情绪信息的多通道整合

自然环境中人类情绪信息的交流是依靠多个感觉通道实现的,多通道整合是情绪加工的基础。近年来的行为学、电生理学与神经成像的研究表明,情绪信息的加工具有跨通道自动整合的特点,它发生在认知加工的早期阶段,与颞上回、颞中回、海马旁回和丘脑等脑区密切相关。不同情绪的整合既有共同的神经基础,又有各自独特的加工区域。情绪信息的整合机制还可能与加工类型及注意资源有关。在未来研究中,实验的标准化、动态化、自然化有助于提高研究的准确性和研究间的可比性,而对特殊群体的研究,以及综合研究情绪加工与注意等其他认知过程则有助于我们进一步探索多通道整合的神经机制。     

Rational Actions and the Integration of Knowledge

Summary  The paper emphasizes the role of knowledge dimensions of an action which could be regarded as rational. Rational action usually results of specific decision – making process including selection, evaluation and acceptance of a preferred alternative. This process should integrate not only various types of knowledge but also the interdisciplinary or interdepartmental knowledge integration. The integration of knowledge may cover various forms, especially integration of knowledge relating to different domains, of different quality, of knowledge connected with different goal-orientations. The paper stresses the role of the hitherto known and recognized alternatives. The integration procedures should also include the integration of various spheres and types of knowledge with accepted and justified systems of values.     

Proprioception and Motor Control in Parkinson's Disease

ABSTRACT

Parkinson's disease (PD) is a neurodegenerative disorder that leads to a progressive decline in motor function. Growing evidence indicates that PD patients also experience an array of sensory problems that negatively impact motor function. This is especially true for proprioceptive deficits, which profoundly degrade motor performance. This review specifically address the relation between proprioception and motor impairments in PD. It is structured around 4 themes: (a) It examines whether the sensitivity of kinaesthetic perception, which is based on proprioceptive inputs, is actually altered in PD. (b) It discusses whether failed processes of proprioceptive-motor integration are central to the motor problems in PD. (c) It presents recent findings focusing on the link between the proprioception and the balance problems in PD. And (d) it discusses the current state of knowledge of how levodopa medication and deep brain stimulation affect proprioceptive and motor function in PD. The authors conclude that a failure to evaluate and to map proprioceptive information onto voluntary and reflexive motor commands is an integral part of the observed motor symptoms in PD.     

Information integration study of Metelli's and Morinaga's theories of achromatic transparency

Information integration methodology was used to test Metelli's and Morinaga's theories of achromatic transparency. Stimuli were transparent achromatic disks on a background formed by two adjacent horizontal rectangles. The common border of these rectangles divided each disk in two halves. Let P and Q be the luminances of the left and right halves of a disk and let A and B be those of the left and right rectangles, respectively. Transparency is given by the ratio (P – Q)/(A – B) in Metelli's theory and is given by a weighted average of the ratios (P – Q)/(A – Q) and (P – Q)/(P – B) in Morinaga's theory. Participants rated the transparency of disks with A and B fixed and P and Q combined factorially. Morinaga's theory closely predicted the resulting pattern of curves and Metelli's theory predicted it incorrectly. Morinaga's theory could also account well for individual differences in the ratings of transparency. The results support the general idea that transparency depends on the integration of photometric luminance information rather than on the integration of perceived lightness information.     

多感觉整合测量范式中存在的影响因素探讨

已有的多感觉整合研究范式多采用不同单通道刺激和双通道刺激随机呈现的方式进行测量。在这种范式中混有通道转换效应, 该效应可能导致多感觉整合的测量结果不准确。因此, 分析清楚实验范式中通道转换效应的影响因素, 并以此为依据设计合理的整合测量范式, 是进行多感觉整合研究的一个必要前提。本文首先通过实验一验证了在经典的整合测量范式中通道转换效应的影响方式; 进而, 在实验二中通过控制前后刺激的信号强度的一致性, 分析了通道转换效应的特点。综合分析显示, 通道转换效应是由前一刺激差异所造成的对当前刺激通道加工的注意资源分配和警觉水平的变化所导致。该结果表明, 在多感觉行为测量中, 需先根据前一刺激通道分类后再进行分析。     

