Predicting the biological variability of environmental rhythms: Weak or strong anticipation for sensorimotor synchronization?

The internal processes involved in synchronizing our movements with environmental stimuli have traditionally been addressed using regular metronomic sequences. Regarding real-life environments, however, biological rhythms are known to have intrinsic variability, ubiquitously characterized as fractal long-range correlations. In our research we thus investigate to what extent the synchronization processes drawn from regular metronome paradigms can be generalized to other (biologically) variable rhythms. Participants performed synchronized finger tapping under five conditions of long-range and/or short-range correlated, randomly variable, and regular auditory sequences. Combining experimental data analysis and numerical simulation, we found that synchronizing with biologically variable rhythms involves the same internal processes as with other variable rhythms (whether totally random or comprising lawful regularities), but different from those involved with a regular metronome. This challenges both the generalizability of conclusions drawn from regular-metronome paradigms, and recent research assuming that biologically variable rhythms may trigger specific strong anticipatory processes to achieve synchronization.     

Searching in the sand: Protracted video deficit in U.S. preschoolers' spatial recall using a continuous search space

Young children exhibit a video deficit for spatial recall, learning less from on-screen than in-person demonstrations. Some theoretical accounts emphasize memory constraints (e.g., insufficient retrieval cues, competition between memory representations). Such accounts imply memory representations are graded, yet video deficit studies measuring spatial recall operationalize memory retrieval as dichotomous (success or failure). The current study tested a graded-representation account using a spatial recall task with a continuous search space (i.e., sandbox) rather than discrete locations. With this more sensitive task, a protracted video deficit for spatial recall was found in children 4–5 years old (n = 51). This may be due to weaker memory representations in the screen condition, evidenced by higher variability and greater perseverative bias. In general, perseverative bias decreased with repeated trials. The discussion considers how the results support a graded-representation account, potentially explaining why children might exhibit a video deficit in some tasks but not others.

Research Highlights

• The task used a continuous search space (sandbox), making it more difficult and sensitive than spatial recall tasks used in prior video deficit research.
• Spatial recall among 4- and 5-year-old children was more variable after watching hiding events on screen via live video feed than through a window.
• Children's spatial recall from screens was more susceptible to proactive interference, evidenced by more perseverative bias in an A-not-B design.
• The results demonstrate memory representations blend experiences that accumulate over time and explain why the video deficit may be protracted for more difficult tasks.

     

Holding multiple category representations: The role of age,theory of mind,and rule switching in children’s developing cross-classification abilities

Cross-classification, the ability to categorize multifaceted entities in many ways, is a remarkable cognitive milestone for children. Past work has focused primarily on documenting the timeline for when children reach cross-classification competence. However, it is not well understood what cognitive factors underpin children’s improvements. The current study aimed to examine the contributions of age, theory of mind, and rule switching to children’s cross-classification development. We tested 3- to 5-year-old children (N = 75) using a cross-classification task, the Theory of Mind Task Battery, and the Three-Dimensional Change Card Sort test. The results revealed that age and theory of mind predict children’s cross-classification over and above the effects of rule switching. The results also revealed that advanced-level theory of mind reasoning is a particularly strong predictor of cross-classification development. These findings increase understanding of cross-classification within children’s broader cognitive development.     

Fractions as percepts? Exploring cross-format distance effects for fractional magnitudes

This study presents evidence that humans have intuitive, perceptually based access to the abstract fraction magnitudes instantiated by nonsymbolic ratio stimuli. Moreover, it shows these perceptually accessed magnitudes can be easily compared with symbolically represented fractions. In cross-format comparisons, participants picked the larger of two ratios. Ratios were presented either symbolically as fractions or nonsymbolically as paired dot arrays or as paired circles. Response patterns were consistent with participants comparing specific analog fractional magnitudes independently of the particular formats in which they were presented. These results pose a challenge to accounts that argue human cognitive architecture is ill-suited for processing fractions. Instead, it seems that humans can process nonsymbolic ratio magnitudes via perceptual routes and without recourse to conscious symbolic algorithms, analogous to the processing of whole number magnitudes. These findings have important implications for theories regarding the nature of human number sense – they imply that fractions may in some sense be natural numbers, too.     

Moving words: dynamic representations in language comprehension

Eighty-two participants listened to sentences and then judged whether two sequentially presented visual objects were the same. On critical trials, participants heard a sentence describe the motion of a ball toward or away from the observer (e.g., “The pitcher hurled the softball to you”). Seven hundred and fifty milliseconds after the offset of the sentence, a picture of an object was presented for 500 ms, followed by another picture. On critical trials, the two pictures depicted the kind of ball mentioned in the sentence. The second picture was displayed 175 ms after the first. Crucially, it was either slightly larger or smaller than the first picture, thus suggesting movement of the ball toward or away from the observer. Participants responded more quickly when the implied movement of the balls matched the movement described in the sentence. This result provides support for the view that language comprehension involves dynamic perceptual simulations.     

Community as practice: social representations of community and their implications for health promotion

Health promotion researchers and practitioners have increasingly turned to community-based approaches. Although there has been much work around the diverse understandings of the term in areas such as community psychology and sociology, I am concerned with how such understandings relate directly to community health research and practice. From a discursive perspective ‘community’ is seen as a socially constructed representation that is used variously and pragmatically. However, from a wider view, community can be seen as a matter of embodied practice. This paper draws on social representations theory to examine the shifting constructions of ‘community’, the functional use of those understandings in social life, and the practices that suggest that it is important to attend to their use in particular contexts. Accordingly, the paper argues that meanings of community in the health promotion or public health context must be seen as representations used for specific purposes in particular situations. Furthermore, the broader notion of embodied practice in social life has implications for community participation in health promotion. Copyright © 2007 John Wiley & Sons, Ltd.     

Attentional focus effects on joint covariation in a reaching task

Adopting an external focus of attention (EF) has been found beneficial over internal focus (IF) for performing motor skills. Previous studies primarily examined focus of attention (FOA) effects on performance outcomes (such as error and accuracy), with relatively less emphasis on movement coordination. Given that human movements are kinematically and kinetically abundant (Gefland & Latash, 1998), FOA instructions may change how motor abundance is utilized by the CNS. This study applied the uncontrolled manifold analysis (UCM) to address this question in a reaching task. Healthy young adults (N = 38; 22 ± 1 yr; 7 men, 31 women) performed planar reaching movements to a target using either the dominant or nondominant arm under two different FOA instructions: EF and IF. Reaching was performed without online visual feedback and at a preferred pace. Joint angles of the clavicle-scapula, shoulder, elbow, and wrist were recorded, and their covariation for controlling dowel endpoint position was analyzed via UCM. As expected, IF led to a higher mean radial error than EF, driven by increases in aiming bias and variability. Consistent with this result, the UCM analysis showed that IF led to higher goal-relevant variance among the joints (V_ORT) compared to EF starting from the first 20% of the reach to the end. However, the goal-irrelevant variance (V_UCM)—index of joint variance that does not affect the end-effector position—did not show FOA effects. The index of stability of joint coordination with respect to endpoint position (ΔV) was also not different between the EF and IF. Consistent with the constrained action hypothesis, these results provide evidence that IF disrupted goal-relevant joint covariation starting in the early phases of the reach without affecting goal-irrelevant coordination.