Gregory A Light

Summary

Affiliation: University of California
Country: USA

Publications

  1. pmc Characterization of neurophysiologic and neurocognitive biomarkers for use in genomic and clinical outcome studies of schizophrenia
    Gregory A Light
    VISN 22 Mental Illness, Research, Education, and Clinical Center MIRECC, San Diego VA Health Care System, La Jolla, California, United States of America
    PLoS ONE 7:e39434. 2012
  2. ncbi request reprint Gamma band oscillations reveal neural network cortical coherence dysfunction in schizophrenia patients
    Gregory A Light
    Department of Psychiatry, University of California, San Diego, La Jolla, California 92093 0804, USA
    Biol Psychiatry 60:1231-40. 2006
  3. ncbi request reprint Stability of mismatch negativity deficits and their relationship to functional impairments in chronic schizophrenia
    Gregory A Light
    Department of Psychiatry, University of California, San Diego, 9500 Gilman Dr, La Jolla, CA 92093 0804, USA
    Am J Psychiatry 162:1741-3. 2005
  4. ncbi request reprint Mismatch negativity deficits are associated with poor functioning in schizophrenia patients
    Gregory A Light
    Department of Psychiatry, University of California, San Diego, La Jolla 92093 0804, USA
    Arch Gen Psychiatry 62:127-36. 2005
  5. pmc Preattentive sensory processing as indexed by the MMN and P3a brain responses is associated with cognitive and psychosocial functioning in healthy adults
    Gregory A Light
    Department of Psychiatry, University of California, San Diego, La Jolla, CA 92093 0804, USA
    J Cogn Neurosci 19:1624-32. 2007
  6. pmc Abnormal auditory N100 amplitude: a heritable endophenotype in first-degree relatives of schizophrenia probands
    Bruce I Turetsky
    Department of Psychiatry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
    Biol Psychiatry 64:1051-9. 2008
  7. ncbi request reprint Startle gating deficits in a large cohort of patients with schizophrenia: relationship to medications, symptoms, neurocognition, and level of function
    Neal R Swerdlow
    Departments of Psychiatry, School of Medicine, University of California San Diego, La Jolla, CA 92093, USA
    Arch Gen Psychiatry 63:1325-35. 2006
  8. pmc Inhibition of the P50 cerebral evoked response to repeated auditory stimuli: results from the Consortium on Genetics of Schizophrenia
    Ann Olincy
    Department of Psychiatry, Veterans Affairs Denver Medical Center VISN 19 MIRECC, CO 80045, USA
    Schizophr Res 119:175-82. 2010
  9. pmc Sex differences in familiality effects on neurocognitive performance in schizophrenia
    Monica E Calkins
    Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104, USA
    Biol Psychiatry 73:976-84. 2013
  10. pmc Genome-wide linkage analyses of 12 endophenotypes for schizophrenia from the Consortium on the Genetics of Schizophrenia
    Tiffany A Greenwood
    Department of Psychiatry, University of California San Diego, La Jolla, Calif, USA
    Am J Psychiatry 170:521-32. 2013

Detail Information

Publications56

  1. pmc Characterization of neurophysiologic and neurocognitive biomarkers for use in genomic and clinical outcome studies of schizophrenia
    Gregory A Light
    VISN 22 Mental Illness, Research, Education, and Clinical Center MIRECC, San Diego VA Health Care System, La Jolla, California, United States of America
    PLoS ONE 7:e39434. 2012
    ..Stability of clinical and functional measures was also assessed...
  2. ncbi request reprint Gamma band oscillations reveal neural network cortical coherence dysfunction in schizophrenia patients
    Gregory A Light
    Department of Psychiatry, University of California, San Diego, La Jolla, California 92093 0804, USA
    Biol Psychiatry 60:1231-40. 2006
    ....
  3. ncbi request reprint Stability of mismatch negativity deficits and their relationship to functional impairments in chronic schizophrenia
    Gregory A Light
    Department of Psychiatry, University of California, San Diego, 9500 Gilman Dr, La Jolla, CA 92093 0804, USA
    Am J Psychiatry 162:1741-3. 2005
    ....