通道估计可靠性先验知识在早期的知觉加工阶段影响多感觉信息整合

统计最优化理论认为, 在多感觉信息整合的过程中, 大脑是以加权平均的方式将多个感觉通道的信息整合为统一的感觉信息, 通道信息的利用权重根据各通道信息的可靠性来确定。近期的几个行为研究结果则显示, 有关通道估计可靠性的先验知识同样能够影响通道信息在整合过程中的利用权重。然而, 这些研究结果不能确定先验知识对多感觉信息整合的影响是发生在认知加工的感知觉阶段还是决策阶段。当前研究致力于对此问题进行探讨。实验通过赋予两种颜色字母不同的视、听一致概率(高概率、低概率), 测量并分析被试在各概率水平下对视听一致刺激的反应时。实验数据显示不同的视听一致概率能够调制对视听一致刺激的反应时。该结果揭示通道估计可靠性先验知识在早期的知觉加工阶段影响多感觉信息整合。     

Multisensory integration in multiple reference frames in the posterior parietal cortex

Spatial information processing takes place in different brain regions that receive converging inputs from several sensory modalities. Because of our own movements—for example, changes in eye position, head rotations, and so forth—unimodal sensory representations move continuously relative to one another. It is generally assumed that for multisensory integration to be an orderly process, it should take place between stimuli at congruent spatial locations. In the monkey posterior parietal cortex, the ventral intraparietal (VIP) area is specialized for the analysis of movement information using visual, somatosensory, vestibular, and auditory signals. Focusing on the visual and tactile modalities, we found that in area VIP, like in the superior colliculus, multisensory signals interact at the single neuron level, suggesting that this area participates in multisensory integration. Curiously, VIP does not use a single, invariant coordinate system to encode locations within and across sensory modalities. Visual stimuli can be encoded with respect to the eye, the head, or halfway between the two reference frames, whereas tactile stimuli seem to be prevalently encoded relative to the body. Hence, while some multisensory neurons in VIP could encode spatially congruent tactile and visual stimuli independently of current posture, in other neurons this would not be the case. Future work will need to evaluate the implications of these observations for theories of optimal multisensory integration.Edited by: Marie-Hélène Giard and Mark Wallace     

Spatial Coupling in the Coordination of Complex Actions

The majority of investigations on coordinated action have focused on temporal constraints in movements. Recent studies have demonstrated spatial constraints when the hands produce different trajectory shapes simultaneously. The focus of the current study was to determine whether spatial coupling occurs in individual parameters of the actions, or whether the shapes per se undergo accommodation. Subjects were tested on a bimanual paradigm to investigate the nature of spatial constraints in complex tasks. Shape and size of the required trajectories were varied for the two limbs. When trajectories that require different shapes were assigned to the two hands,disruption in the spatial characteristics of the trajectories was observed. Disruption in the global patterns of the trajectories could be described on the basis of coupling in individual parameters of action, direction, and amplitude, which could be inferred by decomposing the trajectories into orthogonal components. Amplitude accommodation in these orthogonal components of motion increased linearly with the difference in required amplitude for the two limbs. Interpretations of these effects suggest that directional coupling is a result of interference between two different response plans, whereas amplitude coupling may be related to either planning or execution variables. These results strongly suggest the need for further investigation of the spatial domain of complex coordinated action.     

The role of visible persistence for perception of visual bilateral symmetry1

Abstract: Although the detection of visual bilateral symmetry has been claimed to be highly efficient, the possible involvement and function of visual memory in such efficient mechanisms has rarely been examined. We hypothesized that symmetry perception is rapid, as it can be achieved from rapidly decaying information of visible persistence. To test this hypothesis, we employed a temporal integration paradigm. A symmetric dot pattern was randomly divided into two asymmetric patterns and presented successively with a blank screen presented between patterns. Observers could detect symmetry when the two patterns were presented close in time (Experiment 1), indicating that observers perceived symmetry presumably utilizing visible persistence. In addition, the inverse‐intensity effect of visible persistence (Di Lollo & Bischof, 1995) was evident in our temporal integration task of symmetry (Experiment 2). The results of the current study clearly demonstrate that the detection of symmetry can be achieved based on the visible persistence. The large capacity and high spatial precision of visible persistence might be adequate for the rapid and spatially global encoding of visual symmetry.     

