Sources of difficulty in deductive reasoning: The THOG task

The THOG task presents four designs constructed from two shapes and two colours. Subjects are told that the experimenter has written down one of the shapes and one of the colours and are provided the rule that if, and only if, any design has either the shape or the colour, but not both, written down, then it is a THOG. Finally, they are given an exemplar and are asked to classify the remaining designs. Successful solution requires construction of hypotheses, reasoning under each hypothesis, and comparison of the results under each to reach a final conclusion. Few subjects are able to provide adequate responses on the standard version of the task. We present the results of four experiments, with 160 undergraduates each presented with one of eight versions of the task. Experiments 1 and 2 indicate that (1) some subjects think that the properties that are written down are identical to those of the exemplar, although these are not the same subjects who exhibit the modal error pattern, (2) many subjects correctly understand the disjunction of the rule but fail to consider the hypotheses, and (3) poor initial encoding of the problem is not easily corrected. Experiment 3 investigates the sufficiency of the claim of Griggs and Newstead (1982) that appropriate problem solution follows from explicit presentation of all problem information (including use of positive labels for properties that are not written down), and Experiment 4 investigates the necessity of the claim. The results of Experiments 3 and 4 show that presenting positive category labels does increase the frequency of correct solution; however, positive category labels are not necessary for such improvement. Separation of the labels of the THOG rule from those of the exemplar, or informing subjects that only one other design is a THOG, also increases the frequency of successful solution. The results suggest that many people have some fairly sophisticated reasoning skills. but application of these skills is easily discouraged when the features of the task lead to poor initial encoding.     

Characterizing the time course of an implicature: an evoked potentials study

This work employs Evoked Potential techniques as 19 participants are confronted with sentences that have the potential to produce scalar implicatures, like in Some elephants have trunks. Such an Underinformative utterance is of interest to pragmatists because it can be considered to have two different truth values. It can be considered true when taken at face value but false if one were to treat Some with the implicature Not All. Two accounts of implicature production are compared. The neo-Gricean approach (e.g., Levinson, 2000) assumes that implicatures intrude automatically on the semantics of a term like Some. Relevance Theory (Sperber & Wilson, 1985/1996) assumes that implicatures are effortful and not automatic. In this experiment, the participants are presented with 25 Underinformative sentences along with 25 sentences that are Patently True (e.g. Some houses have bricks) and 25 that are Patently False (e.g. Some crows have radios). As reported in an earlier study (Noveck, 2001), Underinformative sentences prompt strong individual differences. Seven participants here responded true to all (or nearly all) of the Underinformative sentences and the remaining 12 responded false to all (or nearly all) of them. The present study showed that those who responded false to the Underinformative sentences took significantly longer to do so that those who responded true. The ERP data indicate that: (a) the Patently True and Patently False sentences prompt steeper N400's--indicating greater semantic integration--than the Underinformative sentences and that (b) regardless of one's ultimate response to the Underinformative sentences, the N400's were remarkably flat, indicating no particular reaction to these sentences. Collectively, the data are taken to show that implicatures are part of a late-arriving, effort-demanding decision process.     

非小细胞肺癌 EG FR 基因突变检测与临床意义

采用荧光PCR法对199例晚期非小细胞肺癌（NSCLC ）组织进行表皮生长因子受体（EGFR ）基因突变检测,分析EGFR基因突变的分布特征及其与临床病理特征的相关性。结果显示56例（28．1％）存在EGFR基因突变,其中27例（13．6％）为外显子19突变,25例（12．6％）为外显子21突变,2例为外显子18突变,1例外显子20突变,1例外显子18和20的共突变。另外,除广东及安徽省铜陵市外,辽宁地区NSCLC患者EGFR基因突变率及主要突变类型与其他地区相符,常见于外显子19、21突变,其中腺癌、不吸烟患者突变率更高,更适宜EGFR-TKI靶向治疗。     

When children are more logical than adults: experimental investigations of scalar implicature

