When we use a mental filter, we “filter in” some of the information, while we “filter out” other types of information; we focus on one aspect and ignore the rest (this is also referred to as ‘tunnel vision’). Often, we are filtering in the negative and disregarding the positive or neutral. For example, after an enjoyable day, there is one small disagreement and we remember just that one part of the day.

When we focus on the negative parts, it is likely that we’ll keep experiencing the negative feelings that go along with it, thus distorting the truth, and often causing lots of distress.