Abstract
The attentional blink (AB) is a phenomenon, in which the second of two target stimuli (T1 and T2) is not consciously perceived when it appears shortly after the first target stimulus. This phenomenon is well explained by a two-stage model of perception, where an early sensory stage precedes a capacity-limited late stage that recruits the attentional system. As long as T1 occupies the late stage, T2 is missed. The duration of the AB thus reflects the duration of the late stage of perception. We designed an AB task that requires no instruction whatsoever and can be employed with very young infants (N=24 per group). In each trial, sequences of images were presented in parallel in three locations on the screen: left, center and right. Most images were masks (scrambled faces). Among those masks, two faces appeared. The first face (T1) appeared centrally. The second face (T2) appeared either left or right. We measured infants’ tendency to detect and look at T2. We could estimate the duration of the AB by varying the delay between T1 and T2 (first, third or seventh image following T1) and the rate of stimulus presentation (3.33 Hz, 5 Hz, 10 Hz). We found that 5-month-olds missed T2 at 600 and 900 ms but saw T2 at 1400 and 2100 ms, suggesting an AB of about 1150 ms. As infants grow, the AB shrinks: 8-month-olds exhibited an AB that lasted less than 700 ms and 3-year-olds an AB that lasted less than 300 ms. Finally, adults exhibited an AB equivalent to that of 3-year-olds. These findings show that the two-stage organisation of perception is in place early in life and that an acceleration of the late stage of perception is a fundamental aspect of cognitive development, particularly in the course of the first year of life.