Neuroimaging cognitive reappraisal in clinical populations to define neural targets for enhancing emotion regulation. A systematic review

NeuroImage

Volumn 151, Issue , 2017, Pages 105-116

  Zilverstand, Anna ^a   Parvaz, Muhammad A ^a   Goldstein, Rita Z ^a  

^a MOUNT SINAI SCHOOL OF MEDICINE   (United States)

Author keywords

Anxiety disorder; Depression; EEG; Emotion regulation; fMRI; RDoC

Indexed keywords

ADDICTION; ANXIETY DISORDER; ARTICLE; ATTENTION; COGNITION; COGNITIVE REAPPRAISAL; DORSAL ANTERIOR CINGULATE CORTEX; DORSOLATERAL PREFRONTAL CORTEX; EMOTIONALITY; FUNCTIONAL MAGNETIC RESONANCE IMAGING; HUMAN; INFERIOR PARIETAL CORTEX; MOOD DISORDER; NEUROIMAGING; PERSONALITY DISORDER; SCHIZOPHRENIA; SELF REPORT; SYSTEMATIC REVIEW; VENTROLATERAL PREFRONTAL CORTEX; BRAIN; BRAIN MAPPING; COMPLICATION; DIAGNOSTIC IMAGING; ELECTROENCEPHALOGRAPHY; EMOTION; EMOTIONAL DISORDER; MENTAL DISEASE; NUCLEAR MAGNETIC RESONANCE IMAGING; PATHOPHYSIOLOGY; PHYSIOLOGY;

AFFECTIVE SYMPTOMS; BRAIN; BRAIN MAPPING; ELECTROENCEPHALOGRAPHY; EMOTIONS; HUMANS; MAGNETIC RESONANCE IMAGING; MENTAL DISORDERS; NEUROIMAGING;

EID: 85008402172     PISSN: 10538119     EISSN: 10959572     Source Type: Journal    
DOI: 10.1016/j.neuroimage.2016.06.009     Document Type: Article

References (80)

