A tail of two sides: Artificially doubled false positive rates in neuroimaging due to the sidedness choice with t-tests.
Hum Brain Mapp
; 40(3): 1037-1043, 2019 02 15.
Article
en En
| MEDLINE
| ID: mdl-30265768
ABSTRACT
One-sided t-tests are widely used in neuroimaging data analysis. While such a test may be applicable when investigating specific regions and prior information about directionality is present, we argue here that it is often mis-applied, with severe consequences for false positive rate (FPR) control. Conceptually, a pair of one-sided t-tests conducted in tandem (e.g., to test separately for both positive and negative effects), effectively amounts to a two-sided t-test. However, replacing the two-sided test with a pair of one-sided tests without multiple comparisons correction essentially doubles the intended FPR of statements made about the same study; that is, the actual family-wise error (FWE) of results at the whole brain level would be 10% instead of the 5% intended by the researcher. Therefore, we strongly recommend that, unless otherwise explicitly justified, two-sided t-tests be applied instead of two simultaneous one-sided t-tests.
Palabras clave
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Interpretación Estadística de Datos
/
Reacciones Falso Positivas
/
Neuroimagen
Límite:
Humans
Idioma:
En
Año:
2019
Tipo del documento:
Article