  4. ncbi request reprint Mismatch negativity deficits are associated with poor functioning in schizophrenia patients
    Gregory A Light
    Department of Psychiatry, University of California, San Diego, La Jolla 92093 0804, USA
    Arch Gen Psychiatry 62:127-36. 2005
    ..While many studies have reported MMN deficits in schizophrenia patients, little is known about the functional significance of MMN deficits in schizophrenia patients...
  5. pmc Preattentive sensory processing as indexed by the MMN and P3a brain responses is associated with cognitive and psychosocial functioning in healthy adults
    Gregory A Light
    Department of Psychiatry, University of California, San Diego, La Jolla, CA 92093 0804, USA
    J Cogn Neurosci 19:1624-32. 2007
    ....
  6. pmc Abnormal auditory N100 amplitude: a heritable endophenotype in first-degree relatives of schizophrenia probands
    Bruce I Turetsky
    Department of Psychiatry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
    Biol Psychiatry 64:1051-9. 2008
    ..We report initial results from the COGS dataset of auditory N100 amplitude and gating as candidate endophenotypes...
  7. ncbi request reprint Startle gating deficits in a large cohort of patients with schizophrenia: relationship to medications, symptoms, neurocognition, and level of function
    Neal R Swerdlow
    Departments of Psychiatry, School of Medicine, University of California San Diego, La Jolla, CA 92093, USA
    Arch Gen Psychiatry 63:1325-35. 2006
    ..Patients with schizophrenia exhibit deficits in automatic, preattentive sensorimotor gating (prepulse inhibition [PPI]) of the startle reflex...
  8. pmc Inhibition of the P50 cerebral evoked response to repeated auditory stimuli: results from the Consortium on Genetics of Schizophrenia
    Ann Olincy
    Department of Psychiatry, Veterans Affairs Denver Medical Center VISN 19 MIRECC, CO 80045, USA
    Schizophr Res 119:175-82. 2010
    ....
  9. pmc Sex differences in familiality effects on neurocognitive performance in schizophrenia
    Monica E Calkins
    Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104, USA
    Biol Psychiatry 73:976-84. 2013
    ..In view of these findings, the current investigation tested the hypothesis that neurocognitive performance of schizophrenia probands can predict the neurocognitive performance of their unaffected family members...
  10. pmc Genome-wide linkage analyses of 12 endophenotypes for schizophrenia from the Consortium on the Genetics of Schizophrenia
    Tiffany A Greenwood
    Department of Psychiatry, University of California San Diego, La Jolla, Calif, USA
    Am J Psychiatry 170:521-32. 2013
    ..The authors previously demonstrated the heritability of these endophenotypes; in the present study, genetic linkage was evaluated...
  11. doi request reprint Antisaccade performance in schizophrenia patients, their first-degree biological relatives, and community comparison subjects: data from the COGS study
    Allen D Radant
    Department of Psychiatry and Behavioral Sciences, University of Washington and Department of Veteran Affairs, VISN 20, Mental Illness Research, Education, and Clinical Center, Seattle, Washington 98108, USA
    Psychophysiology 47:846-56. 2010
    ..Given the significant heritability of antisaccade performance, the effects of a genetic polymorphism is one possible explanation of our results...
  12. ncbi request reprint Initial heritability analyses of endophenotypic measures for schizophrenia: the consortium on the genetics of schizophrenia
    Tiffany A Greenwood
    Department of Psychiatry, University of California San Diego, La Jolla, USA
    Arch Gen Psychiatry 64:1242-50. 2007
    ..Exploration of the genetic architecture of specific endophenotypes may be a powerful strategy for understanding the genetic basis of schizophrenia...
  13. pmc Multi-site studies of acoustic startle and prepulse inhibition in humans: initial experience and methodological considerations based on studies by the Consortium on the Genetics of Schizophrenia
    Neal R Swerdlow
    Department of Psychiatry, University of California San Diego, San Diego, California, USA
    Schizophr Res 92:237-51. 2007
    ..Genetic studies now often employ multiple, geographically dispersed test sites to accommodate the need for large and complex study samples. Here, we assessed the feasibility of using PPI in multi-site studies...
