Jeff Victoroff
University of Southern California
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Featured researches published by Jeff Victoroff.
Journal of Conflict Resolution | 2005
Jeff Victoroff
This article reviews the state of the art of available theories and data regarding the psychology of terrorism. Data and theoretical material were gathered from the world’s unclassified literature. Multiple theories and some demographic data have been published, but very few controlled empirical studies have been conducted investigating the psychological bases of terrorism. The field is largely characterized by theoretical speculation based on subjective interpretation of anecdotal observations. Moreover, most studies and theories fail to take into account the great heterogeneity of terrorists. Many practical, conceptual, and psychological barriers have slowed progress in this important field. Nonetheless, even at this early stage of terrorism studies, preliminary reports suggest that modifiable social and psychological factors contribute to the genesis of the terrorist mind-set. Psychological scholarship could possibly mitigate the risk of catastrophic attack by initiating the long overdue scientific study of terrorist mentalities.
Neurology | 2002
R. B. Parkinson; Ramona O. Hopkins; H. B. Cleavinger; Lindell K. Weaver; Jeff Victoroff; J. F. Foley; Erin D. Bigler
BackgroundCarbon monoxide (CO) poisoning may result in white matter hyperintensities (WMH) and neurocognitive impairments. ObjectiveTo assess in a prospective study WMH in CO-poisoned patients and their relationship to cognitive functioning. MethodsSeventy-three consecutive CO-poisoned patients were studied. MR scans and neurocognitive tests were administered on day 1 (within 36 hours after CO poisoning), 2 weeks, and 6 months. Age- and sex-matched control subjects for white matter analyses only were obtained from the authors’ normative imaging database. MR scans were rated for WMH in the periventricular and centrum semiovale regions, using a 4-point rating scale. Two independent raters rated the scans, and a consensus was reached. ResultsThirty percent of CO-poisoned patients had cognitive sequelae. Twelve percent of the CO-poisoned patients had WMH, with significantly more periventricular, but not centrum semiovale, WMH than control subjects. The WMH in CO-poisoned patients did not change from day 1 to 6 months. Centrum semiovale hyperintensities were related to worse cognitive performance. Duration of loss of consciousness correlated with cognitive impairment at all three times. Initial carboxyhemoglobin levels correlated with loss of consciousness but not with WMH or cognitive sequelae. ConclusionsCO poisoning can result in brain injury manifested by WMH and cognitive sequelae. The WMH were not related to CO poisoning severity. The WMH occurred in both the periventricular and the centrum semiovale regions; however, only those in the centrum semiovale were significantly associated with cognitive impairments.
Neurology | 1994
Jeff Victoroff; Wendy J. Mack; S. T. Grafton; S. S. Schreiber; H. C. Chui
MR scanning is used in the clinical evaluation of patients with dementia but lacks a reliable method of visual inspection. Two neurologists conducted multiple pilot trials of alternate methods for visual inspection of MRIs, including methods that produced at least 75% interrater agreement in repeat trials, and selected a final method for rating ventricular:brain ratio (VBR), cortical atrophy, and white matter changes. Two other neurologists, new to the method, tested interrater reliability for each component of the method after a brief training session. The correlation of VBR measurement was 0.884 (p = 0.0001). The weighted kappa scores were 0.68 for overall frontal lobe atrophy, 0.38 for right temporal lobe atrophy, 0.20 for left temporal lobe atrophy, and 0.54 for parietal lobe atrophy. The weighted kappa scores were 0.77 for overall periventricular white matter hyperintensities and 0.72 for centrum semiovale hyperintensities. The proposed method may provide a rapid and reliable way to assess VBR, frontal lobe atrophy, parietal lobe atrophy, and white matter changes on brain MRIs in the evaluation of dementia, but it was less reliable for the assessment of temporal lobe atrophy.
