首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 109 毫秒
1.

Background

How do we estimate time when watching an action? The idea that events are timed by a centralized clock has recently been called into question in favour of distributed, specialized mechanisms. Here we provide evidence for a critical specialization: animate and inanimate events are separately timed by humans.

Methodology/Principal Findings

In different experiments, observers were asked to intercept a moving target or to discriminate the duration of a stationary flash while viewing different scenes. Time estimates were systematically shorter in the sessions involving human characters moving in the scene than in those involving inanimate moving characters. Remarkably, the animate/inanimate context also affected randomly intermingled trials which always depicted the same still character.

Conclusions/Significance

The existence of distinct time bases for animate and inanimate events might be related to the partial segregation of the neural networks processing these two categories of objects, and could enhance our ability to predict critically timed actions.  相似文献   

2.
Theories of the origin of life have proposed hypotheses to link inanimate to animate matter. The theory proposed here derived the crucial stages in the origin of animate matter directly from the basic properties of inanimate matter. It asked what were the general characteristics of the link, rather than what might have been its chemical details. Life and its origin are shown to be one continuous physicochemical process of replication, random variation, and natural selection. Since life exists here and now, animate properties must have been initiated in the past somewhere. According to the theory, life originated from an as yet unknown elementary autocatalyst which occurred spontaneously, then replicated autocatalytically. As it multiplied to macroscopic abundance, its replicas gradually exhausted their reactants. Random chemical drift initiated diversity among autocatalysts. Diversity led to competition. Competition and depletion of reactants slowed down the rates of net replication of the autocatalysts. Some reached negative rates and became extinct, while those which stayed positive ``survived.' Thus chemical natural selection appeared, the first step in the transition from inanimate to animate matter. It initiated the first animate property, fitness, i.e., the capacity to adapt to the environment and to survive. As the environment was depleted of reactants, it was enriched with sequels—namely, with decomposition products and all other products which accompany autocatalysis. The changing environment exerted a selective pressure on autocatalysts to replace dwindling reactants by accumulating sequels. Sequels that were incorporated into the autocatalytic process became internal components of complex autocatalytic systems. Primitive forms of metabolism and organization were thus initiated. They evolved further by the same mechanism to ever higher levels of complexity, such as homochirality (handedness) and membranal enclosure. Subsequent evolution by the same mechanism generated cellular metabolism, cell division, information carriers, and a genetic code. Theories of self-organization without natural selection are refuted. Received: 29 March 1996 / Accepted: 30 May 1996  相似文献   

3.
This study explored the influence of 5 types of visual stimulation (1 control condition [no visual stimulation] and 4 experimental conditions [blank television screen; and, televised images depicting humans, inanimate movement, animate movement]) on the behaviour of 125 cats housed in a rescue shelter. Twenty-five cats were randomly assigned to one of the five conditions of visual stimulation for 3 h a day for 3 days. Each cat's behaviour was recorded every 5 min throughout each day of exposure to the visual stimuli. Cats spent relatively little of the total observation time (6.10%) looking at the television monitors. Animals exposed to the programmes depicting animate and inanimate forms of movement spent significantly more of their time looking at the monitors than those exposed to the moving images of humans or the blank screen. The amount of attention that the cats directed towards the television monitors decreased significantly across their 3 h of daily presentation, suggesting habituation. Certain components of the cats’ behaviour were influenced by visual stimulation. Animals in the animate movement condition spent significantly less time sleeping, and displayed a non-significant trend to spend more time resting, and in the exercise area of their pens, than those in the other conditions of visual stimulation. Overall, the results from this study suggest that visual stimulation in the form of two-dimensional video-tape sequences, notably that combining elements of prey items and linear movement, may hold some enrichment potential for domestic cats housed in rescue shelters. Such animals, however, may not benefit from this type of enrichment to the same degree as species with more well-developed visual systems, such as primates.  相似文献   

4.
The transition from inanimate to animate chemistry is thought to involve self-organised networks of molecular species whose collective emergent property gives rise to the overall characteristics of living systems. In the past, simple autocatalytic networks have been constructed that display basic forms of cooperative behaviour. These include reciprocal catalysis, autocratic, and hypercyclic networks. The design and emergent properties of these novel molecular networks are reviewed here.  相似文献   

