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1.
《Social neuroscience》2013,8(6):621-630
Looming stimuli are processed as threatening and activate basic neural defense systems. However, it is unclear how animacy information modulates this response. Participants (N = 25) viewed threatening or neutral images that were either animate (animals) or inanimate (objects) and which either approached (loomed) or receded from the participant. The amygdala was responsive to emotional, animacy, and looming information (particularly to looming threats and looming animate stimuli). Periaqueductal gray was also sensitive to emotional information and particularly responsive to looming threats. The data are interpreted within category-specific models of the amygdala and temporal cortex.  相似文献   

2.
Simple geometric shapes moving in a self-propelled manner, and violating Newtonian laws of motion by acting against gravitational forces tend to induce a judgement that an object is animate. Objects that change their motion only due to external causes are more likely judged as inanimate. How the developing brain is employed in the perception of animacy in early ontogeny is currently unknown. The aim of this study was to use ERP techniques to determine if the negative central component (Nc), a waveform related to attention allocation, was differentially affected when an infant observed animate or inanimate motion. Short animated movies comprising a marble moving along a marble run either in an animate or an inanimate manner were presented to 15 infants who were 9 months of age. The ERPs were time-locked to a still frame representing animate or inanimate motion that was displayed following each movie. We found that 9-month-olds are able to discriminate between animate and inanimate motion based on motion cues alone and most likely allocate more attentional resources to the inanimate motion. The present data contribute to our understanding of the animate–inanimate distinction and the Nc as a correlate of infant cognitive processing.  相似文献   

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Proprioception is the sense of the position of one's own body. Here, we present a case study of an individual with proprioceptive loss in one limb consequent to stroke. The patient indicated that merely touching his impaired arm with his unimpaired arm temporarily restored his proprioception. We examined this claim and the effects of imagined touch by the unimpaired arm. Assessments were made using three-dimensional tracking of reaching trajectories towards targets in conditions of light and darkness. Both actual and imagined touching significantly reduced movement error and jerk, specifically for targets located in regions that both hands would be able to reach.  相似文献   

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The so-called self–other correspondence problem in imitation demands to find the transformation that maps the motor dynamics of one partner to our own. This requires a general purpose sensorimotor mechanism that transforms an external fixation-point (partner’s shoulder) reference frame to one’s own body-centered reference frame. We propose that the mechanism of gain-modulation observed in parietal neurons may generally serve these types of transformations by binding the sensory signals across the modalities with radial basis functions (tensor products) on the one hand and by permitting the learning of contextual reference frames on the other hand. In a shoulder–elbow robotic experiment, gain-field neurons (GF) intertwine the visuo-motor variables so that their amplitude depends on them all. In situations of modification of the body-centered reference frame, the error detected in the visuo-motor mapping can serve then to learn the transformation between the robot’s current sensorimotor space and the new one. These situations occur for instance when we turn the head on its axis (visual transformation), when we use a tool (body modification), or when we interact with a partner (embodied simulation). Our results defend the idea that the biologically-inspired mechanism of gain modulation found in parietal neurons can serve as a basic structure for achieving nonlinear mapping in spatial tasks as well as in cooperative and social functions.  相似文献   

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Cowan N 《Neuropsychologia》2011,49(6):1401-1406
Recent behavioral and neuroscientific evidence speaks to the question of whether the human focus of attention is limited to a single item or can accommodate several items. This issue is fundamental to an understanding of the nature of human cognition and brain function. Here I review evidence from visual working memory tasks and suggest that it supports the concept of a focus of attention that can include several items at once as a core vehicle of working memory, regardless of the stimulus modality. One brain area in particular, the left intraparietal sulcus (IPS), seems critically important in the network underlying the focus of attention as a working memory storage mechanism. This view is reconciled with evidence previously taken to indicate that the focus of attention only includes a single item at a time, which is reinterpreted here.  相似文献   

7.
Simner J  Ludwig VU 《Neurocase》2012,18(2):167-180
We report a single-case study, EB, who experiences synaesthetic sensations of color from tactile stimulation. Developmental synaesthesia is typically characterized by the consistency of synaesthetic pairings over time, in that stimuli tend to generate the same synaesthetic responses on different occasions. Here we demonstrate that EB's touch-color associations are significantly more consistent over time compared to a group of non-synaesthete controls, but that this comes in the face of surprisingly high consistency among non-synaesthetes themselves, for certain tactile stimuli. We show, too, that EB's touch-color correspondences are guided by an implicit rule system, and that this system is shared by non-synaesthetes. Both synaesthetes and non-synaesthetes are sensitive to tactile qualities such as smoothness and softness, and these qualities are systematically related to the luminance and chroma of associated colors.  相似文献   

