questionnaire (SitQ), which has two subscales, both of which measure SMD: the SMD-I and SMD-II. In Study 1, the SitQ was administered to members of a self-help group for balance disorders, a psychiatric sample consisting of patients with panic disorder, nonpanic anxiety disorders, depression, and a sample of normals. SMD levels were the highest in the self-help balance group, next to the highest in the panic groups, and lowest in the remaining groups. In Study 2, the SitQ was administered to otolaryngological patients with vestibular dysfunction and to patients with hearing loss. SMD levels were higher in the vestibular patients. Data on internal consistency, test-retest reliability, and convergent and discriminant validity are presented. The SitQ, particularly the SMD-II, is recommended for quantifying space and motion discomfort in patients with anxiety and/or balance disorders.Study 1 was funded by MH 40757. Study 2 was funded by a grant from the Upjohn Company and MH 19816.     

On the minimal relative motion principle—lateral displacement of a contracting bar

Xausa, Beghi, and Zanforlin (J. Math. Psychol. 45(4) (2001) 635) provide an account of perceptual organization based on their ‘minimal relative motion’ principle. They claim that this principle can account for the percept generated by a contracting bar that is simultaneously translating laterally. We critique the mathematical analysis provided in the aforementioned paper. We conclude that the ‘minimal relative motion’ principle, in the form presented, cannot adequately explain the percept reported by observers.     

运动空间定向判断中的方向偏差及飞行惯性

模拟客体起飞和降落运动,探讨飞行场景中不同运动位置、不同意义客体和运动方向下个体运动空间定向判断能力。结果表明：(1)对降落运动轨迹的判断正确率显著低于起飞运动;(2)无意义客体偏高轨迹的判断正确率显著小于偏低轨迹,表现出方向偏差;(3)飞行场景影响方向偏差的表现形式,当飞机降落运动时,易将偏低路径判断为与预设轨迹相同,而飞机起飞运动时,易将偏高路径判断为相同,表明降落时飞机被知觉为会向斜下方越飞越低,而起飞时飞机会向斜上方越飞越高,表现出飞行惯性。结论：运动空间定向判断受到重力表征及个体知识经验等共同影响,具有认知可渗透性。     

Multi-segmental thoracic spine kinematics measured dynamically in the young and elderly during flexion

In contrast to the cervical and lumbar region, the normal kinematics of the thoracic spine have not been thoroughly investigated. The aim of this study was to characterize normal multi-segmental continuous motion of the whole thoracolumbar spine, during a flexion maneuver, in young and elderly subjects. Forty-two healthy volunteers were analyzed: 21 young (age = 27.00 ± 3.96) and 21 elderly (age = 70.1 ± 3.85). Spinal motion was recorded with a motion-capture system and analyzed using a 3rd order polynomial function to approximate spinal curvature throughout the motion sequence. The average motion profiles of the two age groups were characterized. Flexion timing of the thoracic region of the spine, as compared to the lumbar spine and hips, was found to be different in the two age groups (p = 0.011): a delayed/sequential motion type was observed in most of the young, whereas mostly a simultaneous motion pattern was observed in the elderly subjects. A similar trend was observed in flexion of the lower thoracic segments (p = 0.017). Differences between age groups were also found for regional and segmental displacements and velocities. The reported characterization of the thoracic spine kinematics may in the future support identification of abnormal movement or be used to improve biomechanical models of the spine.     

闪光滞后效应的机制：时间错觉与空间错觉

闪光滞后效应（flash—lag effect,FLE）是指在与某运动物体相同的位置上呈现的闪光（flash）知觉上滞后于该运动物体的视错觉。本文简要介绍了有关闪光滞后效应机制的理论模型。笔者认为,目前各种理论的争议可归结为时间错觉假说与空间错觉假说之争,并在此基础上就今后进一步研究的方向提出了建议。     

Effects of stimulus eccentricity on vection reevaluated with a binocularly defined depth1

Abstract: The effects of stimulus eccentricity (central or peripheral) on vection (visually induced self‐motion perception) were investigated using a stimulus combination consisting of a static foreground and a moving background, the depths of which were defined by binocular disparity. By using these stimulus settings, the effect of stimulus eccentricity can be assessed without any artifacts in the perceived depth of the stimulus, which would covary with the stimulus eccentricity. The results of this psychophysical experiment indicated that stimulus eccentricity cannot affect the strength of vection, and that both the central and peripheral stimuli can induce self‐motion perception with equal magnitudes if the stimulus sizes are equalized. The present investigation, which used a controlled stimulus depth condition, clearly negated the idea of the peripheral dominance of vection, which has been accepted for a long time.     

Children's understanding of directed motion events in an imitation choice task

We investigated children’s understanding of directed motion events using an imitation choice paradigm. A total of 34 children (mean age 33 months) watched a model act out an event containing a manner of motion (hopping or sliding), a motion path (up or down a ramp), and a goal (in or on a bowl). On the children’s apparatus, the locations of the goal objects were different from the model so that the children needed to choose whether to imitate the path or the goal of the model’s event. Children’s choice of which component to imitate, therefore, reflects how they prioritize these event components. Most children showed no bias to imitate the goal of the event and, instead, preferred to imitate the model’s path at the expense of the model’s goal. However, children who spontaneously played with the goal objects during a free play session showed a diminished path preference, choosing to imitate path and goal components equally often. We suggest that children’s prioritization of information within an event depends on how that information is structured within the event itself.     

视觉运动追踪的加工过程

视觉运动追踪是运动知觉研究的一个重要领域。通过构建视觉运动追踪的过程模型和分析每个阶段的认知加工任务, 可以帮助人们认识运动物体识别的本质。视觉运动追踪包括目标获取和运动追踪两个加工过程：目标获取阶段的主要任务是将目标与背景分离, 集中注意力加工追踪目标; 运动追踪阶段的主要任务是启动平滑追踪眼动和追赶性眼跳, 并发挥行为水平、眼动水平和神经活动水平的预测机制。目标获取同时受背景和目标的运动特征和身份特征影响; 运动追踪系统发挥预测机制的基础是客体表征连续性, 而客体表征连续性的建立同时依赖于目标时空属性和身份特征的编码加工。因此, 视觉运动追踪是视觉系统对客体运动信息和身份语义信息整合的结果。其中, 客体运动信息的加工特性已经获得了比较广泛的研究, 而语义信息加工机制还有待进一步加强。