A perceptual phenomenon by whichvarious instances of stimuli equally distant from each other in their physicalproperties are mapped to different perceptual categories (i.e., /b/ and /p/). Thus, it means that a change insome variable along a continuum not perceived as gradual but as an instance of a discrete categorie. Some stimuli are perceived as belonging to the same category, while a sharp boundarybetween a few stimuli is perceived. In the context of speech, categoricalperception enables people to recognize words even when vowels may bepronounced differently. Moreover, it is influenced by the linguistic environment. Using a number of standardized procedures to test speech perception in infants (e.g., conditioned head turning response), an important research enterprise is how it facilitates word acquisition There is also a body of infant research focused on other modalities than speech (e.g., perception of facial expressions , and it may in fact involve cross-modal perception.
See Configural processing, Cross-modal perception, Face processing, Speech development