I have watched to new episode of Scishow on that scientists added 3 new senses (Thermoception, Proprioception and Equilibrioception) to our 5 sense list, and was wondering what makes a 'sense'?

Wiki definition:

A sense is a physiological capacity of organisms that provides data for perception.

Does that mean fatigue (feeling tired) is a sense too?

  • $\begingroup$ Well, some guys consider we have as many as 21 senses. I don't think tiredness can be considered a sense, it can be partial inhibition of all senses. You might want to read my answer to know more about tiredness. $\endgroup$ Sep 23 '16 at 16:29
  • $\begingroup$ I would think "fatigue" is a state, which the other sense alert you to due changes away from homeostasis $\endgroup$
    – SciEnt
    Sep 23 '16 at 18:48
  • $\begingroup$ @another'Homosapien' beside that-21 with known-receptors ; I think as the "feel"s of "joy", "sorrow", "fear" etc as specific, clear-cut fundamental senses (not mere some mixture of other senses), and on same way, "time", "space", "number", "shapes" etc. Also Wikipedia have articles on "time perception" (en.wikipedia.org/wiki/Time#Time_perception and en.wikipedia.org/wiki/Time_perception). $\endgroup$ Sep 24 '16 at 13:29
  • $\begingroup$ I feel many sort of fatigue. For say after running or such physical task I feel a mixture of "Pain+Heat+partial inhibition of mental activity (But not sleepy)". After cramming a long dull text I feel very sleepy. After performing a big arithmetic calculation I feel some inhibition of mental activity (but not sleepy) + some pain in eye, neck and various part in head. After end-part of a long tour-program I feel a mixture of Lack-of-appetite+anxiety+sleepiness. After a sleepless night beside a hospital, I feel vomit + increased level of alertness + No sleep. $\endgroup$ Sep 24 '16 at 13:47

To me, the defining characteristic of a sense is that it assimilates information from the external environment for your body to use if necessary. This is also the way the textbooks I've taught from treat it. Thermoception senses external temperature, your body evaluates and, if need be, you take action. Equilibroception senses gravity to help you evaluate your orientation with respect to the Earth.

Proprioception is a hard one to categorize. Some of what is classified as such seem to rely on only internal sensors such as how much a muscle is stretched. Other aspects of proprioception rely on muscle tension which would indeed be affected by gravity and qualify proprioception as a sense by this definition.

I would say fatigue is not a sense because it is based on internal messages. How about a "sense of hunger"? I'd again say no, hunger is also the result of internal messages. Your sense of smell can lead to hunger but the information gathered was odor, not hunger.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.