© 2006 Japanese Psychological Association. Published by Blackwell Publishers Ltd.

Japanese Psychological Research

doi: 10.1111./j.1468-5884.2006.00314.x
2006, Volume 48, No. 3, 126–140

Blackwell Publishing Asia

ORIGINAL ARTICLEAction-oriented representation of spaceAction-oriented representation of peripersonal and
extrapersonal space: Insights from manual and
locomotor actions

1

TAKAHIRO HIGUCHI

2

Department of Health Promotion Science, Tokyo Metropolitan University, 1-1,
Minami-Ohsawa, Hachioji, Tokyo 192-0397, Japan and Department of
Kinesiology, University of Waterloo, 200 University Avenue West, Waterloo,
Ontario N2L 3G1, Canada

KUNIYASU IMANAKA

Department of Health Promotion Science, Tokyo Metropolitan University, 1-1,
Minami-Ohsawa, Hachioji, Tokyo 192-0397, Japan

AFTAB E. PATLA

Department of Kinesiology, University of Waterloo, 200 University Avenue
West, Waterloo, Ontario N2L 3G1, Canada

Abstract:

This paper reviews behavioral evidence demonstrating that space is accurately
represented in the brain in relation to action capabilities. We initially review intriguing
neuropsychological findings that show that space is differentially represented depending on
whether the area is in reach of the hand (peripersonal space) or out of reach of the hand
(extrapersonal space). We then review the literature on the characteristics of locomotor
actions for avoiding obstacles to show that the relative dimensions of obstacles to relevant
body parts are accurately represented at least one step before the obstacles are reached,
i.e., while the obstacles are present in the extrapersonal space. The findings obtained from
a number of studies on manual and locomotor actions will yield tentative conclusions: (a)
the representation of one’s body (body schema) is deeply involved in one’s representation
of space; (b) the representation of space is modified in response to alteration of action
capabilities, although this is likely to occur only for well-learned actions, irrespective of the
type; and (c) representation of space centered on the hand somewhat differs from that
centered on the whole body.

Key words:

perceptual-motor task, spatial perception, peripersonal space, body schema,

adaptation.

Motor actions require the egocentric coding
of space. To manually reach an object, for
instance, the information about the location of
the object with respect to the position of the
hand is necessary. To walk through a narrow
passage created by pedestrians, the informa-
tion about the size of the passage relative to
the width of the body is required. One of the

1

We would like to thank Genevieve Desmarais and Daniel S. Marigold for their helpful comments on the manuscript.
This research was supported by a Grant-in-Aid for the Japanese Society for Promotion of Science fellows (No. 08827)
for the first author.

2

Correspondence concerning this article should be sent to: Takahiro Higuchi, Department of Health Promotion Science,
Tokyo Metropolitan University, 1-1, Minami-Ohsawa, Hachioji, Tokyo 192-0397, Japan. (Email: higuchit@comp.metro-u.ac.jp)

© Japanese Psychological Association 2006.

Action-oriented representation of space

127

central issues on motor actions has been how
space is egocentrically represented in the
brain to achieve a desired act. Jeannerod
(1994, 2005) reviewed a broader range of
literature and showed evidence that there are
multiple levels of representation for action.
Jeannerod characterized the representation
involving the egocentric coding of space as being
at a lower level and operated by nonconscious
systems. The objective of the present paper is
to review recent findings on the nature of ego-
centric representation of space for motor action.
We focus on behavioral evidence in humans
and add information from electrophysiological
studies in monkeys where necessary.
Recently, it has become apparent that space
is differentially represented depending on
whether the area is accessible. Evidence stems
from neuropsychological studies of patients
with right-hemisphere brain damage. Some
of the patients showed symptoms of contra-
lesional spatial neglect for nearby space that was
accessible by the hand (termed “peripersonal
space”), but not for distant space (termed
“extrapersonal space;” Berti & Frassinetti, 2000;
Halligan & Marshall, 1991), or vice versa
(Cowey, Small, & Ellis, 1999; Ackroyd, Rid-
doch, Humphreys, Nightingale, & Townsend,
2002). This suggests that peripersonal and
extrapersonal space are differentially repres-
ented in the brain. Surprisingly, immediately
after the patients held a stick to extend their
reach, the neglected area was extended (or
reduced) along with the length of the stick
(Ackroyd et al., 2002; Berti & Frassinetti,
2000). These intriguing findings, supported by
electrophysiological studies testing macaque
monkeys (Iriki, Tanaka, & Iwamura, 1996),
demonstrate that the representation of space
accurately reflects the action capabilities. When
a person’s action capabilities are altered by
adding a hand-held stick, the representations
of space are modified as a result.
These findings led many researchers to
believe that the representation of the bio-
mechanical properties of the body, which is
termed as “body schema” (Head & Holmes,
1911), is involved in the representation of
space. The existence of the body schema in the
brain has been demonstrated with neuropsy-
chological findings showing that brain damage
could cause a dissociation between spatial
knowledge about the human body and the
external environment (e.g., Ogden, 1985; Sirigu,
Grafman, Bressler, & Sunderland, 1991). The
body schema codes the position of body parts
with respect to one another over time, result-
ing in an internal dynamic model of the body
(Buxbaum, Giovannetti, & Libon, 2000). The
body schema therefore provides the central
nervous system (CNS) with information about
the action capabilities. Furthermore, the body
schema can cover extracorporeal (i.e., not
related to the body) objects that are in contact
with or in close proximity with the body, such
as clothes, rings, or tools (Aglioti, Smania,
Manfredi, & Berlucchi, 1996; Berlucchi &
Aglioti 1997). Thus, it is likely that the repre-
sentation of space is modified in response to
altered action capabilities by a hand-held stick
(Ackroyd et al., 2002; Berti & Frassinetti, 2000)
because the body schema is deeply involved in it.
To date, the issue of peripersonal and
extrapersonal spaces has been tested mostly
with space surrounding the hand. There are few
studies that directly test this issue with space
surrounding different body parts or the whole
body (Berti et al., 2002). Therefore, it is far from
clear whether space is similarly represented for
motor actions other than manual actions. How-
ever, indirect but ample evidence obtained from
studies on locomotor actions has shown that
space is accurately represented in relation to a
person’s action capabilities but in somewhat
different manners for manual and locomotor
actions. A number of studies regarding loco-
motor actions have demonstrated that, while an
object of interest (e.g., the goal or obstacles)
exists in the extrapersonal space, the CNS starts
adjusting the parameters of locomotor actions
to properly interact with the object. This is
exemplified by the finding that adjusting the
length of the stride to step over an obstacle begins
a few steps before stepping over it (Moraes,
Lewis, & Patla, 2004). These results suggest
that space in the distance is likely to be pro-
actively represented to enable the CNS to control
locomotor actions in a feedforward manner.