Is there a burden attached to synaesthesia? Health screening of synaesthetes in the general population.

Synaesthesia has long been considered a benign alternative form of perception most often associated with positive rather than negative outcomes. The condition has been associated with a variety of cognitive and perceptual advantages, including benefits in memory, processing speed, and creativity. It is not currently recognized in the DSM-IV.

How arbitrary is language?

It is a long established convention that the relationship between sounds and meanings of words is essentially arbitrary--typically the sound of a word gives no hint of its meaning. However, there are numerous reported instances of systematic sound-meaning mappings in language, and this systematicity has been claimed to be important for early language development. In a large-scale corpus analysis of English, we show that sound-meaning mappings are more systematic than would be expected by chance.

Impaired artificial grammar learning in agrammatism.

It is often assumed that language is supported by domain-specific neural mechanisms, in part based on neuropsychological data from aphasia. If, however, language relies on domain-general mechanisms, it would be expected that deficits in non-linguistic cognitive processing should co-occur with aphasia. In this paper, we report a study of sequential learning by agrammatic aphasic patients and control participants matched for age, socio-economic status and non-verbal intelligence.

Patients with hemianopic alexia adopt an inefficient eye movement strategy when reading text.

Patients with an acquired homonymous hemianopia often adapt over a period of a few months to compensate for some of the impairments caused by their visual field defect. Changes in their eye movement patterns have been demonstrated as performance on visual tasks improves with time; however, these patients often complain of persistent text reading problems. Using a video-based eye-movement tracking system, we investigated the text reading behaviour of patients with established hemianopic alexia (>6 months post deficit), a condition affecting left-to-right readers, with a homonymous field defect that encroaches into their right foveal/parafoveal visual field.

An anatomically constrained, stochastic model of eye movement control in reading.

This article presents SERIF, a new model of eye movement control in reading that integrates an established stochastic model of saccade latencies (LATER; R. H. S.

Toward an appropriate baseline for measures of eye movement behavior during reading.

In empirical studies of human eye movement behavior during reading, it is common to compute various summary measures from the data, but these measures are typically not evaluated with respect to corresponding measures of baseline performance. The authors present a method for deriving an appropriate baseline by mapping the actual behavior to a random perturbation of the text being read, and they find surprising similarities between the baseline and the empirical data. The practical message from these findings is that the importance of a particular factor in explaining either empirical or simulated eye movement patterns should be evaluated using an appropriate baseline.

The potential contribution of preplanned refixations to the preferred viewing location.

On the basis of recent evidence for the preplanning of refixation saccades in reading-like tasks (e.g., Beauvillain, Vergilino, & Dukic, 2000), we proposed that for a proportion of words refixated during natural reading, the refixation sequence is planned before the word is fixated, and that the saccade target for these cases is near the beginning of the word.

The implications of foveal splitting for saccade planning in reading.

The human fovea and visual pathways are precisely split: information in one hemifield is initially projected to the contralateral visual cortex. This fundamental anatomical constraint on word recognition in reading has been largely ignored in eye movement research. We explore the consequences of this constraint through analyses of a large corpus of eye movement data, and demonstrate that aspects of saccade planning (target selection, initial landing position) are sensitive to both hemispheres, estimated uncertainty about the identity of the currently fixated word.

Dyslexics' eye fixations may accommodate to hemispheric desynchronization.

We argue that the vertical division of the fovea and the hemispheric division of the brain condition reading, and that hemispheric desynchronization is a proximal cause of dyslexia. We predict that dyslexics' fixation behaviour in reading accommodates to problematic hemispheric transfer/coordination, with fixations projecting more letter-information directly to the left hemisphere to facilitate processing. We analysed eye movements of 24 dyslexics and 24 normal readers.

Eye movements reveal the on-line computation of lexical probabilities during reading.

Skilled readers are able to derive meaning from a stream of visual input with remarkable efficiency. In this article, we present the first evidence that statistical information latent in the linguistic environment can contribute to an account of reading behavior. In two eye-tracking studies, we demonstrate that the transitional probabilities between words have a measurable influence on fixation durations, and using a simple Bayesian statistical model, we show that lexical probabilities derived by combining transitional probability with the prior probability of a word's occurrence provide the most parsimonious account of the eye movement data.

Low-level predictive inference in reading: the influence of transitional probabilities on eye movements.

We report the results of an investigation into the ability of transitional probability (word-to-word contingency statistics) to account for reading behaviour. Using a corpus of eye movements recorded during the reading of newspaper text, we demonstrate both the forward [P(n/n-1)] and backward [P(n/n+1)] transitional probability measures to be predictive of first fixation and gaze durations: the higher the transitional probability, the shorter the fixation time. Initial fixation position was also affected by the forward measure; we observed a small rightward shift for words that were highly predictable from the preceding word.