5.
The interrelations of physics and biology are discussed. It is shown that Darwin can be considered as one of the founders of the important field of contemporary physics called physics of dissipative structures or synergetics. The theories of gradual and punctual evolution are presented. The contradiction between these theories can be solved on the basis of molecular theory of evolution and on the basis of the phenomenological physical treatment. The general physical properties of living systems, considered as open systems being far from equilibrium, are listed and simple non-linear mathematical models describing gradual and punctual speciation are suggested. The usual pictures which present these two kinds of speciation can possess physico-mathematical sense. Punctuated speciation means bifurcation, a kind of non-equilibrium phase transition.  相似文献   

6.
Recent advances in the convergence of the biological, chemical, physical, and engineering sciences have opened new avenues of research into the interfacing of diverse biological moieties with inanimate platforms. A main aspect of this field, the integration of live cells with micro-machined platforms for high throughput and bio-sensing applications, is the subject of the present review. These unique hybrid systems are configured in a manner that ensures positioning of the cells in designated patterns, and enables cellular viability maintenance, and monitoring of cellular functionality. Here we review both animate and inanimate surface properties and how they affect cellular attachment, describe relevant modifications of both types of surfaces, list technologies for platform engineering and for cell deposition in the desired configurations, and discuss the influence of various deposition and immobilization methods on the viability and performance of the immobilized cells.  相似文献   

7.
Recent advances in the convergence of the biological, chemical, physical, and engineering sciences have opened new avenues of research into the interfacing of diverse biological moieties with inanimate platforms. A main aspect of this field, the integration of live cells with micro-machined platforms for high throughput and bio-sensing applications, is the subject of the present review. These unique hybrid systems are configured in a manner that ensures positioning of the cells in designated patterns, and enables cellular viability maintenance, and monitoring of cellular functionality. Here we review both animate and inanimate surface properties and how they affect cellular attachment, describe relevant modifications of both types of surfaces, list technologies for platform engineering and for cell deposition in the desired configurations, and discuss the influence of various deposition and immobilization methods on the viability and performance of the immobilized cells.  相似文献   

8.
The aim of the present fMRI study was to investigate the neural circuits of two stages of grammatical encoding in sentence production. Participants covertly produced sentences on the basis of three words (one verb and two nouns). In the functional level condition both nouns were animate and so were potential competitors for the grammatical function of subject. In the positional level condition the first noun was animate whereas the second was inanimate. We found activation of Broca''s and adjacent areas, previously indicated as responsible for syntactic processing. Additionally, a later onset of the activation in three brain areas in the functional level condition suggests that there is indeed a competition for assignment of subjecthood. The results constrain theories of grammatical encoding, which differ in whether they assume two separate processing levels or only one.  相似文献   

9.
What differentiates the living from the nonliving? What is life? These are perennial questions that have occupied minds since the beginning of cultures. The search for a clear demarcation between animate and inanimate is a reflection of the human tendency to create borders, not only physical but also conceptual. It is obvious that what we call a living creature, either bacteria or organism, has distinct properties from those of the normally called nonliving. However, searching beyond dichotomies and from a global, more abstract, perspective on natural laws, a clear partition of matter into animate and inanimate becomes fuzzy. Based on concepts from a variety of fields of research, the emerging notion is that common principles of biological and nonbiological organization indicate that natural phenomena arise and evolve from a central theme captured by the process of information exchange. Thus, a relatively simple universal logic that rules the evolution of natural phenomena can be unveiled from the apparent complexity of the natural world.  相似文献   

10.
Pogun S 《Bio Systems》2001,63(1-3):101-114
Interesting and intriguing questions involve complex systems whose properties cannot be explained fully by reductionist approaches. Last century was dominated by physics, and applying the simple laws of physics to biology appeared to be a practical solution to understand living organisms. However, although some attributes of living organisms involve physico-chemical properties, the genetic program and evolutionary history of complex biological systems make them unique and unpredictable. Furthermore, there are and will be 'unobservable' phenomena in biology which have to be accounted for.  相似文献   

