Editing Positronic brain (section)

==Conceptual overview==
Asimov remained vague about the technical details of positronic brains except to assert that their substructure was formed from an alloy of [[platinum]] and [[iridium]]. They were said to be vulnerable to radiation and apparently involve a type of [[volatile memory]] (since robots in storage required a power source keeping their brains "alive"). The focus of Asimov's stories was directed more toward the [[software]] of robots—such as the [[Three Laws of Robotics]]—than the hardware in which it was implemented, although it is stated in his stories that to create a positronic brain without the Three Laws, it would have been necessary to spend years redesigning the fundamental approach toward the brain itself.<ref>{{Cite book |last=Asimov |first=Isaac |title=The Complete Robot |publisher=Harper Collins |year=1982 |isbn=9780586057247 |edition=1993 |location=Harper Collins Manufacturing Glasgow |pages=171 |language=en}}</ref>

Within his stories of [[robotics]] on [[Earth]] and their development by [[U.S. Robots and Mechanical Men|U.S. Robots]], Asimov's positronic brain is less of a [[plot device]] and more of a technological item worthy of study.{{Citation needed|date=December 2023}}

A positronic brain cannot ordinarily be built without incorporating the Three Laws; any modification thereof would drastically modify robot behavior. Behavioral dilemmas resulting from conflicting potentials set by inexperienced and/or malicious users of the robot for the Three Laws make up the bulk of Asimov's stories concerning robots. They are resolved by applying the [[science]] of logic and [[psychology]] together with [[mathematics]], the supreme solution finder being [[Susan Calvin|Dr. Susan Calvin]], Chief [[Robopsychology|Robopsychologist]] of U.S. Robots.

The Three Laws are also a [[wikt:bottleneck|bottleneck]] in brain sophistication. Very complex brains designed to handle world economy interpret the First Law in an expanded sense to include humanity as opposed to a single human; in Asimov's later works like ''[[Robots and Empire]]'' this is referred to as the "[[Zeroth law of robotics|Zeroth Law]]". At least one brain constructed as a calculating [[machine]], as opposed to being a robot control circuit, was designed to have a flexible, childlike personality so that it was able to pursue difficult problems without the Three Laws inhibiting it completely. Specialized brains created for overseeing world economics were stated to have no personality at all.

Under specific conditions, the Three Laws can be obviated, with the modification of the actual robotic design.
* Robots that are of low enough value can have the Third Law deleted; they do not have to protect themselves from harm, and the brain size can be reduced by half.{{Citation needed|date=September 2019}}
* Robots that do not require orders from a human being may have the Second Law deleted, and therefore require smaller brains again, providing they do not require the Third Law.{{Citation needed|date=September 2019}}
* Robots that are disposable, cannot receive orders from a human being and are not able to harm a human, will not require even the First Law. The sophistication of positronic circuitry renders a brain so small that it could comfortably fit within the skull of an insect.{{Citation needed|date=September 2019}}

Robots of the last type directly parallel contemporary industrial robotics practice, though real-life robots do contain safety sensors and systems (a weak form of the First Law; the robot is a safe tool to use, but has no "judgment", which is implicit in Asimov's own stories).