Mutual Interactions Between Speech and Finger Movements

Speech output and finger movements were recorded as right-handed males repeated a syllable while making cyclical finger movements in three experimental conditions: (a) maintaining constant amplitude in both response systems; (b) alternating speech amplitude while attempting to maintain constant finger movement amplitude; and (c) alternating finger movement amplitude while attempting to maintain constant speech amplitude. Observations showed that output of the two response systems was coupled (one syllable was uttered with each finger movement) and entrained in amplitude (the amplitude pattern of the response that the subject attempted to keep constant followed that of the concurrently-active amplitude-modulated response).

These interactions were bidirectional and were present with both left-handed and right-handed finger movements. The interactions are more extensive and subtle than mere interference with one response system by the other, and apparently do not depend on anatomical overlap of the responding neural systems.     

Coupling of Eye,Finger, Elbow,and Shoulder Movements During Manual Aiming

Temporal and spatial coupling of point of gaze (PG) and movements of the finger, elbow, and shoulder during a speeded aiming task were examined. Ten participants completed 40-cm aiming movements with the right arm, in a situation that allowed free movement of the eyes, head, arm, and trunk. On the majority of trials, a large initial saccade undershot the target slightly, and 1 or more smaller corrective saccades brought the eyes to the target position. The finger, elbow, and shoulder exhibited a similar pattern of undershooting their final positions, followed by small corrective movements. Eye movements usually preceded limb movements, and the eyes always arrived at the target well in advance of the finger. There was a clear temporal coupling between primary saccade completion and peak acceleration of the finger, elbow, and shoulder. The initiation of limb-segment movement usually occurred in a proximal-to-distal pattern. Increased variability in elbow and shoulder position as the movement progressed may have served to reduce variability in finger position. The spatial-temporal coupling of PG with the 3 limb segments was optimal for the pick up of visual information about the position of the finger and the target late in the movement.     

Anticipatory Planning of Sequential Hand and Finger Movements

ABSTRACT

Hand movements may be anticipatorily planned to reach an immediate target and at the same time facilitate movements to subsequent targets. Researchers have proposed that in anticipatory planning, information about subsequent targets needs to be processed to engage in the planning of the next movement. To test this hypothesis, the authors varied the information 48 participants had about to-be-executed two-step hand and finger movement sequences prior to a choice reaction signal. Movements were initialized faster if participants had advance information about the second target of the sequence than if participants had no advance information at all. The results imply that movement segments to late targets in a movement sequence may be at least partially planned, even if information about earlier targets is not yet available.     

手指的感知、运动以及数量表征对数字认知的促进作用

手指是儿童在习得数字符号之前最常使用的表征数量的工具,大量研究都表明手指在数字认知中具有促进作用。但是,目前仍不清楚手指在数字认知中的作用机制。综述从手指感知、手指运动以及手指数量表征三个方面总结了手指在数字认知中所起的作用。手指感知可能通过影响儿童的数量表征能力间接地影响其它数学能力;与表征量有关的手指运动可能促进了数量大小的加工。关于手指数量表征在数字认知中的作用存在两种有争议的观点：一种认为手指数量表征促进了儿童由非符号数量表征向符号数量表征的转化;另一种认为手指数量表征可能是一种数量语义表征方式。未来应该在发展、作用机制、性别差异等方向继续开展研究,进一步探讨手指在数字认知中所起的作用。     

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.     

Eye Movements and Visual Encoding During Scene Perception

ABSTRACT— The amount of time viewers could process a scene during eye fixations was varied by a mask that appeared at a certain point in each eye fixation. The scene did not reappear until the viewer made an eye movement. The main finding in the studies was that in order to normally process a scene, viewers needed to see the scene for at least 150 ms during each eye fixation. This result is surprising because viewers can extract the gist of a scene from a brief 40- to 100-ms exposure. It also stands in marked contrast to reading, as readers need only to view the words in the text for 50 to 60 ms to read normally. Thus, although the same neural mechanisms control eye movements in scene perception and reading, the cognitive processes associated with each task drive processing in different ways.     

