Concepts and conceptual change

This paper argues that questions concerning the nature of concepts that are central in cognitive psychology are also important to epistemology and that there is more to conceptual change than mere belief revision. Understanding of epistemic change requires appreciation of the complex ways in which concepts are structured and organized and of how this organization can affect belief revision. Following a brief summary of the psychological functions of concepts and a discussion of some recent accounts of what concepts are, I propose a view of concepts as complex computational structures. This account suggests that conceptual change can come in varying degrees, with the most extreme consisting of fundamental conceptual reorganizations. These degrees of conceptual change are illustrated by the development of the concept of an acid.I am grateful to Michael Ranney and Gilbert Harman for comments on an earlier version of this paper.     

An on-line assessment of causal reasoning during comprehension

Fletcher and Bloom (1988) have argued that as readers read narratives, clause by clause, they repeatedly focus their attention on the last preceding clause that contains antecedents but no consequences in the text. This strategy allows them to discover a causal path linking the text's opening to its final outcome while minimizing the number of times long-term memory must be searched for missing antecedents or consequences. In order to test this hypothesis, we examined the reading times of 25 subjects for each clause of eight simple narrative texts. The results show that: (1) causal links between clauses that co-occur in short-term memory (as predicted by the strategy) increase the time required to read the second clause; (2) potential causal links between clauses that never co-occur in short-term memory (again as predicted by the strategy) have no effect on reading time; and (3) reinstatement searches are initiated at the end of sentences that are causally unrelated to the contents of short-term memory or that contain clauses that satisfy goals no longer in short-term memory. These results support the claim that subjects engage in a form of causal reasoning when they read simple narrative texts.     

Bilingual language processing after a lesion in the left thalamic and temporal regions. A case report with early childhood onset.

This case study concerns an 18-year-old bilingual girl who suffered a radiation lesion in the left (dominant) thalamic and temporal region when she was 4 years old. Language and memory assessment revealed deficits in auditory short-term memory, auditory word comprehension, nonword repetition, syntactic processing, word fluency, and confrontation naming tasks. Both languages (English and Dutch) were found to be affected in a similar manner, despite the fact that one language (English) was acquired before and the other (Dutch) after the period of lesion onset. Most of the deficits appear to be related to verbal (short-term) memory dysfunction. Several hypotheses of subcortical involvement in memory processes are discussed with reference to existing theories in this area.     

Discriminative properties of morphine that modulate associations between tastes and lithium chloride

Wistar rats learned to withhold consumption of a target solution when morphine preceded presentation of the target solution and lithium chloride (LiCl) and to consume the same target solution when saline preceded the presentation of the solution. After this serial feature discrimination training, morphine did not block the formation of a Pavlovian association between saccharin and LiCl but did suppress consumption of familiar tap water. After Pavlovian conditioning, morphine blocked the formation of an association between saccharin and LiCl but did not suppress consumption of a familiar tap water solution. The roles of morphine and saline can be interchanged. It appears that the morphine discriminative stimulus is calling up a representation of neither the conditioned stimulus nor the unconditional stimulus alone, but rather a modified representation of some aspect of their association.     

Time courses in visual-information processing: Some theoretical considerations

Summary In the literature two different views with regard to the time course of activation of recognition units —hypothetical entities that represent identity information —are proposed. Both views are derived from a restricted set of phenomena in visual perception. The first view gets its intuitions from phenomena such as those summarized by Bloch's law; these phenomena show integration or summation of activation over time. This grow-and-grow view assumes that recognition units accumulate activation gradually over times The second view finds its inspiration in phenomena such as Mach-bands and simultaneous contrast; these phenomena show inhibition or steady-state suppression over time. This grow-and-shrink view assumes that the activation levels increase fast initially and then start to decrease.The perception literature strongly suggests that it may be light intensity that determines whether mainly integration (and phenomena such as Bloch's law) or inhibition (and phenomena such as Mach-bands) is obtained. So it is also likely that both information-processing views apply only to a limited range of intensity conditions; the grow-and-grow view to conditions of low-flight intensities, and the grow-and-shrink view to conditions of intermediate-and high-light intensities.It is argued that, to arrive at a complete view, a visual phenomenon that applies to the complete range of light intensities should be taken as a background for generating hypotheses about time courses in visual-information processing. The Broca-Sulzer effect is such a phenomenon. Starting from this phenomenon a simple, synthesizing, information-processing model is derived that is compatible with both the grow-and-grow view and the grow-andshrink view. It is shown that, besides the relevant temporal properties, this model also produces the appropriate spatial properties.     

