Trends in Cognitive Sciences
Tools for the body (schema)
Section snippets
Tool-use: a clue to the plasticity of body representation and space coding
Although the length of our effectors (mainly the arms) limits our action space, we can use many different tools (from forks to pick up hot food to hyper-technological telesurgery devices) to extend our physical body structure and, consequently, our action space.
Early intuitions (e.g. [1]) suggested that manipulated objects, or items of clothing 27, 28 become ‘incorporated into the body schema’. In recent years there has been an explosion of interest in trying to verify such an intriguing
Neurophysiology of tool-use in macaque monkeys
Japanese macaques can be trained to be dexterous tool-users [29], even though they rarely exhibit tool-use behaviour in their natural habitat (see Box 1). After two weeks of training [30], when a food pellet was dispensed beyond the reach of the hands, monkeys skilfully used a rake to pull the food closer, where they could reach it with their unaided hand. Thus, the tool effectively extended the animals’ reaching distance. In these monkeys, neuronal activity was recorded from the intraparietal
Behavioural effects of tool-use in normal humans
Inspired by the experiments on macaque monkeys described above, several researchers have recently investigated the behavioural effects of tool-use in human observers, in order to ascertain whether similar neural mechanisms exist in the two species. These studies share a basic logic; that is, to identify whether tool-assisted reaching for stimuli presented beyond the hand's normal or unaided reach would produce similar behavioural effects as direct reaching for nearby stimuli (i.e. in reachable
Neuropsychological effects of tool-use in brain-damaged patients
Further clues to the behavioural, and possibly neural, implications of tool-use have recently come from brain-damaged patients, particularly those patients who exhibit unilateral spatial neglect or extinction. Neglect patients typically ignore stimuli contralateral to the side of their brain damage (contralesional stimuli) [37], whereas extinction patients can detect unilateral stimuli on both sides of space, but ignore contralesional stimuli only when presented together with competing
Conclusions
Tool-use represents a huge achievement in human evolution and a distinct way for humans [48] to fulfil many everyday activities. This review has examined a specific aspect of research on tool-use, namely, to what extent the effective use of a tool can induce a plastic modification of the body representation in the brain. This sheds light not only on some basic neural mechanisms of tool-use, but also on some general mechanisms of body representation 4, 5 and their relationship with the
Acknowledgements
We are grateful to Nicholas Holmes, Charles Spence, Alessandro Farnè, Scott Johnson-Frey and other anonymous referees for their helpful comments on an early version of the paper.
References (74)
- et al.
The body in the brain: neural bases of corporeal awareness
Trends Neurosci.
(1997) Multisensory integration and the body schema: close to hand and within reach
Curr. Biol.
(2003)Action-oriented spatial reference frames in cortex
Neuron
(1998)The organization of the cortical motor system: new concepts
Electroencephalogr. Clin. Neurophysiol.
(1998)- et al.
Spatial maps for the control of movement
Curr. Opin. Neurobiol.
(1998) Grasping objects: the cortical mechanisms of visuomotor transformation
Trends Neurosci.
(1995)Functional and dynamic properties of visual peripersonal space
Trends Cogn. Sci.
(2002)Evidence for a disturbance of the body schema in neglect
Brain Cogn.
(1998)- et al.
The concept of the body schema: a critical review and some experimental results
Cortex
(1971) What is crossed in crossed-hand effects?
Acta Psychol. (Amst.)
(1986)
Tool-use changes multimodal spatial interactions between vision and touch in normal humans
Cognition
Attention and the crossmodal construction of space
Trends Cogn. Sci.
Activation in the ipsilateral posterior parietal cortex during tool use: a pet study
Neuroimage
Attentional competition between modalities: extinction between touch and vision after right hemisphere damage
Neuropsychologia
Reaching with a tool extends visual–tactile interactions into far space: evidence from cross-modal extinction
Neuropsychologia
What's so special about human tool use?
Neuron
Tool-use learning induces BDNF expression in a selective portion of monkey anterior parietal cortex
Brain Res. Mol. Brain Res.
Tool-use learning selectively induces expression of brain-derived neurotrophic factor, its receptor trkB, and neurotrophin 3 in the intraparietal multisensory cortex of monkeys
Brain Res. Cogn. Brain Res.
Functional brain mapping of monkey tool use
Neuroimage
The neural bases of complex tool use in humans
Trends Cogn. Sci.
Tool use and mechanical problem solving in apraxia
Neuropsychologia
Self-images in the video monitor coded by monkey intraparietal neurons
Neurosci. Res.
Rapid learning of sequential tool use by macaque monkeys
Physiol. Behav.
Sensory disturbances from cerebral lesions
Brain
L'aschématie
Rev. Neurol.
Body schema and intentionality
Visual capture of touch: out-of-the-body experiences with rubber gloves
Psychol. Sci.
Left tactile extinction following visual stimulation of a rubber hand
Brain
How the brain represents the body: insights neurophysiology and psychology
Rubber hands ‘feel’ touch that eyes see
Nature
Projecting sensations to external objects: evidence from skin conductance response
Proc. R. Soc. Lond. B. Biol. Sci.
Seeing your own touched hands in a mirror modulates cross-modal interactions
Psychol. Sci.
The Image and Appearance of the Human Body: Studies in the Constructive Energies of the Psyche
The space around us
Science
Coding of visual space by premotor neurons
Science
Coding of peripersonal space in inferior premotor cortex (area f4)
J. Neurophysiol.
Ventral intraparietal area of the macaque: congruent visual and somatic response properties
J. Neurophysiol.
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