Visual enhancement of touch and the bodily self

We experience our own body through both touch and vision. We further see that others’ bodies are similar to our own body, but we have no direct experience of touch on others’ bodies. Therefore, relations between vision and touch are important for the sense of self and for mental representation of one’s own body. For example, seeing the hand improves tactile acuity on the hand, compared to seeing a non-hand object. While several studies have demonstrated this visual enhancement of touch (VET) effect, its relation to the ‘bodily self’, or mental representation of one’s own body remains unclear. We examined whether VET is an effect of seeing a hand, or of seeing my hand, using the rubber hand illusion. In this illusion, a prosthetic hand which is brushed synchronously—but not asynchronously—with one’s own hand is felt to actually be one’s hand. Thus, we manipulated whether or not participants felt like they were looking directly at their hand, while holding the actual stimulus they viewed constant. Tactile acuity was measured by having participants judge the orientation of square-wave gratings. Two characteristic effects of VET were observed: (1) cross-modal enhancement from seeing the hand was inversely related to overall tactile acuity, and (2) participants near sensory threshold showed significant improvement following synchronous stroking, compared to asynchronous stroking or no stroking at all. These results demonstrate a clear functional relation between the bodily self and basic tactile perception.     

Multisensory Information in the Control of Complex Motor Actions

ABSTRACT— For many of the complex motor actions we perform, perceptual information is available from several different senses including vision, touch, hearing, and the vestibular system. Here I discuss the use of multisensory information for the control of motor action in three particular domains: aviation, sports, and driving. It is shown that performers in these domains use information from multiple senses—frequently with beneficial effects on performance but sometimes with dangerous consequences. Applied psychologists have taken advantage of our natural tendency to integrate sensory information by designing multimodal displays that compensate for situations in which information from one or more of our senses is unreliable or is unattended due to distraction.     

情景变换诱发已消退恐惧记忆重现的神经环路

暴露疗法是治疗创伤后应激障碍的主要行为疗法。当被试反复暴露于可引起恐惧反应的条件刺激(如白噪音), 但却不伴有非条件刺激(如足底电击)时, 恐惧记忆将被消退, 形成消退记忆。但恐惧记忆并未从根本上被擦除, 当被试在消退训练以外的情景暴露于条件刺激时, 已消退的恐惧记忆将会重现。海马、内侧前额叶皮层、杏仁核等脑区及其相互连接的神经环路是情景诱发恐惧记忆重现的生理基础。情景变化诱发恐惧记忆重现过程中, 海马可能是通过直接投射至杏仁核基底核、杏仁核外侧核或通过边缘前皮质间接调控杏仁核基底核、杏仁核外侧核的功能, 产生恐惧反应。     

质地密度逐渐变化对触觉识别的作用

研究关于输入、本体感受和输出对表面触觉认知的影响,旨在探索运用触觉识别质地密度逐渐变化的表面时,理论关于表面粗糙度恒定的情况下,主动手指运动产生的信息不影响触觉认知的解释是否仍然成立。实验采用表面质地密度呈正态曲线式逐渐变化,组成正负两组变化方向。正方向变化为表面质点密度向中逐渐增大,与手指触摸运动的加减速方式一致;负方向变化为表面质点密度向中逐渐减小,与手指触摸运动的加减速方式相反;另外包括一个表面密度不变的平面。让被试辨别表面质地密度变化的方向,结果发现被试能够很好地判别表面质地密度变化的方向,但在判别正向变化的表面时显得更准确;当表面密度没有变化时,被试倾向于判别为正向变化。这一发现没有支持表面密度恒定的触觉认知解释模型。与常规直觉相反,研究还发现即时反馈并没有改进触觉识别,反而降低了辨别的正确率。质地密度逐渐变化的触觉识别在变化的大小、准确和自信心方面都显示了不同,但没有发现认知学习作用该触觉任务辨别的过程。基于这些发现,文章讨论了触觉质地感知和有关存在的理论解释模式。     

TOUCH,SOUND, AND THINGS WITHOUT THE MIND

Abstract: Two notable thought experiments are discussed in this article: Reid's thought experiment about whether a being supplied with tactile sensations alone could acquire the conception of extension and Strawson's thought experiment about whether a being supplied with auditory sensations alone could acquire the conception of mind‐independent objects. The experiments are considered alongside Campbell's argument that only on the so‐called relational view of experience is it possible for experiences to make available to their subjects the concept of mind‐independent objects. I consider how the three issues ought to be construed as raising questions about woulds, coulds, or shoulds—and argue that only on the normative construal of them are they resolvable as intended by the a priori methods of the philosophers who pose them.     

