Injury to the right frontal and left temporo-parietal areas can cause Fregoli syndrome. Research by Feinberg, et al. has shown that significant deficits in executive and memory functions follow shortly after damage in the right frontal or left temporoparietal areas. Tests performed on patients that have suffered from a brain injury revealed that basic attention ability and visuomotor processing speed are typically normal. However, these patients made many errors when they were called to participate in detailed attention tasks. Selective attention tests involving auditory targets were also performed, and brain-injured patients had many errors; this meant that they were deficient in their response regulation and inhibition.