Journal of Neuroimaging | 2006
Ramona O. Hopkins; Callie J. Beck; David L. Burnett; Lindell K. Weaver; Jeff Victoroff; Erin D. Bigler
Background and Purpose. White matter hyperintensities (WMHs) are bright objects observed in the white matter on brain magnetic resonance (MR) imaging. WMHs are often reported as “normal” findings but may represent pathological changes. The prevalence of WMHs appears to increase with increasing age although both the typical timing and clinical significance of their appearance among medically and neurologically healthy persons remains unclear. We assessed the prevalence of WMHs in a cohort of younger healthy subjects. Methods. Our study comprised 243 healthy subjects ages 16‐65 years from our prospective normative MR imaging database. MR scans were rated for presence of periventricular and centrum semiovale WMHs using a four‐point visual semi‐quantitative scale. Results. WMHs occurred in 5.3% (13 of 243) of subjects. All WMHs were small (rating of 0.5) except one subject age 65 years who had large WMHs (ratings of 2). The median age for subjects with no WMHs was 34.5 years compared to 57.0 years for subjects with WMHs. There were no gender differences (P= .76). Older age correlated with presence of WMHs (r= 0.24; P= .01). Age greater than 55 years had a 10‐fold increase in the prevalence of WMHs compared to age ≤55 years (odds ratio = 10.01; 95% confidence interval = 3.1‐32.3; P < .001). Conclusion. WMHs were uncommon in a younger healthy population screened for comorbid diseases, but increased 10‐fold in subjects over 55 years of age. When present, the WMHs are generally small (rating of 0.5). While large WMHs appear to be associated with cognitive deterioration, the optimum threshold for identification, clinical significance, and prognostic value of smaller white matter changes requires further research.
International Journal of Law and Psychiatry | 2009
Allan Siegel; Jeff Victoroff
The present paper reviews and summarizes the basic findings concerning the nature of the neurobiological and behavioral characteristics of aggression and rage. For heuristic purposes, the types of aggression will be reduced to two categories - defensive rage (affective defense) and predatory attack. This approach helps explain both the behavioral properties of aggression as well as the underlying neural substrates and mechanisms of aggression both in animals and humans. Defensive rage behavior is activated by a threatening stimulus that is real or perceived and is associated with marked sympathetic output. This yields impulsivity with minimal cortical involvement. Predatory attack behavior in both animals and humans is generally planned, taking minutes, hours, days, weeks, months, or even years (with respect to humans) for it to occur and is directed upon a specific individual target; it reflects few outward sympathetic signs and is believed to require cortical involvement for its expression. Predatory attack requires activation of the lateral hypothalamus, while defensive rage requires activation of the medial hypothalamus and midbrain periaqueductal gray (PAG). Both forms of aggressive behavior are controlled by components of the limbic system, a region of the forebrain that is influenced by sensory inputs from the cerebral cortex and monoaminergic inputs from the brainstem reticular formation. Control of aggressive tendencies is partly modifiable through conditioning and related learning principles generated through the cerebral cortex.
Dementia and Geriatric Cognitive Disorders | 1998
Jeff Victoroff; Wendy J. Mack; Kristy A. Nielson
This study was designed to determine the relationship between psychiatric features of dementia and their impact on caregivers. 35 patient-caregiver pairs were evaluated at two university-affiliated dementia clinics, using standard instruments to rate patient psychiatric features and caregiver burden and depression. There were highly significant correlations between patient agitation and both caregiver burden (r = 0.59, p = 0.0002) and depression (r = 61, p = 0.0001). These associations remained significant after adjusting for multiple demographic and dementia variables. There was no significant association between patient delusions, hallucinations, or depression and caregiver burden or depression. Agitation, particularly physical aggression, may impact caregivers even more than does the cognitive status of the demented patient.
American Journal of Psychiatry | 2009
Jason Schiffman; Holger J. Sørensen; Justin Maeda; Erik Lykke Mortensen; Jeff Victoroff; Kentaro Hayashi; Niels M. Michelsen; Morten Ekstrøm; Sarnoff A. Mednick
OBJECTIVE The authors examined whether motor coordination difficulties assessed in childhood predict later adult schizophrenia spectrum outcomes. METHOD A standardized childhood neurological examination was administered to a sample of 265 Danish children in 1972, when participants were 10-13 years old. Adult diagnostic information was available for 244 members of the sample. Participants fell into three groups: children whose mothers or fathers had a psychiatric hospital diagnosis of schizophrenia (N=94); children who had at least one parent with a psychiatric record of hospitalization for a nonpsychotic disorder (N=84); and children with no parental records of psychiatric hospitalization (N=66). Psychiatric outcomes of the offspring were assessed through psychiatric interviews in 1992 when participants were 31-33 years of age, as well as through a scan of national psychiatric registers completed in May 2007. RESULTS Children who later developed a schizophrenia spectrum disorder (N=32) displayed significantly higher scores on a scale of coordination deficits compared with those who did not develop a mental illness in this category (N=133). CONCLUSIONS Results from this study provide further support for the neurodevelopmental hypothesis of schizophrenia and underscore the potential role of cerebellar and/or basal ganglia abnormalities in the etiology and pathophysiology of schizophrenia.
