The decrease in responsiveness that follows
continuous stimulation (adaptation) is common to all
sensory systems, including olfaction. With continued
exposure to chronically present ambient odors,
individuals’ perception of odor intensity is greatly
reduced. Moreover, these perceptual changes can be
profound and durable. It is commonly reported that
following extended absences from the odorous
environment, reexposure may still fail to elicit
perception at the original intensity.
Most research on olfactory adaptation examines
relatively transient changes in stimulus detection or
perceived intensity—rarely exceeding several hours
and often less—but because olfactory adaptation can
be produced with relatively short exposures, these
durations are sufficient for investigating many
parameters of the phenomenon. However, exposures
to odors in natural environments often occur over far
longer periods, and the resulting adaptations may
differ qualitatively from short-term olfactory
adaptation. For example, studies show that even brief
periods of odorant stimulation produce transient
reductions in receptors in the olfactory epithelium, a
process termed “receptor fatigue.” Prolonged odor
stimulation, however, could produce more
long-lasting reductions in response, possibly
involving structures higher in the central nervous
system pathway.The passage asserts which of the following about the exposures involved in the “research on olfactory adaptation” (line 11)?The exposures are of long enough duration for researchers to investigate many aspects of olfactory adaptation.,
The exposures have rarely consisted of reexposures following extended absences from the odorous environment.,
The exposures are intended to reproduce the relatively transient olfactory changes typical of exposures to odors in natural environments.,
Those exposures of relatively short duration are often insufficient to produce the phenomenon of receptor fatigue in study subjects.,
Those exposures lasting several hours produce reductions in receptors in the olfactory epithelium that are similar to the reductions caused by prolonged odor stimulation.
2 Explanations
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jahnavi jha
Can you kindly explain why is "C" wrong as it tells as that the study is intending to produce effects typical of what is seen in natural environment.
"Most research on olfactory adaptation examines relatively transient changes in stimulus detection or perceived intensity—rarely exceeding several hours and often less (.....). However, exposures to odors in natural environments often occur over far longer periods, and the resulting adaptations may differ qualitatively from short-term olfactory adaptation."
Ok, so we are told that when research is done on olfactory adaptation, it looks at changes that take place over a few hours. And we are told that in natural environments, exposures to odors happen over much longer periods.
Therefore, the exposures to odors that take place in a research setting are not really trying to "reproduce the relatively transient olfactory changes typical of exposures to odors in natural environments." That's because in natural environments, it's not typical (or common) to have olfactory changes over short periods of time. It's more typical to have changes over long periods of time (for example, a person who lives by the sea gets used to the salty smell of the sea).
2 Explanations