Definition of "subthreshold" [subthreshold]

• Psychology Not strong enough to be perceived or to produce a response. Used of a stimulus. (adjective)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "So far, these ultralow-energy devices have operated at extremely low "subthreshold" voltages, from around 200 millivolts down to the theoretical lower limit of 36 millivolts."
• "To meet the criteria for a prodromal group, subjects need to present with what clinicians call "subthreshold" psychotic symptoms."
• "When viewed over the past 12 months, the figures were 0.4 percent for bipolar I, 0.3 percent for bipolar II, 0.8 percent for subthreshold bipolar, and 1.5 percent for the spectrum."