Talk:Psycholinguistics/Hemispheric Lateralization

I thoroughly enjoyed this chapter and felt like I learned a lot. I wasn’t expecting to realize how diverse lateralization can be and how many things there are that can affect it. I really liked the layout – I thought it was very organized and, for the most part, very easy to understand. However, there are a few things that I think could possibly cause a bit of confusion. These suggestions are minor but I think they could make your chapter even better!

In the introduction you state that “The hemispheric lateralization of language functions has been suggested to be associated […], and a variance amongst cultures.” By “a variance amongst cultures” I believe you mean that lateralization can be dependent on or influenced by one’s culture, but I found myself reading it over as I felt that that part of the sentence didn’t quite fit. For better flow, I would try re-wording it, or even including that fact in it’s own sentence.

With regards to Carl Wernicke, I was left wondering how the temporal lobe seems to disrupt language capabilities? It may be interesting to include if it is not too complicated. For example, predominantly, did it affect comprehension? Did it effect production? Or do we even know of a specific function affected by damage to the left temporal lobe? This information would be well suited in this section and might leave it even more complete.

Under “Split-Brain Patients” you explained a scenario of presenting a word to one hemisphere or the other. By “presented to the right hemisphere,” I just want to clarify that you mean that the word is shown on the patient’s left? It may be good to clear this up, as it might not be intuitive for all readers. However, it is a very interesting fact; I wonder if they even realize that they saw a word, and if it’s just a production issue where they say “nothing” because they cannot verbalize what they saw. From your explanation I gather that the latter is true.

I think there might have been a slight mix-up in a sentence in the “Wada test” section. I didn’t correct this because I want to be sure, but I think you may have mixed up left and right-handed people – 98% or right-handed have left dominant language, and 70% of left, correct? If so, that just needs to be switched in the last paragraph. Also in this section, I felt the sentence “It then serves to anaesthetize that side of the brain for approximately 10 minutes, after which it begins to wear off and the functions which were disrupted by the anaesthetic gradually return, often displaying aphasic errors” could be clearer. Do the aphasic errors occur when the patient is anesthetized? That would make sense to me intuitively but the sentence kind of tells me differently.

It may add to the organization to include subheadings under the umbrella heading “Electrical Stimulation, TMS and Imaging,” although this is just a thought and not absolutely necessary. I am not sure if it is necessary to have two “left” words in the sentence “Penfield found that stimulating the left frontal or temporal regions of the left hemisphere,” so thought I would bring it to your attention. Additionally, the following sentence seems to contradict the mentioned sentence; from what I gather, one sentence states that electrical stimulation accelerates speech and another inhibits or disrupts speech? Maybe I am reading it improperly, but I think it could probably be a little clearer.

In the TMS section, it may be worthwhile to give a quick explanation as to why the magnetic stimulation passing through multiple media would be an obvious drawback. For someone with no background in even a similar subject, they may not realize what this means. For example, you could add to the final sentence: “therefore is not always completely precise after traveling through so much media.” This is just a suggestion to make things that much more clear!

Finally for this section, it may be possible to improve upon the sentence under Imaging: “There has been some controversy regarding bilateral activation shown in fMRI studies […].” Would it make sense to break it up into more than one sentence, something like “However, there has been some controversy regarding bilateral activation shown in fMRI studies. It has been suggested that perhaps the right hemisphere is involved in aspects of speech that are not measured by such tests as the Wada procedure.” In my opinion, given that it still conveys your intended message, I believe this is a little easier to understand. The other sentence seemed a little long/run-on.

Lastly, I feel that a sentence under the “Culture and Lateralization” heading could be cleared up. The sentence “Asian languages show more bilateral activation during speech than European languages […] also show a good deal of bilateral activity” also seems a bit run-on and confusing by the end. I think it would provide more flow to end the sentence after explaining that Asian languages seem to depend more on the right-hemisphere. You could then say, “For example, Chinese characters are more pictorial and rely more on prosody, two aspects which emphasize use of the right hemisphere more than European languages.”

Ultimately, I learned more than expected from this chapter and honestly had a hard time finding things to improve upon. However, I believe my suggestions, though minor, would be beneficial to your chapter. I think you made great use of scholastic articles as well as textbook material and created a very thorough chapter on hemispheric lateralization that would allow anyone to learn something about the topic. If I were grading this, I would give it an A-range grade! Keep up the great work.

Grechukk 02:22, 28 February 2011 (UTC)