The capacity of visual short-term memory within and between hemifields

Visual short-term memory (VSTM) and attention are both thought to have a capacity limit of four items [e.g. Luck, S. J., & Vogel, E. K. (1997). The capacity of visual working memory for features and conjunctions. Nature, 309, 279-281; Pylyshyn, Z. W., & Storm, R. W. (1988). Tracking multiple independent targets: evidence for a parallel tracking mechanism. Spatial Vision, 3, 179-197.]. Using the multiple object visual tracking paradigm (MOT), it has recently been shown that twice as many items can be simultaneously attended when they are separated between two visual fields compared to when they are all presented within the same hemifield [Alvarez, G. A., & Cavanagh, P. (2004). Independent attention resources for the left and right visual hemifields (Abstract). Journal of Vision, 4(8), 29a.]. Does VSTM capacity also increase when the items to be remembered are distributed between the two visual fields? The current paper investigated this central issue in two different tasks, namely a color and spatial location change detection task, in which the items were displayed either in the two visual fields or in the same hemifield. The data revealed that only memory capacity for spatial locations and not colors increased when the items were separated between the two visual fields. These findings support the view of VSTM as a chain of capacity limited operations where the spatial selection of stimuli, which dominates in both spatial location VSTM and MOT, occupies the first place and shows independence between the two fields.     

Experiencing nearby locations together in time: the role of spatiotemporal contiguity in children's memory for location

Three studies investigated how experiencing nearby locations together in time influences memory for location. Seven-, 9-, and 11-year-old children and adults learned 20 object locations in a small-scale space. The space was divided into regions by lines or walls. In Study 1, participants learned the locations either region by region or in a random order. Following learning, participants replaced the objects without the aid of the dots marking the locations and the boundaries subdividing the space. They replaced the objects in any order they chose. After experiencing the locations in random orders during learning, only adults underestimated distances between locations belonging to the same group (i.e., region). Conversely, 9- and 11-year-old children and adults who had experienced the locations region by region during learning underestimated these distances. These findings suggest that experiencing nearby locations together in time increases the weight children assign to categorical information in their estimates of location. Results from Studies 2 and 3 in which participants learned the locations region by region and then replaced the objects region by region (Study 2) or in a random order (Study 3) were similar, highlighting the importance of spatiotemporal cues in memory for location. (c) 2002 Elsevier Science (USA).     

Crossed aphasia: an analysis of the symptoms,their frequency,and a comparison with left-hemisphere aphasia symptomatology

This study presents a thorough analysis of published crossed aphasia (CA) cases, including for the first time the cases published in Japanese. The frequency of specific symptoms was determined, and symptomatology differences based on gender, familial sinistrality, and CA subtype were investigated. Results suggested that the CA population is comparable to the left-hemisphere patient population. However, male were significantly more likely than female CA subjects to show a positive history of familial sinistrality. Typical right-hemisphere (i.e., nonlanguage-dominant) symptoms were frequent but rarely carefully reported or assessed. Results are compared with previous CA reviews and left-hemisphere aphasia. Suggestions for a more systematic assessment of the CA symptomatology are presented.     

蛋白质组学与神经科学:从蛋白质到网络

多蛋白质信号复合物在所有细胞中都很重要,它们在脑内信息处理也有着重要作用。质谱、双向凝胶电泳、蛋白亲和技术、高通量的免疫组化方法和蛋白质组信息学都蛋白质组学研究的主要手段。应用蛋白质组学方法可以研究多蛋白信号复合的功能,多样性与组成的动态变化。因此,蛋白质组学发展使得人们从单个蛋白质的研究上升到对蛋白质网络的研究。蛋白质组学研究将为神经与精神疾病的诊断技术与治疗手段提供一条新的道路。     

Predictors of early person reference development: Maternal language input,attachment and neurodevelopmental markers

In a longitudinal natural language development study in Germany, the acquisition of verbal symbols for present persons, absent persons, inanimate things and the mother–toddler dyad was investigated. Following the notion that verbal referent use is more developed in ostensive contexts, symbolic play situations were coded for verbal person reference by means of noun and pronoun use. Depending on attachment classifications at twelve months of age, effects of attachment classification and maternal language input were studied up to 36 months in four time points. Hierarchical regression analyses revealed that, except for mother absence, maternal verbal referent input rates at 17 and 36 months were stronger predictors for all referent types than any of the attachment organizations, or any other social or biological predictor variable. Attachment effects accounted for up to 9.8% of unique variance proportions in the person reference variables. Perinatal and familial measures predicted person references dependent on reference type. The results of this investigation indicate that mother-reference, self-reference and thing-reference develop in similar quantities measured from the 17-month time point, but are dependent of attachment quality.     

