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Research Interests
My general area of
research is cognitive development in infancy and
early childhood. I focus on the early development of
categorization and the development of the
animate-inanimate distinction, both of which are
among the most fundamental cognitive skills.
Categorization is especially important to infants,
young children, and adults as it is the primary means
of coding experience, which in turn reduces demands
on inherently limited memory storage and perceptual
and reasoning processes. The development of the
concept of animacy represents the most basic division
between different ontological kinds, and it is
thought to be a crucial building block for
children’s emerging representations about the
world around them. In my work, I am attempting to
provide an account for the development of conceptual
knowledge in infancy and childhood, with a focus on
the relationship between early categorization and
knowledge about natural kinds and artifacts. Thus
far, I have shown that infant rely on perceptual
features and the functions of those features to
categorize objects, and that learning the
associations among these properties in turn may lead
to the development of deeper, conceptual knowledge
about ontological kinds.
Research on early categorization
My primary research
focus has been on the development of categorization
in infancy. In much of this research, I have used the
sequential touching or object manipulation technique
in which infants are presented with eight toys from
two categories – say, for example, four animals
and four vehicles - and allowed to play with them
freely. If infants know or detect that some of the
objects are alike, they will touch sequentially those
objects. Using this technique, George Butterworth and
I (Rakison & Butterworth, 1998a, 1998b), found
that infants, particularly those under 22 months, do
not have a conceptual understanding of category
members as “the same kind of thing”, as has
been generally assumed. Rather, infants rely on the
perceptible properties of objects to categorize
superordinate domains like animals and vehicles. In
particular, infants attend to the parts – for
example, legs, wheels - of objects and the structural
configuration given by those parts.
In a later series of
experiments with the same paradigm, I found infants
categorize at the basic level by attending to parts
of objects and not by using knowledge about category
relatedness or nonobvious properties (Rakison &
Cohen, 1999). Infants attended only to those parts
(e.g., legs, wings) with a functional significance
for an object (e.g., movement type) and not to
smaller, functionally insignificant parts (e.g.,
facial features).
Research on the development of an
animate-inanimate distinction:
A second program of research concerns the development
of infants’ notion of animacy, the acquisition
of which is thought to be one of the cornerstones of
cognitive development (e.g., Leslie, 1995; Mandler,
1992). This line of study is particularly crucial
because very little is known about how infants begin
to categorize and make inductive inferences on the
basis of objects’ internal, nonobvious
attributes rather than their external, perceptual
appearance. I am working on the mechanisms that
underlie the development of infants’
understanding that distinct ontological kinds possess
different physical and psychological causal
characteristics. Specifically, I am examining whether
10- to 18-month-old infants acquire different aspects
of the distinction between animate and inanimate
objects by attending to object properties such as
type of motion, shape, and functional parts.
In one series of studies with the habituation
procedure, I tested the hypothesis that emerged from
my earlier work that infants’ earliest
distinction between animates and inanimates comes
from the correlation between large, moving,
functional parts and the path of motion of an object
(e.g., linear versus nonlinear). The results
supported the hypothesis, and suggest a developmental
trend whereby 14-month-old infants associate object
motion to relevant object parts and then later,
around 18 months, extend this correlation to whole
objects (Rakison & Poulin-Dubois, under review). Click here to see a movie of
the stimuli
and test yourself! (requires Shockwave).. In
addition, I am examining whether part-motion
correlations provide the foundation for infants’
knowledge of animates as agents in causal events and
as self-propelling entities.
I have also examined infants’ inductions about
the movements of objects. Using the inductive
generalization procedure developed by Mandler and
McDonough (1996), I have tested whether infants
generalize motion events from one category member to
another. The data suggest that infants’
understanding of the forms of motion of different
domains develops later than previously thought, and
is based on perceptual attributes such as shape and
parts. Moreover, I have found that infants’
performance is better described in terms of imitation
and perceptual matching than as induction based on
conceptual knowledge (Poulin-Dubois & Rakison,
under review).
Research
on Predator Avoidance Mechanims in Infants and Adults:
click here.
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