“Therefore, could you please tell us who you are?”

The empty feeling had returned full force. “I wish I could,” Derec said hoarsely. “Stars, how I wish I could.”

Chapter 14. Kate

“How interesting!” Dr. Galen exclaimed. “Do you mean to say that you have no personal memories whatsoever?”

Derec repeated the now familiar litany of events which began with his waking in the survival capsule. Partly because he was growing weary of the tale himself and partly to minimize questions, he glossed over some of the details, including the fact that the raider had been screwed by aliens.

“I will have to amend your chart to reflect this state of retrograde amnesia,” Dr. Galen said when Derec was through. “This is a much more fascinating problem than your other injuries. As a matter of fact, amnesia is a hobby of mine.”

“What do you mean, a hobby?”

“Perhaps I should say specialty, but that does not convey the deep intellectual satisfaction it gives me.”

“How many cases have you treated?”

“You will be my first,” Dr, Galen said. “I am tremendously pleased by the opportunity.”

“Your first?” Derec said, incredulous. “How can you call yourself a specialist, then? And what do you mean saying that you’re ‘fascinated’ or ‘pleased’? You’re not programmed to experience emotion.”

“Strictly speaking, that is correct,” Dr. Galen agreed. “But the concept of losing one’s sense of identity has always created the kind of positive positronic state which I associate with the termfascination. You see, due to the memory structure of the positronic brain, it is quite impossible for a robot to forget anything, least of all its own identity. Amnesia represents a state for which robot experience offers no analogue.”

“The lure of the unknown.”

“Diagnostic robots such as myself are constructed with a reinforced curiosity integral,” Dr. Galen said. “Perhaps that is a contributing factor.”

Derec felt as though he were being lectured in his own specialty. “But positronic brains go south all the time,” he protested. “They’re vulnerable to hard radiation, to glitches in the power supply-lots of things can go wrong.”

“That is correct, Derec. But those conditions you describe would result in mental shutdown, and in some instances the complete destruction of the positronic brain. However, humans are frequently able to continue to function with such a major system failure. That is what I find fascinating. Beyond that, I believe that robots have much to contribute to the investigation of human brain function, including memory defects.”

“Why is that?”

“I note that many human philosophers have recognized that the search for self-knowledge is the hardest search of all. It is extremely difficult for the human brain to contemplate and analyze the human brain. Its limitations make it impossible to see its limitations.”

Derec found himself in agreement with the robot. “The only thing a camera can’t see is itself. The only thing a ruler can’t measure is itself.”

“Quite. Questions of human brain functions have therefore been the slowest to yield to investigation by human researchers. Many aspects of human behavior are still puzzles despite centuries of neurological and biochemical studies.”

“So what do you thinkyou can do?”

Dr. Galen spread his hands wide. “Positronic brains were not developed by copying how human brains function. They were developed by copying how human beings behave. Therefore, though the positronic brain is the product of the human brain, it represents a distinct form of intelligence and a different perspective.”

“Are you saying that positronic brains are more capable than human brains?”

“The key is that a robot does what it does differently than a human brain,” Dr. Galen said diplomatically. “I am convinced that it is an invention of the human brain which will eventually unlock the secrets of the human brain. So I am pleased to have the opportunity to do more than study and speculate.”

Derec shook his head. “Forget it. I don’t want to be a lab animal.”

“Forgive me,” Dr. Galen said. “In my enthusiasm I neglected to make clear that my primary interest is to help you. There are tests which I can perform to determine the cause of your condition. Depending on the cause, there may be measures which can be taken to reverse your condition.”

“Do you mean you can bring my memory back?”

“I will not know the likelihood of that until I have examined you.”

Derec regarded the promise of a magic cure with skepticism. “Look, I’m not going to be here very long,” he said. “Let’s not start something we won’t have time to finish.”

“I do not understand.”

“You said that ships call here every two months. If I’ve been here six weeks, my ride out of here should show up in two weeks-probably less.”

“No, Derec,” Dr. Galen corrected. “Fariiscame and went while you were recovering. The next vessel, theHeritage, is due in six weeks, three days.”

Derec stared. “A ship’s already been here? Then why am I still here?” he demanded.

“This station’s medical facilities are superior to those on boardFariis. It was not possible to release you to them in your condition.”

Derec closed his eyes and sighed. “All right. Probe away.” His eyes opened and he struggled to a seated position. “But I want to know what you’re doing before you do it, do you hear?”

“Thank you, Derec,” Dr. Galen said politely. “What do you know of amnesia?”

“Just what I see on the hypervision.”

“That is unfortunate,” Dr. Galen said.

“It’s just a saying. Actually, I don’t even remember that.”

“That is just as well,” Dr. Galen replied. “Amnesia has been used as a convenient device in fiction for centuries, usually in defiance of known facts. A common plot is for a victim to suffer a blow to the head, forget everything and everyone and begin leading a new life, then be restored in the closing scene by another blow.”

“That does sound sort of familiar. Maybe I have seen one or two like that,” Derec admitted.

“Please do your best to forget them,” Dr. Galen said disapprovingly. “They will only hinder understanding.”

Over the next three days, Derec learned a great deal about amnesia. He had had no idea how many kinds of amnesia there were and how many different causes had been identified. Under other circumstances, it would have been more than he wanted to know. But since he was personally affected, he avidly absorbed everything Dr. Galen told him.

Amnesia could affect the past (retrograde) or the present (anterograde). It could have physical causes (organic) or emotional ones (psychogenic). Some amnesiacs were unable to remember anything for more than a few seconds, while others would forget everything for only a few seconds at a time. Some victims knew that they were having difficulty, while others passionately denied it.

Nine out of every ten cases of amnesia, Derec learned, had some specific physical cause. Those causes were as different as inflammation of the whorled and folded outer layer of the brain, hardening of the cerebral arteries, electric shock, and deficiency of B vitamins. (Also on the list, but nowhere near the top, was a blow to the head.)

“In more primitive times, many cases of true organic amnesia were wrongly diagnosed as psychogenic,” Dr. Galen said as though outraged by the fact. “Patients who needed drugs or surgery were offered hypnosis and psychotherapy.”

“Maybe all amnesias have some physical cause,” Derec suggested. “Maybe the ten percent we still think are psychogenic are the ones we just haven’t found the organic cause for.”

But Dr. Galen dissented. “The distinction between mind and brain has not been completely erased by medical science. The mind is more than the sum of the brain’s parts. There are things that happen at that level of synergy which cannot be traced to specific physical events.”