Indeterminacy of the isomorphism heuristic

Summary We are less prone today than in Köhler's time to believe in a unified science. The Gestalt program could therefore safely abandon the psychophysical isomorphism heuristic if it wished to. Indeterminacy of the heuristic might be a reason for doing so. The determination of the components involved in the isomorphism of the visual field as well as the electrocortical events would have to occur simultaneously. In the Gestalt program, however, components are determined by their position in the whole. They can therefore not be compared in different contexts, so no independent test of a candidate heuristic is possible.     

The Holocaust and Its Effects on Survivors: An Overview

The Nazi Holocaust has had continuing and widely reverberating consequences not only for the Jewish survivors but for the world at large. These consequences are detailed, first through a personal account of an Auschwitz survivor, and then through a discussion of the adaptive measures of concentration camp inmates and the long-term psychiatric and psychological effects on survivors and their families. The Survivor or Concentration Camp Syndrome and its relationship to the Post-Traumatic Stress Disorder is described. Indirect effects of the Holocaust have been manifested in various ways, particularly through various levels of psychologic denial displayed by Holocaust criminals and (at least during the early postwar period) by the German public. The Holocaust has had profound effects on the ways the Jewish people regard themselves and are seen by others. Finally, the Holocaust can be seen as offering a kind of paradigmatic signature to the worldview of the end of the 20th century, emphasizing the persistence of evil and the limitations of the idea of progress.     

False Consensus,Stereotypic Cues,and the Perception of Integrative Potential in Negotiation1

We argue that negotiators' fixed-sum perceptions are caused by the same judgment process that creates false consensus. Bargainers' reliance on their own preferences as a cue to others' preferences leads them to anticipate a fixed-sum conflict. When presented with stereotypic cues, subjects in a negotiating experiment anticipated the variable-sum nature of the task and subsequently realized highly efficient settlements extremely quickly. Surprisingly, even when the party's preferences were unrepresentative of the stereotype, agreements were no less efficient than in the absence of the cue. The implications of these findings for bargaining research and practice are discussed.     

Causal Attributions for Poorly Performing Projects: Their Effect on Project Continuation Decisions

This study examined the escalation problem within an attribution theory framework. Students read a case scenario containing causal attribution information that described a poorly performing project under their supervision. They made estimates of its future success, as well as a decision whether to continue it. Perceived stability of causality had the primary effect on expectancy of success. A project whose performance downturn was attributed to a stable cause had a lower expectancy. Locus of causality had a smaller but still significant effect. Project downturns attributed to internal causes had a lower expectancy. Expectancy of success was significantly correlated with project continuation decisions. Discrepancies between these results and those reported by Staw and Ross (1978) are accounted for in terms of Weiner's (1985, 1986) attributional analysis.     

Fractal Images of Formal Systems

Formal systems are standardly envisaged in terms of a grammar specifying well-formed formulae together with a set of axioms and rules. Derivations are ordered lists of formulae each of which is either an axiom or is generated from earlier items on the list by means of the rules of the system; the theorems of a formal system are simply those formulae for which there are derivations. Here we outline a set of alternative and explicitly visual ways of envisaging and analyzing at least simple formal systems using fractal patterns of infinite depth. Progressively deeper dimensions of such a fractal can be used to map increasingly complex wffs or increasingly complex value spaces, with tautologies, contradictions, and various forms of contingency coded in terms of color. This and related approaches, it turns out, offer not only visually immediate and geometrically intriguing representations of formal systems as a whole but also promising formal links (1) between standard systems and classical patterns in fractal geometry, (2) between quite different kinds of value spaces in classical and infinite-valued logics, and (3) between cellular automata and logic. It is hoped that pattern analysis of this kind may open possibilities for a geometrical approach to further questions within logic and metalogic.\looseness=-1