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.     

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.     

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。     

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.     

EVENT SEGMENTATION

ABSTRACT— One way to understand something is to break it up into parts. New research indicates that segmenting ongoing activity into meaningful events is a core component of perception and that this has consequences for memory and learning. Behavioral and neuroimaging data suggest that event segmentation is automatic and that people spontaneously segment activity into hierarchically organized parts and subparts. This segmentation depends on the bottom-up processing of sensory features such as movement and on the top-down processing of conceptual features such as actors' goals. How people segment activity affects what they remember later; as a result, those who identify appropriate event boundaries during perception tend to remember more and to learn more proficiently.     

Attention to endpoints: a cross-linguistic constraint on spatial meaning

We investigate a possible universal constraint on spatial meaning. It has been proposed that people attend preferentially to the endpoints of spatial motion events, and that languages may therefore make finer semantic distinctions at event endpoints than at event beginnings. We test this proposal. In Experiment 1, we show that people discriminate the endpoints of spatial motion events more readily than they do event beginnings-suggesting a non-linguistic attentional bias toward endpoints. In Experiment 2, speakers of Arabic, Chinese, and English each described a set of spatial events displayed in video clips. Although the spatial systems of these languages differ, speakers of all three languages made finer semantic distinctions at event endpoints, compared to event beginnings. These findings are consistent with the proposal that event endpoints are privileged over event beginnings, in both language and perception.     

La chair vécue du cerveau : un objet épistémologique du cerveau psychologique

The psychological brain is an object, invented in the history of psychophysiology, which finds today an epistemological renewal in the neurosciences of the action and the emotion: the moving body is from now on an alive subject in the heart of psychological research.     

Cortical locus of coherent motion deficits in deaf poor readers

Samar and Parasnis [Samar, V. J., & Parasnis, I. (2005). Dorsal stream deficits suggest hidden dyslexia among deaf poor readers: correlated evidence from reduced perceptual speed and elevated coherent motion detection thresholds. Brain and Cognition, 58, 300-311.] reported that correlated measures of coherent motion detection and perceptual speed predicted reading comprehension in deaf young adults. Because deficits in coherent motion detection have been associated with dyslexia in the hearing population, and because coherent motion detection is strongly dependent on extrastriate cortical area MT, these results are consistent with the claim that hidden dyslexia occurs within the deaf population and is associated with deficits in MT. However, coherent motion detection can also be influenced by subcortical deficits in both magnocellular and parvocellular pathways. To confirm the putative cortical locus of coherent motion perception deficits, we measured contrast thresholds for detecting the direction of movement of drifting sine wave gratings in the same participant group as [Samar, V. J., & Parasnis, I. (2005). Dorsal stream deficits suggest hidden dyslexia among deaf poor readers: correlated evidence from reduced perceptual speed and elevated coherent motion detection thresholds. Brain and Cognition, 58, 300-311.], under stimulus conditions that selectively biased for input from the subcortical magnocellular and parvocellular pathways, respectively. Contrast thresholds were not related to reading comprehension performance under either the magnocellular or parvocellular conditions. Furthermore, the previously reported correlations among reading comprehension, coherent motion thresholds, and perceptual speed remained significant even after contrast thresholds and non-verbal IQ were controlled in partial correlation analyses. In addition, coherent motion detection thresholds were found to correlate specifically with a reading-IQ discrepancy score, one commonly used indicator of dyslexia. These results provide direct psychophysical evidence that the previously reported deficit in coherent motion detection in deaf poor readers does not involve subcortical pathway deficits, but rather is associated with a cortical deficit likely involving area MT. They also strengthen the argument for the existence of hidden dyslexia in the deaf adult population.