11.
A high profile context in which physics and biology meet today is in the new field of systems biology. Systems biology is a fascinating subject for sociological investigation because the demands of interdisciplinary collaboration have brought epistemological issues and debates front and centre in discussions amongst systems biologists in conference settings, in publications, and in laboratory coffee rooms. One could argue that systems biologists are conducting their own philosophy of science. This paper explores the epistemic aspirations of the field by drawing on interviews with scientists working in systems biology, attendance at systems biology conferences and workshops, and visits to systems biology laboratories. It examines the discourses of systems biologists, looking at how they position their work in relation to previous types of biological inquiry, particularly molecular biology. For example, they raise the issue of reductionism to distinguish systems biology from molecular biology. This comparison with molecular biology leads to discussions about the goals and aspirations of systems biology, including epistemic commitments to quantification, rigor and predictability. Some systems biologists aspire to make biology more similar to physics and engineering by making living systems calculable, modelable and ultimately predictable-a research programme that is perhaps taken to its most extreme form in systems biology's sister discipline: synthetic biology. Other systems biologists, however, do not think that the standards of the physical sciences are the standards by which we should measure the achievements of systems biology, and doubt whether such standards will ever be applicable to 'dirty, unruly living systems'. This paper explores these epistemic tensions and reflects on their sociological dimensions and their consequences for future work in the life sciences.  相似文献   

12.
Captive prosimians housed in a semi-natural laboratory environment were exposed to novel stimuli, both animate (cat, snake) and inanimate (empty box). Observations were made by means of closed circuit TV. Animate stimuli elicited considerably more interest (about 42% of a test session) than the inanimate stimulus (about 12% of the test session). The more vulnerable species, the slow loris, displayed as much curiosity as the less vulnerable species, the greater galago; but, in the presence of live stimuli, lorises were more cautious. They moved slowly and silently, employed contact as a mode of investigation significantly less often than galagos, spent significantly less time than galagos investigating from within 3 ft, took significantly longer than galagos to make their first approaches to within the 3 ft zone, and, once there, stayed for significantly shorter visits than galagos. The data demonstrate: (1) that prosimians are highly responsive to novelty if the stimuli are appropriate; and (2) that it is important to take into account not just whether animals investigate but also how they investigate.  相似文献   

13.
The present paper critically deals with the widely accepted but nevertheless in recent years controversely discussed paradigms that the immune system may discriminate between self and nonself and harmless and dangerous, respectively. Concepts like these, and there are some more in actual immunology, -show that contemporary life sciences still are biased towards teleologic and anthropocentric thinking, though the existence of a priori purpose directed causalities has been denied by philosophers from time immemorial. A problem of current immunological language is in this context the usage of numerous metaphors predominantly borrowed from the field of brain functions, a usance that holds the risk of aggravating misinterpretations. In this context some of the paradigms ruling current immunology will be reviewed and discussed in the light of an emergent understanding of the fundamental principles of complex systems being widely spread in our inanimate and animate world.  相似文献   

14.
This ERP study used electrophysiological technique to examine how individual differences in the speed of working memory updating influence the use of syntactic and semantic information during on-line sentence argument interpretation, and the time course of that working memory updating effect. The basic structure of the experimental sentences was “Noun + Verb + adverb + ‘le’ + a two-character word”, with the Noun being the sentence initial argument. This initial argument is animate or inanimate and the following verb disambiguates it as an agent or patient. The results at the initial argument revealed that, the quick-updating group elicited a larger positivity over the frontal cortex (within 500–800 ms post-noun onset) as compared with the slow-updating group. At the following disambiguating verb, the slow-updating group only showed a word order effect, indicating that the patient-first condition elicited a larger P600 (within 500–1,000 ms post-verb onset) than the agent-first one; for the quick-updating group, at the early stage of processing, the patient-first sentences elicited a larger N400 (within 300–500 ms post-verb onset) than the agent-first ones only when the initial argument was inanimate; however, at the late stage, the patient-first sentences elicited an enhanced P600 (within 800–1,000 ms post-verb onset) only when the initial argument was animate. These results suggested that the speed of working memory updating not only influences the maintenance of sentence argument when the contents of working memory change but also influences the efficiency of integrating that argument with the verb at a late time point. When integrating the argument with the disambiguating verb, individuals with quick-updating ability can combine multiple sources of information (both noun animacy and word order), and conduct rapid and fine-grained two-stage processing; individuals with slow-updating ability, however, only rely on one dominant source of information types (word order), and conducted slow and course-grained processing.  相似文献   