A conversational implicature is an inference that consists of attributing to a speaker an implicit meaning that goes beyond the explicit linguistic meaning of an utterance. This paper experimentally investigates scalar implicature, a paradigmatic case of implicature in which a speaker's use of a term like Some indicates that the speaker had reasons not to use a more informative term from the same scale, e.g. All; thus, Some implicates Not all. Pragmatic theorists like Grice would predict that a pragmatic interpretation is determined only after its explicit, logical meaning is incorporated (e.g. where Some means at least one). The present work aims to developmentally examine this prediction by showing how younger, albeit competent, reasoners initially treat a relatively weak term logically before becoming aware of its pragmatic potential. Three experiments are presented. Experiment 1 presents a modal reasoning scenario offering an exhaustive set of conclusions; critical among these is participants' evaluation of a statement expressing Might be x when the context indicates that the stronger Must be x is true. The conversationally-infelicitous Might be x can be understood logically (e.g. as compatible with Must) or pragmatically (as exclusive to Must). Results from 5-, 7-, and 9-year-olds as well as adults revealed that (a) 7-year-olds are the youngest to demonstrate modal competence overall and that (b) 7- and 9-year-olds treat the infelicitous Might logically significantly more often than adults do. Experiment 2 showed how training with the modal task can suspend the implicatures for adults. Experiment 3 provides converging evidence of the developmental pragmatic effect with the French existential quantifier Certains (Some). While linguistically-sophisticated children (8- and 10-year-olds olds) typically treat Certains as compatible with Tous (All), adults are equivocal. These results, which are consistent with unanticipated findings in classic developmental papers, reveal a consistent ordering in which representations of weak scalar terms tend to be treated logically by young competent participants and more pragmatically by older ones. This work is also relevant to the treatment of scalar implicatures in the reasoning literature.     

Implicatures et développement

We summarize our work on pragmatic inference-making in children, while generally focusing on scalar implicatures. Such inferences arise when a relatively weak term implies the rejection of a stronger one. For example, some is often understood to mean not all. While adults readily draw such implicatures, children tend to rely on the terms’ minimal, lexically encoded meanings (with which some is compatible with all). Given that children’s treatments coincide with logical ones, children end up appearing more logical than adults on standard reasoning tasks. We describe this effect in detail while showing that (a) even young children can be encouraged to carry out implicatures and, that; (b) evidence of non-pragmatic behavior is best explained as due to unavailable effort.     

Spatial associations in relational reasoning: evidence for a SNARC-like effect

Relational reasoning (A > B, B > C, therefore A > C) shares a number of similarities with numerical cognition, including a common behavioural signature, the symbolic distance effect. Just as reaction times for evaluating relational conclusions decrease as the distance between two ordered objects increases, people need less time to compare two numbers when they are distant (e.g., 2 and 8) than when they are close (e.g., 3 and 4). Given that some remain doubtful about such analogical representations in relational reasoning, we determine whether numerical cognition and relational reasoning have other overlapping behavioural effects. Here, using relational reasoning problems that require the alignment of six items, we provide evidence showing that the subjects' linear mental representation affects motor performance when evaluating conclusions. Items accessible from the left part of a linear representation are evaluated faster when the response is made by the left, rather than the right, hand and the reverse is observed for items accessible from the right part of the linear representation. This effect, observed with the prepositions to the left of and to the right of as well as with above and below, is analogous to the SNARC (Spatial Numerical Association of Response Codes) effect, which is characterized by an interaction between magnitude of numbers and side of response.     

How reaction time measures elucidate the matching bias and the way negations are processed

Matching bias refers to the non-normative performance that occurs when elements mentioned in a rule do not correspond with those in a test item (e.g., consider the double mismatch between the rule If there is a not a T on the card then there is not a 4 and a card showing H6). One aim of the present work is to capture matching bias via reaction times as participants carry out truth-table evaluation tasks. Experiment 1 requires participants to verify conditional rules, and Experiment 2 to falsify them as the paradigm (a) employs four types of conditional sentences that systematically rotate negatives in the antecedent and consequent; and (b) presents predominantly cases having true antecedents. These experiments reveal that mismatching is linked to higher rates of incorrect responses and slower evaluation times. A second aim is to investigate the way not is processed. We compare a narrow view of negations, which argues that negation only denies information (e.g., not-T only says there is no T), to a search for alternatives view, which says that negations function to prime appropriate alternatives (e.g., not-T primes a search for other letters). Findings from both experiments support a narrow reading view.