, Volume 9, Issue 3, pp 500–508 | Cite as

Reaction Time Variability in ADHD: A Review

  • Leanne Tamm
  • Megan E. Narad
  • Tanya N. Antonini
  • Kathleen M. O’Brien
  • Larry W. HawkJr.
  • Jeffery N. Epstein


For the past decade, intra-individual variability in reaction times on computerized tasks has become a central focus of cognitive research on Attention-Deficit/Hyperactivity Disorder (ADHD). Numerous studies document increased reaction time variability among children and adults with ADHD, relative to typically developing controls. However, direct comparisons with other disorders with heightened reaction time variability are virtually nonexistent, despite their potential to inform our understanding of the phenomenon. A growing literature examines the sensitivity of reaction time variability to theoretically and clinically relevant manipulations. There is strong evidence that stimulus treatment reduces reaction time variability during a range of cognitive tasks, but the literature is mixed regarding the impact of motivational incentives and variation in stimulus event rate. Most studies of reaction time variability implicitly assume that heightened reaction time variability reflects occasional lapses in attention, and the dominant neurophysiological interpretation suggests this variability is linked to intrusions of task-negative brain network activity during task performance. Work examining the behavioral and neurophysiological correlates of reaction time variability provides some support for these hypotheses, but considerably more work is needed in this area. Finally, because conclusions from each of domains reviewed are limited by the wide range of measures used to measure reaction time variability, this review highlights the need for increased attention to the cognitive and motivational context in which variability is assessed and recommends that future work always supplement macro-level variability indices with metrics that isolate particular components of reaction time variability.


reaction time variability response variability intra-individual variability ADHD attentional processes coefficient of variation 


Required Author Forms

Disclosure forms provided by the authors are available with the online version of this article.

Supplementary material

13311_2012_138_MOESM1_ESM.pdf (511 kb)
ESM 1(PDF 510 kb)


  1. 1.
    Froehlich TE, Lanphear BP, Epstein JN, Barbaresi WJ, Katusic SK, Kahn RS. Prevalence, recognition, and treatment of attention-deficit/hyperactivity disorder in a national sample of US children. Arch Pediatr Adolesc Med 2007;161:857–864.PubMedGoogle Scholar
  2. 2.
    Nigg JT, Casey BJ. An integrative theory of attention-deficit/ hyperactivity disorder based on the cognitive and affective neurosciences. Dev Psychopathol 2005;17:785–806.PubMedGoogle Scholar
  3. 3.
    Solanto MV, Abikoff H, Sonuga-Barke E, et al. The ecological validity of delay aversion and response inhibition as measures of impulsivity in AD/HD: a supplement to the NIMH multimodal treatment study of AD/HD. J Abnorm Child Psychol 2001;29:215–228.PubMedGoogle Scholar
  4. 4.
    Willcutt EG, Doyle AE, Nigg JT, Faraone SV, Pennington BF. Validity of the executive function theory of attention-deficit/hyperactivity disorder: a meta-analytic review. Biol Psychiatry 2005;57:1336–1346.PubMedGoogle Scholar
  5. 5.
    Sonuga-Barke EJ, Sergeant JA, Nigg J, Willcutt E. Executive dysfunction and delay aversion in attention deficit hyperactivity disorder: nosologic and diagnostic implications. Child Adolesc Psychiatr Clin N Am 2008;17:367–384, ix.PubMedGoogle Scholar
  6. 6.
    Buzy WM, Medoff DR, Schweitzer JB. Intra-individual variability among children with ADHD on a working memory task: an ex-Gaussian approach. Child Neuropsychol 2009;15:441–459.PubMedGoogle Scholar
  7. 7.
    Karatekin C. A test of the integrity of the components of Baddeley's model of working memory in attention-deficit/hyperactivity disorder (ADHD). J Child Psychol Psychiatry 2004;45:912–926.PubMedGoogle Scholar
  8. 8.
