图形同一性对视觉似动的影响

该研究以单字母为刺激材料考察了图形同一性对视觉似动的影响。按照图形同一性、字母顺序及图形位移方向的不同,字母图形分成４类。另外还比较了聚焦和不聚焦条件下的实验结果。实验中要求被试对字母作左向、右向或来回运动的判断。结果表明似动现象不仅受到刺激间的空间关系的影响,而且也受到刺激间的图形同一性的影响。     

Detection and discrimination of optical flow components

Observers viewed animation sequences consisting of random dots, some of which moved coherently in a given direction (signal dots) and the rest of which moved randomly (noise dots). Using forced-choice procedures, detectability of weak signals within noise was measured for translation, rotation, and expansion/contraction. Sensitivity to all motion types was approximately equal, with practiced observers reliably detecting coherent motion at signal levels as low as 4%. Observers were able to identify the motion structure presented on a given trial at signal levels corresponding to the detection threshold, implying that the neural signals supporting detection are labeled for motion type. Results are discussed in the context of hierarchical analysis of optic flow in which all motion types are registered as patterns of activity among neurons comprising a single mechanism.     

Something in the way she moves: biological motion,body shape,and attractiveness in women

Most previous research into the attractiveness of women’s bodies has relied on static stimuli such as line-drawings or photographs, particularly focusing on the role of body-mass index (BMI) and waist-to-hip ratio (WHR). However, real attractiveness judgments are invariably made on moving bodies, and movement may contain important information about attractiveness. We measured the importance of movement in attractiveness judgments by using motion-capture to isolate dynamic cues from 37 female walkers, and compare ratings of 75 participants made on these, static photographs, and the original videos. Multiple regression analysis revealed that both dynamic and static cues were important in the attractiveness of women’s bodies. Furthermore, BMI and WHR predicted attractiveness, but BMI was more important in dynamic rather than static cues, while WHR was important for both static and dynamic cues. These findings suggest that movement plays a crucial part in the attractiveness of female bodies and cannot be ignored in studies of human mate choice. Furthermore, dynamic and static cues may contain differential information related to female body shape, which further research should attempt to elucidate.     

遮挡范式下运动速度和方向对碰撞时间估计绩效指标的影响

为探索运动速度和方向对碰撞时间（TTC）估计的影响,采用3运动速度×4运动方向的双因素设计开展了实验研究。结果发现,在相对慢速条件下,受试者TTC估计的准确性显著差于相对中速和相对快速条件;仅在相对慢速条件下受试者对竖直方向的TTC估计准确度显著差于水平方向、低估TTC的比例显著高于高估TTC的比例。结果表明,运动速度对TTC估计绩效指标的影响相对较强,运动方向对其影响相对较弱;两个因素的影响存在交互作用。     

Infant perception of causal motion produced by humans and inanimate objects

Both the movements of people and inanimate objects are intimately bound up with physical causality. Furthermore, in contrast to object movements, causal relationships between limb movements controlled by humans and their body displacements uniquely reflect agency and goal-directed actions in support of social causality. To investigate the development of sensitivity to causal movements, we examined the looking behavior of infants between 9 and 18 months of age when viewing movements of humans and objects. We also investigated whether individual differences in gender and gross motor functions may impact the development of the visual preferences for causal movements. In Experiment 1, infants were presented with walking stimuli showing either normal body translation or a “moonwalk” that reversed the horizontal motion of body translations. In Experiment 2, infants were presented with unperformable actions beyond infants’ gross motor functions (i.e., long jump) either with or without ecologically valid body displacement. In Experiment 3, infants were presented with rolling movements of inanimate objects that either complied with or violated physical causality. We found that female infants showed longer looking times to normal walking stimuli than to moonwalk stimuli, but did not differ in their looking time to movements of inanimate objects and unperformable actions. In contrast, male infants did not show sensitivity to causal movement for either category. Additionally, female infants looked longer at social stimuli of human actions than male infants. Under the tested circumstances, our findings indicate that female infants have developed a sensitivity to causal consistency between limb movements and body translations of biological motion, only for actions with previous visual and motor exposures, and demonstrate a preference toward social information.     

Assessment of information content in visual signal: analysis of optical flow fractal complexity

We make a first attempt at distinguishing an information-carrying visual signal by comparing visual characteristics of American Sign Language to everyday human motion, to identify what clues might be available in one but not in the other. The comparison indicated significantly higher fractal complexity in sign language across tested frequency bands (0.01–15?Hz), as compared to everyday motion. A comparison of our results with other work showing high fractal complexity in the speech signal allows us to suggest the underlying properties of linguistic signals which allow babies to “tune into” a specific channel, or modality, during language acquisition.     

老年人整体运动敏感性降低的脑灰质体积变化基础

本研究使用多体素模式分析方法和随机点阵范式,首次探索了老年人整体运动敏感性（GMS）下降和其脑灰质体积下降间的关系。结果发现,老年人GMS显著低于年轻人,老年人V5/MT、V3和额顶等脑区灰质体积显著小于年轻人;V5/MT和V3区的灰质体积信号可以有效预测个体的GMS。结果提示,V5/MT区和V3区,特别是V3区的灰质体积下降可能是老年人GMS下降的主要原因;而基于“去分化假设”,全脑范围内其余脑区的灰质体积下降可能也在一定程度上与老年人GMS下降有关。     

The impact of physical load on duration estimation in sport

We investigated whether physical load has an influence on the accuracy of duration estimation of sporting activities presented in real time and slow motion. 86 participants were studied in two single sessions of 45 min each.Our results showed no general effects for physical load, when comparing physical load versus rest. However, we could replicate findings of past research (Schütz et al., 2021), showing that the duration of sports performance is estimated more accurately when presented in real time compared to slow motion. Further we found, that under physical load, participants perceiving the physical exercise as hard (RPE ≥15) estimated time significantly shorter and more accurately compared to participants perceiving the physical exercise as light or moderate (RPE <15).Thus, our results suggest that using slow motion may worsen the assessment of sports performance. Additionally, we could show that intense physical exertion contributes to reducing the overestimation of time.     

Motion as a natural category for pigeons: Generalization and a feature-positive effect

Three groups of pigeons were trained with a modified discriminative autoshaping procedure to discriminate video images of other pigeons on the basis of movement. Birds of all groups were shown the same video images of other pigeons, which were either moving or still. The group to whom food was presented only after moving images learned the discrimination very quickly. A second group, to whom food was given only after still images, and a pseudocategory group, to whom food was presented after arbitrarily chosen stimuli, showed no evidence of discrimination during acquisition training. Extinction conditions led to clear differences in peck rates to moving and still images in the second group but not in the pseudocategory group. The result is related to the feature-positive effect. Generalization tests showed that the discrimination performance was based on visual features of the stimuli but was invariant against changes of size, perspective, brightness, and color. Furthermore, discrimination was maintained when novel images of pigeons under different viewing angles and seven other types of motion categories were presented. It is argued that the discrimination is based not on a common motion feature but on motion concepts or high-order generalization across motion categories.