Selective attention to particular aspects of incoming sensory information is enabled by a network of neural areas that includes frontal cortex, posterior parietal cortex, and, in the visual domain, visual sensory regions. Although progress has been made in understanding the relative contribution of these different regions to the process of visual attentional selection, primarily through studies...

The four types of order whose inter-relations are considered in this paper may be called, for brevity, (1) serial order; (2) betweenness; (3) cyclic order; and (4) separation. We first recapitulate the known sets of postulates which define each of these types as an abstract system, and recall the usual geometric interpretation of each type; we then develop the way in which each of these four ty...

If the cortex is an associative memory, strongly connected cell assemblies will form when neurons in different cortical areas are frequently active at the same time. The cortical distributions of these assemblies must be a consequence of where in the cortex correlated neuronal activity occurred during learning. An assembly can be considered a functional unit exhibiting activity states such as f...

This article examines the evidence that certain deficits in information processing and attentional functioning are present across populations at risk for schizophrenic disorder, with active schizophrenic psychotic symptomatology, and in relative remission after a schizophrenic psychosis. In addition, the evidence that some deficits in processing information occur only in the actively psychotic ...

Substantive scientific letter writing is a cost-effective mode of complementing observational and experimental research. The value of such philosophically uncommitted and unsponsored well-balanced scientific activity has been relegated. Critical letter writing entails the abilities to: maintain rational scepticism; refuse to conform in order to explain data; persist in keeping common sense cent...

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priorities permit. The comments should not exceed 350 words in length, with a maximum of five references; one figure or table can be printed. Exceptions may occur under particular circumstances. Contributions may include comments on articles published in this periodical, or they may be reports of unique educational character. Please include a cover letter with a complete list of authors (includ...

Discussions of the standardization of English vocabulary are seldom taken up with questions of morphology. Yet there is a history of, often strikingly similar, attempts to influence the use of particular word-formation processes, such as the proscription of individual lexical items on morphological grounds, or more precisely, the grounds that an affix is being “overextended”. This is not a refe...

What factors determine the implementation of attentional set? It is often assumed that set is determined only by experimenter instructions and characteristics of the immediate stimulus environment, yet it is likely that other factors play a role. The present experiments were designed to evaluate the latter possibility; specifically, the role of past experience was probed. In a 320-trial trainin...

An outburst of the X-ray transient source XTE J1806–246 (2S1803–245) was observed by the Rossi X-ray Timing Explorer from April-July 1998. Strong quasi-periodical oscillations (QPO) with a central peak frequency around 9 Hz was detected in one observation of the series performed by the PCA/RXTE experiment. The X-ray flux from the source during the observation with QPO was maximal. The energy sp...