Features of the Expert-System-Shell SPIRIT

The inference process in a probabilistic and conditional environmentunder minimum relative entropy, permits the acquisition of basicknowledge, the consideration of - even uncertain - ad hoc knowledge,and the response to queries. Even if these procedures are wellknown in the relevant literature their realisation for large-scaleapplications needs a sophisticated tool, allowing the communicationwith the user as well as all relevant logical transformationsand numerical calculations. SPIRIT is an Expert-System-Shellfor these purposes. Even for hundreds of – consistent– facts about the involved variables’ dependenciesthe shell automatically generates the corresponding epistemicstate, thus permitting the derivation of conclusions from theacquired knowledge. These conclusions’ reliability orprecision can be checked, inviting the user to enrich the knowledgeby further facts, if desired. Any inconsistencies among providedfacts are detected, and their elimination will be supportedby the shell. Knowledge acquisition can come from provided factsby a knowledge engineer as well as from real world data; inductivelearning supports the use of such data. An important capabilityof the shell is the calculation of impacts upon ideas or conceptsfrom a given stimulus. This paper is a brief survey of theoreticalconcepts and the corresponding features of the system, whichare accompanied by illustrative examples.     

Searching for the Trace: The Influence of Age, Lexical Activation and Working Memory on Sentence Processing

To investigate the stability of trace reactivation in healthy older adults, 22 older volunteers with no significant neurological history participated in a cross-modal priming task. Whilst both object relative center embedded (ORC) and object relative right branching (ORR) sentences were employed, working memory load was reduced by limiting the number of words separating the antecedent from the gap for both sentence types. Analysis of the results did not reveal any significant trace reactivation for the ORC or ORR sentences. The results did reveal, however, a positive correlation between age and semantic priming at the pre-gap position and a negative correlation between age and semantic priming at the gap position for ORC sentences. In contrast, there was no correlation between age and priming effects for the ORR sentences. These results indicated that trace reactivation may be sensitive to a variety of age related factors, including lexical activation and working memory. The implications of these results for sentence processing in the older population are discussed.     

Seeing red primes tomato: evidence for comparable priming from colour and colour name primes to semantically related word targets

There is ample evidence that an independent processing stream exists that subserves the perception and appreciation of colour. Neurophysiological research has identified separate brain mechanisms for the processing of wavelength and colour, and neuropsychological studies have revealed selective colour disorders, such as achromatopsia, colour agnosia, and colour anomia. The aim of the present study is to investigate whether the perception of colour may, despite its independent processing, influence other cognitive functions. Specifically, we investigate the possibility that the perception of a colour influences higher order processes such as the activation of semantically related concepts. We designed an associative priming task involving a colour prime (e.g. a red patch or the word RED) and a lexical decision response to a semantically related (‘tomato’ vs. ‘timato’) or unrelated (‘grass’ vs. ‘griss’) word target. The results of this experiment indicate that there is comparable facilitation of accessing colour-related semantics through the perception of a colour or the reading of a colour name. This suggests that colour has a direct effect on higher order level, cognitive processing. These results are discussed in terms of current models of colour processing.     

Are generalised scalar implicatures generated by default? An on-line investigation into the role of context in generating pragmatic inferences

Recent research in semantics and pragmatics has revived the debate about whether there are two cognitively distinct categories of conversational implicatures: generalised and particularised. Generalised conversational implicatures are so-called because they seem to arise more or less independently of contextual support. Particularised implicatures are more context-bound. The Default view is that generalised implicatures are default inferences and that their computation is relatively autonomous--being computed by some default mechanism and only being open to cancellation at a second stage when contextual assumptions are taken into consideration (i.a.). It is at that second stage where contextual assumptions are considered that particularised implications are computed. By contrast, Context-Driven theorists claim that both generalised and particularised implicatures are generated by the same process and only where there is contextual support (Chierchia, 2004; Horn, 1984; Levinson, 2000 i.a.). In this paper, we present three on-line studies of the prototypical cases of generalised implicatures: the scalar implicatures 'some of the Fs' > 'not all the Fs' and 'X or Y' > 'either X or Y but not both'. These studies were designed to test the context-dependence and autonomy of the implicatures. Our results suggest that these scalar implicatures are dependent on the conversational context and that they show none of the autonomy predicted by the Default view. We conclude with a discussion of the degree to which such implicatures are purely context-driven and whether an interactionist default position may also be plausible.     