1. Albein-Urios, N., Verdejo-Román, J., Asensio, S., Soriano-Mas, C., Martínez-González, J.M., Verdejo-García, A., Re-appraisal of negative emotions in cocaine dependence: dysfunctional corticolimbic activation and connectivity. Addict. Biol. 19 (2014), 415–426, 10.1111/j.1369-1600.2012.00497.x.
2. Amstadter, A., Emotion regulation and anxiety disorders. J. Anxiety Disord. 22:2 (2008), 211–221, 10.1016/j.janxdis.2007.02.004.
3. Beauregard, M., Paquette, V., Lévesque, J., Dysfunction in the neural circuitry of emotional self-regulation in major depressive disorder. Neuroreport 17:8 (2006), 843–846, 10.1097/01.wnr.0000220132.32091.9f.
4. Beck, A.T., Rush, A.J., Shaw, B.F., Emery, G., Cognitive Therapy of Depression. 1979, The Guilford Press, New York.
5. Blair, K.S., Geraci, M., Smith, B.W., Hollon, N., DeVido, J., Otero, M.,.. Pine, D.S., Reduced dorsal anterior cingulate cortical activity during emotional regulation and top-down attentional control in generalized social phobia, generalized anxiety disorder, and comorbid generalized social phobia/generalized anxiety disorder. Biol. Psychiatry 72:6 (2012), 476–482, 10.1016/j.biopsych.2012.04.013.
6. Brühl, A.B., Delsignore, A., Komossa, K., Weidt, S., Neuroimaging in social anxiety disorder—a meta-analytic review resulting in a new neurofunctional model. Neurosci. Biobehav. Rev. 47 (2014), 260–280, 10.1016/j.neubiorev.2014.08.003.
7. Buhle, J.T., Silvers, J.A., Wager, T.D., Lopez, R., Onyemekwu, C., Kober, H.,.. Ochsner, K.N., Cognitive reappraisal of emotion: a meta-analysis of human neuroimaging studies. Cereb. Cortex 24:11 (2014), 2981–2990, 10.1093/cercor/bht154.
8. Chen, C.-H., Suckling, J., Lennox, B.R., Ooi, C., Bullmore, E.T., A quantitative meta-analysis of fMRI studies in bipolar disorder. Bipolar Disord. 13:1 (2011), 1–15, 10.1111/j.1399-5618.2011.00893.x.
9. Cole, M.W., Schneider, W., The cognitive control network: integrated cortical regions with dissociable functions. NeuroImage 37:1 (2007), 343–360, 10.1016/j.neuroimage.2007.03.071.
10. Corbetta, M., Shulman, G.L., Control of goal-directed and stimulus-driven attention in the brain. Nat. Rev. Neurosci. 3:3 (2002), 215–229, 10.1038/nrn755.
11. Costafreda, S.G., Brammer, M.J., David, A.S., Fu, C.H.Y., Predictors of amygdala activation during the processing of emotional stimuli: a meta-analysis of 385 PET and fMRI studies. Brain Res. Rev. 58:1 (2008), 57–70, 10.1016/j.brainresrev.2007.10.012.
12. Davis, T.S., Mauss, I.B., Lumian, D., Troy, A.S., Shallcross, A.J., Zarolia, P.,.. McRae, K., Emotional reactivity and emotion regulation among adults with a history of self-harm: laboratory self-report and functional MRI evidence. J. Abnorm. Psychol. 123:3 (2014), 499–509, 10.1037/a0036962.
13. Delvecchio, G., Sugranyes, G., Frangou, S., Evidence of diagnostic specificity in the neural correlates of facial affect processing in bipolar disorder and schizophrenia: a meta-analysis of functional imaging studies. Psychol. Med. 43 (2012), 553–569, 10.1017/S0033291712001432.
14. Denny, B.T., Fan, J., Liu, X., Ochsner, K.N., Guerreri, S., Mayson, S.J.,.. Koenigsberg, H.W., Elevated amygdala activity during reappraisal anticipation predicts anxiety in avoidant personality disorder. J. Affect. Disord. 172 (2015), 1–7, 10.1016/j.jad.2014.09.017.
15. Dillon, D.G., Pizzagalli, D.A., Evidence of successful modulation of brain activation and subjective experience during reappraisal of negative emotion in unmedicated depression. Psychiatry Res. Neuroimaging 212:2 (2013), 99–107, 10.1016/j.pscychresns.2013.01.001.
16. Eklund, A., Nichols, T., Knutsson, H., Can Parametric Statistical Methods Be Trusted for fMRI Based Group Studies?. 2015 (arXiv:1511.01863).
