Current Research

Categorization in infancy

Categorization in infancy is based on bottom-up processes (i.e. perceptual abstraction) as well as on top-down processes (i.e. memory activation). As work conducted in our lab has shown, top-down processes play an important role even at a preverbal age. Infants perform a global-to-basic-level shift, with more abstract categories (i.e. animates vs. inanimates) developing earlier than basic-level categories like dogs, cats, chairs or tables (Pauen, 2002a). As indicated by follow-up studies, these categorical distinctions reflect conceptual knowledge (Pauen, 2002b). So far, only behavioural measures have been used to study infant categorization. In our lab, we also use heart rate measure (Elsner, Pauen & Jeschonek, 2006) and ERP-measures (see Figure 1) to validate behavioural data. Corresponding studies demonstrate that even the brains of 7-month-old infants respond differently to animal and vehicle pictures. Furthermore, we found that 12-month-olds show different brain responses when looking at pictures of artefacts or animals accompanied by matching vs. non-matching sounds. Taken together, our studies provide first neuropsychological evidence for the early emergence of a knowledge-based animate-inanimate distinction.

Pauen Fig1
Fig. 1 . Infant prepared to conduct an EPR-Study on categorization

Causal and functional reasoning in infancy

This line of research focuses on the question what kind of knowledge about objects infants acquire during the first year of life. One of the key attributes of animates is selfinitiated movement. Using newly developed experimental paradigms, we have shown that even 7-month-olds are able to attribute the cause of a given motion to animates rather than inanimates. When watching an unfamiliar animal moving around together with a ball, they attribute the cause of this motion to the animal rather than the ball (see Figure 2). Yet another line of research focuses on how infants use functional knowledge to guide their categorization of artefacts. Based on the finding that 12-month-olds categorize objects differently after their functional use has been demonstrated than without a corresponding demonstration (Träuble & Pauen, 2007) we now explore in more detail the conditions that support this kind of functional learning (social cues, objects cues; e.g. Elsner & Pauen, 2007).

Pauen Fig2
Fig. 2. Infant participating in a study on early causal reasoning: It watches an animal and a ball rolling together. Later, looking time measures will reveal whether the motion has been attributed to the animal or the ball.

Relation between early cognitive development and language acquisition

In early lexical acquisition, noun understanding emerges quite early. To better understand how preverbal categorization and noun comprehension interact, we investigate the impact of labelling on categorization performance in infants 7 to 12 months of age. Results reveal that in very young infants, nouns increase general attention for objects, but do not change the pattern of categorization, whereas for older infants who are about to learn basic-level categorical distinctions, nouns can indeed help to make these distinctions within a given global domain. Furthermore, we are interested in studying whether early preverbal categorization skills have prognostic value for later intelligence. Investigating the relation between verbal and non-verbal measures of intelligence for preschoolers, we found that non-verbal categorization skills in a basiclevel task at 11 months of age and noun comprehension at 12 months of age (assessed via parental questionnaires) covariate. Furthermore, recent data from our German Language Development Study reveals that verbal and nonverbal measures of intelligence in 4- to 5-year olds are more closely related that originally thought.

Development of analogical reasoning

This line of studies focuses on the beginnings of analogical reasoning in human infants. We approach this issue by conducting comparative studies with infants, monkeys and chimpanzees in collaboration with primate labs at the MPI in Leipzig as well as the monkey-lab at the University of Rome. Our studies and collaborations focus on three related topics: (1) intermodal integration of dynamic displays, (2) perceptual understanding of the sameness and differentness relation, and (3) tool-use as well and relational mapping. 1. Infants are shown dynamic displays presenting one upward and one downward moving circle, accompanied either by a tone of rising or descending pitch. Using a preferential-looking paradigm, we will find out whether intermodal relational mappings typically found in adults (i.e. an upward movement is associated with a rising pitch) are rooted in basic intermodal perceptual integration of the brain from birth on, or can better be explained by learning processes occurring later in life. In similar ways, we plan to explore other intermodal relations, such as the relation between luminance and pitch. 2. One very basic perceptual relation that plays a crucial role in categorization is the relation of sameness / differentness. Existing animal studies suggest that monkeys are capable of judging sameness and differentness, when provided with at least 8 to 16 pictures that either look identical or different from each other. This leaves open the question whether they really understood the underlying concept or solved the task by simply recognizing that the elements of some complex display either showed a graphical pattern or did not. Ruling out this methodological problem, the present study will compare monkey and infant performance in a response-match-to sample task, using only two simple graphic figures per display that are either the same or different from each other. 3. Analogical reasoning plays a crucial role in problem solving. Together with Rome we designed a tool-use study in which monkeys and infants learn to use one of three stick, differing in the appearance of their handles as well as in the length of the sticks, to push some reward out of a tube. Only the longest of the three sticks reaches the reward in the tube – thus providing an effective tool. Following a training phase, the infants and animals will get a new set of tools. All three sticks have the same length as before, but the handles are exchanged. It will be tested whether the infants / monkeys focus on the functionally relevant feature (i.e. stick length) or the perceptually salient cue (i.e. the handle) when choosing their tool.

Editor: Email
Latest Revision: 2013-03-25
zum Seitenanfang/up