1 3
Exp Brain Res (2016) 234:627–636
DOI 10.1007/s00221-015-4488-1
RESEARCH ARTICLE
Deaf, blind or deaf-blind: Is touch enhanced?
Costanza Papagno
1,2
· Carlo Cecchetto
1
· Alberto Pisoni
1,2
· Nadia Bolognini
1,2,3
Received: 5 July 2015 / Accepted: 29 October 2015 / Published online: 16 November 2015
© Springer-Verlag Berlin Heidelberg 2015
Introduction
When someone looses one type of sensory input, s/he may
compensate by using the sensory information from other
senses. However, loss of one type of sensory information,
at specific developmental times, may lead to generalized
deficits. We are endowed with distinct sensory systems,
specific for each sensory modality, connected with spe-
cialized brain regions. The fact that we are provided with
distinct sensory channels allows us experiencing uni-
modal, modality-specific, sensations, allowing a parallel
processing of different sensations that will then be unified
in a multimodal percept (Neville and Bavelier 2002). This
multisensory integration is made possible by extensive
and dynamic neural interactions, which in turn are highly
influenced by our own experiences and developmental con-
straints (Calvert and Thesen 2004).
Given our multisensory representation of reality, we
could expect that the loss of one sense must lead to a func-
tional loss. In this perspective, it is plausible that losing
or lacking a sensory modality alters the capacities of pro-
cessing, understanding or interacting, with the world, and
leads to functional and, perhaps structural, plastic changes
in the brain. On the other hand, the lack or loss of a sen-
sory modality may lead to a compensatory enhancement of
other senses, resulting even in functional gains and com-
pensations through cross-modal plasticity, namely the re-
organization of deprived and spared sensory networks (e.g.
Merabet and Pascual-Leone 2010; Bolognini et al. 2013;
Heimler et al. 2014).
Blind participants exhibit superior performance as com-
pared to sighted individuals in a series of auditory tasks.
For example, they have a better accuracy for auditory pitch
discrimination and pitch–timbre categorization (Wan et al.
2010), as well as for olfaction (Cuevas et al. 2009) when
Abstract When someone looses one type of sensory
input, s/he may compensate by using the sensory informa-
tion conveyed by other senses. To verify whether loosing a
sense or two has consequences on a spared sensory modal-
ity, namely touch, and whether these consequences depend
on the type of sensory loss, we investigated the effects of
deafness and blindness on temporal and spatial tactile tasks
in deaf, blind and deaf-blind people. Deaf and deaf-blind
people performed the spatial tactile task better than the
temporal one, while blind and controls showed the oppo-
site pattern. Deaf and deaf-blind participants were impaired
in temporal discrimination as compared to controls, while
deaf-blind individuals outperformed blind participants in
the spatial tactile task. Overall, sensory-deprived partici-
pants did not show an enhanced tactile performance. We
speculate that discriminative touch is not so relevant in
humans, while social touch is. Probably, more complex tac-
tile tasks would have revealed an increased performance in
sensory-deprived people.
Keywords Deafness · Blindness · Deaf-blind · Tactile
temporal discrimination · Tactile spatial discrimination
* Costanza Papagno
costanza.papagno@unimib.it
1
Department of Psychology, University of Milano-Bicocca,
Piazza dell’Ateneo Nuovo 1, 20126 Milan, Italy
2
NeuroMI, Milan Centre for Neuroscience, Milan, Italy
3
Laboratory of Neuropsychology, IRCCS Istituto Auxologico
Italiano, Milan, Italy