Multisensory integration of vision and touch in nonspatial feature discrimination tasks

Multisensory integration of nonspatial features between vision and touch was investigated by examining the effects of redundant signals of visual and tactile inputs. In the present experiments, visual letter stimuli and/or tactile letter stimuli were presented, which participants were asked to identify as quickly as possible. The results of Experiment 1 demonstrated faster reaction times for bimodal stimuli than for unimodal stimuli (the redundant signals effect (RSE)). The RSE was due to coactivation of figural representations from the visual and tactile modalities. This coactivation did not occur for a simple stimulus detection task (Experiment 2) or for bimodal stimuli with the same semantic information but different physical stimulus features (Experiment 3). The findings suggest that the integration process might occur at a relatively early stage of object-identification prior to the decision level.     

Motivational Effects of Outcome Feedback on Motor Performance

This study examined the effects of success and failure feedback on subsequent motor performance. Based upon the general motivation (or level-of-aspiration) hypothesis, initial success should lead to better subsequent performance than does initial failure, while the reverse prediction was derived from the cognitive dissonance theory. To test these rival hypotheses, two experiments were conducted on undergraduate male students (n =120) performing a motor maze task. Initial failure improved subjects’ subsequent performance, thus supporting the dissonance theory. However, this effect was observed only under low-ego-involving conditions, thereby suggesting that the effects of dissonance and ego involvement are interdependent. The findings were discussed in terms of motivational and informational/attributional effects of outcome feedback on motor performance.     

Development of rule-based eye-hand-decoupling in children and adolescents

In the present study, we characterize how the ability to decouple guiding visual information from a motor action emerges during childhood and adolescence. Sixty-two participants (age range 8–15 yrs.) completed two eye-hand coordination tasks. In a direct interaction task, vision and motor action were in alignment, and participants slid their finger along a vertical touch screen to move a cursor from a central target to one of four peripheral targets. In an eye-hand-decoupled task, eye and hand movements were made in different planes and cursor feedback was 180° reversed. We analyzed whether movement planning, timing and trajectory variables differed across age in both task conditions. There were no significant relationships between age and any movement planning, timing, or execution variables in the direct interaction task. In contrast, in the eye-hand-decoupled task, we found a relationship between age and several movement planning and timing variables. In adolescents (13–15 yrs.), movement planning and timing was significantly shorter than that of young children (8–10 yrs.). Eye-hand-decoupled maturation emerged mainly during late childhood (11–12 yrs.). Notably, we detected performance differences between young children and adolescents exclusively during the eye-hand decoupling task which required the integration of rule-based cognitive information into the motor action. Differences were not observed during the direct interaction task. Our results quantify an important milestone for eye-hand-decoupling development in late childhood, leading to improved rule-based motor performance in early adolescence. This eye-hand-decoupling development may be due to frontal lobe development linked to rule-based behavior and the strengthening of fronto-parietal networks.     

Evidence Supporting the Importance of Peripheral Visual Information for the Directional Control of Aiming Movement

The focus of the present study was on determining whether the high level of directional accuracy found in aiming studies in which the subjects can see their hand in the visual periphery supports the existence of a kinetic visual channel or, rather, the advantage of binocular over monocular vision for movement directional control. The limits of this kinetic visual channel were also explored. The results of the 1st experiment indicated that seeing one's hand in the visual periphery is sufficient to ensure optimal directional aiming accuracy. Further, no differences in aiming accuracy were noted between monocular and binocular vision. These results supported the existence of a visual kinetic channel. In the 2nd experiment, whether this kinetic visual channel would operate with movements slower (55°/s) than those usually used in studies that had proved its existence (over 110°/s) was determined. The results indicated that this visual kinetic channel was operative even at relatively slow movement velocities. Central vision of the hand seemed to be used for on-line directional control of relatively slow movements.     

