Two experiments using a realistic version of the selection task examined the relationship between participants' probability estimates of finding a counter example and their selections. Experiment 1 used everyday categories in the context of a scenario to determine whether or not the number of instances in a category affected the estimated probability of a counter-example. Experiment 2 modified the scenario in order to alter participants' estimates of finding a specific counter-example. Unlike Kirby 1994a, but consistent with his proposals, both studies (...) showed that probability estimates significantly predicted selection. Overall results point to the value of understanding selections in terms of their subjective expected utility. (shrink)

This paper develops the view that in arguing informally individuals construct a dual representation in which there is a coupling of arguments and the structure of the qualitative (mental) causal model to which these refer. Invited to consider a future possibility, individuals generate a causal model and mentally simulate the consequences of certain actions. Their arguments refer to the causal paths in the model. Correspondingly, faced with specific arguments about a policy option they generate a model with particular causal paths (...) and mentally simulate the outcomes. The results of Experiment 1 are consistent with this notion. Decisions on the percentage of funds to be allocated to genetically modified (GM) crop research depended on the structure of the arguments elicited in response to imagining a future state of affairs. Specifically, the presence of a dissuasive argument eliminated the impact of any persuasive argument. The non-monotonic properties of everyday informal argument can then be seen as a corollary of change to causal structure in the model. The dual representation view predicts that the impact of a dissuasive argument will depend on the structure of the causal model. Experiment 2 tested and confirmed this prediction by requiring individuals to judge the relative persuasiveness of two cases referring either to a model with two independent causal paths or to a model in which one causal path depended on the other. In contrast to Experiment 1, prior opinion on GM crop research did not affect allocation decisions. An advisory role in contrast to a participant role may encourage a more decontextualised mode of thinking. According to the dual representation view, ease of mental simulation should exert wide-ranging effects on judgements and the rhetoric of arguments should also be important. The paper concludes with a discussion of some of these expectations. (shrink)

Abstract In order to be a general theory of human cognition, the theory of mental models needs to accommodate a variety of forms of reasoning in addition to deduction. The mental model theory of induction is a crucial step in establishing generality. After suggesting that the theory of mental models can also account for abduction and analogy, the paper points out that inductive performance is likely to be constrained both by the nature of the representation used and by strategic factors. (...) Since human cognition involves the communication of arguments, a final section explores the relationship between the theory of mental models and the notion of an argument. It proposes that models can contain tokens of inductive arguments which can be referred to in the course of other arguments. (shrink)

Functional imaging studies of neurologically intact adults have demonstrated that the right posterior cerebellum is activated during verb generation, semantic processing, sentence processing, and verbal fluency. Studies of patients with cerebellar damage converge to show that the cerebellum supports sentence processing and verbal fluency. However, to date there are no patient studies that investigated the specific importance of the right posterior cerebellum in language processing, because: case studies presented patients with lesions affecting the anterior cerebellum, and group studies combined patients (...) with lesions to different cerebellar regions, without specifically reporting the effects of right posterior cerebellar damage. Here we investigated whether damage to the right posterior cerebellum is critical for sentence processing and verbal fluency in four patients with focal stroke damage to different parts of the right posterior cerebellum. We examined detailed lesion location by going beyond common anatomical definitions of cerebellar anatomy, and employed a recently proposed functional parcellation of the cerebellum. All four patients experienced language difficulties that persisted for at least a month after stroke but three performed in the normal range within a year. In contrast, one patient with more damage to lobule IX than the other patients had profound long-lasting impairments in the comprehension and repetition of sentences, and the production of spoken sentences during picture description. Spoken and written word comprehension and visual recognition memory were also impaired, however, verbal fluency was within the normal range, together with object naming, visual perception and verbal short-term memory. This is the first study to show that focal damage to the right posterior cerebellum leads to language difficulties after stroke; and that processing impairments persisted in the case with most damage to lobule IX. We discuss these results in relation to current theories of cerebellar contribution to language processing. Overall, our study highlights the need for longitudinal studies of language function in patients with focal damage to different cerebellar regions, with functional imaging to understand the mechanisms that support recovery. (shrink)