Coordination of Eye and Leg Movements During Visually Guided Stepping

In the present study, 2 related hypotheses were tested: first, that vision is used in a feedforward control mode during precision stepping onto visual targets and, second, that the oculomotor and locomotor control centers interact to produce coordinated eye and leg movements during that task. Participants' (N = 4) eye movements and step cycle transition events were monitored while they performed a task requiring precise foot placement at every step onto irregularly placed stepping stones under conditions in which the availability of visual information was either restricted or intermittently removed altogether. Accurate saccades, followed by accurate steps, to the next footfall target were almost always made even when the information had been invisible for as long as 500 ms. Despite delays in footlift caused by the temporary removal (and subsequent reinstatement) of visual information, the mean interval between the start of the eye movement and the start of the swing toward a target did not vary significantly (p > .05). In contrast, the mean interval between saccade onset away from a target and a foot landing on that target (stance onset) did vary significantly (p < .05) under the different experimental conditions. Those results support the stated hypotheses.     

Influence of Strategy on Muscle Activity During Impact Movements

Participants (N = 10) made flexions or extensions about the elbow. Movements either were pointing (i.e., self-terminated) or terminated by impact on a barrier. The author examined how the trajectory and the electromyographic (EMG) patterns varied according to the distance moved, the instruction provided concerning speed, or the type of termination. Variations in kinematics induced by changes in the target distance or the instruction regarding speed were the same for impact and pointing movements. In comparison with a pointing movement of similar distance and speed instruction, an impact movement (a) accelerated longer and reached a higher velocity, (b) had a longer agonist EMG burst, and (c) had a low level of contraction that started slightly after the agonist burst and continued throughout the movement but had little or no antagonist burst. Because the different types of movements required different forces from the muscles, there were systematic, task-specific differences in EMG patterns that reflected task-specific differences in central control. The results of this experiment demonstrate that impact movements share some of the rules used in the control of other tasks, such as pointing and reversing movements. The sharing is not imposed by mechanical or physiological constraints but, rather, represents the imposition of internal constraints.     

Scrutinization, Spatial Attention, and the Spatial Programming of Saccadic Eye Movements

Results are presented from an experiment in which subjects' eye movements were recorded while they carried out two visual tasks with similar material. One task was chosen to require close visual scrutiny; the second was less visually demanding. The oculomotor behaviour in the two tasks differed in three ways. (1) When scrutinizing, there was a reduction in the area of visual space over which stimulation influences saccadic eye movements. (2) When moving their eyes to targets requiring scrutiny, subjects were more likely to make a corrective saccade. (3) The duration of fixations on targets requiring scrutiny was increased. The results are discussed in relation to current theories of visual attention and the control of saccadic eye movements.     

多目标视觉追踪的注意策略及其眼动模式

该研究采用多目标追踪任务(MOT)对追踪过程中被试的眼动进行记录,探讨追踪过程中的眼动模式及目标数量与刺激物大小变化对眼动模式的影响。结果表明,在追踪过程中,视觉系统采用知觉组织加工策略,以被追踪目标构成的多边形中心为注意中心;追踪成绩受到注意资源限制,随着目标数量的增加,每个目标获得的资源减少;获得较多注意资源的目标更容易被有效追踪,获得资源较少的目标更容易丢失;目标与非目标属性的共同变化不影响追踪眼动模式和追踪成绩。     

Head and Trunk Movements During Turning Gait in Children with Cerebral Palsy

Thirty children with cerebral palsy (CP) and 22 typical developing (TD) were tested with 3D-gait analysis. At turning, trunk rotation was larger in CP2 (GMFCS II) than in TD and CP1 (GMFCS I), and head flexion was larger in CP3 (GMFCS III) than TD. Maximum head and trunk flexion values during the entire trial were larger in CP3 than in the other groups, and trunk flexion was larger in CP2 than in TD. Trial time increased with GMFCS-level. Less trunk rotation than TD and CP1 reflects spatial insecurity in CP2, which in CP3 is compensated by the walker. The flexed head and trunk in CP3 and trunk in CP2 may reflect deficits in proprioception and sensation requiring visual control of the lower limbs.     

