Mad Cow And Alzheimer’s Have Surprising Link : NPR. If this research showing a link between prion proteins and the deleterious effects of beta-amyloid plaques in rat brains holds true in humans, it has huge implications for finding a cure for Alzheimer’s disease. That would be as big as the polio vaccine or eradicating small pox. This is some research that is worth watching closely.
Aphasia Syndromes
Aphasia is an acquired disorder of language. It can manifest in various ways, including difficulty speaking or difficulty understanding speech or language. Stroke is the most common cause of aphasia with up to 40% of stroke patients experiencing some sort of aphasia. Depending on the nature of the injury (e.g., stroke, tumor, trauma), aphaisa can be temporary or permanent. Even in cases of severe stroke, some types and aspects of aphasia are treatable, with language improving over time. While language does not usually return to pre-morbid functional levels, many people with aphasia benefit greatly from speech therapy.
The following videos demonstrate two different types of aphasia – Broca’s aphasia (or non-fluent) and Wernicke’s aphasia (or fluent). Notice the differences between the aphasias.
Here is a patient with Broca’s aphasia.
Here is a patient with Wernicke’s aphasia.
At INS
I’m at INS (the annual conference of the International Neuropsychological Society) in Atlanta so I won’t be updating the blog until next week.
PBS Frontline Explores Parkinson’s Disease
Here is the video PBS recently made about Parkinson’s disease called My Father, My Brother, and Me. From what I’ve watched so far, it’s done a good job putting a face to Parkinson’s disease while also focusing on the research and clinical aspects of it.
Hypothesis Testing in Psychology Research
Hypothesis testing first starts with theory. Theories are particular assumptions about the way things are. After a theory is formulated, a conceptual hypothesis is created, which is a more specific (than pure theory) prediction about the outcome of something. Next an experimental hypothesis is created. This is where definitions are operationalized so specific matters can be tested. For example, you could operationalize affection as number of hugs and kisses and other related actions. Then you statistically hypothesize in order to measure and test one of two hypotheses: the null, or H0, which represents non-effect (i.e. no difference between samples or populations, or whatever was tested), and an alternate hypothesis, H1.
The alternate hypothesis is that there is a difference, or an effect. It can be that one mean is greater than another, or that they are just not equal. So, the purpose of statistical testing is to test the truth of a theory or part of a theory. In other words, it is a way to look at predictions to see if they are accurate. To do this, researchers test the null hypothesis. We do not test the alternate hypothesis (which is what we think will happen). We do this because we base our testing on falsification logic (i.e., it only takes one example to prove a theory is wrong but conversely you cannot prove that a theory is right without infinite examples, so we look for examples where we are wrong).
The probability associated with a statistical test is assigned to the possibility of the occurrence of Type I error. This is the probability that you will reject the null hypothesis when in fact the null is true and thus should not have been rejected. It is saying there was an effect or a difference when there really was not.
The process of statistical testing can result in probability statements about the theories under consideration but only under certain conditions. Statistical testing and hypothesizing is representative of theory when it is conceptually (verbally and operationally) connected to theory. This means that there has to be a logical and direct association between the statistical probability statements and the theory in order for those statements to represent the overarching theory. This link is forged by the experimental and conceptual hypotheses.