Olfactory space has a higher dimensionality than does any other class of sensory stimuli, and the olfactory system receives input from an unusually large number of unique information channels. This suggests that aspects of olfactory processing may differ fundamentally from processing in other sensory modalities. This review summarizes current understanding of early events in olfactory processing. We focus on how odors are encoded by the activity of primary olfactory receptor neurons, how odor codes may be transformed in the olfactory bulb, and what relevance these codes may have for downstream neurons in higher brain centers. Recent findings in synaptic physiology, neural coding, and psychophysics are discussed, with reference to both vertebrate and insect model systems.

Early events in olfactory processing

Naturalistic quantification of canine olfactory sensitivity

Using a conditioning paradigm, the olfactory sensitivity of three squirrel monkeys to nine odorants representing different chemical classes as well as members of a homologous series of substances was investigated. The animals significantly discriminated dilutions as low as 1:10,000 n-propionic acid, 1:30,000 n-butanoic acid and n-pentanoic acid, 1:100,000 n-hexanoic acid, 1:1Mio n-heptanoic acid, 1:30, 000 1-pentanol, 1:300,000 1,8-cineole, 1:1Mio n-heptanal and 1:30Mio amyl acetate from the near-odorless solvent, with single individuals scoring even slightly better. The results showed (i) the squirrel monkey to have an unexpectedly high olfactory sensitivity, which for some substances matches or even is better than that of species such as the rat or the dog, and (ii) a significant negative correlation between perceptibility in terms of olfactory detection thresholds and carbon chain length of carboxylic acids. These findings support the assumptions that olfaction may play a significant and hitherto underestimated role in the regulation of primate behavior, and that the concept of primates as primarily visual and 'microsmatic' animals needs to be revised.

'Microsmatic' primates revisited: olfactory sensitivity in the squirrel monkey.

We examined the ability of domestic dogs to choose the larger versus smaller quantity of food in two experiments. In experiment 1, we investigated the ability of 29 dogs (results from 18 dogs were used in the data analysis) to discriminate between two quantities of food presented in eight different combinations. Choices were simultaneously presented and visually available at the time of choice. Overall, subjects chose the larger quantity more often than the smaller quantity, but they found numerically close comparisons more difficult. In experiment 2, we tested two dogs from experiment 1 under three conditions. In condition 1, we used similar methods from experiment 1 and tested the dogs multiple times on the eight combinations from experiment 1 plus one additional combination. In conditions 2 and 3, the food was visually unavailable to the subjects at the time of choice, but in condition 2, food choices were viewed simultaneously before being made visually unavailable, and in condition 3, they were viewed successively. In these last two conditions, and especially in condition 3, the dogs had to keep track of quantities mentally in order to choose optimally. Subjects still chose the larger quantity more often than the smaller quantity when the food was not simultaneously visible at the time of choice. Olfactory cues and inadvertent cuing by the experimenter were excluded as mechanisms for choosing larger quantities. The results suggest that, like apes tested on similar tasks, some dogs can form internal representations and make mental comparisons of quantity.

/pdf/quantity-based-judgments-in-the-domestic-dog-canis-lupus-3tbrgwszr9.pdf

Quantity-based judgments in the domestic dog (Canis lupus familiaris).

Linking gustatory neurobiology to behavior in vertebrates.

Odor psychophysics in vertebrates.

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

J.C. Walker

Author Tools

Chat about Author

Papers

Odor psychophysics in vertebrates.