触觉二维图像识别的认知机制

触觉二维图像可以辅助视觉受损人群, 将视觉信息转化为触觉信息, 从而感知外部世界。触觉二维图像的识别可能是通过触觉信息在大脑中进行“视觉转化”的方式而完成, 并且会受到图形的几何特征、视角与透视、视觉经验、视觉表象能力、触觉探索过程、训练以及年龄的影响。探索触觉二维图像识别的认知神经机制, 对于触觉二维图像设计的改进和可用性的提高, 具有重要意义。     

The development of visual search in infants and very young children.

In two experiments, 90 1- to 3-year-olds were trained in a new nonverbal task to touch a video screen that displayed a unique target resembling a popular television character. The target appeared among varying numbers of distractors that resembled another familiar television character and was either a uniquely colored shape (the feature search task) or a unique color-shape combination (the conjunction search task). Each correct response triggered a sound and produced four animated objects on the screen. Irrespective of age and experimental design (between-subjects or within-subjects), children's reaction time (RT) patterns resembled those obtained from adults in corresponding search tasks: The RT slope for feature search was flat and independent of distractor number, whereas the RT slope for conjunction search increased linearly with distractor number. These results extend visual search effects found with adults to infants and very young children and suggest that the basic perceptual processes underlying visual search are qualitatively invariant over ontogeny.     

Mutual regulation between infant facial affect and maternal touch in depressed and nondepressed dyads

The ability to regulate affect is important for later adaptive child development. In the first months of life, infants have limited resources for regulating their own affects (e.g. by gaze aversion), and for this reason they are dependent on external affect regulation from their parents. Previous research suggests that touch is an important means through which parents regulate their infants’ affects. Also, previous research has shown that post-partum depressed (PPD) mothers and nonclinical mothers differ in their touching behaviors when interacting with their infants. We examined the affect-regulating function of affectionate, caregiving and playful maternal touch in 24 PPD and 47 nonclinical mother-infant dyads when infants were four months old. In order to investigate the direction of effects and to account for repeated observations, the data were analysed using time-window sequential analysis and Generalized Estimating Equations. The results showed that mothers adapt their touching behaviors according to negative infant facial affect; thus, when the infant displays negative facial affect, the mothers were less likely to initiate playful touch and more likely to initiate caregiving touch. Unexpectedly, only in the PPD dyads, were the mothers more likely to initiate affectionate touch when their infants were displaying negative facial affect. Our results also showed that mothers use specific touch types to regulate infants’ negative and positive affects; infants are more likely to initiate positive affect during periods with playful touch, and more likely to terminate negative affect during periods with caregiving touch.     

Which limb is it? Responses to vibrotactile stimulation in early infancy

This study focuses on how the body schema develops during the first months of life, by investigating infants’ motor responses to localized vibrotactile stimulation on their limbs. Vibrotactile stimulation was provided by small buzzers that were attached to the infants’ four limbs one at a time. Four age groups were compared cross‐sectionally (3‐, 4‐, 5‐, and 6‐month‐olds). We show that before they actually reach for the buzzer, which, according to previous studies, occurs around 7–8 months of age, infants demonstrate emerging knowledge about their body's configuration by producing specific movement patterns associated with the stimulated body area. At 3 months, infants responded with an increase in general activity when the buzzer was placed on the body, independently of the vibrator's location. Differentiated topographical awareness of the body seemed to appear around 5 months, with specific responses resulting from stimulation of the hands emerging first, followed by the differentiation of movement patterns associated with the stimulation of the feet. Qualitative analyses revealed specific movement types reliably associated with each stimulated location by 6 months of age, possibly preparing infants’ ability to actually reach for the vibrating target. We discuss this result in relation to newborns’ ability to learn specific movement patterns through intersensory contingency.

Statement of contribution

what is already known on infants’ sensorimotor knowledge about their own bodies

• 3‐month‐olds readily learn to produce specific limb movements to obtain a desired effect (movement of a mobile).
• infants detect temporal and spatial correspondences between events involving their own body and visual events.

what the present study adds

• until 4–5 months of age, infants mostly produce general motor responses to localized touch.
• this is because in the present study, infants could not rely on immediate contingent feedback.
• we propose a cephalocaudal developmental trend of topographic differentiation of body areas.