Читать книгу Lifespan Development - Tara L. Kuther - Страница 266

In infants’ eyes, all of the world is new—“one great blooming, buzzing confusion,” in the famous words of 19th-century psychologist William James (1890). How do infants think about and make sense of the world? As infants are bombarded with a multitude of stimuli, encountering countless new objects, people, and events, they form concepts by naturally grouping stimuli into classes or categories. Categorization, grouping different stimuli into a common class, is an adaptive mental process that allows for organized storage of information in memory, efficient retrieval of that information, and the capacity to respond with familiarity to new stimuli from a common class (Quinn, 2016). Infants naturally categorize information, just as older children and adults do (Rosenberg & Feigenson, 2013). Without the ability to categorize, we would have to respond anew to each novel stimulus we experience.

Just as in studying perception and attention, developmental researchers must rely on basic learning capacities, such as habituation, to study how infants categorize objects (Rigney & Wang, 2015). For example, infants are shown a series of stimuli belonging to one category (e.g., fruit: apples and oranges) and then are presented with a new stimulus of the same category (e.g., a pear or a lemon) and a stimulus of a different category (e.g., a cat or a horse). If an infant dishabituates or shows renewed interest by looking longer at the new stimulus (e.g., cat), it suggests that he or she perceives it as belonging to a different category from that of the previously encountered stimuli (Cohen & Cashon, 2006). Using this method, researchers have learned that 3-month-old infants categorize pictures of dogs and cats differently based on perceived differences in facial features (Quinn, Eimas, & Rosenkrantz, 1993).

Figure 5.6 Rovee-Collier Ribbon Study

Young infants were taught to kick their foot to make an attached mobile move. When tested one week later the infants remembered and kicked their legs vigorously to make the mobile move.

Source: Nick Alexander; Levine and Munsch (2010).

Infants’ earliest categories are based on the perceived similarity of objects (Rakison & Butterworth, 1998). By 4 months, infants can form categories based on perceptual properties, grouping objects that are similar in appearance, including shape, size, and color (Quinn, 2016). As early as 7 months of age, infants use conceptual categories based on perceived function and behavior (Mandler, 2004). Moreover, patterns in 6- to 7-month-old infants’ brain waves correspond to their identification of novel and familiar categories (Quinn, Doran, Reiss, & Hoffman, 2010). Seven- to 12-month-old infants use many categories to organize objects, such as food, furniture, birds, animals, vehicles, kitchen utensils, and more, based on both perceptual similarity and perceived function and behavior (Bornstein & Arterberry, 2010; Mandler & McDonough, 1998; Oakes, 2010).

Researchers also use sequential touching tasks to study the conceptual categories that older infants create (Perry, 2015). Infants are presented with a collection of objects from two categories (e.g., four animals and four vehicles) and their patterns of touching are recorded. If the infants recognize a categorical distinction among the objects, they touch those from within a category in succession more than would be expected by chance. Research using sequential touching procedures has shown that 12- to 30-month-old toddlers organize objects first at a global level and then at more specific levels. They categorize at more inclusive levels (e.g., animals or vehicles) before less inclusive levels (e.g., types of animals or types of vehicles) and before even less inclusive levels (e.g., specific animals or vehicles) (Bornstein & Arterberry, 2010). Infants’ and toddlers’ everyday experiences and exploration contribute to their growing capacity to recognize commonalities among objects, group them in meaningful ways, and use these concepts to think and solve problems.

Recognizing categories is a way of organizing information that allows for more efficient thinking, including storage and retrieval of information in memory. Therefore, advances in categorization are critical to cognitive development. The cognitive abilities that underlie categorization also influence language development as words represent categories, ways of organizing ideas and things. In the Applying Developmental Science feature, we look at the baby signing movement, which proposes that infants can apply gestures as symbols in order to communicate.

As shown in Table 5.2, information processing capacities, such as attention, memory, and categorization skill, show continuous change over the first 3 years of life (Rose, Feldman, & Jankowski, 2009). Infants get better at attending to the world around them, remembering what they encounter, and organizing and making sense of what they learn. Infants’ emerging cognitive capacities influence all aspects of their development and functioning, including intelligence. Cognitive development is also influenced by the contexts in which infants and children live.