    Klein RM, Castel AD, Pratt J. The effects of memory load on the time course of inhibition of return. Psychon Bull Rev 2006;13:294–299.PubMedGoogle Scholar
  9. 9.
    Johnson KA, Kelly SP, Bellgrove MA, et al. Response variability in attention deficit hyperactivity disorder: evidence for neuropsychological heterogeneity. Neuropsychologia 2007;45:630–638.PubMedGoogle Scholar
  10. 10.
    Hervey AS, Epstein JN, Curry JF, et al. Reaction time distribution analysis of neuropsychological performance in an ADHD sample. Child Neuropsychol 2006;12:125–140.PubMedGoogle Scholar
  11. 11.
    Rubia K, Russell T, Overmeyer S, et al. Mapping motor inhibition: conjunctive brain activations across different versions of go/no-go and stop tasks. Neuroimage 2001;13:250–261.PubMedGoogle Scholar
  12. 12.
    Uebel H, Albrecht B, Asherson P, et al. Performance variability, impulsivity errors and the impact of incentives as gender-independent endophenotypes for ADHD. J Child Psychol Psychiatry 2010;51:210–218.PubMedGoogle Scholar
  13. 13.
    Vaurio RG, Simmonds DJ, Mostofsky SH. Increased intra-individual reaction time variability in attention-deficit/hyperactivity disorder across response inhibition tasks with different cognitive demands. Neuropsychologia 2009;47:2389–2396.PubMedGoogle Scholar
  14. 14.
    Andreou P, Neale BM, Chen W, et al. Reaction time performance in ADHD: improvement under fast-incentive condition and familial effects. Psychol Med 2007:1–13.Google Scholar
  15. 15.
    Epstein JN, Langberg JM, Rosen PJ, et al. Evidence for higher reaction time variability for children with ADHD on a range of cognitive tasks including reward and event rate manipulations. Neuropsychology 2011;25:427–441.PubMedGoogle Scholar
  16. 16.
    Klotz JM, Johnson MD, Wu SW, Isaacs KM, Gilbert DL. Relationship between reaction time variability and motor skill development in ADHD. Child Neuropsychol 2011. doi:10.1080/09297049.2011.625356.
  17. 17.
    Desman C, Petermann F, Hampel P. Deficit in response inhibition in children with attention deficit/hyperactivity disorder (ADHD): impact of motivation? Child Neuropsychol 2008;14:483–503.PubMedGoogle Scholar
  18. 18.
    Adams ZW, Roberts WM, Milich R, Fillmore MT. Does response variability predict distractibility among adults with attention-deficit/hyperactivity disorder? Psychol Assess 2011;23:427–436.PubMedGoogle Scholar
  19. 19.
    Dhar M, Been PH, Minderaa RB, Althaus M. Information processing differences and similarities in adults with dyslexia and adults with Attention Deficit Hyperactivity Disorder during a Continuous Performance Test: a study of cortical potentials. Neuropsychologia 2010;48:3045–3056.PubMedGoogle Scholar
  20. 20.
    Verte S, Geurts HM, Roeyers H, Oosterlaan J, Sergeant JA. Executive functioning in children with autism and Tourette syndrome. Dev Psychopathol 2005;17:415–445.PubMedGoogle Scholar
  21. 21.
    Kaiser S, Roth A, Rentrop M, Friederich HC, Bender S, Weisbrod M. Intra-individual reaction time variability in schizophrenia, depression and borderline personality disorder. Brain Cogn 2008;66:73–82 [Epub 2007 Jul 2].PubMedGoogle Scholar
  22. 22.
    Bora E, Vahip S, Akdeniz F. Sustained attention deficits in manic and euthymic patients with bipolar disorder. Prog Neuropsychopharmacol Biol Psychiatry 2006;30:1097–1102.PubMedGoogle Scholar
  23. 23.
    Segalowitz SJ, Dywan J, Unsal A. Attentional factors in response time variability after traumatic brain injury: an ERP study. J Int Neuropsychol Soc 1997;3:95–107.PubMedGoogle Scholar
  24. 24.
