Broca's Brain

Broca's Brain: Reflections on the Romance of Science is a 1979 book by astrophysicist Carl Sagan. Its chapters were originally articles published between 1974 and 1979 in various magazines, including Atlantic Monthly, New Republic, Physics Today, Playboy and Scientific American. In the introduction, Sagan writes:

Title

The title essay is named in honor of the French physician, anatomist and anthropologist, Paul Broca (1824–1880). He is best known for his discovery that different functions are assigned to different parts of the brain. He believed that by studying the brains of cadavers and correlating the known experiences of the former owner of the organs, human behavior could eventually be discovered and understood. To that end, he saved hundreds of human brains in jars of formalin; among the collection is his own neural organ. When Sagan finds it in Musée de l'Homme, he poses questions that challenge some core ideas of human existence such as "How much of that man known as Paul Broca can still be found in this jar?" - a question that evokes both religious and scientific argument.

Expressive aphasia

Expressive aphasia (non-fluent aphasia) is characterized by the loss of the ability to produce language (spoken or written). A person with expressive aphasia will exhibit effortful speech. Speech may only include important content words and leave out insignificant words, like "the". This is known as "telegraphic speech". The person may still be understood, but sentences will not be grammatical. In very severe forms of Expressive Aphasia, a person may only speak using single word utterances. It is one subset of a larger family of disorders known collectively as aphasia. Expressive aphasia differs from dysarthria, which is typified by a patient's inability to properly move the muscles of the tongue and mouth to produce speech. Expressive aphasia also differs from apraxia of speech which is a motor disorder characterized by an inability to create and sequence motor plans for speech. Comprehension is typically only mildly to moderately impaired in expressive aphasia due to difficulty understanding complex grammar. This contrasts with receptive aphasia, which is distinguished by a patient's inability to comprehend language or speak with appropriately meaningful words. Expressive aphasia is also known as Broca's aphasia in clinical neuropsychology and agrammatic aphasia in cognitive neuropsychology and is caused by acquired damage to the anterior regions of the brain, including (but not limited to) the left posterior inferior frontal gyrus or inferior frontal operculum, also described as Broca's area (Brodmann area 44 and Brodmann area 45) Expressive aphasia is also a symptom of some migraine attacks.