  14. pmc Sensory and sensorimotor gating-disruptive effects of apomorphine in Sprague Dawley and Long Evans rats
    Michelle R Breier
    Department of Psychiatry, University of California, San Diego School of Medicine, La Jolla, CA 92093 0804, USA
    Behav Brain Res 208:560-5. 2010
    ..Here, we investigated whether SD and LE rats differ in sensitivity to APO effects on N40 gating or amplitude...
  15. pmc Effects of olanzapine, risperidone and haloperidol on prepulse inhibition in schizophrenia patients: a double-blind, randomized controlled trial
    Jonathan K Wynn
    Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, CA, USA
    Schizophr Res 95:134-42. 2007
    ..The results are discussed in terms of animal models, neural substrates, and treatment implications...
  16. ncbi request reprint An event-related brain potential study of direct and indirect semantic priming in schizophrenia
    Michael Kiang
    University of California, San Diego, 9500 Gilman Dr, La Jolla, CA 92093 0515, USA
    Am J Psychiatry 165:74-81. 2008
    ..The authors tested these hypotheses using the N400 event-related brain potential as a probe of activation of concepts in semantic memory...
  17. pmc Demand and modality of directed attention modulate "pre-attentive" sensory processes in schizophrenia patients and nonpsychiatric controls
    Anthony J Rissling
    Department of Psychiatry, University of California San Diego, La Jolla, CA 92093 0804, United States
    Schizophr Res 146:326-35. 2013
    ....
  18. ncbi request reprint P50 suppression in individuals at risk for schizophrenia: the convergence of clinical, familial, and vulnerability marker risk assessment
    Kristin S Cadenhead
    Department of Psychiatry, University of California San Diego, La Jolla, California 92093 0810, USA
    Biol Psychiatry 57:1504-9. 2005
    ..The aim of the present study was to determine whether individuals "at risk" for schizophrenia have deficits in P50 suppression, a preattentive measure of sensory gating...
  19. ncbi request reprint Cognitive, neurophysiological, and functional correlates of proverb interpretation abnormalities in schizophrenia
    Michael Kiang
    Department of Cognitive Science, University of California San Diego, La Jolla, California 92093, USA
    J Int Neuropsychol Soc 13:653-63. 2007
    ..These results offer no support for disorganized associations in abnormal proverb interpretation in schizophrenia, but implicate WM deficits, perhaps as a part of a syndrome related to generalized frontal cortical dysfunction...
  20. pmc Neurophysiological endophenotypes of schizophrenia: the viability of selected candidate measures
    Bruce I Turetsky
    Department of Psychiatry, 10th Floor, Gates Building, University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104, USA
    Schizophr Bull 33:69-94. 2007
    ..We conclude with a discussion of the few studies thus far that have employed a multivariate approach with these candidates...
  21. ncbi request reprint Female schizophrenia patients have prepulse inhibition deficits
    David L Braff
    Department of Psychiatry, University of California, San Diego, La Jolla, CA 92093 0804, USA
    Biol Psychiatry 57:817-20. 2005
    ..This study was designed to determine whether female schizophrenia patients have lower levels of PPI than normal females...
  22. pmc Analysis of 94 candidate genes and 12 endophenotypes for schizophrenia from the Consortium on the Genetics of Schizophrenia
    Tiffany A Greenwood
    Department of Psychiatry, University of California at San Diego, La Jolla, CA 92093 0804, USA
    Am J Psychiatry 168:930-46. 2011
    ....
  23. pmc Reduced multisensory integration in patients with schizophrenia on a target detection task
    Lisa E Williams
    Department of Psychology, University of California, San Diego, CA, United States
    Neuropsychologia 48:3128-36. 2010
    ....
  24. ncbi request reprint Prepulse inhibition and P50 suppression are both deficient but not correlated in schizophrenia patients
    David L Braff
    Department of Psychiatry, School of Medicine, University of California, San Diego, California 92093 0804, USA
    Biol Psychiatry 61:1204-7. 2007
    ..The relationship between PPI and P50 suppression in schizophrenia patients has remained unclear...
  25. pmc Deficient prepulse inhibition in schizophrenia detected by the multi-site COGS
    Neal R Swerdlow
    Department of Psychiatry, University of California San Diego, La Jolla, CA, United States Electronic address
    Schizophr Res 152:503-12. 2014
    ..These findings are being extended in a 5-site "COGS-2" study of 1800 patients and 1200 unrelated HCS to facilitate genetic analyses. We describe a planned interim analysis of COGS-2 PPI data...