    Stuss D, Pogue D, Buckle L, Bondar J. Characterization of stability of performance in patients with traumatic brain injury: Variability and consistency on reaction time tests. Neuropsychology 1994;8:316–324.Google Scholar
  25. 25.
    Tinius TP. The intermediate visual and auditory continuous performance test as a neuropsychological measure. Arch Clin Neuropsychol 2003;18:199–214.PubMedGoogle Scholar
  26. 26.
    Whyte J, Polansky M, Fleming M, Coslett HB, Cavallucci C. Sustained arousal and attention after traumatic brain injury. Neuropsychologia 1995;33:797–813.PubMedGoogle Scholar
  27. 27.
    Duchek JM, Balota DA, Tse CS, Holtzman DM, Fagan AM, Goate AM. The utility of intraindividual variability in selective attention tasks as an early marker for Alzheimer's disease. Neuropsychology 2009;23:746–758.PubMedGoogle Scholar
  28. 28.
    Gorus E, De Raedt R, Lambert M, Lemper JC, Mets T. Reaction times and performance variability in normal aging, mild cognitive impairment, and Alzheimer's disease. J Geriatr Psychiatry Neurol 2008;21:204–218.PubMedGoogle Scholar
  29. 29.
    Egeland J. Frequency of attention deficit in first-episode schizophrenia compared to ADHD. Appl Neuropsychol 2010;17:125–134.PubMedGoogle Scholar
  30. 30.
    Thaler NS, Allen DN, Park BS, McMurray JC, Mayfield J. Attention processing abnormalities in children with traumatic brain injury and attention-deficit/hyperactivity disorder: differential impairment of component processes. J Clin Exp Neuropsychol 2010;32:929–936.PubMedGoogle Scholar
  31. 31.
    Parasuraman R, Nestor P. Attention and driving. Assessment in elderly individuals with dementia. Clin Geriatr Med 1993;9:377–387.PubMedGoogle Scholar
  32. 32.
    Leth-Steensen C, Elbaz ZK, Douglas VI. Mean response times, variability, and skew in the responding of ADHD children: a response time distributional approach. Acta Psychol (Amst) 2000;104:167–190.Google Scholar
  33. 33.
    Epstein JN, Hwang ME, Antonini T, Langberg JM, Altaye M, Arnold LE. Examining predictors of reaction times in children with ADHD and normal controls. J Int Neuropsychol Soc 2010;16:138–147.PubMedGoogle Scholar
  34. 34.
    Toplak ME, Dockstader C, Tannock R, Toplak ME, Dockstader C, Tannock R. Temporal information processing in ADHD: findings to date and new methods. J Neurosci Methods 2006;151:15–29.PubMedGoogle Scholar
  35. 35.
    Castellanos FX, Sonuga-Barke EJ, Scheres A, Di Martino A, Hyde C, Walters JR. Varieties of attention-deficit/hyperactivity disorder-related intra-individual variability. Biol Psychiatry 2005;57:1416–1423.PubMedGoogle Scholar
  36. 36.
    Bellgrove MA, Hester R, Garavan H. The functional neuroanatomical correlates of response variability: evidence from a response inhibition task. Neuropsychologia 2004;42:1910–1916.PubMedGoogle Scholar
  37. 37.
    Kuntsi J, Oosterlaan J, Stevenson J. Psychological mechanisms in hyperactivity. I. Response inhibition deficit, working memory impairment, delay aversion, or something else? J Child Psychol Psychiatry 2001;42:199–210.Google Scholar
  38. 38.
    Scheres A, Oosterlaan J, Sergeant JA. Response execution and inhibition in children with AD/HD and other disruptive disorders: The role of behavioural activation. J Child Psychol Psychiatry Allied Discip 2001;42:347–357.PubMedGoogle Scholar
  39. 39.
