Timing strategies used in defensive blinking to optical collisions in 5-to7-month-old infants

When objects approach on a collision course, young babies will blink to pro tect their eyes. The timing of the blink is crucial, since it serves to pro tect the eyes from being injured. The image of a looming virtual object app roached infants under different constant velocities and constant accelerati ons. The youngest infants (5-6 months) blinked when the image of the virtua l object reached a threshold visual angle, while older infants (6-7 months) geared their blinks to the image's time-to-collision. Infants using a stra tegy based on time coped successfully with all approach conditions, while i nfants using a strategy based on visual angle had difficulty with the faste st accelerative approach condition. The findings indicate that infants arou nd 6 months of age shift to a more sophisticated strategy based on time, al lowing them to deal with more demanding perceptual tasks. (C) 2000 Elsevier Science Inc. All rights reserved.