Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Scents will not rouse us from slumber, says new Brown University study


While sound can disrupt sleep, scents cannot. People cannot rely on their sense of smell to awaken them to the danger of fire, according to a new Brown University study.

Study participants easily detected odors when awake and in the early transition into sleep (Stage One sleep) but, once asleep, did not. The findings indicate a significant alteration of perceptual processing as a function of sleep.

“Human olfaction appears insufficiently sensitive and reliable to act as a sentinel system,” said Rachel S. Herz, visiting assistant professor of psychology and an author of a study titled “Minimal Olfactory Perception During Sleep: Why Odor Alarms Will Not Work for Humans,” published in a recent issue of the journal Sleep.

Researchers studied the effects of two scents – the pleasurable peppermint and offensive pyridine – on six participants in their early 20s.

Over two nights, participants wore an elastic chinstrap to encourage nose breathing. Researchers presented odors through a tube attached to an air-dilution device. The odors were tested during moderately deep Stage Two sleep, deep Stage Four sleep and REM (rapid eye movement) sleep.

No one responded to peppermint during sleep. Responses to the intense and noxious pyridine were infrequent and did not wake any participants in the deepest stage of sleep. Pyridine is a component of coal tar and used as a herbicide for firewood, and thus a likely byproduct of many real fires, according to the authors.

However, sound woke the participants regardless of the sleep stage. A moderately loud auditory tone produced arousal from sleep virtually every time the scents did not.

Most odors stimulate people’s trigeminal nerve to some degree, which is relevant to detection of the scent. Both odors used in the study were of comparable trigeminal strength even though one was pleasant and the other aversive at high concentrations.

“As the saying goes,” said the paper’s co-author Mary A. Carskadon, “we ‘wake up and smell the coffee,’ not the other way around.” Carksadon is a professor of psychiatry and human behavior in the Brown Medical School and director of chronobiology at E.P. Bradley Hospital.

The research was supported by a Grass Foundation Trustee Grant and approved by the Institutional Review Board of the E.P. Bradley Hospital.

Kristen Cole | Brown University
Further information:

More articles from Studies and Analyses:

nachricht Diagnoses: When Are Several Opinions Better Than One?
19.07.2016 | Max-Planck-Institut für Bildungsforschung

nachricht High in calories and low in nutrients when adolescents share pictures of food online
07.04.2016 | University of Gothenburg

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Ice shelf vibrations cause unusual waves in Antarctic atmosphere

25.10.2016 | Earth Sciences

Fluorescent holography: Upending the world of biological imaging

25.10.2016 | Power and Electrical Engineering

Etching Microstructures with Lasers

25.10.2016 | Process Engineering

More VideoLinks >>>