![]() That limitation, however, might be considered a “straw man” argument and be readily supplanted by models involving multiple dissociations. A fundamental limitation is the assumption of modularity of function, which assumes that each structure and function can be separate and dissociable ( Shallice, 1988), and that there are at most two components to differentiate from one another ( Baddeley, 2003). Sullivan, in Handbook of Clinical Neurology, 2014 Multiple dissociations and relevance to establishing network selectivityĪlthough the classic double dissociation model and its modifications provide strong evidence for selective brain structure–function relations, there are theoretic limitations to this model ( Van Orden et al., 2001 Barr and Goldberg, 2003). Because of the variability of tests within a domain, such double dissociation can only be obtained through statistical methods that equalize individual pairs of specific tests. There is a naive belief that if tests are derived from the same domain, then they are measuring the same function and thus are interchangeable. Either the raw scores are fixed or equivalent scale scores are created. Equating may be accomplished in one of two ways. This provides the same fixed difference or ratio between tests each time the tests are administered. This invariance requirement means that the test scores must be standardized so that the differences between scores will remain invariant. Although this is obvious on this elementary level, the implications for more complex assessments are often overlooked. This means that the tests in double dissociation must be invariant from one administration to another. Next, in double dissociation, for the results to be reliable, the same tests must be used for each assessment. Russell, in The Scientific Foundation of Neuropsychological Assessment, 2012 Invariance of Tests While the samples are admittedly small, the interaction between the clinical diagnosis of TS versus TS+ and the “hemi” designation is significant (Fisher exact probabilities test, P=0.04762).Įlbert W. These breakdowns are summarized in Table 15.11. ![]() ![]() Among the seven “symmetric TS”/presumably relatively bilateral frontostriatal dysfunction cases, the breakdown between the TS and TS+ diagnoses was roughly equal (four with pure TS, two with TS comorbid with ASD, and one with TS comorbid with ADHD). By contrast, of the four “left hemi-TS”/presumed right frontostriatal dysfunction cases, zero cases had the diagnosis of pure TS and all four cases had the diagnosis of TS+ (three of TS comorbid with ADHD and one of TS comorbid with ASD). Of the five “right hemi-TS”/presumed left frontostriatal dysfunction cases, four cases had the diagnosis of pure TS and one case had the diagnosis of TS+ (TS comorbid with ADHD). A double dissociation between the left hemi-TS versus right hemi-TS groups and the clinical diagnosis emerged. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |