Pupillary responses and associated vergence eye movements were monitored during imagery of objects of differing sizes (“large” or “small”) from varying distances (“near” or “far”). Objects’ imagined size and distance affected oculomotor behavior. Objects visualized as “far” resulted in the larger pupil dilations and smaller visual angle, while small objects imagined “near” were associated with smaller pupils in contrast to relatively larger pupils when imagined as “far” away. Furthermore, near objects resulted in larger visual angle, and particularly, vergence (...) adjustments were observed that were dependent on imagined size and distance of the small objects. The findings are consistent with the idea that imagery emulates perception, also at the embodied level of oculomotor behaviors. (shrink)

: This article provides replies to, and comments on, the contributions to the special issue on the philosophy of information. It seeks to highlight con‐vergences and points of potential agreement, while offering clarifications and further details. It also answers some criticisms and replies to some objections articulated in the special issue.

Dual task is known to affect postural stabilty in children. We explored the effect of visual tasks on postural control in dyslexic and in age-matched non-dyslexic children. Thirty dyslexic children (mean age: 9.80 ± 0.28 years) were compared with thirty non-dyslexic children (mean age: 9.92 ± 0.35 years). All children underwent ophthalmologic and optometric evaluation. Eye movements were recorded by a video-oculography system (EyeBrain ® T2) and postural sway was recorded simultaneously by a force platform (TechnoConept®). Both groups of children (...) performed fixations, pursuits, pro- and anti-saccades tasks. Dyslexic children showed significantly poor near fusional vergence ranges (convergence and divergence) with respect to the non-dyslexic children. During the postural task, quality of fixation and anti-saccade performance in dyslexic children were significantly worse compared to non-dyslexic children. In contrast, the number of catch-up saccades during pursuits and the latency of pro-and anti-saccades were similar in both groups of children examined. Concerning postural quality, dyslexic children were more unstable than age-matched non-dyslexic children. For both groups of children tested we also observed that executing saccades (pro- and anti-saccades) reduced postural values significantly in comparison with fixation and pursuit tasks. The impairment in convergence and divergence fusional capabilities could be due to an immaturity in cortical structures controlling the vergence system. The poor oculomotor performance reported in dyslexic children suggested a deficit in allocating visual attention and their postural instability observed is in line with the cerebellar impairment previously reported in dyslexic children. Finally, pro- or anti-saccades reduce postural values compared to fixation and pursuit tasks in both groups of children tested, suggesting a different influence of visual tasks on postural control according to their attentional demand. (shrink)

The iCat is a user-interface robot with the ability to express a range of emotions through its facial features. This article summarizes our research to see whether we can increase the believability and likability of the iCat for its human partners through the application of gaze behaviour. Gaze behaviour serves several functions during social interaction such as mediating conversation flow, communicating emotional information and avoiding distraction by restricting visual input. There are several types of eye and head movements that are (...) necessary for realizing these functions. We designed and evaluated a gaze behaviour system for the iCat robot that implements realistic models of the major types of eye and head movements found in living beings: vergence, vestibulo ocular reflexive, smooth pursuit movements and gaze shifts. We discuss how these models are integrated into the software environment of the iCat and can be used to create complex interaction scenarios. We report about some user tests and draw conclusions for future evaluation scenarios. (shrink)