Visuospatial neglect after stroke is often characterized by a disengage deficit on a cued orienting task, in which individuals are disproportionately slower to respond to targets presented on the contralesional side of space following an ispilesional cue as compared to the reverse. The purpose of this study was to investigate the generality of the finding of a disengage deficit on another measure of cued attention, the temporal order judgment (TOJ) task, that does not depend upon speeded manual responses. Individuals with (...) right hemisphere stroke with and without spatial neglect and older healthy controls were tested with both a speeded RT cueing task and an unspeeded TOJ-with-cuing task. All stroke patients evidenced a disengage deficit on the speeded RT cueing task, although the size and direction of the bias was not associated with the severity of neglect. In contrast, few neglect patients showed a disengage deficit on the TOJ task. This discrepancy suggests that the disengage deficit may be related to task demands, rather than solely due to impaired attentional mechanisms per se. Further, the results of our study show that the disengage deficit is neither necessary nor sufficient for neglect to manifest. (shrink)
Recently, Jonardan Ganeri reviewed the collaborative translation of the first chapter of Gaṅgeśa's Tattvacintāmaṇi by Stephen H. Phillips and N. S. Ramanuja Tatacharya (Ganeri 2007). The review is quite favorable, and we have no desire to dispute his kind words. Ganeri does, however, put forth an argument in opposition to a fundamental line of interpretation given by Phillips and Ramanuja Tatacharya about the nature of pramāṇa, knowledge sources, as understood by Gaṅgeśa and, for that matter, Nyāya tradition. This response is (...) meant to answer the argument and reassert an understanding of pramāṇa as factive, that is, as knowledge sources that are inerrant. We argue that this is the best reading of Gaṅgeśa himself .. (shrink)
With the emergence of service provisioning environments and new networking capabilities, antagonistic businesses have been able to collaborate securely by sharing information in order to have a beneficial result for all. This collaboration has sometimes been imposed by state legislation and sometimes been desirable by the firms themselves so as to resolve frequently occurring abnormalities. In any case, as information exchange takes place between antagonistic firms, security and privacy issues arise. In the context of this paper, a collaborative environment has (...) been analyzed for enterprises that set out in the banking sector. A Grid-based Anti-Money Laundering (AML) system has been developed in an effort to take advantage of the Grid infrastructure, supporting the secure and trustful exchange of information between financial institutions and ensuring the confidentiality of the data transferred and the authentication of the users to whom they are available. Special emphasis is put on security mechanisms for supporting identity and privacy management as well as in Service Level Agreements (SLA) enforcement for enabling a trust enforcement platform in a collaboration business model. (shrink)
Analogy by priming learned transformations of (causally) related objects fails to explain an important class of inference involving abstract source-target relations. This class of analogical inference extends to ad hoc relationships, precluding the possibility of having learned them as object transformations. Rather, objects may be placed into momentarily corresponding, symbolic, source-target relationships just to complete an analogy.
Religious pluralis does have, as James Kraft says, a negative impact on the epistemic confidence with which one holds a religious position, when epistemology is thought on both the externalist and internalist lines. I also conclude both that there is a resulting epistemic humility and that a tolerance of religious diversity results from it, but I reach these conclusions for entirely different reasons. Epistemic humility and religious tolerance are fostered by the realization that many religions are striving for the infinite, (...) though all have limited views of it. (shrink)
One of the hallmarks of human cognition is the capacity to generalize over arbitrary constituents. Recently, Marcus (1998, 1998a, b; Cognition 66, p. 153; Cognitive Psychology 37, p. 243) argued that this capacity, called universal generalization (universality), is not supported by Connectionist models. Instead, universality is best explained by Classical symbol systems, with Connectionism as its implementation. Here it is argued that universality is also a problem for Classicism in that the syntax-sensitive rules that are supposed to provide causal explanations (...) of mental processes are either too strict, precluding possible generalizations; or too lax, providing no information as to the appropriate alternative. Consequently, universality is not explained by a Classical theory. (shrink)
Perruchet & Vinter claim that with the additional capacity to determine whether two arbitrary stimuli are the same or different, their association-based PARSER model is sufficient to account for learning transfer. This claim overstates the generalization capacity of perceptual versus nonperceptual (symbolic) relational processes. An example shows why some types of learning transfer also require the capacity to bind arbitrary representations to nonperceptual relational symbols.
Cowan's review shows that a short-term memory limit of four items is consistent with a wide range of phenomena in the field. However, he does not explain that limit, whereas an existing theory does offer an explanation for capacity limitations. Furthermore, processing capacity limits cannot be reduced to storage limits as Cowan claims.
The great Advaita Vedāntin Śaṅkara puts forth a mystic parallelism thesis that is identified and examined here: mystical and sensory experiences are epistemically parallel. Among the conclusions drawn are that the Advaita metaphysics precludes successful defense of a Brahman-centered philosophy on the basis of such a thesis because Advaita precludes a story about how the experience of its Brahman could arise. Thus Śaṅkara needs "scripture" (śruti) to secure important parts of his view. A truly mystical Vedānta, in contrast, would not.
Minds are said to be systematic: the capacity to entertain certain thoughts confers to other related thoughts. Although an important property of human cognition, its implication for cognitive architecture has been less than clear. In part, the uncertainty is due to lack of precise accounts on the degree to which cognition is systematic. However, a recent study on learning transfer provides one clear example. This study is used here to compare transfer in humans and feedforward networks. Simulations and analysis show, (...) that while feedforward networks with shared weights are capable of exhibiting transfer, they cannot support the same degree of transfer as humans. One interpretation of these results is that common connectionist models lack explicit internal representations permitting rapid learning. (shrink)
The core issue of our target article concerns how relational complexity should be assessed. We propose that assessments must be based on actual cognitive processes used in performing each step of a task. Complexity comparisons are important for the orderly interpretation of research findings. The links between relational complexity theory and several other formulations, as well as its implications for neural functioning, connectionist models, the roles of knowledge, and individual and developmental differences, are considered.
Human cognition is said to be systematic: cognitive ability generalizes to structurally related behaviours. The connectionist approach to cognitive theorizing has been strongly criticized for its failure to explain systematicity. Demonstrations of generalization notwithstanding, I show that two widely used networks (feedforward and recurrent) do not support systematicity under the condition of local input/output representations. For a connectionist explanation of systematicity, these results leave two choices, either: (1) develop models capable of systematicity under local input/output representations; or (2) justify the (...) choice of similarity-based (nonlocal) component representations sufficient for systematicity. (shrink)
At root, the systematicity debate over classical versus connectionist explanations for cognitive architecture turns on quantifying the degree to which human cognition is systematic. We introduce into the debate recent psychological data that provides strong support for the purely structure-based generalizations claimed by Fodor and Pylyshyn (1988). We then show, via simulation, that two widely used connectionist models (feedforward and simple recurrent networks) do not capture the same degree of generalization as human subjects. However, we show that this limitation is (...) overcome by tensor networks that support relational processing. (shrink)