Mothers' voices: Coping with their children's initial disability diagnosis

For parents of infants and toddlers receiving a diagnosis of disability, a variety of responses may result. Yet, little is known about the specific ways families cope with the initial diagnosis. This qualitative study investigated 6 mothers' memories of their children's diagnoses. Mothers described their use of both palliative strategies (denying, questioning, and wishful thinking) and problem‐solving strategies (searching for information, seeking social support, reframing, and seeking spiritual support) to cope with their children's initial diagnoses. The results of this study may improve professionals' understanding of parents' need for information and support at the time of initial diagnosis.     

Hefting for a maximum distance throw: a smart perceptual mechanism

Objects for throwing to a maximum distance were selected by hefting objects varying in size and weight. Preferred weights increased with size reproducing size-weight illusion scaling between weight and volume. In maximum distance throws, preferred objects were thrown the farthest. Throwing was related to hefting as a smart perceptual mechanism. Two strategies for conveying high kinetic energy to projectiles were investigated by studying the kinematics of hefting light, preferred, and heavy objects. Changes in tendon lengths occurring when objects of varying size were grasped corresponded to changes in stiffness at the wrist. Hefting with preferred objects produced an invariant phase between the wrist and elbow. This result corresponded to an optimal relation at peak kinetic energy for the hefting. A paradigm for the study of perceptual properties was compared to size-weight illusion methodology.     

Seeing Where the Stone Is Thrown by Observing a Point-Light Thrower: Perceiving the Effect of Action Is Enabled by Information,Not Motor Experience

People are very adept at perceiving biological motion (e.g., Johansson, 1973 Johansson, G. (1973). Visual perception of biological motion and a model for its analysis. Perception & Psychophysics, 14(2), 201–211.[Crossref], [Web of Science ®] , [Google Scholar]). This ability has been an essential life skill to members of this social species. The human niche during the ice age was socially coordinated hunting for big game. Being able to judge the location targeted by the throw of a conspecific would be a valuable perceptual ability that we now study to investigate 2 competing theories of biological motion perception: Common Coding (CC; Prinz, 1997 Prinz, W. (1997). Perception and action planning. European Journal of Cognitive Psychology, 9(2), 129–154.[Taylor & Francis Online], [Web of Science ®] , [Google Scholar]) and Kinematic Specification of Dynamics (KSD; Runeson & Frykholm, 1983 Runeson, S., & Frykholm, G. (1983). Kinematic specification of dynamics as an informational bias for person-and-action perception: Expectation, gender recognition, and deceptive intent. Journal of Experimental Psychology: General, 112, 585–615.[Crossref], [Web of Science ®] , [Google Scholar]). The 2 theories diverge in attributing perceptual ability to either motor or visual experience, respectively. To test predictions of the CC theory, we performed 3 experiments to manipulate observers' specific motor experience while they judged the targeted location of throwing by watching point-light displays. In Experiment 1, we tested whether the identity of the thrower in the display mattered. In Experiment 2, we tested whether the motor expertise of the observer mattered. In Experiment 3, we tested whether the gender/style of throwing demonstrated by the point-light thrower mattered. The combined results failed to support CC theory, suggesting that motor experience is not required for the perception of action. Because all participants judged the target location of throwing quite well, KSD theory suggests that the kinematic information available in the displays may have enabled the perception. We performed Experiment 4 to analyze the information. We found that the judgment pattern exhibited by the observers in both Experiments 1 and 2 was well predicted by the KSD theory. Thus, we concluded that the perception of biological motion is enabled by visual information and improved by visual experience.     

Distortions in definite distance and shape perception as measured by reaching without and with haptic feedback

Psychophysical studies reveal distortions in perception of distance and shape. Are reaches calibrated to eliminate distortions? Participants reached to the front, side, or back of a target sphere. In Experiment 1, feedforward reaches yielded distortion and outward drift. In Experiment 2, haptic feedback corrected distortions and instability. In Experiment 3, feedforward reaches with only haptic experience of targets replicated the shape distortions but drifted inward. This showed that outward drift in Experiment 1 was visually driven. In Experiment 4, visually guided reaches were accurate when participants used binocular vision but when they used monocular vision, reaches were distorted. Haptic feedback corrected inaccuracy and instability of distance but did not correct monocular shape distortions. Dynamic binocular vision is representative and accurate and merits further study.     

When kinesthetic information is neglected in learning a Novel bimanual rhythmic coordination

Many studies have shown that rhythmic interlimb coordination involves perception of the coupled limb movements, and different sensory modalities can be used. Using visual displays to inform the coupled bimanual movement, novel bimanual coordination patterns can be learned with practice. A recent study showed that similar learning occurred without vision when a coach provided manual guidance during practice. The information provided via the two different modalities may be same (amodal) or different (modality specific). If it is different, then learning with both is a dual task, and one source of information might be used in preference to the other in performing the task when both are available. In the current study, participants learned a novel 90° bimanual coordination pattern without or with visual information in addition to kinesthesis. In posttest, all participants were tested without and with visual information in addition to kinesthesis. When tested with visual information, all participants exhibited performance that was significantly improved by practice. When tested without visual information, participants who practiced using only kinesthetic information showed improvement, but those who practiced with visual information in addition showed remarkably less improvement. The results indicate that (1) the information is not amodal, (2) use of a single type of information was preferred, and (3) the preferred information was visual. We also hypothesized that older participants might be more likely to acquire dual task performance given their greater experience of the two sensory modes in combination, but results were replicated with both 20- and 50-year-olds.     

Reaching measures of monocular distance perception: forward versus side-to-side head movements and haptic feedback

We investigated whether forward or side-to-side head movements yielded more accurate and precise monocular egocentric distance information, as shown by performance in a reaching task. Observers wore a head-mounted camera and display to isolate the optic flow generated by their head movements and had to reach to align a stylus directly under a target surface. Performance in the two head movement conditions was also tested with normal monocular vision. We tested performance in the two head movement conditions when the observers were given haptic feedback and compared performance when haptic feedback was removed. Performance was both more accurate and more precise in the forward head movement condition than in the side-to-side head movement condition. Performance in the side-to-side condition also deteriorated more after the removal of haptic feedback than did performance in the forward head movement condition. In the normal monocular condition, performance was comparable for the two head movement conditions. The implications for enucleated patients are discussed.     

Center of mass perception: Perturbation of symmetry

Bingham and Muchisky (1993) found that observers were very accurate in determining the location of the center of mass in planar objects. Systematic errors were affected primarily by object orientation, while random errors varied with the amount of symmetry. Radial and axial reflective symmetry affected errors in different ways. In the current study, we investigated the different effects of axial reflective versus rotational symmetry. All random errors decreased with increasing rotational symmetry. Axial reflective symmetry further reduced errors in the direction perpendicular to the axis. We replicated the effect on systematic error of orientation. However, we also found an effect of the perturbation of symmetry that suggested that observers used an approximation to symmetry. To investigate this possibility, we constructed a series of objects in which axial reflective symmetry was established and then perturbed by varying amounts. We found that systematic errors were structured by the underlying approximate symmetries, and we discuss the problem of quantifying symmetry.     

Causation,causal perception,and conservation laws

We investigated the perception of causation via the ability to detect conservation violations in simple events. We showed that observers were sensitive to energy conservation violations in free-fall events. Furthermore, observers were sensitive to gradually perturbed energy dynamics in such events. However, they were more sensitive to the effect of decreasing gravity than to that of increasing gravity. Displays with decreasing gravity were the only displays in which the energy profile was dominated by (apparent) potential energy, leading to an asymmetric trajectory.