8.
Recent studies suggest the existence of a visuo-tactile mirror system, comprising the primary (SI) and secondary (SII) somatosensory cortices, which matches observed touch with felt touch. Here, repetitive transcranial magnetic stimulation (rTMS) was used to determine whether SI or SII play a functional role in the visual processing of tactile events. Healthy participants performed a visual discrimination task with tactile stimuli (a finger touching a hand) and a control task (a finger moving without touching). During both tasks, rTMS was applied over either SI or SII, and to the occipital cortex. rTMS over SI selectively reduced subject performance for interpreting whether a contralateral visual tactile stimulus contains a tactile event, whereas SII stimulation impaired visual processing regardless of the tactile component. These findings provide evidence for a multimodal sensory-motor system with mirror properties, where somatic and visual properties of action converge. SI, a cortical area traditionally viewed as modality-specific, is selectively implicated in the visual processing of touch. These results are in line with the existence of a sensory mirror system mediating the embodied simulation concept.  相似文献   

9.
Specializations for electroreception in sense organs and brain centers are found in a wide variety of fishes and amphibians, though probably in a small minority of teleost taxa. No other group of vertebrates or invertebrates is presently suspected to have adaptations for electroreception in the definition given here. The distribution among fishes is unlike any other sense modality in that it has apparently been invented, lost completely and reinvented several times independently, using distinct receptors and central nuclei in the medulla. There are so far no clearly borderline or transitional fishes, either physiologically or anatomically. We rather expect a few new electroreceptive taxa to be found. The evoked potential method and the newly validated central anatomical criteria provide two useful tools for searching. Although Myxiniformes probably lack electroreception, it is well developed in Petromyzoniformes and in all other non-teleost fishes except Holostei. Thus Elasmobranchia, Holocephala, Dipneusti, Crossopterygii, Polypteriformes and Chondrostei have the physiological and anatomical specializations in a common form consistent with a single origin in primitive vertebrates. Amphibian ancestors probably inherited the system from a stem similar to one of these and passed it on at least to the ambystomatoid and salamandroid urodeles, apparently after losing the kinocilium of the sense cell. The suggestion of electroreception in ichthyophid apodans from skin histology has not been confirmed physiologically, behaviorally or by brain anatomy. With respect to more advanced fishes the most parsimonious interpretation is that the entire system, peripheral and central was lost in ancestors of holostean and teleostean fishes and new systems reinvented in Siluriformes, in Gymnotiformes, in Xenomystinae and in Mormyriformes. These 4 taxa must represent at least two, and probably 3 or 4 independent inventions, presumably from mechanoreceptive lateral line organs and brain centers.  相似文献   

10.
Specializations for electroreception in sense organs and brain centers are found in a wide variety of fishes and amphibians, though probably in a small minority of teleost taxa. No other group of vertebrates or invertebrates is presently suspected to have adaptations for electroreception in the definition given here. The distribution among fishes is unlike any other sense modality in that it has apparently been invented, lost completely and reinvented several times independently, using distinct receptors and central nuclei in the medulla. There are so far no clearly borderline or transitional fishes, either physiologically or anatomically. We rather expect a few new electroreceptive taxa to be found. The evoked potential method and the newly validated central anatomical criteria provide two useful tools for searching.Although Myxiniformes probably lack electroreception, it is well developed in Petromyzoniformes and in all other non-teleost fishes except Holostei. Thus Elasmobranchia, Holocephala, Dipneusti, Crossopterygii, Polypteriformes and Chondrostei have the physiological and anatomical specializations in a common form consistent with a single origin in primitive vertebrates. Amphibian ancestors probably inherited the system from a stem similar to one of these and passed it on at least to the ambystomatoid and salamandroid urodeles, apparently after losing the kinocilium of the sense cell. The suggestion of electroreception in ichthyophid apodans from skin histology has not been confirmed physiologically, behaviorally or by brain anatomy. With respect to more advanced fishes the most parsimonious interpretation is that the entire system, peripheral and central was lost in ancestors of holostean and teleostean fishes and new systems reinvented in Siluriformes, in Gymnotiformes, in Xenomystinae and in Mormyriformes. These 4 taxa must represent at least two, and probably 3 or 4 independent inventions, presumably from mechanoreceptive lateral line organs and brain centers.  相似文献   