  26. pmc Disentangling early sensory information processing deficits in schizophrenia
    Anthony J Rissling
    Department of Psychiatry, University of California San Diego, La Jolla, CA 92093 0804, USA
    Clin Neurophysiol 123:1942-9. 2012
    ....
  27. pmc Electroencephalography (EEG) and event-related potentials (ERPs) with human participants
    Gregory A Light
    Department of Psychiatry, University of California, San Diego, La Jolla, California, USA
    Curr Protoc Neurosci . 2010
    ..These paradigms can be used to assess the integrity of early sensory processing in normal individuals and clinical populations, such as individuals with schizophrenia...
  28. doi request reprint Fronto-temporal-mesolimbic gene expression and heritable differences in amphetamine-disrupted sensorimotor gating in rats
    Neal R Swerdlow
    Department of Psychiatry, School of Medicine, University of California San Diego, La Jolla, CA 92093 0804, USA
    Psychopharmacology (Berl) 224:349-62. 2012
    ..These differences may inform us about the biology of PPI deficits in disorders such as schizophrenia...
  29. pmc Hierarchical organization of gamma and theta oscillatory dynamics in schizophrenia
    Kenji Kirihara
    Department of Psychiatry, University of California, San Diego, La Jolla, California 92093 0804, USA
    Biol Psychiatry 71:873-80. 2012
    ....
  30. pmc Forebrain gene expression predicts deficits in sensorimotor gating after isolation rearing in male rats
    Neal R Swerdlow
    Department of Psychiatry, UCSD School of Medicine, 9500 Gilman Dr, La Jolla, CA 92093 0804, USA Electronic address
    Behav Brain Res 257:118-28. 2013
    ..These results support the model that specific gene-behavior relationships moderate the impact of early-life experience on SZ-linked behavioral and neurophysiological markers. ..
  31. ncbi request reprint Paternal age of schizophrenia probands and endophenotypic differences from unaffected siblings
    James Schmeidler
    Department of Psychiatry, Icahn School of Medicine at Mount Sinai School, One Gustave L Levy Place, Box 1230, New York, NY, USA
    Psychiatry Res 219:67-71. 2014
    ..A possible explanation is that the identification of heritable endophenotypes was based on samples for which schizophrenia was attributable to inherited rather than de novo/non-inherited causes. ..
  32. ncbi request reprint Sensory and sensorimotor gating deficits after neonatal ventral hippocampal lesions in rats
    Neal R Swerdlow
    Department of Psychiatry, University of California, San Diego, La Jolla, CA 92093, USA
    Dev Neurosci 34:240-9. 2012
    ..In this study, lesion effects were detected prior to pubertal onset, and were sustained well into adulthood...
  33. ncbi request reprint Preattentional and attentional cognitive deficits as targets for treating schizophrenia
    David L Braff
    Department of Psychiatry, Medical Center, University of California, 200 West Arbor Drive, San Diego, CA 92103 8816, USA
    Psychopharmacology (Berl) 174:75-85. 2004
    ..These neurophysiological measures cover a spectrum from automatic preattentional to attention-dependent processes...
  34. pmc Superior size-weight illusion performance in patients with schizophrenia: evidence for deficits in forward models
    Lisa E Williams
    Department of Psychology, University of California San Diego, 9500 Gilman Drive 0109, La Jolla, CA 92093 0109, USA
    Schizophr Res 121:101-6. 2010
    ..The current findings are consistent with a dysfunctional forward model mechanism in this population. Future studies to elucidate the locus of this impairment using variations on the current study are also proposed...
  35. ncbi request reprint Neurophysiological measures of sensory registration, stimulus discrimination, and selection in schizophrenia patients
    Anthony J Rissling
    Department of Psychiatry, University of California, San Diego, CA 92093 0804, USA
    Curr Top Behav Neurosci 4:283-309. 2010
    ....
