These results also indicate that perceived spatial intervals between the pairs of flashes in the familiarization phase were distorted for the infants, resulting in a preference for the novel array in the test phase.
For the familiarization phase, six different colour video clips of two female faces were recorded.
For the familiarization phase, we measured and analyzed infants' total looking time (i.e. the sum of the looking time for right and left presentation fields) in each trial.
In both cases, the MEG scanning session was further subdivided into two blocks, each containing 20 images from the familiarization phase (referred to as "familiar images") and 20 images not previously presented (referred to as "novel images") (subjects could pause for 20 s between blocks).
This part (session) was further subdivided into two blocks containing each 20 images from the familiarization phase (referred to as "familiar images") and 20 previously not presented images (referred to as "novel images"; subjects could pause for 20 s between blocks).
To test whether the infants habituated to stimuli in the familiarization phase, we compared the sum of looking times for the first and second trials with that for the third and fourth trials using a two-tailed paired t-test.
Infants were exposed to a Chinese face during the familiarization phase and then tested with the familiar and novel Chinese face.
One day before training, the chicks were deprived of food for 3 h and underwent a familiarization phase.
Upon completion of the familiarization phase, the following instruction was given to the subject for the execution of the experimental tasks: "You have to reach the blue target with the red dot, as fast as possible, by transferring your weight in the direction of the target and then stay as long as possible within the target, or if this is not possible, stay as near to the target as possible.
For instance, if the stimuli in the familiarization phase were expected to cause spatial distortions corresponding to the upper-long array (that is, either in "upward/−" or "downward/+"), the upper-short array was defined as the novel array in the test phase and the upper-long was defined as the familiar array.
