Anatomical Correlates of the "Closing-In" Phenomenon

The “closing-in” phenomenon is defined as a tendency to draw objects as closely as possible or overlap the figures in severe cases.1 It was first described by Mayer-Gross.2 Since then, this phenomenon has been reported in patients with various brain lesions and in normal children.3-5 It frequently occurs in patients with Alzheimer’s disease (AD) and is considered a specific neurocognitive indicator of AD.1,6 Little is known about the mechanisms by which the closingin phenomenon occurs. However, several hypotheses have been proposed to explain the pathophysiology of the closingin phenomenon. Mayer-Gross2 described the phenomenon as an aspect of constructional apraxia that reflects “the fear of empty space”. In addition, de Ajuriaguerra et al.4 described the closAnatomical Correlates of the “Closing-In” Phenomenon