OLFACTION AND SPACE
Our lab evolves in punctuated equilibria, slowly developing theoretical frameworks that then are used to focus a small number of targeted empirical studies. These frameworks form a limbic trilogy: the parallel map theory of hippocampal function, the olfactory spatial hypothesis of main olfactory system function and, under development, the PROUST hypothesis of the evolutionary interplay between functions of the main and the vomeronasal olfactory systems. This theoretical work has led to fundamental studies in neuroscience on synaptic plasticity (Hoang et al., 2018. Hippocampus) and human functional imaging (Dahani et al. 2018. Nature Communications).
The role of olfaction in navigation was an essential component of the argument for parallel maps in the hippocampus (Jacobs & Schenk, 2003) [HIPPOCAMPAL MAPS]. The olfactory spatial hypothesis took this one step farther, proposing that the main olfactory system also maps space using a parallel map architecture and is an essential part of the hippocampal navigation system in most vertebrates (Jacobs, 2012). The PROUST hypothesis proposes that it was the increasing specialization of the main olfactory system for spatial encoding that led to the evolution of a robust second system in terrestrial vertebrates. By extending PROUST to questions of nose morphology in primates, including humans, the navigational nose hypothesis offers the first olfactory function hypothesis for the human external nose [HUMAN SPATIAL EVOLUTION].
These theoretical developments led to the funding of a NSF Ideas Lab research consortium, a team using diverse methods and species to identify the universal algorithms of olfactory navigation: Kathy Nagel (NYU), Justus Verhagen (John Pierce Lab, Yale), John Crimaldi (Univ. Colorado), Jonathan Victor (Weill Cornell Medicine) and Bard Ermentrout (Univ. Pittsburgh) and Nathan Urban (Univ. Pittsburgh). Our lab works on two species in this effort: humans [HUMAN SPATIAL EVOLUTION] and trained search dogs. Despite their societal importance, there are few behavioral studies of olfactory orientation in dogs. Collaborating with CARDA, the California Rescue Dog Association and other Ideas Lab teams, we are currently studying the influence of environmental conditions on search accuracy. As a champion species, the behavior of search dogs defines the high end of the performance spectrum and gives us a powerful system with which to understand human olfactory navigation [HUMAN SPATIAL EVOLUTION].
(In prep) Jacobs, L. F. Perceiving and representing odor utility in space and time: how phylogenetic constraints and habitat structure shaped the evolution of olfactory systems in vertebrates. American Naturalist, Synthesis review.
(in prep) Jinn, J., Connor, E. & Jacobs, L.F. Influence of environmental factors on search dog strategy and performance.
(in prep) Jinn, J., Connor, E., Crimaldi, J. & Jacobs, L.F. Navigation in a virtual odor plume.
(in prep) Jinn, J. & Jacobs, L.F. Human spatial orientation within an experimental olfactory landscape.
(In press) Jacobs, L. F. (2018) The navigational nose: a new hypothesis for the function of the human external pyramid. Journal of Experimental Biology.
Jacobs, L. F., Arter, J., Cook, A., & Sulloway, F. J. (2015). Olfactory orientation and navigation in humans. PLoS ONE, 10(6), e0129387. doi:10.1371/journal.pone.0129387.s001
Jacobs, L. F., & Menzel, R. (2014) Navigation outside the box: what the lab can learn from the field and what the field can learn from the lab. Movement Ecology 2, 3. doi 10.1186/10.1186/2051-3933-2-3.
Jacobs, L. F. (2012). From chemotaxis to the cognitive map: the function of olfaction. Proceedings of the National Academy of Sciences, 109, 10693–10700.
Feener, D.H., Jacobs, L.F., and Schmidt, J.O. (1996). Specialized parasitoid attracted to a pheromone of ants. Animal Behaviour 51, 61-66.