Evolutionary Pluralism: A New System of Systems Philosophy

When Darwin wrote his ‘On the origin of species…” (1859) he focused on evolution as a property of living organisms in interaction with abiotic and biotic elements in the world. This viewpoint is still dominant amongst biologists. For particle physicists and cosmologists evolution refers to a larger scale, ranging from quarks and atoms to galaxies, stars and planets (i.e. Pagels 1985, Hawking 1988). To close the gap between such different viewpoints, a wide range of perspectives on an interdisciplinary understanding of system development has been published (i.e. Teilhard de Chardin 1966, von Bertalanffy 1968, Varela 1979, Prigogine and Stengers 1984, Laszlo 1996). As an integrative concept, the construction of nature from a hierarchy of system layers forms a central tenet in general system research and the stepwise construction of this layered hierarchy can be regarded as an interdisciplinary evolution theory. Surprisingly, the literature offers no unequivocal rules to recognise a multilayer hierarchy in nature. This presents an obstacle for interdisciplinary approaches to evolution.

Searching a solution to part of the above hierarchy problem, the present paper is dedicated to the analysis of a special kind of layering in natural systems, which is based on transitions between ‘building block’ systems. To identify these building blocks, and the transitions from building block x at level A, to building block y at level B, the focus of this study is further limited to ‘hypercydic dynamics’ and ‘containment’. On the basis of these criteria, a hierarchy is created which shows no possibilities for ‘bypasses’. It connects hadrons to atoms, atoms to cells, and cells to neural networks. Implications of this hierarchy for system studies and evolution are discussed.     

Suggested reading

The problem of mystical/meditational experience is discussed from the point of view of the neural network theory, considering also the approach to (sub) quantum physics by Bohm and Hiley. It has been argued that the appearance of global uniform neural patterns, i.e. those with coherent activities of constitutive neurons, function as the basis of mystical unity. Various processes occurring as the result of the collective dynamics of a complex neural system are compared and correlated with mystical phenomenology on the one hand, and with quantum processes or neurophysiological effects on the other. Awareness may be a quantum phenomenon, so some speculations about neural‐quantum interactions and analogies are presented. The contact with the symmetric subquantum “sea”, in which the brain is embedded, may provide the background for the most radical experiences. Special attention is devoted to implicit versus explicit mental and transcendental processes, and to their multi‐level parallelism. Evolution towards transcendental consciousness brings an alternative lifestyle for the future.     

Nonlinear synthesis and co‐evolution of complex systems

Today a change is imperative in approaching global problems: what is needed is not arm‐twisting and power politics, but searching for ways of co‐evolution in the complex social and geopolitical systems of the world. The modern theory of self‐organization of complex systems provides us with an understanding of the possible forms of coexistence of heterogeneous social and geopolitical structures at different stages of development regarding the different paths of their sustainable co‐evolutionary development. The theory argues that the evolutionary channel to the observed increasing complexity is extremely narrow and only certain discrete spectra of relatively stable self‐maintained structures are feasible in complex systems. There exists a restricted set of ways of assembling a complex evolutionary whole from diverse parts. The law of nonlinear synthesis of complex structures reads: the integration of structures in more complex ones occurs due to the establishment of a common tempo of their evolution. On the basis of the theory, we can see not only desirable but also attainable futures.     

The autonomy of social reality: On the contribution of the theory of systems to the theory of society 1

Many contemporary schools of thought contend that the autonomy of the human world is an impossible and dangerous goal to aim at. It is shown that this is the result of the unwarranted identification of autonomy with self‐mastery. Autonomy has to be conceived of in terms of complexity and self‐transcendence (a bootstrapping). Among the paradigms that are thus revisited: Structuralism, Deconstruction, Methodological Individualism.     

Emergence of a Social Inquiry Group: A Story of Fractals and Networks

This article relates the emergence of a group of faculty researchers utilizing complexity science approaches. The narrative emerges from three projects combining research into complexity, communities, and technologies. Details of how the research was initiated, and the nature and quality of the conversational method, are provided. In addition, theoretical concepts that were consciously applied and others that arose through insights from the data as it was collected are discussed. Although this is like most real narratives, a never-ending story, it concludes with a presentation of some of the ideas that separate complexity-informed research from other paradigms.