PMC:4620161 / 29297-30718 JSONTXT

{"target":"http://pubannotation.org/docs/sourcedb/PMC/sourceid/4620161","sourcedb":"PMC","sourceid":"4620161","source_url":"https://www.ncbi.nlm.nih.gov/pmc/4620161","text":"Area-under-the-curve (AUC)\nThe multiple estimates associated with the multiple basis functions can be reduced to a single value, which is the area under the curve of the estimated response function. The AUC hypotheses for the two prototypes (2a) and (2b) become (4a) H01AUC:∑j=1mαj = 0, (4b) H02AUC:∑j=1mα1j = ∑j=1mα2j.\nThat is, the sum of the m coefficients (or area under the HDR curve) is used to summarize the overall response amplitude per subject in one- or two-sample t-test at the group level. The AUC hypotheses (4a) and (4b) are essentially a zero-way interaction (or intercept) and a one-way interaction (or the main effect of Group or Condition) respectively and can be performed under the AN(C)OVA, GLM, or MVM framework. Their geometrical interpretations are as follows (cf. Table 1). The data for H01AUC lie on an ℝm−1 isosurface (or hyperplane) α1 + … + αm = c, and the associated test for AUC (4a) is executed on the distance between the data isosurface and the null isosurface α1 + … + αm = 0. As the correct null hypothesis for MVT (2a) is only a subset of AUC (4a), the rejection domain of AUC (4a) is only a subset of the rejection domain for MVT (2a), leading to a misrepresentation in (4a) and a detection failure when a data point lies on α1 + … + αm = 0 but not at the origin (i.e., the HDR curve has roughly equal area below and above the x-axis, e.g., a large undershoot). Similarly for H02AUC.","divisions":[{"label":"title","span":{"begin":0,"end":26}},{"label":"p","span":{"begin":27,"end":319}},{"label":"label","span":{"begin":262,"end":266}},{"label":"label","span":{"begin":287,"end":291}}],"tracks":[]}