We examine how opinion on a controversial real-world issue shifts as a function of reading relevant arguments and engaging in a specific mental simulation about a future, fictional state of affairs involving the target issue. Individuals thought either counterfactually about a future event (“if only X had not happened …”) or semifactually about it (“even if X had not happened …”). In Experiment 1, as expected, individuals became more in favour of a course of action (the electronic tagging of children) (...) after reading relevant supporting arguments. They also became more in favour after they thought counterfactually how a negative future event could have been avoided if only electronic tagging had not been banned some years earlier. The effects of argument relevance and type of mental simulation were additive. Using a similar procedure but a different target issue (whether the UK should join the Economic Monetary Union), Experiment 2 confirmed that the type of mental simulation exerts a substantial effect on the impact of relevant arguments. Much weaker effects arose when the mental simulation was not relevant to the target issue. We set and discuss our results in terms of dual-processing theory. (shrink)

Living organisms are the ultimate survivalists, having evolved phenotypes with unprecedented adaptability, ingenuity, resourcefulness, and versatility compared to human technology. To harness these properties, functional descriptions and design principles from all sources of biodiversity information must be collated − including the hundreds of thousands of possible survival features manifest in natural history museum collections, which represent 12% of total global biodiversity. This requires a consortium of expert biologists from a range of disciplines to convert the observations, data, and hypotheses into (...) the language of engineering. We hope to unite multidisciplinary biologists and natural history museum scientists to maximize the coverage of observations, descriptions, and hypotheses relating to adaptation and function across biodiversity, to make it technologically useful. This is to be achieved by developments in meta‐ taxonomic classification, phylogenetics, systematics, biological materials research, structure and morphological characterizations, and ecological data gathering from the collections − the aim being to identify and catalogue features essential for good biomimetic design. (shrink)

Two experiments, using a mock legal case, confirmed the causal role of arguments in verdict decisions and explored the process involved. Experiment 1 showed that verdicts varied with the strength of counter-arguments and Experiment 2 showed that the use of background information that undermined such arguments determined the verdict reached. Such results confirm the causal role of arguments but do not speak to the representations constructed. In both experiments we analysed the reasons proposed for verdicts. Participants generally represented the state (...) of affairs, and conjectured state of affairs, to which the arguments referred. Experiment 2 also asked participants about the number of causal possibilities they envisaged. Confidence in the verdict was moderated by the strength of counter-arguments but in different ways for those who envisaged a single causal account as opposed to two causal accounts. In the former case, confidence decreased with the rated strength of counter-arguments. In the latter case, confidence increased. We suggest that verdicts are abductive explanations of the events generated through a process of mental simulation. (shrink)

Hardman in press claims that the results of Green and Larking 1995 favour a mental rules theory account of performance in the selection task over a mental model theory account. This reply rebuts his claim.

Using fMRI, we investigated how right temporal lobe gliomas affecting the posterior superior temporal sulcus alter neural processing observed during speech perception and production tasks. Behavioural language testing showed that three pre-operative neurosurgical patients with grade 2, grade 3 or grade 4 tumours had the same pattern of mild language impairment in the domains of object naming and written word comprehension. When matching heard words for semantic relatedness (a speech perception task), these patients showed under-activation in the tumour infiltrated right (...) superior temporal lobe compared to 61 neurotypical participants and 16 patients with tumours that preserved the right postero-superior temporal lobe, with enhanced activation within the (tumour-free) contralateral left superior temporal lobe. In contrast, when correctly naming objects (a speech production task), the patients with right postero-superior temporal lobe tumours showed higher activation than both control groups in the same right postero-superior temporal lobe region that was under-activated during auditory semantic matching. The task dependent pattern of under-activation during the auditory speech task and over-activation during object naming was also observed in eight stroke patients with right hemisphere infarcts that affected the right postero-superior temporal lobe compared to eight stroke patients with right hemisphere infarcts that spared it. These task-specific and site-specific cross-pathology effects highlight the importance of the right temporal lobe for language processing and motivate further study of how right temporal lobe tumours affect language performance and neural reorganisation. These findings may have important implications for surgical management of these patients, as knowledge of the regions showing functional reorganisation may help to avoid their inadvertent damage during neurosurgery. (shrink)