Emotions and mood changes form a part of our daily life experience; Emotions change under different circumstances and color our perception of the world. When the person is in a happy mood, the world around appear beautiful and satisfying. But the same world is perceived as very disturbing when the person is in a bad mood. Leuba and Lucas (1945) conducted a experiment to see the impact of mood on perception. Subjects were hypnotize and suggested to be either in a happy mood, critical mood, or in an anxious mood. Then pictures were shown to them. It was found that the perception of these men varied according to their moods.
McGinnis (1949) presented his subjects with a set of words, some of which were neutral in affect and some were taboo or anxiety provoking word Identification thresholds were measured by increasing the exposure duration of a word until the subject correctly read it out. At the same time, their galvanic skin responses were also measured. It was observed that the taboo wore had higher thresholds than the neutral words; during the pre-identification trial the subjects gave higher galvanic skin responses to the taboo words than the neutral words.