When we use a video of flashing light in the headturn preference procedure during familiarization and test, infants fail to discriminate our target words. However, when we use a more engaging visual stimuli, a video of spinning colorful pinwheel in HTPP, they succesfully discriminate the target words. It sounds like using a more engaging stimuli reinforces infants' discrimination at test. Why does it not detract from processing of the sounds?