  36. pmc Association analysis of 94 candidate genes and schizophrenia-related endophenotypes
    Tiffany A Greenwood
    Department of Psychiatry, University of California San Diego, La Jolla, California, United States of America
    PLoS ONE 7:e29630. 2012
    ..The observation of extensive pleiotropy for some genes and singular associations for others in our data may suggest both converging and independent genetic (and neural) pathways mediating schizophrenia risk and pathogenesis...
  37. pmc Realistic expectations of prepulse inhibition in translational models for schizophrenia research
    Neal R Swerdlow
    Department of Psychiatry, UCSD School of Medicine, La Jolla, CA, 92093 0804, USA
    Psychopharmacology (Berl) 199:331-88. 2008
    ..This rapid expansion and broad application of PPI as a tool for understanding schizophrenia has, at times, outpaced critical thinking and falsifiable hypotheses about the relative strengths vs. limitations of this measure...
  38. pmc Neurophysiologic markers of abnormal brain activity in schizophrenia
    Anthony J Rissling
    Department of Psychiatry, University of California San Diego, La Jolla, 92093 0804, USA
    Curr Psychiatry Rep 12:572-8. 2010
    ....
  39. pmc Older patients with schizophrenia: does military veteran status matter?
    Steven R Thorp
    Department of Psychiatry, University of California, San Diego, California 92108, USA
    Am J Geriatr Psychiatry 20:248-56. 2012
    ..The objective of this study was to examine the influence of military veteran status within a data set of older patients with schizophrenia or schizoaffective disorder...
  40. pmc Convergence and divergence in the neurochemical regulation of prepulse inhibition of startle and N40 suppression in rats
    Neal R Swerdlow
    Department of Psychiatry, UCSD School of Medicine, La Jolla, CA 92093 0804, USA
    Neuropsychopharmacology 31:506-15. 2006
    ..Despite similarities in drug sensitivity, these results suggest that distinct neurobiological mechanisms underlie drug-induced deficits in PPI and N40 gating...
  41. pmc The 5-choice continuous performance test: evidence for a translational test of vigilance for mice
    Jared W Young
    Department of Psychiatry, University of California San Diego, La Jolla, California, United States of America
    PLoS ONE 4:e4227. 2009
    ..Although vigilance is assessed frequently using the continuous performance test (CPT) in humans, few tests specifically assess vigilance in rodents...
  42. ncbi request reprint Efficacy and tolerability of low-dose donepezil in schizophrenia
    Steven K Erickson
    University of Rochester Medical Center, Department of Psychiatry, New York 14642, USA
    Clin Neuropharmacol 28:179-84. 2005
    ..These results suggest that donepezil may be helpful as adjunctive therapy for the treatment of psychiatric symptoms and cognitive impairment in a subgroup of schizophrenic patients...
  43. pmc Coupling of gene expression in medial prefrontal cortex and nucleus accumbens after neonatal ventral hippocampal lesions accompanies deficits in sensorimotor gating and auditory processing in rats
    Neal R Swerdlow
    Department of Psychiatry, UCSD School of Medicine, 9500 Gilman Dr, Mail Code 0804, La Jolla, CA 92093 0804, USA Electronic address
    Neuropharmacology 75:38-46. 2013
    ..We assessed PPI, auditory-evoked responses and expression of 7 schizophrenia-related genes in mPFC and NAC, in adult rats after sham- or real NVHLs...
  44. ncbi request reprint Neurobiological measures of schizotypal personality disorder: defining an inhibitory endophenotype?
    Kristin S Cadenhead
    Department of Psychiatry, University of California, San Diego, La Jolla, 92093 0810, USA
    Am J Psychiatry 159:869-71. 2002
    ....
  45. ncbi request reprint On the waveform of the acoustic startle blink in the paradigm of prepulse inhibition - methodological and physiological aspects
    Ulrich Meincke
    Department of Psychiatry, University of California San Diego, La Jolla, USA
    Neuropsychobiology 52:24-7. 2005
    ..These findings support the view that both components of the acoustically evoked OOM response exhibit similar plasticity in the paradigm of prepulse inhibition...
