As some of you may know I not only teach animal sensory science at University but I also teach hundreds of students every year about human olfaction, mostly in the form of wine tasting. We take our wine tasting very seriously with students learning to recognise and separate different odours and finally to evaluate the concentrations of separate odours by sniffing. It sounds like fun but after a few hours of this many students have a headache without ever swallowing a single drop. Concentration is needed and it takes many hours of training even to be able to recognise a few odours. This is one of the reasons I was particularly interested in the attached paper by Jess Porter published in Nature Neuroscience from the very well respected labs of Brent Craven and Gary Settles.
Porter states that “the mechanisms of scent-trail tracking, a critical ability for dogs, remains unknown, and key questions, such as whether mammals use inter-nostril comparisons to aid scent-tracking, remain unanswered”. This is such an important piece of knowledge we are missing, particularly for those people who are using dogs in scientific research or are looking to train dogs in fields that require proofing. However it is a difficult field of study mainly because it is hard to ask a dog exactly what they are thinking and what their strategies are for following and odour. Until this paper we have only really been able to determine certain strategies based on observation. Porter etal however came up with a solution to this dilemma, they used humans! When I say they used humans I mean they literally got people to get down on all fours and follow a track by sniffing! Porter et al state that “Humans are an appealing animal model because they can follow task instructions and accurately report behavioral strategies. Humans also tolerate manipulations, such as nostril occlusion, that may aggravate even well-trained dogs. However, whether humans are a valid model for this task is unknown. Therefore,
we first set out to ask whether humans can scent-track”. And as it turned out, we can! Who knew?!
The researchers found that (i) humans can scent-track, (ii) they improve with practice, (iii) the human nostrils sample spatially distinct regions separated by ~3.5 cm and, critically, (iv) scent-tracking is aided by inter-nostril comparisons.
From this research we have learnt that dogs (who have FAR SUPERIOR olfaction to humans) smell with each nostril separately and can determine direction of odours. Please have a read of this paper, it is not very long and has some fascinating and actually quite amusing information.
Porter states that “the mechanisms of scent-trail tracking, a critical ability for dogs, remains unknown, and key questions, such as whether mammals use inter-nostril comparisons to aid scent-tracking, remain unanswered”. This is such an important piece of knowledge we are missing, particularly for those people who are using dogs in scientific research or are looking to train dogs in fields that require proofing. However it is a difficult field of study mainly because it is hard to ask a dog exactly what they are thinking and what their strategies are for following and odour. Until this paper we have only really been able to determine certain strategies based on observation. Porter etal however came up with a solution to this dilemma, they used humans! When I say they used humans I mean they literally got people to get down on all fours and follow a track by sniffing! Porter et al state that “Humans are an appealing animal model because they can follow task instructions and accurately report behavioral strategies. Humans also tolerate manipulations, such as nostril occlusion, that may aggravate even well-trained dogs. However, whether humans are a valid model for this task is unknown. Therefore,
we first set out to ask whether humans can scent-track”. And as it turned out, we can! Who knew?!
The researchers found that (i) humans can scent-track, (ii) they improve with practice, (iii) the human nostrils sample spatially distinct regions separated by ~3.5 cm and, critically, (iv) scent-tracking is aided by inter-nostril comparisons.
From this research we have learnt that dogs (who have FAR SUPERIOR olfaction to humans) smell with each nostril separately and can determine direction of odours. Please have a read of this paper, it is not very long and has some fascinating and actually quite amusing information.
Figure 1 Human subject’s path following a scent trail, as compared to a dog’s path. (a) Path of a dog following the scent trail of a pheasant dragged through a field (scent trail in yellow, dog’s path in red; from ref. 15). (b) Path of a human following a scent trail of chocolate essential oil through a field (scent trail in yellow, human’s path in red). Porter et.al .(2007)
Porter, J., Craven, B., Khan, RM., Chang, S., Kang, I., Judkewicz, B., Volpe, J., Settles, G. and Sobel, N. (2007) Mechanisms of scent-tracking in humans. Nature Neuroscience, Vol 10 / 1.
Porter, J., Craven, B., Khan, RM., Chang, S., Kang, I., Judkewicz, B., Volpe, J., Settles, G. and Sobel, N. (2007) Mechanisms of scent-tracking in humans. Nature Neuroscience, Vol 10 / 1.
