From Congo:
Peter Elliot's difficulties began on the morning of February 2, 1979. Amy lived in a mobile home on the Berkeley campus; she spent nights there alone, and usually provided an effusive greeting the next day. However, on that morning the Project Amy staff found her in an uncharacteristic sullen mood; she was irritable and bleary-eyed, behaving as if she had been wronged in some fashion.

Elliot felt that something had upset her during the night. When asked, she kept making signs for "sleep box," a new word pairing he did not understand. That in itself was not unusual; Amy made up new word pairings all the time, and they were often hard to decipher. Just a few days before, she had bewildered them by talking about "crocodile milk." Eventually, they realized that Amy's milk had gone sour, and that since she disliked crocodiles (which she had only seen in picture books), she somehow decided that sour milk was "crocodile milk."

Now she was talking about "sleep box". At first they though she might be referring to her nestlike bed. It turned out she was using "box" in her usual sense, to refer to the television set.

Everything in her trailer, including the television, was controlled on a twenty-four hour cycle by the computer. They ran a check to see if the television had been turned on during the night, disturbing her sleep. Since Amy like to watch television, it was conceivable that she had managed to turn it on herself. But Amy looked scornful as they examined the actual television in the trailer. She clearly meant something else.

Finally, they determined that by "sleep box" she meant "sleep pictures." When asked about these sleep pictures, Amy signed that they were "bad pictures" and "old pictures" and that they "make Amy cry."

She was dreaming.