Related Experiment Videos
The development of visual pursuit during the first months of life
D Lengyel1, S Weinacht, J Charlier
1Department of Strabismus and Neuroophthalmology, Kantonsspital St. Gallen, Switzerland.
Insights
Infant visual pursuit is present from birth, with no significant improvements in speed or duration in the first four months. However, infants show increased attention and tracking time as they age.
Area of Science:
- Developmental neuroscience
- Infant visual development
- Ophthalmology
Background:
- Limited research exists on infant smooth pursuit.
- Understanding early visual tracking is crucial for development.
Purpose of the Study:
- To quantify visual pursuit capabilities in infants from 1 day to 16 weeks old.
- To investigate changes in smooth pursuit parameters over early infancy.
Main Methods:
- Infrared photo-oculography recorded eye movements in 97 healthy infants (0-16 weeks).
- Stimulus: a horizontally moving square with vertical gratings (7.5 deg/s).
Main Results:
- Smooth pursuit segments were observed within the first two weeks.
- No significant increases in pursuit velocity, gain, or duration were found up to 16 weeks.
- Total pursuit time (smooth + saccadic) significantly increased with age.
Conclusions:
- Smooth pursuit is functional at birth.
- The ocular pursuit mechanism is mature early on and not significantly enhanced by attention in the first months.
- Increased total tracking time reflects developing attentional capabilities.
Background:
There are few previous investigations of smooth pursuit in infants. The aim of our study was to quantify visual pursuit in infants between 1 day and 16 weeks of age.
Methods:
Eye movements of 97 healthy infants between 1 day and 16 weeks of age were recorded one to seven times with infrared photo-oculography. For stimulation of visual pursuit a square of 9.4 deg of visual angle with vertical gratings moved horizontally at a constant velocity of 7.5 deg/s.
Results:
In the first 2 weeks of life, segments of smooth pursuit were measured with a maximum velocity of 7.93 deg/s, with a maximum gain of 1.06 and a maximal duration of 3.16 s. In sequential recordings no significant increases of velocity, gain or duration were found. However, the total time the subjects followed the stimulus with smooth plus saccadic pursuit increased significantly with age (from a median of 39.0% to a median of 61.5% of examination time).
Conclusion:
This study clearly demonstrates that smooth pursuit is already present in the first week of life. We found no significant increase in velocity, gain and duration of smooth pursuit segments in the first 16 weeks of life with our recording technique. However, the total pursuit time, reflecting attention, increased with age. The ocular machinery to drive pursuit appears to be in place at birth and seems not to be influenced by increased attention in the first months of life.