Synaptic fusion
Synaptic fusion was one of the final steps in the android duplication process used in the ancient technology devised by the "" that was later discovered on Exo III by Doctor Roger Korby in 2261. 

The synaptic fusion process occurred during the synchronization of synthetic organs from the host body to the android body, where the mental patterns of the host were duplicated, then processed for the direct transfer of all mental characteristics, including memories, attitudes and abilities. This final step was then activated within the android through its cortex circuits. Though a viable android duplicate was then formed at that point, a further continuation of the process was capable of transferring the "very consciousness" or the "soul" of someone into the android body. 

The entire process from this technique was completed on the dying bodies of Doctor's Roger Korby and  during the early 2260s. Korby later used this same process, short of the conclusive transfer of consciousness, on James T. Kirk in 2266, during his attempt to use the  android to take over command of the . ()

By the 24th century, a seemingly identical technique was independently devised by Doctor Noonian Soong. The experimental process, described as a synaptic scanning technique was used by Soong on his dying wife, Juliana, in 2338, after they moved to Terlina III. The synaptic scanning technique allowed Soong to archive the memories of Juliana Tainer, and to then transfer her "consciousness" into a new android body. Soong was not certain that the technique would be successful, but when Juliana awoke, she fully believed that she was still a Human being. ()

Around this time, too, Doctor Ira Graves made similar progress in the field of molecular cybernetics on Gravesworld, in his attempt of "bridging the gap between man and machine."  The final result of Graves' research was reached just prior to his death in 2365. His undefined, yet fundamentally identical synaptic transfer process, allowed him the ability "to transfer the wealth of my knowledge into a computer. Before I die, I plan to transfer my great intelligence into [such a] machine." However, to Graves fortune, a distress call sent on his behalf, brought to his rescue the  and along with it the Soong-type android, Lieutenant Commander Data. 

Familiar with Noonian Soong's work, Graves successfully guessed when his apparent protégé placed Data's "off button", and afterward, Graves further transferred his mind into Data's "frame," later saying of the results, "I never imagined how much of my self I would retain. My feelings, my dreams." 

Graves personality immediately overtook Data's own personality, however, Graves was not prepared for the consequences associated with the actions he was taking from within an android body. After injuring several individuals, Graves ultimately deposited his intellect into the computer of the , and as according to Captain Jean-Luc Picard, of the transfer, "there is knowledge but no consciousness. The human equation has been lost." Meanwhile the revived Commander Data retained no recollection of the actions carried out while his body was under Graves' control. ()

See also 
Soong Method

Medical scans
Medical procedures
Computer programming