    Sergeant JA, Geurts H, Huijbregts S, et al. The top and the bottom of ADHD: a neuropsychological perspective. Neurosci Biobehav Rev 2003;27:583–592.PubMedGoogle Scholar
  40. 40.
    Wagenmakers EJ, Brown S. On the linear relation between the mean and the standard deviation of a response time distribution. Psychol Rev 2007;114:830–841.PubMedGoogle Scholar
  41. 41.
    Epstein JN, Brinkman WB, Froehlich T, et al. Effects of stimulant medication, incentives, and event rate on reaction time variability in children with ADHD. Neuropsychopharmacology 2011;36:1060–1072.PubMedGoogle Scholar
  42. 42.
    Sabol KE, Richards JB, Broom SL, Roach JT, Hausknecht K. Effects of stimulus salience and methamphetamine on choice reaction time in the rat: central tendency versus distribution skew. Behav Pharmacol 2003;14:489–500.PubMedGoogle Scholar
  43. 43.
    Spencer SV, Hawk LW, Richards JB, Shiels K, Pelham WE, Waxmonsky JG. Stimulant treatment reduces lapses in attention among children with ADHD: the effects of methylphenidate on intra-individual response time distributions. J Abnorm Child Psychol 2009;37:805–816.PubMedGoogle Scholar
  44. 44.
    Williams BR, Strauss EH, Hultsch DF, Hunter MA, Tannock R. Reaction time performance in adolescents with attention deficit/hyperactivity disorder: evidence of inconsistency in the fast and slow portions of the RT distribution. J Clin Exp Neuropsychol 2007;29:277–289.PubMedGoogle Scholar
  45. 45.
    Russell VA, Oades RD, Tannock R, et al. Response variability in Attention-Deficit/Hyperactivity Disorder: A neuronal and glial energetics hypothesis. Behav Brain Funct 2006;2:30.PubMedGoogle Scholar
  46. 46.
    Di Martino A, Ghaffari M, Curchack J, et al. Decomposing intra-subject variability in children with attention-deficit/hyperactivity disorder. Biol Psychiatry 2008;64:607–614.PubMedGoogle Scholar
  47. 47.
    Huang-Pollock CL, Mikami AY, Pfiffner L, McBurnett K. ADHD subtype differences in motivational responsivity but not inhibitory control: evidence from a reward-based variation of the stop signal paradigm. J Clin Child Adolesc Psychol 2007;36:127–136.PubMedGoogle Scholar
  48. 48.
    Nigg JT. The ADHD response-inhibition deficit as measured by the stop task: replication with DSM-IV combined type, extension, and qualification. J Abnorm Child Psychol 1999;27:393–402.PubMedGoogle Scholar
  49. 49.
    Shanahan MA, Pennington BF, Willcutt EW. Do motivational incentives reduce the inhibition deficit in ADHD? Dev Neuropsychol 2008;33:137–159.PubMedGoogle Scholar
  50. 50.
    Pasini A, Paloscia C, Alessandrelli R, Porfirio MC, Curatolo P. Attention and executive functions profile in drug naive ADHD subtypes. Brain Dev 2007;29:400–408.PubMedGoogle Scholar
  51. 51.
    Solanto MV, Gilbert SN, Raj A, et al. Neurocognitive functioning in AD/HD, predominantly inattentive and combined subtypes. J Abnorm Child Psychol 2007;35:729–744.PubMedGoogle Scholar
  52. 52.
    Wahlstedt C. Neuropsychological deficits in relation to symptoms of ADHD: independent contributions and interactions. Child Neuropsychol 2009;15:262–279.PubMedGoogle Scholar
  53. 53.
    Wahlstedt C, Thorell LB, Bohlin G. Heterogeneity in ADHD: neuropsychological pathways, comorbidity and symptom domains. J Abnorm Child Psychol 2009;37:551–564.PubMedGoogle Scholar
  54. 54.