17. Erk, S., Mikschl, A., Stier, S., Ciaramidaro, A., Gapp, V., Weber, B., Walter, H., Acute and sustained effects of cognitive emotion regulation in major depression. J. Neurosci. 30:47 (2010), 15726–15734, 10.1523/JNEUROSCI.1856-10.2010.
18. Etkin, A., Wager, T.D., Functional neuroimaging of anxiety: a meta-analysis of emotional processing in PTSD, social anxiety disorder, and specific phobia. Am. J. Psychiatry 164:10 (2007), 1476–1488, 10.1176/appi.ajp.2007.07030504.
19. Etkin, A., Egner, T., Kalisch, R., Emotional processing in anterior cingulate and medial prefrontal cortex. Trends Cogn. Sci. 15:2 (2011), 85–93, 10.1016/j.tics.2010.11.004.
20. Frank, D.W., Dewitt, M., Hudgens-Haney, M., Schaeffer, D.J., Ball, B.H., Schwarz, N.F.,.. Sabatinelli, D., Emotion regulation: quantitative meta-analysis of functional activation and deactivation. Neurosci. Biobehav. Rev. 45 (2014), 202–211, 10.1016/j.neubiorev.2014.06.010.
21. Gaebler, M., Daniels, J., Lamke, J.-P., Fydrich, T., Walter, H., Behavioural and neural correlates of self-focused emotion regulation in social anxiety disorder. J. Psychiatry Neurosci. 39:4 (2014), 249–258, 10.1503/jpn.130080.
22. Goldin, P.R., McRae, K., Ramel, W., Gross, J.J., The neural bases of emotion regulation: reappraisal and suppression of negative emotion. Biol. Psychiatry 63:6 (2008), 577–586, 10.1016/j.biopsych.2007.05.031.
23. Goldin, P.R., Manber, T., Hakimi, S., Canli, T., Gross, J.J., Neural bases of social anxiety disorder. Emotional reactivity and cognitive regulation during social and physical threat. Arch. Gen. Psychiatry, 66(2), 2009, 170, 10.1001/archgenpsychiatry.2008.525.
24. Goldin, P.R., Manber-Ball, T., Werner, K., Heimberg, R., Gross, J.J., Neural mechanisms of cognitive reappraisal of negative self-beliefs in social anxiety disorder. Biol. Psychiatry 66:12 (2009), 1091–1099, 10.1016/j.biopsych.2009.07.014.
25. Goldstein, R.Z., Volkow, N.D., Dysfunction of the prefrontal cortex in addiction: neuroimaging findings and clinical implications. Nat. Rev. Neurosci. 12:11 (2011), 652–669, 10.1038/nrn3119.
26. Goldstein, R.Z., Craig, A.D.B., Bechara, A., Garavan, H., Childress, A.R., Paulus, M.P., Volkow, N.D., The neurocircuitry of impaired insight in drug addiction. Trends Cogn. Sci. 13:9 (2009), 372–380, 10.1016/j.tics.2009.06.004.
27. Goodkind, M., Eickhoff, S.B., Oathes, D.J., Jiang, Y., Chang, A., Jones-Hagata, L.B.,.. Etkin, A., Identification of a common neurobiological substrate for mental illness. JAMA Psychiatry, 72(4), 2015, 305, 10.1001/jamapsychiatry.2014.2206.
28. Greening, S.G., Osuch, E.A., Williamson, P.C., Mitchell, D.G.V., The neural correlates of regulating positive and negative emotions in medication-free major depression. Soc. Cogn. Affect. Neurosci. 9:5 (2014), 628–637, 10.1093/scan/nst027.
29. Groenewold, N.a., Opmeer, E.M., de Jonge, P., Aleman, A., Costafreda, S.G., Emotional valence modulates brain functional abnormalities in depression: evidence from a meta-analysis of fMRI studies. Neurosci. Biobehav. Rev. 37:2 (2013), 152–163, 10.1016/j.neubiorev.2012.11.015.
30. Gross, J.J., Emotion regulation: affective, cognitive, and social consequences. Psychophysiology 39:3 (2002), 281–291, 10.1017/S0048577201393198.
31. Hajcak, G., Nieuwenhuis, S., Reappraisal modulates the electrocortical response to unpleasant pictures. Cogn. Affect. Behav. Neurosci. 6:4 (2006), 291–297, 10.3758/CABN.6.4.291.
32. Hajcak, G., MacNamara, A., Olvet, D.M., Event-related potentials, emotion, and emotion regulation: an integrative review. Dev. Neuropsychol. 35:2 (2010), 129–155, 10.1080/87565640903526504.
33. Hamilton, J.P., Etkin, A., Furman, D.J., Lemus, M.G., Johnson, R.F., Gotlib, I.H., Functional neuroimaging of major depressive disorder: a meta-analysis and new integration of base line activation and neural response data. Am. J. Psychiatry 169:7 (2012), 693–703, 10.1176/appi.ajp.2012.11071105.
