Richard A. Faldowski

Perceptual dimensions of tactile surface texture: A multidimensional scaling analysis

The purpose of this study was to examine the subjective dimensionality of tactile surface texture perception. Seventeen tactile stimuli, such as wood, sandpaper, and velvet, were moved across the index finger of the subject, who sorted them into categories on the basis of perceived similarity. Multidimensional scaling (MDS) techniques were then used to position the stimuli in a perceptual space on the basis of combined data of 20 subjects. A three-dimensional space was judged to give a satisfactory representation of the data. Subjects’ ratings of each stimulus on five scales representing putative dimensions of perceived surface texture were then fitted by regression analysis into the MDS space. Roughness-smoothness and hardness-softness were found to be robust and orthogonal dimensions; the third dimension did not correspond closely with any of the rating scales used, but post hoc inspection of the data suggested that it may reflect the compressional elasticity (“springiness”) of the surface.

Classroom emotional climate as a moderator of anxious solitary children's longitudinal risk for peer exclusion: a child × environment model.

This study tests the ability of classroom emotional climate to moderate anxious solitary childrens risk for peer exclusion over a 3-year period from 3rd through 5th grade. Six hundred eighty-eight children completed peer nominations for anxious solitude and peer exclusion in the fall and spring semesters of each grade, and observations of classroom emotional climate were conducted at the same time points. Results revealed a positive relation between anxious solitude and peer exclusion in the fall semester of each grade. However, in classrooms with supportive versus unsupportive emotional climates, this relation demonstrated a different pattern of change from fall to spring semesters. In classrooms with supportive emotional climates, children with high versus low levels of anxious solitude experienced relative elevation in fall peer exclusion, but this disappeared by the spring, such that spring peer exclusion levels were equalized among children who differed in anxious solitude. This result is consistent with hypotheses guided by the Child × Environment model. However, in classrooms with unsupportive emotional climates, results did not conform to expectations that children with high anxious solitude would experience stable or increased peer exclusion over time.

27 Multivariate statistical visualization

Publisher Summary This chapter focuses on dynamic statistical graphics methods for exploring multivariate data, methods that are called “multivariate statistical visualization methods,” and discusses the three major aspects of multivariate statistical visualization—namely, data visualization, model visualization, and analysis visualization. Multivariate statistical visualization methods capitalize on the pattern recognition power of human vision and on the computational power of graphics workstations to help data analysts look for structure (to form hypotheses) that may be in their multivariate data. The goal of multivariate statistical visualization is to aid in forming hypotheses about the datas high-dimensional (hD) geometric structure. To do this, the visualization must (1) respect the datas high-dimensional geometry; (2) respect the users three-dimensional perception; and; (3) respect the workstations two-dimensional screen and its other computational limits. Thus, the problem that all multivariate statistical visualization methods must tackle is the way to present hD information in a 2D plane such that the 3D perception of a user can understand the hD geometry.

Anxious solitude and the middle school transition: A diathesis × stress model of peer exclusion and victimization trajectories.

Consistent with a Diathesis × Stress model, it was hypothesized that anxious solitude (individual vulnerability) and the middle school transition (environmental stress) would jointly predict peer exclusion and victimization trajectories. Youth (N = 688) were followed from 3rd through 7th grade, with the middle school transition in 6th grade. Peer-reported peer exclusion and physical victimization trajectories across the middle school transition were modeled with piecewise growth curves. As expected, anxious solitude predicted elevated exclusion and victimization in both elementary and middle school. Nonetheless, exclusion and victimization declined after the transition on average, and anxious solitary youth versus average youth experienced greater relative declines. The pattern of results suggests that the collective renegotiation of peer relations after the transition, rather than posttransition decline in classroom emotional support, contributed to the posttransition decline in peer mistreatment.

Gossip: The Architecture of SpreadPlots

A spreadplot is a visualization that simultaneously shows several different views of a dataset or model. The individual views can be dynamic, can support high-interaction direct manipulation, and can be algebraically linked with each other, possibly via an underlying statistical model. Thus, when a data analyst changes the information shown in one view of a statistical model, the changes can be processed by the model and instantly represented in the other views. Spreadplots simplify the analysts task when many different plots are relevant to the analysis at hand, as is the case in regression analysis, where there are many plots that can be used for model building and diagnosis. On the other hand, the development of a visualization involving many dynamic, highly interactive, directly manipulable graphics is not a trivial task. This article discusses a software architecture which simplifies the spreadplot developers task. The architecture addresses the two main problems in constructing a spreadplot, simplifying the layout of the plots and structuring the communication between them.

Sensory and repetitive behaviors among children with autism spectrum disorder at home

Atypical sensory and repetitive behaviors are defining features of autism spectrum disorder and are thought to be influenced by environmental factors; however, there is a lack of naturalistic research exploring contexts surrounding these behaviors. This study involved video recording observations of 32 children with autism spectrum disorder (2–12 years of age) engaging in sensory and repetitive behaviors during home activities. Behavioral coding was used to determine what activity contexts, sensory modalities, and stimulus characteristics were associated with specific behavior types: hyperresponsive, hyporesponsive, sensory seeking, and repetitive/stereotypic. Results indicated that hyperresponsive behaviors were most associated with activities of daily living and family-initiated stimuli, whereas sensory seeking behaviors were associated with free play activities and child-initiated stimuli. Behaviors associated with multiple sensory modalities simultaneously were common, emphasizing the multi-sensory nature of children’s behaviors in natural contexts. Implications for future research more explicitly considering context are discussed.