    Gomez-Guerrero L, Martin CD, Mairena MA, et al. Response-time variability is related to parent ratings of inattention, hyperactivity, and executive function. J Atten Disord 2011;15:572–582.PubMedGoogle Scholar
  55. 55.
    Epstein JN, Erkanli A, Conners CK, Klaric J, Costello JE, Angold A. Relations between Continuous Performance Test performance measures and ADHD behaviors. J Abnorm Child Psychol 2003;31:543–554.PubMedGoogle Scholar
  56. 56.
    Corkum PV, Siegel LS. Is the Continuous Performance Task a valuable research tool for use with children with Attention-Deficit-Hyperactivity Disorder? J Child Psychol Psychiatry 1993;34:1217–1239.PubMedGoogle Scholar
  57. 57.
    Rapport MD, Kofler MJ, Alderson RM, Timko TM, Jr., Dupaul GJ. Variability of attention processes in ADHD: observations from the classroom. J Atten Disord 2009;12:563–573.PubMedGoogle Scholar
  58. 58.
    Walhovd KB, Fjell AM. White matter volume predicts reaction time instability. Neuropsychologia 2007;45:2277–2284.PubMedGoogle Scholar
  59. 59.
    Murtha S, Cismaru R, Waechter R, Chertkow H. Increased variability accompanies frontal lobe damage in dementia. J Int Neuropsychol Soc 2002;8:360–372.PubMedGoogle Scholar
  60. 60.
    Stuss DT, Murphy KJ, Binns MA, Alexander MP. Staying on the job: the frontal lobes control individual performance variability. Brain 2003;126:2363–2380.PubMedGoogle Scholar
  61. 61.
    Bunce D, Anstey KJ, Christensen H, Dear K, Wen W, Sachdev P. White matter hyperintensities and within-person variability in community-dwelling adults aged 60–64 years. Neuropsychologia 2007;45:2009–2015.PubMedGoogle Scholar
  62. 62.
    Simmonds DJ, Fotedar SG, Suskauer SJ, Pekar JJ, Denckla MB, Mostofsky SH. Functional brain correlates of response time variability in children. Neuropsychologia 2007;45:2147–2157.PubMedGoogle Scholar
  63. 63.
    Yarkoni T, Barch DM, Gray JR, Conturo TE, Braver TS. BOLD correlates of trial-by-trial reaction time variability in gray and white matter: a multi-study fMRI analysis. PLoS ONE 2009;4:e4257.PubMedGoogle Scholar
  64. 64.
    Weissman DH, Warner LM, Woldorff MG. Momentary reductions of attention permit greater processing of irrelevant stimuli. Neuroimage 2009;48:609–615.PubMedGoogle Scholar
  65. 65.
    Kelly AM, Uddin LQ, Biswal BB, Castellanos FX, Milham MP. Competition between functional brain networks mediates behavioral variability. Neuroimage 2008;39:527–537.PubMedGoogle Scholar
  66. 66.
    Greicius MD, Krasnow B, Reiss AL, Menon V. Functional connectivity in the resting brain: a network analysis of the default mode hypothesis. Proc Natl Acad Sci USA 2003;100:253–258.PubMedGoogle Scholar
  67. 67.
    Raichle ME, MacLeod AM, Snyder AZ, Powers WJ, Gusnard DA, Shulman GL. A default mode of brain function. Proc Natl Acad Sci USA 2001;98:676–682.PubMedGoogle Scholar
  68. 68.
    Helps SK, Broyd SJ, James CJ, Carl A, Sonuga-Barke E. The attenuation of very low frequency brain oscillations in transitions from a rest state to active attention. J Psychophysiol 2009;23:191–198.Google Scholar
  69. 69.
    MacDonald SW, Li SC, Backman L. Neural underpinnings of within-person variability in cognitive functioning. Psychol Aging 2009;24:792–808.PubMedGoogle Scholar
  70. 70.
    Tian L, Jiang T, Liang M, et al. Enhanced resting-state brain activities in ADHD patients: a fMRI study. Brain Dev 2008;30:342–348.PubMedGoogle Scholar
  71. 71.