Practice and Component Submovements: The Roles of Programming and Feedback in Rapid Aimed Limb Movements

An experiment is reported in which subjects (N = 30) practiced rapid aimed limb movements (wrist rotations), with either full visual feedback, no visual feedback, or delayed visual feedback. Previous research has indicated that, with practice, subjects increase the distance and duration of ballistic primary submovements and decrease the distance and duration of corrective secondary submovements. The design of the present experiment permitted the determination of whether these practice-related changes are results of improved programming of the primary submovement or of more efficient processing involved in the production of secondary submovements. The results suggest that improved programming occurs with practice. Furthermore, it appears that visual feedback is not solely responsible for the production of secondary submovements.     

Prenatal Representations of Family in Parents and Coparental Interactions as Predictors of Triadic Interactions During Infancy

In this study, we explored the predictive role of family interactions and family representations in mothers and fathers during pregnancy for postnatal mother–father–infant interactions during the first 2 years after birth. Families (N = 42) were seen at the fifth month of pregnancy and at 3 and 18 months after birth. During pregnancy, parents were asked to play with their baby at the first meeting by using a doll in accordance with the procedure of the prenatal Lausanne Trilogue Play (LTP; A. Corboz‐Warnery & E. Fivaz‐Depeursinge, 2001; E. Fivaz‐Depeursinge, F. Frascarolo‐Moutinot, & A. Corboz‐Warnery, 2010). Family representations were assessed by administering the Family System Test (T. Gehring, 1998). Marital satisfaction and the history of the couple were assessed through self‐reported questionnaires. At 3 and 18 months, family interactions were assessed in the postnatal LTP. Infant temperament was assessed through parent reports. Results show that (a) prenatal interactions and child temperament are the most important predictors of family interactions and (b) paternal representations are predictive of family interactions at 3 months. These results show that observational assessment of “nascent” family interactions is possible during pregnancy, which would allow early screening of family maladjustment. The findings also highlight the necessity of taking into account paternal representations as a significant variable in the development of family interactions.     

Understanding Triadic and Family Group Interactions During Infancy and Toddlerhood

This paper outlines recent conceptual and methodological developments in the assessment of triadic and family group process during infancy and toddlerhood. Foundations of the emerging family group process are identified, and conditions specific to the assessment of the family during the early phases of family formation are summarized. Both microanalytic and global approaches to evaluating mother–father–child interactions are discussed. We highlight both similarities and differences in the strategies and methods employed by several different investigators who have been studying the group dynamics of families with infant and toddler children, and underscore several important family patterns and emerging themes that appear to be cutting across these different methods and measurement strategies. Preliminary evidence for the validity and clinical significance of family-level assessments is summarized, and directions currently being pursued by researchers engaged in studies of the family triad are outlined. We close by identifying several conceptual and clinical issues that remain to be addressed by subsequent work.     

Parental Behaviors During Family Interactions Predict Changes in Depression and Anxiety Symptoms During Adolescence

This study investigated the prospective, longitudinal relations between parental behaviors observed during parent-adolescent interactions, and the development of depression and anxiety symptoms in a community-based sample of 194 adolescents. Positive and negative parental behaviors were examined, with negative behaviors operationalized to distinguish between observed parental expressions of aggression and dysphoria. Results showed that higher levels of parental aggression prospectively predicted higher levels of both depression and anxiety symptoms in adolescents over two-and-a-half years, whereas higher levels of positive parental behaviors prospectively predicted lower levels of depression symptoms only. Parental dysphoric behavior was not related to changes in either symptom dimension. These results suggest that patterns of parental behaviors may be differentially associated with depressive versus anxious outcomes in adolescents, and highlight the potential role for family-focused prevention or treatment interventions aimed at reducing an escalation of depression and anxiety symptoms in adolescence.     

