Wei Chen
Department of Psychology, Shaoxing University
Chun–Lei Shen
School of Rehabilitation Science,Shanghai University of Traditional Chinese Medicine
Ti–Fei Yuan
The Center for Brain Cognitive Experiment and Theory Research,Nanjing Normal University
Alien hand syndrome (AHS) represents a remarkable neuropsychiatric disorder. According to phenomenological psychopathology, one of the patient’s hands displays purposeful, coordinated behavior or posture as if it has “a will of its own,” with contrasting behavior that opposes or interferes with motor activities in the other hand. The patient therefore experiences “estranged body” feelings and loses their sense of bodily ownership. At present, it has been suggested that imbalance within the medial and lateral systems, the isolation and dysfunction of internal and external driving systems,and body-neuromatrix distortion could be among the leading causes of AHS. Both precuneus as well as the IFG may be regarded as neural correlates of alien hand movements. Additionally, effective therapeutic approaches including behavioral rehabilitation training, medical treatment, and physical therapy have been developed to counter AHS. The present paper summarizes recent advances in both basic knowledge and clinical interventions for AHS. In closing, we propose that future studies should focus on the construction of a standard symptom assessment system, the achievement of the reciprocal constraints of the first person and third person methods, and the design of experiments that induce alien hand experiences in normal subjects that will help to further understand the mechanisms of AHS.
Keywords: alien hand syndrome, phenomenological psychopathology, sense of ownership, dualpremotor system, internal and external driven systems, body matrix, body schema