Search

Despite its importance to everyday functioning, reasoning is underexplored in developmental dyslexia. The current study investigated verbal deductive reasoning on the Wason selection task, not previously used in dyslexia research despite its well-established pedigree. Reasoning rule was manipulated, with the conditional rules varying in the logical values presented. The word frequency and imageability of the word terms was also manipulated. Twenty-six adults with dyslexia and 31 adults without dyslexia completed Wason selection task problems. No group difference in reasoning accuracy or completion time was found. However, the participants were most accurate when reasoning with the rule type "If p, then not q" and least accurate with the rule type "If p then q". More trials were also answered correctly when the word terms were highly imageable but of average word frequency. These findings are in line with the general reasoning literature. Dyslexia status did not interact with either rule type or word term type. The study expands upon previous research by testing verbal deductive reasoning in dyslexia, highlighting the role of imageability in facilitating reasoning performance for all, regardless of the presence or absence of dyslexia. Implications for the design of educational materials are considered. [ABSTRACT FROM AUTHOR]

The diagnosis of specific language impairment (SLI) requires non-verbal ability to be in the normal range, but little is known regarding the extent to which general reasoning skills are preserved during development. A total of 122 children were tested; 40 SLI, 42 age-matched controls, and 40 younger language-matched controls. Deductive reasoning tasks were given in both verbal and pictorial presentation types, namely the relational inference task and the reduced array selection task (RAST). Pictorial presentation facilitated all groups for all tasks equally. For the relational inference task, SLI performance was below both age and language matches. For the RAST, contextual information facilitated all groups equally. SLI performance was intermediate between age and language matches. It is concluded that the non-verbal versus verbal distinction is a complex one and that non-verbal reasoning can draw upon linguistic processes. It is also suggested that SLI reasoning depends upon precise task demands, here the need to sequence information in working memory, and the need for explicit reasoning with conditional rules. Reasoning processes may not be equivalent to normally developing children, even when tasks appear non-verbal.

A sample (n=48) of eight-year-olds with specific language impairments is compared with age-matched (n=55) and language matched controls (n=55) on a range of tasks designed to test the interdependence of language and mathematical development. Performance across tasks varies substantially in the SLI group, showing profound deficits in production of the count word sequence and basic calculation and significant deficits in understanding of the place-value principle in Hindu-Arabic notation. Only in understanding of arithmetic principles does SLI performance approximate that of age-matched-controls, indicating that principled understanding can develop even where number sequence production and other aspects of number processing are severely compromised.

The number skills of groups of 7- to 9-year-old children with specific language impairment (SLI) attending mainstream or special schools were compared with an age and nonverbal reasoning matched group (age control [AC]) and with a younger group matched on oral language comprehension. The SLI groups performed below the AC group on every skill. They also showed lower working memory functioning and had received lower levels of instruction. Nonverbal reasoning, working memory functioning, language comprehension, and instruction accounted for individual variation in number skills to differing extents depending on the skill. These factors did not explain the differences between SLI and AC groups on most skills.

A broad definition of the term strategy is used and it is suggested that selection biases exist in certain circumstances and must be accounted for in models of strategy selection.

The number skills of groups of 7- to 9-year-old children with specific language impairment (SLI) attending mainstream or special schools were compared with an age and nonverbal reasoning matched group (age control [AC]) and with a younger group matched on oral language comprehension. The SLI groups performed below the AC group on every skill. They also showed lower working memory functioning and had received lower levels of instruction. Nonverbal reasoning, working memory functioning, language comprehension, and instruction accounted for individual variation in number skills to differing extents depending on the skill. These factors did not explain the differences between SLI and AC groups on most skills. Keywords: number development, working memory, specific language impairment, instruction

Three experiments are reported, which are based upon the Wason four-card selection task inspection time paradigm, in which subjects solve computer-presented trials while using a mouse to indicate the card currently under consideration. Evans (1996) had shown that selected cards were inspected for longer than non-selected cards, and this was taken as support for the existence of pre-conscious heuristic processes that direct attention towards relevant aspects of a problem. However, Roberts (1998b) suggested that this inspection time effect is artefactual, due to task format induced biases. Experiment 1 utilized a 'change' task: Cards were presented either as selected or not selected, and subjects changed these where necessary. This demonstrated an association between card selection and inspection time independently of one between the act of response and inspection time. Experiment 2 utilized a standard selection task, but subjects either responded within 2 s of each card presentation, or made selections with no time pressure. The curtailment of thinking time increased matching behaviour--more cards matching the terms in the rules were selected--and was replicated in Experiment 3 using a within-subjects design. Overall, the data support Evans' heuristic-analytic framework albeit with some caveats.

Individual differences are indeed an important aid to our understanding of human cognition, but the importance of the rationality debate is open to question. An understanding of the process involved, and how and why differences occur, is fundamental to our understanding of human reasoning and decision making.

An experiment is reported in which two designs of Berlin U-/S-Bahn network maps were compared for usability. One was conventional, based on standard schematic design rules used worldwide: Straight lines with tightly radiused corners, and only horizontal, vertical, or 45° diagonal angles permitted. The other was a novel concept, based on concentric circles and spokes radiating from a central point. The former has the benefit of simple line trajectories, the latter potentially has the benefit of a coherent overall appearance. The experiment investigated both an objective performance measure (time required to plan complex journeys) and a variety of subjective measures (choice between maps, ratings of statements associated with usability, direct ratings of usability). All subjects planned journeys using both designs. Overall, performance was worse for the concentric circles map, and it received poor ratings. However, in line with previous research, objective and subjective measures were dissociated. For example, many subjects expressed a preference for the design that was not the best for them in terms of objective performance. [ABSTRACT FROM AUTHOR]