STUDY RATIONALE Dream research, unlike sleep research, has not greatly developed anymore as there are few dream research laboratories only and not much systematic dream research is done outside the laboratory either(1) although validated methods of collecting and analyzing dream reports on the basis of the coding system developed by Calvin S. Hall and Robert Van de Castle are readily available.(2) According to Domhoff et al.,(3) the main features of the default dream network include the medial prefrontal cortex, the medial temporal lobe, the bilateral inferior parietal lobule/temporoparietal junction, and the posterior cingulate cortex, with the medial pre- frontal cortex and the posterior cingulate cortex serving as major hubs. The dorsal medial subsystem including the dorsomedial prefrontal cortex, the temporoparietal junction/anterior inferior parietal lobule, the lateral temporal cortex, and temporopolar cortex (the anterior pole of the temporal lobe) is activated by instructions to think about the present situation or a present mental state (''present self'').(3) The medial temporal subsystem including the ventral medial prefrontal cortex, posterior inferior parietal lobule, retrosplenial cortex, parahippocampal cortex, and hippocampal formation is activated by thinking about personal situations and decisions in the future (''future self'').(3) A lot of what is known about the neuronal function of dreaming comes from lesion studies that are well-summarized by Solms.(4) To the best knowledge, investigators are the first to prospectively investigate the change of dream content in patients electively undergoing surgical resection of brain tissue (i.e. the anterior temporal lobe for temporal lobe epilepsy).