34. Heller, A.S., Johnstone, T., Shackman, A.J., Light, S.N., Peterson, M.J., Kolden, G.G.,.. Davidson, R.J., Reduced capacity to sustain positive emotion in major depression reflects diminished maintenance of fronto-striatal brain activation. Proc. Natl. Acad. Sci. U. S. A. 106:52 (2009), 22445–22450, 10.1073/pnas.0910651106.
35. Hilbert, K., Lueken, U., Beesdo-Baum, K., Neural structures, functioning and connectivity in Generalized Anxiety Disorder and interaction with neuroendocrine systems: a systematic review. J. Affect. Disord. 158 (2014), 114–126, 10.1016/j.jad.2014.01.022.
36. Hu, T., Zhang, D., Wang, J., Mistry, R., Ran, G., Wang, X., Relation between emotion regulation and mental health: a meta-analysis review. Psychol. Rep. 114:2 (2014), 341–362, 10.2466/03.20.PR0.114k22w4.
37. Johnstone, T., van Reekum, C.M., Urry, H.L., Kalin, N.H., Davidson, R.J., Failure to regulate: counterproductive recruitment of top-down prefrontal-subcortical circuitry in major depression. J. Neurosci. 27:33 (2007), 8877–8884, 10.1523/JNEUROSCI.2063-07.2007.
38. Kanske, P., Heissler, J., Schönfelder, S., Wessa, M., Neural correlates of emotion regulation deficits in remitted depression: the influence of regulation strategy, habitual regulation use, and emotional valence. NeuroImage 61:3 (2012), 686–693, 10.1016/j.neuroimage.2012.03.089.
39. Kanske, P., Schönfelder, S., Forneck, J., Wessa, M., Impaired regulation of emotion: neural correlates of reappraisal and distraction in bipolar disorder and unaffected relatives. Transl. Psychiatry, 5, 2015, e497, 10.1038/tp.2014.137.
40. Kessler, R.C., Aguilar-Gaxiola, S., Alonso, J., Chatterji, S., Lee, S., Ormel, J.,.. Wang, P.S., The global burden of mental disorders: an update from the WHO World Mental Health (WMH) Surveys. Epidemiol. Psichiatr. Soc. 18:1 (2009), 23–33, 10.1017/S1121189X00001421.
41. Koenigsberg, H.W., Fan, J., Ochsner, K.N., Liu, X., Guise, K.G., Pizzarello, S.,.. Siever, L.J., Neural correlates of the use of psychological distancing to regulate responses to negative social cues: a study of patients with borderline personality disorder. Biol. Psychiatry 66 (2009), 854–863, 10.1016/j.biopsych.2009.06.010.
42. Kohn, N., Eickhoff, S.B., Scheller, M., Laird, A.R., Fox, P.T., Habel, U., Neural network of cognitive emotion regulation - an ALE meta-analysis and MACM analysis. NeuroImage 87 (2014), 345–355, 10.1016/j.neuroimage.2013.11.001.
43. Konova, A.B., Moeller, S.J., Goldstein, R.Z., Common and distinct neural targets of treatment: changing brain function in substance addiction. Neurosci. Biobehav. Rev. 37 (2013), 2806–2817, 10.1016/j.neubiorev.2013.10.002.
44. Lang, P.J., Bradley, M.M., Cuthbert, B.N., International Affective Picture System (IAPS): Affective Ratings of Pictures and Instruction Manual. Technical Report A-8. Gainesville, Florida, USA. 2008.
45. Lang, S., Kotchoubey, B., Frick, C., Spitzer, C., Grabe, H.J., Barnow, S., Cognitive reappraisal in trauma-exposed women with borderline personality disorder. NeuroImage 59:2 (2012), 1727–1734, 10.1016/j.neuroimage.2011.08.061.
46. Livingstone, K., Harper, S., Gillanders, D., An exploration of emotion regulation in psychosis. Clin. Psychol. Psychother. 16:5 (2009), 418–430, 10.1002/cpp.635.
47. Lueckmann, H.C., Jacobs, H.I.L., Sack, A.T., The cross-functional role of frontoparietal regions in cognition: internal attention as the overarching mechanism. Prog. Neurobiol. 116 (2014), 66–86, 10.1016/j.pneurobio.2014.02.002.
48. Manber-Ball, T., Ramsawh, H.J., Campbell-Sills, L., Paulus, M.P., Stein, M.B., Prefrontal dysfunction during emotion regulation in generalized anxiety and panic disorders. Psychol. Med. 43:7 (2013), 1475–1486, 10.1017/S0033291712002383.
