title: Fictitious inhibitory differences: how skewness and slowing distort the estimation of stopping latencies.
abstract: The stop-signal paradigm is a popular method for examining response inhibition and impulse control in psychology, cognitive neuroscience, and clinical domains because it allows the estimation of the covert latency of the stop process: the stop-signal reaction time (SSRT). In three sets of simulations, we examined to what extent SSRTs that were estimated with the popular mean and integration methods were influenced by the skew of the reaction time distribution and the gradual slowing of the response latencies. We found that the mean method consistently overestimated SSRT. The integration method tended to underestimate SSRT when response latencies gradually increased. This underestimation bias was absent when SSRTs were estimated with the integration method for smaller blocks of trials. Thus, skewing and response slowing can lead to spurious inhibitory differences. We recommend that the mean method of estimating SSRT be abandoned in favor of the integration method.
authors: Department of Psychology, College of Life and Environmental Sciences, Washington Singer Laboratories, Streatham Campus, Exeter, EX4 4QG, United Kingdom. f.l.j.verbruggen@exeter.ac.uk
authors: Frederick
authors: F
authors: Verbruggen
authors: Christopher D
authors: CD
authors: Chambers
authors: Gordon D
authors: GD
authors: Logan
mesh_terms: D003198:Computer Simulation / Q000706:statistics & numerical data; D006801:Humans; D007266:Inhibition, Psychological; D008960:Models, Psychological; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology*
references: Psychol Rev. 2014 Jan;121(1):66-95
references: 24490789
references: Neurosci Biobehav Rev. 2009 May;33(5):631-46
references: 18835296
references: J Exp Psychol Learn Mem Cogn. 2011 Mar;37(2):392-404
references: 21171806
references: Neuropsychology. 2011 Jul;25(4):427-441
references: 21463041
references: Front Psychol. 2012 Feb 21;3:37
references: 22363308
references: J Exp Psychol Gen. 2007 Aug;136(3):414-29
references: 17696691
references: Trends Cogn Sci. 2008 Nov;12(11):418-24
references: 18799345
references: Biol Psychiatry. 2011 Jun 15;69(12):e55-68
references: 20932513
references: Neurosci Biobehav Rev. 2009 May;33(5):647-61
references: 18822313
references: Dev Psychol. 1999 Jan;35(1):205-13
references: 9923475
references: Behav Brain Res. 2012 Apr 1;229(1):123-30
references: 22245527
references: Biol Psychiatry. 2006 Nov 15;60(10):1088-97
references: 16806097
references: Acta Psychol (Amst). 2003 Feb;112(2):105-42
references: 12521663
references: J Exp Psychol Hum Percept Perform. 2009 Jun;35(3):835-54
references: 19485695
references: Behav Res Methods. 2008 May;40(2):479-83
references: 18522058
references: Acta Psychol (Amst). 2004 May;116(1):21-37
references: 15111228
references: Acta Psychol (Amst). 2000 May;104(2):167-90
references: 10900704
references: J Exp Psychol Hum Percept Perform. 2008 Apr;34(2):413-26
references: 18377179
references: Behav Brain Res. 1998 Jul;94(1):33-43
references: 9708837
references: Psychol Bull. 1993 Nov;114(3):510-32
references: 8272468
references: J Abnorm Psychol. 2005 May;114(2):216-22
references: 15869352
references: Psychol Bull. 1979 May;86(3):446-61
references: 451109
references: Hum Brain Mapp. 2013 Sep;34(9):2015-24
references: 22359406
references: J Exp Psychol Hum Percept Perform. 2010 Apr;36(2):430-47
references: 20364928
references: J Cogn Neurosci. 2010 Jul;22(7):1479-92
references: 19583473