15.
AIMS: In spite of the importance of many species of Candida as human pathogens, little is known about their ability to survive on animate and inanimate surfaces. Such information is essential in understanding the vehicles and modes of their spread, and in designing proper infection control strategies against them. The aim of this study was to generate comparative quantitative data in this regard. METHODS AND RESULTS: The survival of one clinical isolate each of Candida albicans and C. parapsilosis on two types of hard inanimate surfaces (glass and stainless steel) and two types of fabrics (100% cotton and a blend of 50% cotton and 50% polyester) was evaluated under ambient conditions (air temperature 22 +/- 2 degrees C; relative humidity 45-62%) using quantitative test protocols. The survival of C. albicans was also assessed on human skin, using the fingerpads of adult volunteers as carriers. Each carrier surface received 10 microl of the test suspension containing a soil load to simulate body fluids. When dried on glass and stainless steel carriers, C. albicans and C. parapsilosis remained viable for at least three and 14 days, respectively. Both species could survive for at least 14 days on both types of fabric. On the skin, 20% of the viable C. albicans remained detectable one hour post-inoculation. SIGNIFICANCE AND IMPACT OF THE STUDY: This quantitative and comparative study demonstrated the potential for, and differences in the ability of clinically significant species of Candida to remain viable on porous and non-porous inanimate surfaces as well as on human hands. These results should help in understanding the epidemiology of nosocomial infections due to Candida, and in designing better prevention and control strategies against them.  相似文献   

16.
Given that biological motion is both detected and preferred early in life, we tested the hypothesis that biological motion might be instrumental to infants’ differentiation of animate and inanimate categories. Infants were primed with either point-light displays of realistic biological motion, random motion, or schematic biological motion of an unfamiliar shape. After being habituated to these displays, 12-month-old infants categorized animals and vehicles as well as furniture and vehicles with the sequential touching task. The findings indicated that infants primed with point-light displays of realistic biological motion showed better categorization of animates than those exposed to random or schematic biological motion. These results suggest that human biological motion might be one of the motion cues that provide the building blocks for infants’ concept of animacy.  相似文献   

17.
18.
Theoretical accounts as well as behavioral studies reporting animacy effects offer inconsistent and sometimes contradictory results. A possible explanation for these inconsistencies may be inadvertent biases in the stimuli selected for test – with category-specific effects driven by characteristics of test stimuli other than animacy per se. In this study, we pit animacy against feature structure (intra-item variability), in a picture-word matching task. For unimpaired adults, regardless of whether objects were from animate (mammals; insects) or inanimate (clothes; musical instruments) superordinate categories, participants were faster to match basic level labels with objects from categories with low intra-item variability (mammals; clothes) than from categories with high intra-item variability (insects; instruments). Thus, pitting animacy against variability allowed us to clarify that observable differences in processing speed between animals and instruments are systematically driven by the intra-item variability of the superordinate categories, and not by animacy itself.  相似文献   

19.
The anterior inferotemporal cortex (IT) is the highest stage along the hierarchy of visual areas that, in primates, processes visual objects. Although several lines of evidence suggest that IT primarily represents visual shape information, some recent studies have argued that neuronal ensembles in IT code the semantic membership of visual objects (i.e., represent conceptual classes such as animate and inanimate objects). In this study, we investigated to what extent semantic, rather than purely visual information, is represented in IT by performing a multivariate analysis of IT responses to a set of visual objects. By relying on a variety of machine-learning approaches (including a cutting-edge clustering algorithm that has been recently developed in the domain of statistical physics), we found that, in most instances, IT representation of visual objects is accounted for by their similarity at the level of shape or, more surprisingly, low-level visual properties. Only in a few cases we observed IT representations of semantic classes that were not explainable by the visual similarity of their members. Overall, these findings reassert the primary function of IT as a conveyor of explicit visual shape information, and reveal that low-level visual properties are represented in IT to a greater extent than previously appreciated. In addition, our work demonstrates how combining a variety of state-of-the-art multivariate approaches, and carefully estimating the contribution of shape similarity to the representation of object categories, can substantially advance our understanding of neuronal coding of visual objects in cortex.  相似文献   

20.
Cull P 《Bio Systems》2007,88(3):178-184
N. Rashevsky (1899-1972) was one of the pioneers in the application of mathematics to biology. With the slogan: mathematical biophysics : biology :: mathematical physics ; physics, he proposed the creation of a quantitative theoretical biology. Here, we will give a brief biography, and consider Rashevsky's contributions to mathematical biology including neural nets and relational biology. We conclude that Rashevsky was an important figure in the introduction of quantitative models and methods into biology.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号