|
| |
|
|
|
|
||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | ||||
First published online August 3, 2006
Journal of Experimental Biology 209, 3266 (2006)
Published by The Company of Biologists 2006
doi: 10.1242/jeb.02411
Correspondence |
What can bees really tell us about the face processing system in humans?
1 Department of Psychology, The University of Sheffield, UK
2 Department of Psychology, University of Glasgow, UK
* e-mail: o.pascalis{at}sheffield.ac.uk
Cognitive abilities present in humans, such as face processing, are likely
to have evolved under various ecological pressures. A comparable and
specialized face processing system observed in sheep and non-human primates
suggests a possible common origin in evolution
(Pascalis et al., 1999
;
Kendrick et al., 2001;
Parr, 2003). However, it is
important to determine when this system emerged during evolution if we are to
fully understand it. Studies conducted with honeybees (Apis
mellifera) and wasps (Polistes fuscatus) could potentially
contribute to our understanding of this ability.
Dyer et al. have demonstrated that bees are able to learn and recognise the
picture of a human face when paired with a novel face
(Dyer et al., 2005), which is
consistent with our existing knowledge of the bees' visual ability. However,
we believe that Dyer's extrapolations about how recognition is achieved and
whether or not it is facilitated by specialised brain regions are
misleading.
Face recognition is carried out by an automated and specific process in
humans, which is known as configural processing (perceiving metrical relations
between face features). Contrary to Dyer's argument and to earlier research
findings (Diamond and Carey,
1977), it is now debatable whether such processing develops late
in childhood (Schwarzer et al.,
2005). Furthermore, studies that have created `visual experts' who
develop configural processing for non-face objects require many more hours of
intensive training than reported by Dyer et al. In their study, there is no
clear evidence of configural processing and it is likely that the bees'
recognition relied on specific features.
In human adults, functional neuroimaging studies have identified a network
of areas within the ventral temporal cortex that are highly responsive to
faces (Haxby et al., 2000),
with maximum selectivity in the right middle fusiform gyrus: the so-called
`fusiform face area' (FFA) (Kanwisher et
al., 1997). A comparable functional specialization supports face
processing in the primate brain (Tsao et
al., 2006). Critically, however, normal face identification relies
on the integrity of this complex network, as prosopagnosic patients with
lesions sparing the FFA show impaired use of optimal information for face
identification (Caldara et al.,
2005; Schiltz et al.,
2006).
With data collected from just five bees, it is too speculative to conclude
that specialised brain regions are not necessary for face processing in
humans. Humans and bees have not shared a common ancestor for roughly 600
million years and have evolved very differently since this separation. We can
therefore expect them to process faces differently. Clearly, more studies are
required to determine how the honeybee succeeds in simple face
matching tasks before attempting to establish potential similarities between
its visual recognition abilities and those of different species. It is first
necessary to establish whether bees are able to recognise or categorise
conspecifics in a similar way to the wasp
(Tibbetts, 2002;
Tibbetts and Dale, 2004).
Given that humans appear capable of only processing faces confined to human
and non-human primate categories, it would be somewhat paradoxical if the bee
demonstrated recognition with human faces but not with conspecifics. Finally,
artificial computing systems without a neural substrate also demonstrate an
optimal ability to recognize individual faces. Does such evidence question the
neural specificity of face processing in humans?
References
Caldara, R., Schyns. P., Mayer, E., Smith, M., Gosselin, F. and Rossion, B. (2005). Does prosopagnosia take the eyes out of face representations? Evidence for a defect in representing diagnostic facial information following brain damage. J. Cog. Neurol. 17,1652 -1666.[CrossRef]
Diamond, R. and Carey, S. (1977). Developmental changes in the representation of faces. J. Exp. Child Psychol. 23,1 -22.[CrossRef][Medline]
Dyer, A. G., Neumeyer, C. and Chittka, L.
(2005). Honeybee (Apis mellifera) vision can
discriminate between and recognise images of human faces. J. Exp.
Biol. 208,4709
-4714.
Haxby, J. V., Hoffman, E. A. and Gobbini, M. I. (2000). The distributed human neural system for face perception. Trends Cogn. Sci. 4,223 -233.[CrossRef][Medline]
Kanwisher, N., McDermott, J. and Chun, M. M.
(1997). The fusiform face area: a module in human extrastriate
cortex specialized for face perception. J. Neurosci.
17,4302
-4311.
Kendrick, K. N., da Costa, A. P., Leigh, A. E., Hinton, M. R. and Pierce, J. W. (2001). Sheep don't forget a face. Nature 441,165 -166.[CrossRef]
Parr, L. (2003). The discrimination of faces
and their emotional contents by chimpanzees (Pan troglodytes).
Ann. New. York. Acad. Sci.
1000,56
-78.
Pascalis, O., Petit, O., Kim, J. H. and Campbell, R. (1999). Picture perception in primate: the case of face perception. Curr. Psychol. Cogn. 18,889 -922.
Schiltz, C., Sorger, B., Caldara, R., Ahmed, F., Mayer, E.,
Goebel, R. and Rossion, B. (2006). Impaired face
discrimination in acquired prosopagnosia is associated with abnormal response
to individual faces in the right middle fusiform gyrus. Cerebr.
Cortex 16,574
-586.
Schwarzer, G., Huber, S. and Dümmler, T. (2005). Gaze behavior in analytical and holistic face processing. Mem. Cog. 33,344 -354.
Tibbetts, E. A. (2002). Visual signals of individual identity in the wasp Polistes fuscatus. Proc. R. Soc. Lond. B 269,1423 -1428.[Medline]
Tibbetts, E. A. and Dale, J. (2004). A socially enforced signal of quality in a paper wasp. Nature 432,218 -222.[CrossRef][Medline]
Tsao, D. Y., Winrich A., Freiwald, W. A., Tootell, R. B. H. and
Livingstone, M. S. (2006). A cortical region consisting
entirely of face-selective cells. Science
311,670
-674.
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