Deficient implicit phonological representations in children with dyslexia

This study tested the segmentation hypothesis of dyslexia by measuring implicit phonological representations in reading-disabled 11- to 13-year-olds. Implicit measures included lexical gating, priming, and syllable similarity tasks designed to reduce metalinguistic demands. Children with dyslexia performed consistently worse than CA and RA controls when more segmental representations were required across all three tasks. Implicit phonological representations were correlated with measures of speech perception, phoneme awareness, and phonological short-term memory, but not rapid automatized naming, and accounted for unique variance in predicting reading ability. Results provide strong support for less mature implicit phonological representations in children with dyslexia.     

Pulling out the intentional structure of action: the relation between action processing and action production in infancy

Adults and children readily construct action representations organized with respect to an ultimate goal. These representations allow one to predict the consequences of action, interpret and describe actions, and categorize action sequences. In this paper, we explore the ontogeny of hierarchically organized action representations, and its relation to infants' ability to produce similar sequences. To do so, we examine infants' perception and performance of a means-end sequence: pulling a cloth to retrieve a toy. Using a visual habituation paradigm, we demonstrate that 12-month-old infants understand that the initial step of the cloth-pulling sequence is directed toward the ultimate goal of attaining the toy, and use their knowledge of the causal constraints of the sequence to make this goal attribution. Ten-month-olds, however, appear transitional with respect to this understanding: their ability to identify the goal of the cloth-pulling sequence is related to their own ability to planfully solve a similar sequence. These findings are consistent with a burgeoning body of literature suggesting an intimate link between action production and perception, and suggest that this link is in place by at least 10 months of age.     

Interface Problems: Structural Constraints on Interpretation?

Five experiments investigated the interpretation of quantified noun phrases in relation to discourse structure. They demonstrated, using questionnaire and on-line reading techniques, that readers in English prefer to give a quantified noun phrase in (VP-external) subject position a presuppositional interpretation, in which the noun phrase limits or restricts the interpretation of an already available set, rather than giving it a nonpresuppositional or existential interpretation, in which it introduces completely new entities into the discourse. Experiment 1 showed that readers prefer a presuppositional interpretation of three ships over the existential interpretation in Five ships appeared on the horizon. Three ships sank. Experiment 2 showed longer reading times in sentences that are disambiguated toward the existential interpretation than in sentences that permit the presuppositional interpretation. Experiment 3 suggested that the presuppositional preference is greater when the phrase three ships occurs outside the verb phrase than when it occurs inside the verb phrase. Experiment 4 showed that Korean subjects marked with a topic marker received more presuppositional interpretations than subjects marked with a nominative marker. Experiment 5 showed that German subjects in VP-external (but nontopic) position received more presuppositional interpretations than VP-internal subjects. The results suggest the syntactic position of a phrase is one determinant of its interpretation, as expected according to the mapping hypothesis of Diesing (1992).This research was supported in part by grants HD-18708 and HD-17246 to the University of Massachusetts. Rayner was also supported by a Research Scientist Award (MH01255).     

The propositional structure of discourse in the two cerebral hemispheres

Readers construct at least two interrelated representations when they comprehend a text: (a) a representation of the explicit ideas in a text and the relations among them (i.e., a propositional representation) and (b) a representation of the context or situation to which a text refers (i.e., a discourse model). In a recent study, found evidence that readers' representations were structured according to propositional relations, but only in the left hemisphere. Both hemispheres, however, appeared to represent contextually relevant semantic information. The goal in the current study was to examine further the organization of explicit text concepts in the two hemispheres. We used an item-priming-in-recognition paradigm in combination with a lateralized visual-field manipulation. We found evidence for a propositionally structured representation in the left hemisphere, that is, priming effects that reflected the linear distance between primes and targets in the propositional structure of passages. We also found that the right hemisphere represented explicit text concepts, but we found no evidence that these concepts were organized structurally. In a second experiment, we found our item priming effects reflected the representation of text information in memory and did not reflect lexical-semantic priming at test.     

Detached Mindfulness In Cognitive Therapy: A Metacognitive Analysis And Ten Techniques

This paper describes the nature and information processing requirements of detached mindfulness. The construct emerged from the self-regulatory information processing theory of emotional disorder (Wells & Matthews, 1994), and is viewed as a metacognitive state that facilitates change in core underlying pathological processes. Detached mindfulness has multiple components, requiring the activation of metacognitive knowledge, metacognitive monitoring and control, suspension of conceptual processing, attentional flexibility, and a de-centered relationship with thoughts. A model of the cognitive structures and processes supporting the state is presented. Implications of the model for the scientific development and effective use of mindfulness techniques are discussed. Ten techniques for rapidly achieving detached mindfulness in the course of metacognitive therapy are described.Address correspondence to Professor Adrian Wells, Academic Division of Clinical Psychology, The University of Manchester, Rawnsley Building, Manchester Royal Infirmary, Oxford Road, Manchester M13 9WL, UK; e-mail: Adrian.Wells@manchester.ac.uk.