Aphasia is retrieval, not loss
After a stroke, the words are often still stored. What fails is finding and sorting them. They crowd one another, and the mouth may produce only the wrong ones, which can come out oddly funny and charming.
BioMed

Aphasia after stroke can damage access to words while leaving a person's intelligence and relationships intact.
After a stroke, the words are often still stored. What fails is finding and sorting them. They crowd one another, and the mouth may produce only the wrong ones, which can come out oddly funny and charming.
The brain has zones where input from the senses mixes with emotion, memory and resemblance. Damage to one such zone can strip language of its meaning and feeling. The same injury can also hit music's rhythm, numbers, writing, and telling left from right.
Serious brain damage need not be a fixed endpoint. Undamaged parts of the brain can take over work from wounded parts. After such an injury, the direction left open is improvement, which is a reason not to give up hope.
Revving up the brain does not by itself produce creative thinking; watchful calm works better. Good improvisation means choosing the best option rather than the first one that comes to mind.
What we call creativity is not one faculty. It is a blend of many traits, including risk-taking, perseverance, mastery of a craft, disciplined spontaneity, obsession put to use, a child's wonder in a learned adult, and resistance to the status quo.
A person with aphasia keeps a working mind but finds that everyone around them seems to speak a foreign tongue, and that no one understands what they say. The experience can be terrifying. It can feel like the end of life, not a problem with words.
When a sound arrives, the brain first decides what kind of thing it is: human speech, a syllable, a real word, or nonsense. Understanding language depends on this sorting step, which happens before any meaning is grasped.
A stroke can damage procedural memory as well as words. This is the brain's stored sense of how to go about doing things, so a person may also have to relearn the steps of familiar tasks.
Standard speech exercises can fail a person whose mind and vocabulary don't fit the template. A partner who knows the person deeply, and also understands how the brain handles language, can design a custom program around that person's own words and interests. In this book's case, this sometimes meant working in spite of the professionals, and the husband went on to write again and make puns.
When a relationship has been built on talk, losing language threatens the relationship itself, not just one person. A communication board offers a tiny fraction of what the couple once shared. The partners must invent new ways to stay close.