Coordination Between Arm and Leg Movements During Locomotion

To evaluate the contrasting dynamical and biomechanical interpretations of the 2:1 frequency coordination between arm and leg movements that occurs at low walking velocities and the 1:1 frequency coordination that occurs at higher walking velocities, the authors conducted an experiment in which they quantified the effect of walking velocity on the stability of the frequency and phase coordination between the individual limb movements. Spectral analyses revealed the presence of 2:1 frequency coordination as a consistent feature of the data in only 3 out of 8 participants at walking velocities ranging from 1.0 to 2.0 km/h, in spite of the fact that the eigenfrequencies of the arms were rather similar across participants. The degree of interlimb coupling, as indexed by weighted coherence and variability of relative phase, was lower for the arm movements and for ipsilateral and diagonal combinations of arm and leg movements than for the leg movements. Furthermore, the coupling between all pairs of limb movements was found to increase with walking velocity, whereas no clear signs were observed that the switches from 2:1 to 1:1 frequency coordination and vice versa were preceded by loss of stability. Therefore, neither a purely biomechanical nor a purely dynamical model is optimally suited to explain these results. Instead, an integrative model involving elements of both approaches seems to be required.     

Bimanual coupling effects during arm immobilization and passive movements

When humans simultaneously perform different movements with both hands, each limb movement interferes with the contralateral limb movement (bimanual coupling). Previous studies on both healthy volunteers and patients with central or peripheral nervous lesions suggested that such motor constraints are tightly linked to intentional motor programs, rather than to movement execution. Here, we aim to investigate this phenomenon, by using a circles-lines task in which, when subjects simultaneously draw lines with the right hand and circles with the left hand, both the trajectories tend to become ovals (bimanual coupling effect). In a first group, we immobilized the subjects’ left arm with a cast and asked them to try to perform the bimanual task. In a second group, we passively moved the subjects’ left arm and asked them to perform voluntary movements with their right arm only. If the bimanual coupling arises from motor intention and planning rather than spatial movements, we would expect different results in the two groups. In the Blocked group, where motor intentionality was required but movements in space were prevented by immobilization of the arm, a significant coupling effect (i.e., a significant increase of the ovalization index for the right hand lines) was found. On the contrary, in the Passive group, where movements in space were present but motor intentionality was not required, no significant coupling effect was observed. Our results confirmed, in healthy subjects, the central role of the intentional and predictive operations, already evidenced in pathological conditions, for the occurrence of bimanual coupling.     

The effect of preview eccentricity in a lexical decision task

We report lexical decision experiments in which eye movements and lexical decision time were analysed. The results show that nonwords produced more fixation than words, and that the time to make a lexical decision was also greater for nonwords. Further, a preview of the stimulus was presented on some occasions either at fixation or peripherally. When the presentation was peripheral the number of refixations and lexical decision times were reduced. Parafoveal previews of words also reduced word length effects on refixations and lexical decision time. These effects decreased (for nonwords) when the case of the letters was changed in the preview. These results are compatible with the idea that the peripheral preview benefit derives from word visual structure in addition to information about word length, word envelope, and single letter identities.     

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。     

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.     

Information–movement coupling in developing cricketers under changing ecological practice constraints

Changing informational constraints of practice, such as when using ball projection machines, has been shown to significantly affect movement coordination of skilled cricketers. To date, there has been no similar research on movement responses of developing batters, an important issue since ball projection machines are used heavily in cricket development programmes. Timing and coordination of young cricketers (n = 12, age = 15.6 ± 0.7 years) were analyzed during the forward defensive and forward drive strokes when facing a bowling machine and bowler (both with a delivery velocity of 28.14 ± 0.56 m s⁻¹). Significant group performance differences were observed between the practice task constraints, with earlier initiation of the backswing, front foot movement, downswing, and front foot placement when facing the bowler compared to the bowling machine. Peak height of the backswing was higher when facing the bowler, along with a significantly larger step length. Altering the informational constraints of practice caused major changes to the information–movement couplings of developing cricketers. Data from this study were interpreted to emanate from differences in available specifying variables under the distinct practice task constraints. Considered with previous findings, results confirmed the need to ensure representative batting task constraints in practice, cautioning against an over-reliance on ball projection machines in cricket development programmes.     

Early perception-action coupling: eye movements and the development of object perception

We investigated the scanning strategies used by 2- to 3.5-month-old infants when viewing partly occluded object displays. Eye movements were recorded with a corneal reflection system as the infants observed stimuli depicting two rod parts above and below an occluding box. Stimulus parameters were chosen on the basis of past research demonstrating the importance of motion, occluder width, and edge alignment to perception of object unity. Results indicated that the infants tailored scanning to display characteristics, engaging in more extensive scanning when unity perception was challenged by a wide occluder or misaligned edges. In addition, older infants tended to scan the lower parts of the displays more frequently than did younger infants. Exploration of individual differences, however, revealed marked contrasts in specific scanning styles across infants. The findings are consistent with views of perceptual development stressing the importance of information processing skills and self-directed action to the acquisition of object knowledge.