Leg Asymmetries and Coordination Dynamics in Walking

Models of interlimb coordination (H. Haken, J. A. S. Kelso, &; H. Bunz, 1985 Haken, H., Kelso, J. A. S. and Bunz, H. 1985. A theoretical model of phase transitions in human hand movements. Biological Cybernetics, 51: 347–356. [Crossref], [PubMed], [Web of Science ®] , [Google Scholar]; P. N. Kugler &; M. T. Turvey, 1987 Kugler, P. N. and Turvey, M. T. 1987. Information, natural law, and the self-assembly of rhythmic movement, Hillsdale, NJ: Erlbaum.  [Google Scholar]) were tested in walking by examining the role of asymmetries between limbs. Participants walked on a treadmill with and without a metronome. Five asymmetry conditions were created via ankle loads of 0, 3, or 6 kg on either leg. With the metronome, participants matched the target period. Without the metronome, stride rate slowed as the mass was increased on either leg. The loads led to an increase in stride period that was predicted by Huygens’ law and the hybrid pendulum-spring model. In agreement with extended Haken–Kelso–Bunz model predictions, leg asymmetries led to deviations from antiphase coordination. Also, perception–action coordination was influenced by the asymmetry between the legs and metronome. In contrast, no predicted stability effects were observed. These findings reveal that some properties of interlimb coordination, apparent in laboratory-based tasks, can also be observed in human walking.     

When the going gets tough,what happens to quiet eye? The role of time pressure and performance pressure during basketball free throws

In aiming sport contexts, the quiet eye (QE) - the final ocular fixation before movement initiation - is a crucial perceptual-cognitive skill. Indeed, an extended QE permits athletes to achieve high performances, aiding optimal attentional control, particularly in situations in which athletes are \"under pressure.\" Such situations are common in sport, especially when time runs out, and even just a few points can mean the difference between victory and defeat. Although QE has been widely investigated across several sports and tasks, no previous studies have considered both the role of time pressure and performance pressure on QE. The current study aimed to comprehend the effect of tough sport situations on QE characteristics. Accordingly, we tested basketball players (competitive-élites and semi-élites) in free throw trials, manipulating both the time available to perform the task and the relevance of the performance. The results showed that time pressure and performance pressure impaired QE characteristics, regardless of expertise levels. Also, time pressure led to a decrease in free throw accuracy. Interestingly, the match between task demands and the ability to cope seemed to play a role on QE, especially in the competitive-élite players, with negative QE characteristics (short and late) when task demands exceeded the ability to cope. These findings suggest that QE research and QE training protocols should account for time pressure, performance pressure, and the players' perceived ability to cope with the requested task.     

Moody and thin-skinned? The interplay of neuroticism and momentary affect in older romantic couples

Neuroticism is associated with heightened reactivity to social stressors. However, little is known about the micro-processes through which neuroticism shapes – and is shaped by – affective experiences in close relationships. We examine the extent to which momentary affect is coupled with one’s relationship partner, whether the strength of this coupling differs depending on levels of neuroticism, and whether this coupling and partner’s overall level of positive or negative affect prospectively contribute to differential (rank-order) changes in neuroticism. Older couples (N = 82, aged 67–93 years) rated their momentary affect six times per day for one week and provided ratings of trait neuroticism at baseline and 18 months later. Multilevel models revealed that among individuals high in neuroticism, individual positive affect was more closely coupled with partner positive affect compared with individuals low in neuroticism. Moreover, neuroticism decreased over time in those participants who showed a higher degree of coupling with partner positive affect and also had a partner with higher overall positive affect. In contrast, neuroticism increased in individuals whose partner had lower overall positive affect. Similar effects were not observed for negative affect. Our findings highlight how relationship partners contribute to daily affective experiences and longer-term changes in neuroticism.     

