Scientists Identify Brain's Concept Control Core

Van Cutter Romney writes "Scientists have identified the part of the brain which matches words to objects. While scanning brains from people who suffer from Semantic Dementia they have found that the front end of the temporal lobe seems to be crucial to conceptual application. A better understanding on how this part of the brain works can help develop therapies to counteract Semantic Dementia — the second most common form of dementia after Alzheimer's disease."

Comments

Semantic what?

[UbuntuDupe]

It would have been nice for a link to describe what Semantic Dementia is so we could get some background info. At least link to wikipedia's article about it. Unfortunately, it's very sparse, but does reveal what I wanted to know:

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Signs and Symptoms

SD patients often present with the complaint of word-finding difficulties. On further questioning, patients often appear to have lost the meaning of certain words (e.g. asking "What is a fish?"). As the disease progresses, behavioural and personality changes are often seen similar to those seen in frontotemporal dementia although cases have been described of 'pure' semantic dementia with few late behavioural symptoms.

Neuropsychology

Patients perform poorly on tests of semantic knowledge. Published tests include both verbal and non-verbal tasks e.g. The Warrington concrete and abstract word synonym test (Warrington EK, McKenna P, Orpwood L. Single word comprehension: a concrete and abstract word synonym test. Neuropsychological Rehabilitation 1998; 8: 143-154.) and The Pyramids and Palm Trees task (Howard and Patterson, 1992)

Testing will also reveal deficits in picture naming (with semantic errors being made e.g. "dog" for a picture of a hippopotamus) and category fluency (e.g. "Please list as many animals as you can in one minute").

Re:I think they've got it!

[Zenaku]

Different functions. Broca's area deals more with parsing grammar. What is a noun and what is a verb, word order, etc. It encodes the thought you want to communicate (or decodes the thought being commicated to you) from the brains inner "mentalese" language, into the grammatically correct sentence structure of whatever language you speak. But it doesn't deal with the semantic meaning of the words. If I say to you "The groglent fumbershun melloped into the borsk." you can tell that the sentance is grammatical, and can probably identify the nouns, verbs and adverbs. But the words don't mean anything.

Imagine that the dictionary in your brain comes in three volumes, and every word you know appears in each volume. Volume 1 only contains the pronunciation of the word. Volume 2 only contains its part of speech. And Volume 3 only contains the definition.