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Of all the senses, touch is the first to develop; it is the most essential to life and a requirement for normal development. Interpersonal touch, including sexual touch, is also the most controversial of the senses, perceived by some as uncomfortable or threatening, and by others as the epitome of sublime pleasure and connection with a partner. An extraordinary and basic way sex therapists can enrich the sexual connection between couples is to introduce caressing exercises that are not goal focused on arousal and orgasm. Caressing exercises assist couples in moving beyond any negative or ambivalent attitudes toward partnered touch, often bringing them to levels of sensual awareness and tactile pleasure that are new and delightful.  相似文献   

13.
The study aimed to explore and synthesize stakeholders' conceptualizations and solutions concerning ADHD in the context of CAMHS. The participants were 28 stakeholders consisting of seven mental heath professionals, two teachers, seven parents/carers, five children referred for an ADHD assessment, two siblings and five peers. Individual, semi-structured interviews were held with all professionals and parents/carers. The children's interviews used methods tailored for junior age children and were semi-structured, individual and in a group format for the peers. All interviews were transcribed verbatim and the children's pictures were analysed. A thematic analysis was undertaken with ADHD thematically emerging as a confusing mess with conflicts reverberating across all levels of analysis from the intra-psychic world of the child to wider social contexts. Professionals attempt to make sense of this mess, parents experience the emotional impact of the mess and children's identities are shaped by it. A reflective space where complexity, uncertainty and hidden feelings are thought about is postulated to reduce confusion and dissonance, and which in turn would enable the system to become more self aware and less na?ve.  相似文献   

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This study provides ecological validity for laboratory findings that people with memory difficulties following brain injury can learn new skills. This was done by testing the acquisition of a useful real-world perceptual-motor skill. Using a conventional computer software training package supplemented by one-to-one coaching, a woman with severely impaired memory and a man with poor memory learned to touch type. They achieved the initial criterion of 20 wpm with over 90% accuracy; reached a top speed of 30 wpm and retained their skill a year later. The memory-impaired participants received short sessions of distributed practice and as far as possible were taught under error-free learning conditions. Their performance was broadly comparable with that of two non-memory-impaired comparison participants in terms of acquisition, consolidation and transfer, speed and accuracy, and retention.  相似文献   

18.
Achieving a sense of purpose during adolescence is a developmental asset; however, searching for that purpose may be a developmental stressor. Supportive parent–child relationships may help youth during this stressful experience. The present study included 207 female students in the sixth, eighth, and tenth grades from two competitive private schools. Searching for purpose negatively predicted self-esteem. Hierarchical linear regression examined moderating effects of parental trust and alienation on searching for purpose as a predictor of self-esteem. Parental alienation significantly moderated the association between search for purpose and girls' self-esteem; conversely, parental trust did not moderate the association. Results suggest that parent–child relationships characterized by high levels of parental alienation may exacerbate the pernicious effects of search for purpose. Person-based analyses found four clusters corresponding to Foreclosed Purpose, Diffused Purpose, Uncommitted Purpose/Moratorium, and Achieved Purpose. We discuss implications for practice and research based on these results.  相似文献   

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The sense organs of the vertebrate head arise predominantly from sensory placodes. The sensory placodes have traditionally been grouped as structures that share common developmental and evolutionary characteristics. In attempts to build a coherent model for development of all placodes, the fascinating differences that make placodes unique are often overlooked. Here I review olfactory placode development with special attention to the origin and cell movements that generate the olfactory placode, the derivatives of this sensory placode, and the degree to which it shows plasticity during development. Next, through comparison with adenohypophyseal, and lens placodes I suggest we revise our thinking and terminology for these anterior placodes, specifically by: (1) referring to the peripheral olfactory sensory system as neural ectoderm because it expresses the same series of genes involved in neural differentiation and differentiates in tandem with the olfactory bulb, and (2) grouping the anterior placodes with their corresponding central nervous system structures and emphasizing patterning mechanisms shared between placodes and these targets. Sensory systems did not arise independent of the central nervous system; they are part of a functional unit composed of peripheral sensory structures and their targets. By expanding our analyses of sensory system development to also include cell movements, gene expression and morphological changes observed in this functional unit, we will better understand the evolution of sensory structures.  相似文献   

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