1.   Our mood states often seem disconnected from events, or disproportionate to them.

2.   Short-term memory is especially sensitive to the effects of prolonged impaired mood states.

3.   The scientists then used the responses to rate the participants using a negative affect scale, which describes unpleasant mood states.

4.   But the positive and negative mood states -- induced respectively by the comedy and the stress documentary -- of the other two groups affected their performance adversely.