Gottman's research has also found evidence for a process of change over time in spouses' perceptions of their relationship that results in a 'distance and isolation' cascade. At some point their spouse's negativity becomes overwhelming, unexpected, and/or intense to the degree that the spouse reaches a level of desperation such that he or she will do anything to stop the behaviour. When this point is reached a perceptual shift occurs in which the feelings of love, respect and safety are replaced by feelings of hurt, sadness, being threatened, fear and anger. Once this perceptual shift has occurred it can be very difficult to view the marriage in any other light and the likelihood of maladaptive attributions that confirm a negative view of the reasons underlying other behaviours is increased.