49. Marin, M.-F., Camprodon, J.A., Dougherty, D.D., Milad, M.R., Device-based brain stimulation to augment fear extinction: implications for PTSD treatment and beyond. Depress. Anxiety 31 (2014), 269–278, 10.1002/da.22252.
50. Marissen, M.A.E., Meuleman, L., Franken, I.H.A., Altered emotional information processing in borderline personality disorder: an electrophysiological study. Psychiatry Res. 181:3 (2010), 226–232, 10.1016/j.pscychresns.2009.10.006.
51. Min, J.A., Yu, J.J., Lee, C.U., Chae, J.H., Cognitive emotion regulation strategies contributing to resilience in patients with depression and/or anxiety disorders. Compr. Psychiatry 54:8 (2013), 1190–1197, 10.1016/j.comppsych.2013.05.008.
52. Moeller, S.J., Maloney, T., Parvaz, M.A., Alia-Klein, N., Woicik, P.A., Telang, F.,.. Goldstein, R.Z., Impaired insight in cocaine addiction: laboratory evidence and effects on cocaine-seeking behaviour. Brain 133:5 (2010), 1484–1493, 10.1093/brain/awq066.
53. Moratti, S., Saugar, C., Strange, B.A., Prefrontal-occipitoparietal coupling underlies late latency human neuronal responses to emotion. J. Neurosci. 31:47 (2011), 17278–17286, 10.1523/JNEUROSCI.2917-11.2011.
54. Morris, R.W., Sparks, A., Mitchell, P.B., Weickert, C.S., Green, M.J., Lack of cortico-limbic coupling in bipolar disorder and schizophrenia during emotion regulation. Transl. Psychiatry, 2(3), 2012, e90, 10.1038/tp.2012.16.
55. New, A.S., Fan, J., Murrough, J.W., Liu, X., Liebman, R.E., Guise, K.G.,.. Charney, D.S., A functional magnetic resonance imaging study of deliberate emotion regulation in resilience and posttraumatic stress disorder. Biol. Psychiatry 66:7 (2009), 656–664, 10.1016/j.biopsych.2009.05.020.
56. Ochsner, K.N., Gross, J.J., The cognitive control of emotion. Trends Cogn. Sci. 9:5 (2005), 242–249, 10.1016/j.tics.2005.03.010.
57. Parvaz, M.A., MacNamara, A., Goldstein, R.Z., Hajcak, G., Event-related induced frontal alpha as a marker of lateral prefrontal cortex activation during cognitive reappraisal. Cogn. Affect. Behav. Neurosci. 12:4 (2012), 730–740, 10.3758/s13415-012-0107-9.
58. Parvaz, M.A., Konova, A.B., Proudfit, G.H., Dunning, J.P., Malaker, P., Moeller, S.J.,.. Goldstein, R.Z., Impaired neural response to negative prediction errors in cocaine addiction. J. Neurosci. 35:5 (2015), 1872–1879, 10.1523/JNEUROSCI.2777-14.2015.
59. Paul, S., Simon, D., Endrass, T., Kathmann, N., Altered emotion regulation in obsessive–compulsive disorder as evidenced by the late positive potential. Psychol. Med., 2015, 1–11, 10.1017/S0033291715001610.
60. Phillips, M.L., Drevets, W.C., Rauch, S.L., Lane, R., Neurobiology of emotion perception II: implications for major psychiatric disorders. Biol. Psychiatry 54:5 (2003), 515–528, 10.1016/S0006-3223(03)00171-9.
61. Rabinak, C.a., MacNamara, A., Kennedy, A.E., Angstadt, M., Stein, M.B., Liberzon, I., Phan, K.L., Focal and aberrant prefrontal engagement during emotion regulation in veterans with posttraumatic stress disorder. Depress. Anxiety 31 (2014), 851–861, 10.1002/da.22243.
62. Ramage, A.E., Laird, A.R., Eickhoff, S.B., Acheson, A., Peterson, A.L., Williamson, D.E.,.. Fox, P.T., A coordinate-based meta-analytic model of trauma processing in posttraumatic stress disorder. Hum. Brain Mapp. 34:12 (2013), 3392–3399, 10.1002/hbm.22155.
63. Reinecke, A., Thilo, K., Filippini, N., Croft, A., Harmer, C.J., Predicting rapid response to cognitive-behavioural treatment for panic disorder: the role of hippocampus, insula, and dorsolateral prefrontal cortex. Behav. Res. Ther. 62 (2014), 120–128, 10.1016/j.brat.2014.07.017.
64. Reinecke, A., Filippini, N., Berna, C., Western, D.G., Hanson, B., Cooper, M.J.,.. Harmer, C., Effective emotion regulation strategies improve fMRI and ECG markers of psychopathology in panic disorder: implications for psychological treatment. Transl. Psychiatry, 5, 2015, e673, 10.1038/tp.2015.160.