    Tian L, Jiang T, Wang Y, et al. Altered resting-state functional connectivity patterns of anterior cingulate cortex in adolescents with attention deficit hyperactivity disorder. Neurosci Lett 2006;400:39–43.PubMedGoogle Scholar
  72. 72.
    Uddin LQ, Kelly AM, Biswal BB, et al. Network homogeneity reveals decreased integrity of default-mode network in ADHD. J Neurosci Methods 2008;169:249–254.PubMedGoogle Scholar
  73. 73.
    Castellanos FX, Kelly C, Milham MP. The restless brain: attention-deficit hyperactivity disorder, resting-state functional connectivity, and intrasubject variability. Can J Psychiatry 2009;54:665–672.PubMedGoogle Scholar
  74. 74.
    Cao Q, Zang Y, Sun L, et al. Abnormal neural activity in children with attention deficit hyperactivity disorder: a resting-state functional magnetic resonance imaging study. Neuroreport 2006;17:1033–1036.PubMedGoogle Scholar
  75. 75.
    Castellanos FX, Margulies DS, Kelly C, et al. Cingulate-precuneus interactions: a new locus of dysfunction in adult attention-deficit/hyperactivity disorder. Biol Psychiatry 2008;63:332–337.PubMedGoogle Scholar
  76. 76.
    Fair DA, Posner J, Nagel BJ, et al. Atypical default network connectivity in youth with attention-deficit/hyperactivity disorder. Biol Psychiatry 2010;68:1084–1091.PubMedGoogle Scholar
  77. 77.
    Fassbender C, Zhang H, Buzy WM, et al. A lack of default network suppression is linked to increased distractibility in ADHD. Brain Res 2009;1273:114–128.PubMedGoogle Scholar
  78. 78.
    Bush G, Valera EM, Seidman LJ. Functional neuroimaging of attention-deficit/hyperactivity disorder: a review and suggested future directions. Biol Psychiatry 2005;57:1273–1284.PubMedGoogle Scholar
  79. 79.
    Fassbender C, Schweitzer JB. Is there evidence for neural compensation in attention deficit hyperactivity disorder? A review of the functional neuroimaging literature. Clin Psychol Rev 2006;26:445–465.PubMedGoogle Scholar
  80. 80.
    Durston S, Mulder M, Casey BJ, Ziermans T, van Engeland H. Activation in ventral prefrontal cortex is sensitive to genetic vulnerability for attention-deficit hyperactivity disorder. Biol Psychiatry 2006;60:1062–1070.PubMedGoogle Scholar
  81. 81.
    Epstein JN. A Pathophysiology of Attention Deficit Hyperactivity Disorder: Clues from Neuroimaging. In: Neuroimaging in Developmental Clinical Neuroscience. Rumsey J, Ernst M, eds. Cambridge: Cambridge University Press, 2009:113–139.Google Scholar
  82. 82.
    Suskauer SJ, Simmonds DJ, Caffo BS, Denckla MB, Pekar JJ, Mostofsky SH. fMRI of intrasubject variability in ADHD: anomalous premotor activity with prefrontal compensation. J Am Acad Child Adolesc Psychiatry 2008;47:1141–1150.PubMedGoogle Scholar
  83. 83.
    Sergeant JA. Modeling attention-deficit/hyperactivity disorder: a critical appraisal of the cognitive-energetic model. Biol Psychiatry 2005;57:1248–1255.PubMedGoogle Scholar
  84. 84.
    Sanders A. Towards a model of stress and human performance. Acta Psychol 1983;53:61–97.Google Scholar
  85. 85.