Movement Related EMGs Become More Variable During Learning of Fast Accurate Movements

Human subjects performed simple flexion and extension movements about the elbow in a visual step-tracking paradigm. Movements were self-terminated. Subjects were instructed to increase movement velocity while maintaining end-point accuracy during practice. The effects of practice on the pattern and variability of EMG activity of the biceps and triceps muscles were studied. Initial movements were performed using reciprocal phasic activation of agonist and antagonist muscles as indicated by surface EMGs. With practice, increases in movement speed were associated with larger agonist and antagonist bursts and an earlier onset of the antagonist burst. Decreased duration of the premovement antagonist silence was also observed during practice.

Decreases in variability of movements during practice were not accompanied by equivalent decreases in variability of the associated EMGs. Surprisingly, both agonist and antagonist EMGs were more variable in faster, practiced movements. The combined agonist-antagonist EMG variability depended on both movement speed and trajectory variability. Lower variability in movements in the presence of greater variability in the related EMGs occurred because of linked variations in agonist and antagonist muscle activities. Variations in the first agonist burst were often compensated for by associated variations in the antagonist and late agonist bursts. These linked variations maintained the limb trajectory relatively constant in spite of large variations in the first agonist burst. Modifications to impulse-variability models are therefore needed to explain compensations for variability in accelerative impulses (produced by the first agonist burst) by linked variations in impulses for deceleration (produced by the antagonist and late agonist bursts).     

Intermanual interactions during simultaneous execution and programming of finger movements

In bimanual movements, some differences between the movements performed by the two hands cause interference, while others do not. Similarly, in choice between responses with the left and right hand some differences between the two movements increase RT, while others do not. It is suggested that both kinds of effects are, at least in part, due to the incompatibility between processes that determine characteristics of movements jointly for both hands and that are present during preparation as well as during execution. This hypothesis implies that during execution of one movement, programming of a different movement to be performed with the other hand should be impaired, as compared to a condition in which the successive movements of both hands are the same. this expectation was confirmed for finger movements of different forms where an effect on choice RT had been shown previously. On the other hand, interference between execution and programming is not to be expected when successive movements differ in characteristics that are likely to be specified separately for each hand, as indicated by a lacking effect in choice experiments. This expectation was confirmed for successive movements performed with different fingers of either hand as compared to movements performed with the same fingers.     

阅读理解中汉语量词的眼动特点分析

采用眼动记录技术探讨被试阅读不同汉语量词的即时加工过程。考查名量词和动量词,以及名量词内部的差异。结果发现:(1)被试在阅读理解过程中对名量词和动量词的眼动特点存在显著差异,名量词获得更多的加工;(2)被试在阅读理解过程中对不同名量词的眼动特点也存在显著差异,个体量词比集合量词和临时量词获得更少的加工。由此可知,不同量词在阅读理解中的信息加工难度是不同的,对于篇章理解而言,其信息含量和信息的重要性也是不同的。     

多目标视觉追踪中物体属性加工的眼动研究*

采用多目标视觉追踪任务(MOT),探讨物体颜色特征对视觉追踪的影响,同时记录被试的眼动情况,探讨追踪过程中颜色特征对眼动模式的影响。结果发现,视觉追踪机制能够对物体的颜色特征进行加工,但加工程度受制于目标物与分心物之间的特征竞争关系。在物体颜色特征条件下,视觉系统采用知觉组织加工策略,以被追踪目标构成的多边形中心为注意中心。在对物体颜色特征的加工中,内源性注意与外源性注意相互影响。