Fixational eye movements are subdivided into tremor, drift, and microsaccades. All three types of miniature eye movements generate small random displacements of the retinal image when viewing a stationary scene. Here we investigate the modulation of microsaccades by shifts of covert attention in a classical spatial cueing paradigm. First, we replicate the suppression of microsaccades with a minimum rate about 150 ms after cue onset. Second, as a new finding we observe microsaccadic enhancement with a maximum rate about 350 ms after presentation of the cue. Third, we find a modulation of the orientation towards the cue direction. These multiple influences of visual attention on microsaccades accentuate their role for visual information processing. Furthermore, our results suggest that microsaccades can be used to map the orientation of visual attention in psychophysical experiments.

In reading research, morphological processing and monomorphemic word identification have generally been treated separately. We describe a computational model that brings both kinds of reading together within a single framework. This model assumes that word knowledge—the orthography, phonology, and meaning of words—accumulates with experiences with individual words and that this knowledge is reflected in two functionally different aspects of word processing—familiarity and availability. We report simulations that demonstrate that the model accounts both for classical effects of frequency and consistency in simple word reading and for morphological effects in the reading of complex words. The morphology simulations naturally capture a distinction between inflectional and derivational morphology without defining this distinction a priori. We discuss the implications of our model for general issues in reading, including individual differences in reading ability.

Cataloguing-in-Publication entry

We present a novel approach to compare saccadic eye movement sequences based on the Needleman-Wunsch algorithm used in bioinformatics to compare DNA sequences. In the proposed method, the saccade sequence is spatially and temporally binned and then recoded to create a sequence of letters which retains fixation location, time and order information. The comparison of two letter sequences is made by maximising the similarity score computed from a substitution matrix which provides the score for all letter pair substitutions and a penalty gap. The substitution matrix provides a meaningful link between each location coded by the individual letters. This link could be distance but could also encode any useful dimension including perceptual or semantic space. We show, by using synthetic and behavioural data, the benefits of this method over existing methods. The Scanmatch toolbox for Matlab is freely available online. ScanMatch 3 The last 30 years has seen an explosion of interest in eye movements as both a topic of study and a research tool to probe perceptual, cognitive and neural processes (Findlay & Gilchrist, 2003; Rayner, 2009). With an increase in the availability of eye trackers and a reduction in their cost, eye movement studies have not only flourished in vision research (e.g. Parkhurst, Law & Niebur, 2002; Tatler, Baddeley & Gilchrist, 2005) but also language (see Rayner,