To Look or Not to Look? Typical and Atypical Development of Oculomotor Control

Abstract

Abstract& The ability to inhibit saccades toward suddenly appearing peripheral stimuli (prosaccades) and direct them to contralateral locations instead (antisaccades) is a crucial marker of eye movement control. Typically developing infants as young as 4-month-olds can learn to inhibit reflexive saccades to peripheral stimuli, but they do not produce antisaccades, whose development later in infancy and its underlying neural computations remain unexplored. Here we tested oculomotor control in typically developing toddlers and toddlers with fragile X syndrome (FXS), a disorder of known genetic origin that allows the investigation of the neurocomputational properties contributing to the development of saccadic control. Typically developing toddlers decreased looking toward peripheral cues that predicted contralateral rewards, whose appearance they anticipated. Furthermore, this correlated with age, indicating a gradual development of saccadic control. In contrast with the typical case, toddlers with FXS did not decrease their looks to peripheral onsets that predicted contralateral events.

The developing cognitive substrate of sequential action control in 9- to 12-month-olds: Evidence for concurrent activation models

“…This eye-tracking paradigm overcomes problems that arise due to underdeveloped motor abilities in infants (Verschoor et al, in press;Wang et al, 2012) and enabled us to administer a paradigm to infants conceptually identical to the original Elsner and Hommel (2001) paradigm. The paradigm uses eye movements as actions, which is appropriate since infants can accurately control their eye movements from at least 4 months of age (Scerif et al, 2005) and these can be considered voluntary goal-directed actions (Gredebäck & Melinder, 2010;Falck-Ytter, Gredebäck, & von Hofsten, 2006;Perra & Gattis, 2010;Senju & Csibra, 2008;). An additional advantage of our paradigm is the concurrent recording of Task-Evoked Pupillary Responses (TEPRs) which is relatively new in developmental research (Falck-Ytter, 2008;Jackson & Sirois, 2009;Laeng, Sirois & Gredebäck, 2012;Verschoor et al, in press).…”

Fragile X Syndrome as a Multilevel Model for Understanding Behaviorally Defined Disorders

“…In fact, these quite subtle symptoms have been shown actually to be able to yield a FXS diagnosis in infancy with some 73% accuracy (Baranek et al, 2005). Furthermore, scientific research has revealed that already in infancy, those with FXS demonstrate poor response inhibition (Scerif, Cornish, Wilding, Driver, & Karmiloff-Smith, 2004, poor saccadic eye-movement control (Scerif, Karmiloff-Smith, Campos, Elsabbagh, Driver, & Cornish, 2005), and prolonged visual attention to objects or what is known as sticky fixation (Roberts, Hatton, Long, Anello, & Colombo, 2012). In subsequent FXS development, school children and adolescents also display poor response inhibition (Sullivan, Hatton, & Hammer, 2007) and atypical patterns of visual attention (Hooper, Hatton, & Baranek, 2000;Munir, Cornish, & Wilding, 2000a, 2000b.…”

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“…Both Johnson [3] and Scerif et al [4] tested infants' ability to inhibit saccades with an infant anti-saccade paradigm. Infant saccades were investigated by manipulating the spatial relationship between central and peripheral stimuli and the location where attractive stimuli appear.…”

“…However, he concluded that 4-month-olds did not produce anti-saccades toward the target location in light of the results of adult anti-saccade (e.g., [5]). Scerif et al [4] also did not recognize anti-saccades in infants, as they classified subjects' responses following the criteria used in adult study [5]. Thus, previous infant studies used adult criteria to classify infant responses in the anti-saccade task.…”

“…Or infant responses during the task should be investigated before applying the criteria or being classified. While neither Johnson [3] nor Scerif et al [4] recognized "anti-saccade" in early infants, by 4 months of age, infants can reportedly be trained to make saccades at particular spatial locations [7,8]. …”