    Sonuga-Barke EJ, Wiersema JR, van der Meere JJ, Roeyers H. Context-dependent dynamic processes in Attention Deficit/Hyperactivity Disorder: Differentiating commong and unique effects of state regualtion deficits and delay aversion. Neuropsychol Rev 2010;20:86–102.PubMedGoogle Scholar
  86. 86.
    van der Meere J, Marzocchi GM, De Meo T. Response inhibition and Attention Deficit Hyperactivity Disorder with and without Oppositional Defiant Disorder screened from a community sample. Dev Neuropsychol 2005;28:459–472.PubMedGoogle Scholar
  87. 87.
    Wiersema R, van der Meere J, Roeyers H, Van Coster R, Baeyens D. Event rate and event-related potentials in ADHD. J Child Psychol Psychiatry 2006;47:560–567.PubMedGoogle Scholar
  88. 88.
    Wiersema JR, van der Meere J, Antrop I, Roeyers H. State regulation in adult ADHD: An event-related potential study. J Clin Exp Neuropsychol 2006;7:1113–1126.Google Scholar
  89. 89.
    Ryan M, Martin R, Denckla MB, Mostofsky SH, Mahone EM. Interstimulus jitter facilitates response control in children with ADHD. J Int Neuropsychol Soc 2010;16:388–393.PubMedGoogle Scholar
  90. 90.
    Slusarek M, Velling S, Bunk D, Eggers C. Motivational effects on inhibitory control in children with ADHD. J Am Acad Child Adolesc Psychiatry 2001;40:355–363.PubMedGoogle Scholar
  91. 91.
    Kuntsi J, Wood AC, Van Der Meere J, Asherson P. Why cognitive performance in ADHD may not reveal true potential: findings from a large population-based sample. J Int Neuropsychol Soc 2009;15:570–579.PubMedGoogle Scholar
  92. 92.
    Gopin CB, Berwid O, Marks DJ, Mlodnicka A, Halperin JM. ADHD Preschoolers With and Without ODD: Do They Act Differently Depending On Degree of Task Engagement/Reward? J Atten Disord 2012. doi:10.1177/1087054711432140.
  93. 93.
    Luman M, Ooserlaan J, Sergeant J. Modulation of response timein in ADHD, effects of reinforcement valence and magnitude. J Abnorm Child Psychol 2008;36:445–456.PubMedGoogle Scholar
  94. 94.
    Sagvolden T, Johansen EB, Aase H, et al. A dynamic developmental theory of attention-deficit/hyperactivity disorder (ADHD) predominantly hyperactive/impulsive and combined subtypes. Behav Brain Sci 2005;28:397–419.PubMedGoogle Scholar
  95. 95.
    Strand MT, Hawk LW, Jr., Bubnik M, Shiels K, Pelham WE, Jr., Waxmonsky JG. Improving Working Memory in Children with Attention-Deficit/Hyperactivity Disorder: The Separate and Combined Effects of Incentives and Stimulant Medication. J Abnorm Child Psychol 2012. doi:10.1007/s10802-012-9627-6.
  96. 96.
    Bubnik MG, Hawk LW, Jr., Strand MT, et al. eds. Intra-individual variability in children with ADHD: treatment effects and construct validity. International Society for Research on Child and Adolescent Psychopathology 2011; Chicago, IL.Google Scholar
  97. 97.
    Boonstra AM, Kooij JJ, Oosterlaan J, Sergeant JA, Buitelaar JK. Does methylphenidate improve inhibition and other cognitive abilities in adults with childhood-onset ADHD? J Clin Exp Neuropsychol 2005;27:278–298.PubMedGoogle Scholar
  98. 98.
    Rosa-Neto P, Lou HC, Cumming P, et al. Methylphenidate-evoked changes in striatal dopamine correlate with inattention and impulsivity in adolescents with attention deficit hyperactivity disorder. Neuroimage 2005;25:868–876.PubMedGoogle Scholar
  99. 99.
    Fitzpatrick PA, Klorman R, Brumaghim JT, Borgstedt AD. Effects of sustained-release and standard preparations of methylphenidate on attention deficit disorder. J Am Acad Child Adolesc Psychiatry 1992;31:226–234.PubMedGoogle Scholar
  100. 100.