Alzheimer Disease & Associated Disorders | 2002
Erin D. Bigler; Burton Kerr; Jeff Victoroff; David F. Tate; John C. S. Breitner
The authors performed quantitative and qualitative image analysis on a sample of the elderly population of Cache County, Utah, relating neuroimaging findings to Mini-Mental Status Examination (MMSE) scores and the presence of the apolipoprotein E ε4 allele. Neuroimaging measures included white, gray, and hippocampal volumes; a ventricle-to-brain ratio (VBR); and qualitative ratings of white matter lesions (WMLs) in the periventricular (PV) and centrum semiovale (CS) regions. Subjects included 85 persons with possible and probable Alzheimer disease (AD), 21 with vascular dementia (VaD), 30 with cognitive symptoms classified as mild/ambiguous (M/A), a heterogenous group of 39 non-AD or VaD subjects but diagnosed with some form of neuropsychiatric disorder (“Mixed Neuropsychiatric” group), and 20 normal control subjects aged 65 years or older. Controlling for age, sex, and length of disease, the authors found that AD and VaD subjects differed significantly from control subjects on WMLs, but only the VaD subjects significantly differed from M/A subjects. The two dementia groups also displayed, as expected, significant cerebral atrophy. The WMLs generally increased with age and severity of dementia. PV WMLs were significantly but only modestly associated with white matter volume loss and greater impairment on the MMSE. Modest correlations were also present between the quantitative measures of cerebral structure and MMSE performance. However, when degree of cerebral atrophy was controlled by using the VBR measure, WML effects on MMSE performance became nonsignificant, with the only significant relationship remaining being that between hippocampal volume and MMSE performance. There were no significant qualitative or quantitative findings related to presence of the ε4 allele and MMSE performance. The role of WMLs in aging and dementia is discussed.
Psychiatry MMC | 2009
Jerrold M. Post; Farhana Ali; Schuyler W. Henderson; Stephen B. Shanfield; Jeff Victoroff; Stevan Weine
This paper reviews current understandings of the psychology of suicide terrorism for psychiatrists and other mental health professionals to help them better understand this terrifying phenomenon. After discussing key concepts and definitions, the paper reviews both group and individual models for explaining the development of suicide terrorists, with an emphasis on “collective identity.” Stressing the importance of social psychology, it emphasizes the “normality” and absence of individual psychopathology of the suicide bombers. It will discuss the broad range of terrorisms, but will particularly emphasize terrorism associated with militant Islam. The article emphasizes that comprehending suicide terrorism requires a multidisciplinary approach that includes anthropological, economic, historical, and political factors as well as psychological ones. The paper concludes with a discussion of implications for research, policy, and prevention, reviewing the manner in which social psychiatric knowledge and understandings applied to this phenomenon in an interdisciplinary framework can assist in developing approaches to counter this deadly strategy.
Experimental Neurology | 1998
Chris Zarow; Jeff Victoroff
The distribution of apolipoprotein E (ApoE) mRNA was characterized in the hippocampus of humans with Alzheimer disease (AD) and in rats with experimental lesions (unilateral ablation of the entorhinal cortex) that model selected features of AD. In both AD and the lesion model, we observed a shift in the location of astrocytes containing prevalent ApoE mRNA from the neuropil to regions with densely packed neurons. The increased abundance of ApoE mRNA in astrocytes close to neuron cell bodies could be indicative of lipid uptake in regions where neurons are degenerating or where synaptic remodeling is taking place.