The multisensory base of bodily coupling in face-to-face social interactions: Contrasting the case of autism with the Möbius syndrome

The perennial question of how we understand others’ emotions and mental states has undertaken an “interactive turn,” emphasizing the crucial role of low-level bodily coupling and second-personal engagements with others as opposed to the individualistic procedure of mental state attribution or “mindreading.” This raises the important question of what counts as foundational for socio-emotional understanding: high-level mentalistic abilities, low-level bodily coupling, or an integrative combination of both? Recent findings on face-based emotion-recognition in individuals with Möbius syndrome (MS) – a rare form of congenital facial paralysis which prevents facial mimicry – cast doubt on the idea that bodily coupling is the foundational component for socio-emotional understanding. Here we argue that the MS case does not pose a threat to the idea that low-level bodily coupling processes are foundational for social cognition. Rather, despite their lack of automatic facial mirroring, MS patients might benefit from spared multisensory integration processing which allows them to establish alternative channels of bodily coupling via different sensory modalities. We contrast MS- and autistic persons’ lack of automatic facial mimicry and argue that this comparison might help us to shed light on the constitutive and foundational role of low-level bodily coupling for socio-emotional understanding.     

Representation recovers information

Early agreement within cognitive science on the topic of representation has now given way to a combination of positions. Some question the significance of representation in cognition. Others continue to argue in favor, but the case has not been demonstrated in any formal way. The present paper sets out a framework in which the value of representation use can be mathematically measured, albeit in a broadly sensory context rather than a specifically cognitive one. Key to the approach is the use of Bayesian networks for modeling the distal dimension of sensory processes. More relevant to cognitive science is the theoretical result obtained, which is that a certain type of representational architecture is necessary for achievement of sensory efficiency. While exhibiting few of the characteristics of traditional, symbolic encoding, this architecture corresponds quite closely to the forms of embedded representation now being explored in some embedded/embodied approaches. It becomes meaningful to view that type of representation use as a form of information recovery. A formal basis then exists for viewing representation not so much as the substrate of reasoning and thought, but rather as a general medium for efficient, interpretive processing.     

Visual information and body sway coupling in infants during sitting acquisition

The purpose of this study was to examine if there is any developmental change in the coupling between visual information and trunk sway in infants as they acquire the sitting position. Twenty-four infants distributed in four groups (6-, 7-, 8-, and 9-month-old) were sat inside a moving room that oscillated back and forward at frequencies of 0.2 and 0.5 Hz. The results revealed that trunk sway matched to the moving room at both frequencies but did not differ among the four age groups. Coherence and gain revealed that the coupling was weaker at 0.2 than at 0.5 Hz. Relative phase showed that at 0.2 Hz, infants were swaying with no lag but at 0.5 Hz they were lagging the room. These results showed that the coupling between visual information and trunk sway in infants varies with the visual stimulus but does not change as infants acquire the sitting position.     

伸手拦截启动中的信息利用

通过两项实验考察时空信息对拦截运动启动的影响: 实验一为知觉估计实验, 通过释放匀速小球模拟拦截过程; 实验二为特定拦截路线情景下的拦截行为实验, 即固定手的拦截方向, 但容许拦截速度自由控制。结果发现, 拦截行为的启动基于综合信息, 在所拦截物体作慢速运动的情景下拦截行为启动偏早, 而在快速运动的情景下启动偏晚, 结果不支持单纯用tau理论解释启动行为。本研究对手的速度伴随效应提出了新的解释。     

手的拦截运动的速度伴随效应及影响因素

对手的拦截运动的理论假设、速度伴随效应及其影响因素进行了总结和分析。指出:(1)“速度伴随效应”的机制可能在于补偿反应延迟、维持必需的注视时间、对即时运动信息的利用或时间-准确性权衡;(2)手的拦截运动指标受目标运动方向、先前任务、练习、目标大小、运动表征和策略以及双眼线索等因素的影响;(3)对拦截运动的进一步研究可在统一理论解释的基础上进行,克服研究方法和范围的局限。