    Teicher MH, Lowen SB, Polcari A, Foley M, McGreenery CE. Novel strategy for the analysis of CPT data provides new insight into the effects of methylphenidate on attentional states in children with ADHD. J Child Adolesc Psychopharm 2004;14:219–232.Google Scholar
  101. 101.
    Tannock R, Schachar R, Logan G. Methylphenidate and cognitive flexibility: dissociated dose effects in hyperactive children. J Abnorm Child Psychol 1995;23:235–266.PubMedGoogle Scholar
  102. 102.
    Epstein JN, Conners CK, Hervey AS, et al. Assessing medication effects in the MTA study using neuropsychological outcomes. J Child Psychol Psychiatry 2006;47:446–456.PubMedGoogle Scholar
  103. 103.
    Johnson KA, Barry E, Bellgrove MA, et al. Dissociation in response to methylphenidate on response variability in a group of medication naive children with ADHD. Neuropsychologia 2008;46:1532–1541.PubMedGoogle Scholar
  104. 104.
    Tucha O, Prell S, Mecklinger L, et al. Effects of methylphenidate on multiple components of attention in children with attention deficit hyperactivity disorder. Psychopharmacol 2006;185:315–326.Google Scholar
  105. 105.
    Salthouse TA, Berish DE. Correlates of within-person (across-occasion) variability in reaction time. Neuropsychology 2005;19:77–87.PubMedGoogle Scholar
  106. 106.
    MacDonald SW, Nyberg L, Backman L. Intra-individual variability in behavior: links to brain structure, neurotransmission and neuronal activity. Trends Neurosci. 2006;29:474–80. Epub 2006 Jul 3.Google Scholar
  107. 107.
    Holden JG. Gauging the fractal dimension of response times from cognitive tasks. In: Contemporary nonlinear methods for behavioral scientists: A webbook tutorial. Riley MA, Van Orden GC, eds. National Science Foundation; 2005:267–318.
  108. 108.
    Ratcliff R. Modeling response signal and response time data. Cogn Psychol 2006;53:195–237.PubMedGoogle Scholar
  109. 109.
    Ratcliff R, Van Zandt T, McKoon G. Connectionist and diffusion models of reaction time. Psychol Rev 1999;106:261–300.PubMedGoogle Scholar
  110. 110.
    McAuley T, Yap M, Christ SE, White DA. Revisiting inhibitory control across the life span: insights from the ex-Gaussian distribution. Dev Neuropsychol 2006;29:447–458.PubMedGoogle Scholar
  111. 111.
    Epstein JN, Tsal Y. Evidence for cognitive training as a treatment strategy for children with attention-deficit/hyperactivity disorder. J ADHD Relat Disord 2010;1:49–64.Google Scholar
  112. 112.
    Tamm L, McCandliss BD, Liang A, Wigal TL, Posner MI, Swanson JM. Can attention itself be trained? Attention training for children at risk for ADHD. Attention Deficit/Hyperactivity Disorder: Concepts, Controversies, New Directions. New York: Informa Healthcare; 2007:399–411.Google Scholar
  113. 113.
    Lutz A, Slagter HA, Rawlings NB, Francis AD, Greischar LL, Davidson RJ. Mental training enhances attentional stability: neural and behavioral evidence. Neurosci 2009;29:13418–13427.Google Scholar

Copyright information

© The American Society for Experimental NeuroTherapeutics, Inc. 2012

Authors and Affiliations

  • Leanne Tamm
    • 1
  • Megan E. Narad
    • 1
  • Tanya N. Antonini
    • 1
  • Kathleen M. O’Brien
    • 1
  • Larry W. HawkJr.
    • 2
  • Jeffery N. Epstein
    • 1
  1. 1.Department of Pediatrics (MC10006)Cincinnati Children’s Hospital Medical CenterCincinnatiUSA
  2. 2.Department of PsychologyUniversity at Buffalo, SUNYBuffaloUSA

Personalised recommendations