A new system for quantitative evaluation of infant gaze capabilities in a wide visual field

BackgroundThe visual assessment of infants poses specific challenges: many techniques that are used on adults are based on the patient’s response, and are not suitable for infants. Significant advances in the eye-tracking have made this assessment of infant visual capabilities easier, however, eye-tracking still requires the subject’s collaboration, in most cases and thus limiting the application in infant research. Moreover, there is a lack of transferability to clinical practice, and thus it emerges the need for a new tool to measure the paradigms and explore the most common visual competences in a wide visual field. This work presents the design, development and preliminary testing of a new system for measuring infant’s gaze in the wide visual field called CareToy C: CareToy for Clinics.MethodsThe system is based on a commercial eye tracker (SmartEye) with six cameras running at 60 Hz, suitable for measuring an infant’s gaze. In order to stimulate the infant visually and audibly, a mechanical structure has been designed to support five speakers and five screens at a specific distance (60 cm) and angle: one in the centre, two on the right-hand side and two on the left (at 30° and 60° respectively). Different tasks have been designed in order to evaluate the system capability to assess the infant’s gaze movements during different conditions (such as gap, overlap or audio-visual paradigms). Nine healthy infants aged 4–10 months were assessed as they performed the visual tasks at random.ResultsWe developed a system able to measure infant’s gaze in a wide visual field covering a total visual range of ±60° from the centre with an intermediate evaluation at ±30°. Moreover, the same system, thanks to different integrated software, was able to provide different visual paradigms (as gap, overlap and audio-visual) assessing and comparing different visual and multisensory sub-competencies. The proposed system endowed the integration of a commercial eye-tracker into a purposive setup in a smart and innovative way.ConclusionsThe proposed system is suitable for measuring and evaluating infant’s gaze capabilities in a wide visual field, in order to provide quantitative data that can enrich the clinical assessment.

[1]  Claes von Hofsten,et al.  Sensitivity to second-order motion in 10-month-olds , 2008, Vision Research.

[2]  Michael C. Frank,et al.  Development of infants’ attention to faces during the first year , 2009, Cognition.

[3]  Lisa M. Oakes,et al.  Advances in Eye Tracking in Infancy Research. , 2012, Infancy : the official journal of the International Society on Infant Studies.

[4]  Santeri Yrttiaho,et al.  Widely applicable MATLAB routines for automated analysis of saccadic reaction times , 2014, Behavior Research Methods.

[5]  J Wattam-Bell,et al.  Changes in Infants' Ability to Switch Visual Attention in the First Three Months of Life , 1992, Perception.

[6]  Scott P. Johnson,et al.  Development of object concepts in infancy: Evidence for early learning in an eye-tracking paradigm , 2003, Proceedings of the National Academy of Sciences of the United States of America.

[7]  C. Hofsten,et al.  Infants predict other people's action goals , 2006, Nature Neuroscience.

[8]  Scott P. Johnson,et al.  Where Infants Look Determines How They See: Eye Movements and Object Perception Performance in 3-Month-Olds. , 2004, Infancy : the official journal of the International Society on Infant Studies.

[9]  David Whitney,et al.  Time Crawls , 2011, Psychological science.

[10]  L. Dubowitz,et al.  Visual function in the newborn: A study of preterm and full-term infants , 1980, Brain and Development.

[11]  D. Corbetta,et al.  Infant Eye-tracking in the Context of Goal-Directed Actions. , 2012, Infancy : the official journal of the International Society on Infant Studies.

[12]  M Matsuzawa,et al.  Development of Saccade Target Selection in Infants , 2001, Perceptual and motor skills.

[13]  C. Von Hofsten,et al.  Predictive tracking over occlusions by 4-month-old infants. , 2007, Developmental science.

[14]  Charles A Nelson,et al.  Relational memory during infancy: evidence from eye tracking. , 2009, Developmental science.

[15]  Irene Leo,et al.  Three-month-olds' visual preference for faces and its underlying visual processing mechanisms. , 2005, Journal of experimental child psychology.

[16]  D. Corbetta,et al.  Infant Eye-Tracking in the Context of Goal-Directed Actions. , 2012 .

[17]  L. Dubowitz,et al.  The Development of Visual Function in Normal and Neurologically Abnormal Preterm and Fullterm Infants , 1982, Developmental medicine and child neurology.

[18]  William V Good,et al.  Visual development in preterm infants , 2005, Developmental medicine and child neurology.

[19]  Marcus Nyström,et al.  Eye tracker data quality: what it is and how to measure it , 2012, ETRA.

[20]  Jukka M. Leppänen,et al.  Robustness and Precision : How Data Quality May Influence Key Dependent Variables in Infant Eye-Tracker Analyses , 2014 .

[21]  Scott P. Johnson,et al.  Location, location, location: development of spatiotemporal sequence learning in infancy. , 2007, Child development.

[22]  Scott P. Johnson,et al.  Learning by selection: visual search and object perception in young infants. , 2006, Developmental psychology.

[23]  Tim H. W. Cornelissen,et al.  Qualitative tests of remote eyetracker recovery and performance during head rotation , 2015, Behavior research methods.

[24]  Scott P Johnson,et al.  Learning and memory facilitate predictive tracking in 4-month-olds. , 2009, Journal of experimental child psychology.

[25]  Giuseppina Sgandurra,et al.  Home-based, early intervention with mechatronic toys for preterm infants at risk of neurodevelopmental disorders (CARETOY): a RCT protocol , 2014, BMC Pediatrics.

[26]  Scott P. Johnson,et al.  Eye Tracking in Infancy Research , 2009, Developmental neuropsychology.

[27]  Matthew M. Doran,et al.  Time course of visual attention in infant categorization of cats versus dogs: evidence for a head bias as revealed through eye tracking. , 2009, Child development.

[28]  Michael C. Frank,et al.  Development of perceptual completion originates in information acquisition. , 2008, Developmental psychology.

[29]  C. Von Hofsten,et al.  Infants' Evolving Representations of Object Motion During Occlusion: A Longitudinal Study of 6- to 12-Month-Old Infants. , 2004, Infancy : the official journal of the International Society on Infant Studies.

[30]  John Colombo,et al.  Visual processing and infant ocular Latencies in the overlap paradigm. , 2006, Developmental psychology.

[31]  A. Macfarlane,et al.  Central and peripheral vision in early infancy. , 1976, Journal of experimental child psychology.

[32]  G. Cioni,et al.  Visual disorders in children with brain lesions: 1. Maturation of visual function in infants with neonatal brain lesions: correlation with neuroimaging. , 2001, European journal of paediatric neurology : EJPN : official journal of the European Paediatric Neurology Society.

[33]  Shinsuke Shimojo,et al.  Development of multisensory spatial integration and perception in humans. , 2006, Developmental science.

[34]  David Whitney,et al.  Spatial Resolution of Conscious Visual Perception in Infants , 2010, Psychological science.