Individuals Poststroke Do Not Perceive Their Spatiotemporal Gait Asymmetries as Abnormal

Background Following stroke, spatiotemporal gait asymmetries persist into the chronic phases, despite the neuromuscular capacity to produce symmetric walking patterns. This persistence of gait asymmetry may be due to deficits in perception, as the newly established asymmetric gait pattern is perceived as normal. Objective The purpose of this study was to determine the effect of usual overground gait asymmetry on the ability to consciously and unconsciously perceive the presence of gait asymmetry in people poststroke. Design An observational study was conducted. Methods Thirty people poststroke walked overground and on a split-belt treadmill with the belts moving at different speeds (0%–70% difference) to impose varied step length and stance time asymmetries. Conscious awareness and subconscious detection of imposed gait patterns were determined for each participant, and the asymmetry magnitudes at those points were compared with overground gait. Results For both spatial and temporal asymmetry variables, the asymmetry magnitude at the threshold of awareness was significantly greater than the asymmetry present at the threshold of detection or during overground gait. Participants appeared to identify belt speed differences using the type of gait asymmetry they typically exhibited (ie, step length or stance time asymmetries during overground gait). Limitations Very few individuals with severe spatiotemporal asymmetry were tested, and participants were instructed to identify asymmetric belt speeds rather than interlimb movements. Conclusions The data suggest that asymmetry magnitudes need to exceed usual overground levels to reach conscious awareness. Therefore, it is proposed that the spatiotemporal asymmetry that is specific to each participant may need to be augmented beyond what he or she usually has during walking in order to promote awareness of asymmetric gait patterns for long-term correction and learning.

Do hand preferences predict stacking skill during infancy

The cascade theory of handedness suggests that hand preferences develop from a history of cascading and sequentially developing manual asymmetries for a variety of actions. Infants who consistently use their preferred hand for a variety of actions likely would gain proficiency using that preferred hand and, consequently, perform more proficiently on other challenging manual tasks. One such task is object stacking, which has been linked with a number of cognitive abilities. If infant hand preference facilitates the development of stacking skill, then this could provide a link by which early hand preference might affect the development of cognition. From a sample of 380 infants assessed for an acquisition hand preference across 6-14 months, 131 infants were assessed for stacking skill from 10 to 14 months at monthly visits. Four unique handedness sub-groups were identified from the 380-infant sample: left, trending right, stable right, or no hand preference. Each of the four hand preference groups exhibited different trajectories in the development of their stacking skills. Left- and stable right-handers stacked more items than infants with no preference by 14 months, whereas infants with a trending right preference did not. The proportion of preferred hand use (right and left) from 6 to 9 months also predicted an earlier initial onset of stacking skill, whereas the proportion of only right hand use did not. Thus, the development of a hand preference predicts an earlier emergence of stacking skill and may have implications for other domains of infant cognitive development.

Listener perceptions of simulated fluent speech in nonfluent aphasia

Background: People with aphasia (PWA) are frequently perceived less favourably by listeners than their peers. These perceptions include incorrect assumptions that can prevent successful social interactions. While communication partner training has been shown to improve social outcomes related to the listener, changing the verbal output of PWA may also yield more favourable listener perceptions about the speech, speaker, and their own affective response. We investigated the effects of artificially altered fluency (i.e., simulated fluency) on listeners’ subjective impressions. Aims: The purpose of the study was to (1) confirm that listeners perceive PWA less favourably than their neurologically healthy peers and (2) determine the effects of simulated fluency on listener perceptions about PWA. Methods & Procedures: Thirty-eight listeners heard nine narrative monologue language samples from three conditions (i.e., speakers with nonfluent aphasia, simulated fluent samples from the same speakers, and neurologically healthy speakers). Listeners responded to a nine-item questionnaire that probed perceptions about speech output, speaker attributes, and listener feelings. Outcomes & Results: Listeners perceived PWA less favourably than their neurologically healthy peers. Simulated fluency yielded more positive listener perceptions for all questionnaire items except speech intelligibility, which was unchanged by simulated fluency. Conclusions: Simulated fluency improved listener perceptions of PWA significantly, indicating that speech fluency may be a socially valid treatment target in aphasia. Beyond direct training of communication partners, changing the verbal output of aphasic speech can also yield more positive listener perceptions of PWA.

A Retrospective Video Analysis of Canonical Babbling and Volubility in Infants with Fragile X Syndrome at 9–12 Months of Age

An infant’s vocal capacity develops significantly during the first year of life. Research suggests early measures of pre-speech development, such as canonical babbling and volubility, can differentiate typical versus disordered development. This study offers a new contribution by comparing early vocal development in 10 infants with Fragile X syndrome and 14 with typical development. Results suggest infants with Fragile X syndrome produce fewer syllables and have significantly lower canonical babbling ratios compared to infants who are typically developing. Furthermore, the particular measures of babbling were strong predictors of group membership, adding evidence regarding the possible utility of these markers in early identification.