65. Rotge, J.-Y., Guehl, D., Dilharreguy, B., Cuny, E., Tignol, J., Bioulac, B.,.. Aouizerate, B., Provocation of obsessive-compulsive symptoms: a quantitative voxel-based meta-analysis of functional neuroimaging studies. J. Psychiatry Neurosci. 33:5 (2008), 405–412.
66. Sarkheil, P., Zilverstand, A., Kilian-Hütten, N., Schneider, F., Goebel, R., Mathiak, K., fMRI feedback enhances emotion regulation as evidenced by a reduced amygdala response. Behav. Brain Res. 281 (2015), 326–332, 10.1016/j.bbr.2014.11.027.
67. Sartory, G., Cwik, J., Knuppertz, H., Schürholt, B., Lebens, M., Seitz, R.J., Schulze, R., In search of the trauma memory: a meta-analysis of functional neuroimaging studies of symptom provocation in posttraumatic stress disorder (PTSD). PLoS One, 8(3), 2013, e58150, 10.1371/journal.pone.0058150.
68. Schulze, L., Domes, G., Krüger, A., Berger, C., Fleischer, M., Prehn, K.,.. Herpertz, S.C., Neuronal correlates of cognitive reappraisal in borderline patients with affective instability. Biol. Psychiatry 69:6 (2011), 564–573, 10.1016/j.biopsych.2010.10.025.
69. Shenhav, A., Botvinick, M.M., Cohen, J.D., The expected value of control: an integrative theory of anterior cingulate cortex function. Neuron 79:2 (2013), 217–240, 10.1016/j.neuron.2013.07.007.
70. Smoski, M.J., Keng, S.L., Schiller, C.E., Minkel, J., Dichter, G.S., Neural mechanisms of cognitive reappraisal in remitted major depressive disorder. J. Affect. Disord. 151:1 (2013), 171–177, 10.1016/j.jad.2013.05.073.
71. Townsend, J.D., Torrisi, S.J., Lieberman, M.D., Sugar, C.A., Bookheimer, S.Y., Altshuler, L.L., Frontal-amygdala connectivity alterations during emotion downregulation in bipolar I disorder. Biol. Psychiatry 73:2 (2013), 127–135, 10.1016/j.biopsych.2012.06.030.
72. van der Meer, L., Swart, M., van der Velde, J., Pijnenborg, G., Wiersma, D., Bruggeman, R., Aleman, A., Neural correlates of emotion regulation in patients with schizophrenia and non-affected siblings. PLoS One, 9(6), 2014, e99667, 10.1371/journal.pone.0099667.
73. Walker, E.R., McGee, R.E., Druss, B.G., Mortality in mental disorders and global disease burden implications. JAMA Psychiatry 72:4 (2015), 334–341, 10.1001/jamapsychiatry.2014.2502.
74. Wang, X., Feng, Z., Zhou, D., Lei, X., Liao, T., Zhang, L.,.. Li, J., Dissociable self effects for emotion regulation: a study of Chinese major depressive outpatients. BioMed Res. Int., 2014, 2014, 390865, 10.1155/2014/390865.
75. Wani, A., Trevino, K., Marnell, P., Husain, M.M., Advances in brain stimulation for depression. Ann. Clin. Psychiatry 25:3 (2013), 217–224.
76. Woodward, S.H., Shurick, A.A., Alvarez, J., Kuo, J., Nonyieva, Y., Blechert, J.,.. Gross, J.J., A psychophysiological investigation of emotion regulation in chronic severe posttraumatic stress disorder. Psychophysiology 52:5 (2015), 667–678, 10.1111/psyp.12392.
77. Wu, L., Winkler, M.H., Wieser, M.J., Andreatta, M., Li, Y., Pauli, P., Emotion regulation in heavy smokers: experiential, expressive and physiological consequences of cognitive reappraisal. Front. Psychol. 6:October (2015), 1–11, 10.3389/fpsyg.2015.01555.
78. Zilverstand, A., Sorger, B., Sarkheil, P., Goebel, R., fMRI neurofeedback facilitates anxiety regulation in females with spider phobia. Front. Behav. Neurosci. 9:June (2015), 1–12, 10.3389/fnbeh.2015.00148.
79. Zilverstand, A., Parvaz, M.A., Moeller, S.J., Goldstein, R.Z., Cognitive interventions for addiction medicine: understanding the underlying neurobiological mechanisms. Prog. Brain Res. 224 (2016), xv–xx, 10.1016/bs.pbr.2015.07.019.
80. Ziv, M., Goldin, P.R., Jazaieri, H., Hahn, K.S., Gross, J.J., Emotion regulation in social anxiety disorder: behavioral and neural responses to three socio-emotional tasks. Biol. Mood Anxiety Disord., 3(1), 2013, 20, 10.1186/2045-5380-3-20.