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Plateau’s spiral

a stimulus used to create a vivid motion aftereffect, consisting of a black and white spiral rotated around its central point. Depending on the direction of rotation, the spiral will appear to expand or contract when steadily viewed while it is rotating. However, when the spiral is stopped, it will appear to move in the opposite direction, producing a perception of expansion or contraction. Moreover, the illusory expansion or contraction will apply to any other stationary object viewed immediately after stopping the spiral. [Joseph Antoine Ferdinand Plateau (1801–1883), Belgian physicist]

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Psychology term of the day

January 3rd 2025

politeness

politeness

n. the process by which a speaker attempts to avoid harm to a listener’s public image or private self-concept through the use of nonthreatening or face-saving forms of speech. Politeness involves steering clear of content or forms of language that might embarrass listeners, make them feel uncomfortable, or lessen their self-respect. It also involves actively using language that maintains or enhances the listener’s dignity, prestige, and autonomy. For example, a speaker might preface the request for a favor by saying, “I’m sorry to bother you, and feel free to say no, but I wonder if you would. . . .” Politeness is one aspect of facework.