Imagination is a cognitive process used in mental functioning and sometimes used in conjunction with psychological imagery. It is considered as such because it involves thinking about possibilities. The cognate term of mental imagery may be used in psychology for denoting the process of reviving in the mind recollections of objects formerly given in sense perception. Since this use of the term conflicts with that of ordinary language, some psychologists have preferred to describe this process as "" or "" or to speak of it as "reproductive" as opposed to "productive" or "constructive" imagination. Constructive imagination is further divided into voluntary imagination driven by the lateral prefrontal cortex (LPFC) and involuntary imagination (LPFC-independent), such as REM-sleep dreaming, daydreaming, hallucinations, and spontaneous insight. The voluntary types of imagination include integration of modifiers, and mental rotation. Imagined images, both novel and recalled, are seen with the "mind's eye".