<unk> , a possible symptom of dopamine dysregulation syndrome (DDS), is the repetition of complex motor behaviours such as collecting or arranging objects.<unk>  is compulsive performance of repetitive, mechanical tasks, such as assembling and disassembling, collecting, or sorting household objects. The term was originally coined to describe complex prolonged, purposeless, and stereotyped behaviour in phenmetrazine and chronic amphetamine users, by Swedish forensic psychiatrist G. Rylander, in 1968. It was later described in Parkinson's disease, but mainly in cases of patients being treated with dopaminergic drugs. It has also been described in methamphetamine and cocaine users, as well as in some patients with gambling addictions, and hypersexuality. For example,<unk>  may consist of activities such as collecting pebbles and lining them up as perfectly as possible; disassembling wristwatches and putting them back together again; or conducting extended monologues devoid of context. People engaging in<unk>  find immersion in such activities comforting, even when it serves no purpose, and generally find it very frustrating to be diverted from them. They are not generally aware that there is a compulsive element, but will continue even when they have good reason to stop. Rylander describes a burglar who started<unk>  and could not stop, even though he was suffering from an increasing apprehension of being caught. Interrupting can lead to various responses, including anger or rage, sometimes to the point of violence.
Punding
Bursting
Logrolling 
Proning
Gargling
Quackery
Spooning
Death grip