Shifting of tonic level, typically in response to changing conditions. For example, the adjustment of electrodermal tonic levels due to temperature changes, reduction of pulse rate between standing and reclining, and faster breathing that accompanies an increase in walking speed. Tonic responses take several seconds or minutes to occur, unlike phasic responses which tend to be very rapid. Some examiners consider changes in tonic activity as diagnostic information in Peak of Tension tests, where a change in the trend of tonic activity can signal that the critical item in the series has passed. Research evidence is lacking despite frequent anecdotal reports.