  46. pmc The use of neurophysiological endophenotypes to understand the genetic basis of schizophrenia
    David L Braff
    Department of Psychiatry, University of California, San Diego, 9500 Gilman Drive, Mail Code 0804, La Jolla 92093, USA
    Dialogues Clin Neurosci 7:125-35. 2005
    ..The power and utility of utilizing endophenotypes to understand the genetics of schizophrenia is discussed in detail in this article...
  47. pmc Electrophysiological insights into conceptual disorganization in schizophrenia
    Michael Kiang
    Department of Cognitive Science, University of California San Diego, 9500 Gilman Dr, Mail Code 0515, La Jolla, CA 92093 0515, USA
    Schizophr Res 92:225-36. 2007
    ....
  48. pmc Advances in endophenotyping schizophrenia
    David L Braff
    Department of Psychiatry, University of California at San Diego, 9500 Gilman Drive, La Jolla, CA 92093 0804, USA
    World Psychiatry 7:11-8. 2008
    ..By identifying the single nucleotide polymorphisms (SNPs) associated with endophenotypes in schizophrenia, psychiatric neuroscientists can select new strong inference based molecular targets for the treatment of schizophrenia...
  49. pmc The Consortium on the Genetics of Endophenotypes in Schizophrenia: model recruitment, assessment, and endophenotyping methods for a multisite collaboration
    Monica E Calkins
    Neuropsychiatry Section, Department of Psychiatry, University of Pennsylvania, 10 Gates, 3400 Spruce St, Philadelphia, PA 19104, USA
    Schizophr Bull 33:33-48. 2007
    ..The purpose of this article is to provide a description of the COGS structure and methods, including participant recruitment and assessment...
  50. pmc Is there an association between advanced paternal age and endophenotype deficit levels in schizophrenia?
    Debby Tsuang
    VISN 20 Geriatric Research, Education, and Clinical Center, VA Puget Sound Health Care System, Seattle, Washington, United States of America Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, Washington, United States of America
    PLoS ONE 9:e88379. 2014
    ..These findings suggest that factors other than advanced paternal age at birth may account for endophenotypic deficit levels in schizophrenia. ..
  51. ncbi request reprint Visual masking as a probe for abnormal gamma range activity in schizophrenia
    Michael Foster Green
    Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, Los Angeles, California 90024 1759, USA
    Biol Psychiatry 53:1113-9. 2003
    ..We conducted two experiments to determine whether visual masking procedures can reveal underlying abnormalities in gamma range oscillations in schizophrenia...
  52. pmc Verbal working memory impairments in individuals with schizophrenia and their first-degree relatives: findings from the Consortium on the Genetics of Schizophrenia
    William P Horan
    Department of Psychiatry and Biobehavioral Sciences, Geffen School of Medicine at University of California Los Angeles, Los Angeles, California 90095 6968, USA
    Schizophr Res 103:218-28. 2008
    ....
  53. ncbi request reprint Successful multi-site measurement of antisaccade performance deficits in schizophrenia
    Allen D Radant
    Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, Washington, United States
    Schizophr Res 89:320-9. 2007
    ..These results confirm previous findings of antisaccade deficits in schizophrenia subjects and support the use of the antisaccade task as a potential schizophrenia endophenotype in multi-site genetic studies...
  54. ncbi request reprint Relationship between P50 suppression and the cortical silent period
    Bertram Moller
    Schizophrenia Program, Centre for Addiction and Mental Health, Universty of Toronto, 250 College Street, M5T IR8, Toronto, Ontario, Canada
    Neuroreport 18:1503-6. 2007
    ....
  55. ncbi request reprint Sensitization and habituation of the acoustic startle reflex in patients with schizophrenia
    Ulrich Meincke
    Department of Psychiatry and Psychotherapy, Technical University of Aachen, Pauwelsstrasse 30, D 52057 Aachen, Germany
    Psychiatry Res 126:51-61. 2004
    ..In addition, the present data have important implications for designing startle studies to assess sensitization, habituation and prepulse inhibition in one session...
  56. ncbi request reprint Event-related gamma activity in schizophrenia patients during a visual backward-masking task
    Jonathan K Wynn
    Department of Psychology, UCLA, Los Angeles, CA, USA
    Am J Psychiatry 162:2330-6. 2005
    ..This study examined event-related gamma range activity during a visual backward-masking task in schizophrenia patients and normal comparison subjects...