All in a Sniff: Olfaction as a Model for Active Sensing

Department of Physiology and Brain Institute, University of Utah, Salt Lake City, UT 84103, USA.
Neuron (Impact Factor: 15.05). 09/2011; 71(6):962-73. DOI: 10.1016/j.neuron.2011.08.030
Source: PubMed

ABSTRACT

Sensation is an active process involving the sampling and central processing of external stimuli selectively in space and time. Olfaction in particular depends strongly on active sensing due to the fact that-at least in mammals-inhalation of air into the nasal cavity is required for odor detection. This seemingly simple first step in odor sensation profoundly shapes nearly all aspects of olfactory system function, from the distribution of odorant receptors to the functional organization of central processing to the perception of odors. The dependence of olfaction on inhalation also allows for profound modulation of olfactory processing by changes in odor sampling strategies in coordination with attentional state and sensory demands. This review discusses the role of active sensing in shaping olfactory system function at multiple levels and draws parallels with other sensory modalities to highlight the importance of an active sensing perspective in understanding how sensory systems work in the behaving animal.

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Available from: Matt Wachowiak, Mar 24, 2014
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    • "Perception is necessary for action (Goodale, 2008); likewise, action plays a pivotal role in perception, in what has become known as active sensing. Active sensing has been shown to play a vital role in perception of various modalities, including the visual, auditory, tactile, and olfactory systems (Schroeder, Wilson, Rad- man,Scharfman, & Lakatos, 2010;Wachowiak, 2011), in humans as well as a variety of other species (Nelson & MacIver, 2006). Active sensing is the movement of the sensors for optimization of sensing performance (Mitchinson & Prescott, 2013), and it plays a central role in the process of perception (Ahissar & Arieli, 2012). "
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    • "We propose that volition may therefore be a primitive capability of vertebrate brains that precedes the advanced cognitive capacities of primates. Animals actively sample their environment using, for example, whisking, sniffing and saccadic eye movements; these active sensing behaviours (Nelson and MacIver, 2006; Kleinfeld et al., 2006; Otero-Millan et al., 2008; Wachowiak, 2011) occur more frequently during periods of active exploration (Poulet and Petersen, 2008; Schroeder et al., 2010). "
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    • "However , recent studies have shown a much more complex scenario in awake animals, requiring re-evaluation of our notions of olfactory processing (Kato et al., 2012; Wachowiak et al., 2013). MCs in awake, behaving animals are spontaneously active (Rinberg and Gelperin, 2006; Rinberg et al., 2006; Davison and Katz, 2007) with firing that is often locked to the respiration cycle (Cury and Uchida, 2010; Wachowiak, 2011). Odor-evoked responses are not encoded in simple changes in firing frequencies; instead, the OB adopts various sophisticated mechanisms, involving the activity of MCs, to detect and encode odors. "
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