Afferent Information for Motor Control: The Role of Visual Information in Different Portions of the Movement

The question addressed in the present study was whether subjects (N = 24) can use visual information about their hand, in the first half of an aiming movement, to ensure optimal directional accuracy of their aiming movements. Four groups of subjects practiced an aiming task in either a complete vision condition, a no-vision condition, or in a condition in which their hand was visible for the first half [initial vision condition (IV)] or the second half of the movement [final vision condition (FV)]. Following 240 trials of acquisition, all subjects were submitted to a transfer test that consisted of 40 trials performed in a no-vision condition. The results indicated that seeing the hand early in movement did not help subjects to optimize either directional or amplitude accuracy. On the other hand, when subjects viewed their hand closer to the target, movements resulted that were as accurate as those performed under a complete vision condition. In transfer, withdrawing vision did not cause any increase in aiming error for the IV or the no-vision conditions. These results replicated those of Carlton (1981) and extended those of Bard and colleagues (Bard, Hay, & Fleury, 1985) in that they indicated that the kinetic visual channel hypothesized by Paillard (1980; Paillard & Amblard, 1985) appeared to be inoperative beyond 40deg of visual angle.     

Roles of Visual Information for Control of Reaching Movements in Children

Poststroke hemiparetic individuals (n = 9) and a control group (n = 9) completed a frequency-scaled circle-drawing task in unimanual and bimanual conditions. Measures of intralimb spatial and temporal task accuracy and interlimb coordination parameters were analyzed. Significant reductions in task performance were seen in both limbs of the patients and controls with the introduction of bimanual movement. Spatial performance parameters suggested that the 2 groups focused on different hands during bimanual conditions. In the controls, interlimb coordination variables indicated predictable hand dominance effects, whereas in the patient group, dominance was influenced by the side of impairment and prior handedness of the individual. Therefore, in this particular bimanual task, performance improvements in the hemiplegic side could not be elicited. Intrinsic coupling asymmetries between the hands can be altered by unilateral motor deficits.     

The Influence of Contraction Types on the Relationship Between the Intended Force and the Actual Force

Abstract

It has been demonstrated that the intended force (subjective estimation of force) does not always match to actual force without external feedback. The purpose of this study was to compare the influence of ballistic and tonic contractions on the relationship between the intended and actual force. Subjects produced isometric force at requested percentages of their MVC (20, 40, 60 and 80%) based on subjective estimation of force under two conditions (tonic and ballistic conditions). The tonic condition was to maintain force production, whereas the ballistic condition was to produce force as fast as possible. As a result, the actual force amplitude, the coefficient of variance and EMG amplitude were larger under the ballistic contraction compared with the tonic condition, even the same intended force levels. These results suggest that different motor unit activity and control systems in the ballistic and tonic contractions could alter the relationship between the intended force and the actual force.     

Perceptual Integration of Timing and Intensity Variations in the Perception of Musical Accents

The author investigated the detection of timing and intensity variations in tone sequences within the framework of perceptual independence or integration. The participants listened to sequences of tones that contained variations in timing, intensity, or both. Each participant tried to detect variations in the dimension that was declared relevant, which was either timing or intensity. The irrelevant dimension was held constant, or varied in a manner uncorrelated with the relevant dimension, or varied in a correlated manner. When the variations in the 2 dimensions were correlated, the correlation could be either positive (i.e., timing and intensity created accents in the same sequences) or negative (i.e., timing and intensity created accents in different sequences). Uncorrelated variation in the irrelevant dimension interfered with the detection of variations in the relevant dimension. In the case of a positive correlation between the 2 dimensions, the detection of variations was better than it was with the absence of variation in the irrelevant dimension only for participants who attended to timing. In the case of a negative correlation, the effect was the opposite. The results showed that timing and intensity accents were not processed by completely independent channels. Rather, information from the 2 dimensions combined at a late stage of processing.