Sara Simon | Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center (original) (raw)

Papers by Sara Simon

Journal of Addictive Diseases, 2001

Forty currently using methamphetamine (MA) abusers, 40 currently using cocaine (COC) abusers, and... more Forty currently using methamphetamine (MA) abusers, 40 currently using cocaine (COC) abusers, and 80 comparison participants who did not use psychostimulants received a cognitive battery and questionnaires covering medical history and stimulant use patterns. Forty comparison participants were matched to the 40 MA users on age, education, ethnicity, and gender. The other 40 comparison participants were matched to the cocaine users on the same variables. This design was chosen because there were significant differences in age and ethnicity between COC and MA users that precluded a direct comparison between the groups. The COC group was older and predominantly African American compared to the predominantly Caucasian MA group. When compared to their matched non-using control groups, both MA and COC abusers were impaired on cognitive measures, but the type and degree of impairments were somewhat different.

Biological Psychiatry, 2005

Archives of General Psychiatry, 2004

Background: Mood disturbances in methamphetamine (MA) abusers likely influence drug use, but the ... more Background: Mood disturbances in methamphetamine (MA) abusers likely influence drug use, but the neurobiological bases for these problems are poorly understood. Objective: To assess regional brain function and its possible relationships with negative affect in newly abstinent MA abusers. Design: Two groups were compared by measures of mood and cerebral glucose metabolism ([ 18 F]fluorodeoxyglucose positron emission tomography) during performance of a vigilance task. Setting: Participants were recruited from the general community to a research center. Participants: Seventeen abstaining (4-7 days) MA abusers (6 women) were compared with 18 control subjects (8 women). Main Outcome Measures: Self-reports of depressive symptoms and anxiety were measured, as were global and relative glucose metabolism in the orbitofrontal, cingulate, lateral prefrontal, and insular cortices and the amygdala, striatum, and cerebellum.

Journal of Addictive Diseases, 2001

Understanding the association between attention deficit hyperactivity disorder (ADHD) and substan... more Understanding the association between attention deficit hyperactivity disorder (ADHD) and substance abuse, specifically methamphetamine (MA) abuse, is challenging, partly because little is known about the specific constellation of cognitive impairments produced by MA. The present investigation serves to address this relationship by comparing the cognitive performance of MA abusers with ADHD symptomatology (n = 28) and MA abusers without ADHD symptomatology (n = 41) on tests of attention, memory and general intellectual functioning, executive functioning, problem solving, verbal fluency, and abstract thinking. Both MA samples had deficiencies in measures of memory and learning function, psychomotor speed and abstract thinking when compared to a control group (n = 40). Additional deficits were noted on tasks involving executive functioning, attention, and general intellectual functioning in MA abusers with ADHD symptomatology. The preliminary data suggests that executive function deficits and some of the symptoms associated with long-term MA use may be due to the fact that a large proportion of MA addicts had ADHD symptomatology as children.

This study tested effects of smoking history and withdrawal using two cognitive tasks: N-Back Tas... more This study tested effects of smoking history and withdrawal using two cognitive tasks: N-Back Task (working memory), Stroop Color Word Interference Task (selective attention, response inhibition). The N-Back Task included three conditions: 0-back (respond when an “X” appears), 1-back (respond when the letter matches the preceding one), 2-back (respond when it matches the letter 2-back in the sequence), 3-back (respond

Difficulty in focusing attention is a feature of the nicotine withdrawal syndrome; and alleviatio... more Difficulty in focusing attention is a feature of the nicotine withdrawal syndrome; and alleviation of this problem by cigarette smoking can undermine attempts to quit. Understanding the neural bases for deficits in focused attention and the effect of acute smoking in abstinent smokers may help tailor the design of treatments for smoking cessation. We tested smokers and nonsmokers (n =

Compared to nonsmokers individuals who smoke cigarettes perform differently on working memory tas... more Compared to nonsmokers individuals who smoke cigarettes perform differently on working memory tasks such as the N-Back task. Here we paired fMRI (BOLD) with this task to assess the neural correlates of this task as a function of smoking status. Two groups (smokers & nonsmokers n=8 3 females/group 20-54 yr) were tested in the afternoon. Smoking ad libitum was allowed

Psychology and Aging, 1992

Measures of spatial cognition, neighborhood knowledge, and neighborhood use from the research des... more Measures of spatial cognition, neighborhood knowledge, and neighborhood use from the research described by Walsh, Krauss, and Regnier (1981) were examined to determine if laboratory tests of spatial cognition were significant predictors of older adults' use of their neighborhoods. The overall results show that laboratory-based measures of spatial cognition and subjects' knowledge of their neighborhoods are both significant predictors of their use of neighborhood goods and services. The ability to learn and remember the location and orientation of objects, when contextual cues were not provided at test, was more predictive of the participants' neighborhood use than either the participants' number of years in the neighborhood or their mobility. Spatial memory as measured by the Educational Testing Service Building Memory task predicted neighborhood knowledge, which was predictive of neighborhood use.

Memory & Cognition, 1987

sis is the semantic integration of visual information with the simultaneously presented auditory/... more sis is the semantic integration of visual information with the simultaneously presented auditory/verbal material. Consistent with this model, young children find the visual information on television more salient and memorable than the audio material (Pezdek & Stevens, 1984), and children use the visually presented information to guide their comprehension of auditorily presented material (Pezdek & Hartman, 1983).

Child Development, 1984

This study compares the relationship between comprehension and memory for text and television, an... more This study compares the relationship between comprehension and memory for text and television, and comprehension and memory for text and radio, 2 stories were edited to create 3 matched versions of each-(1) a storybook with pictures, (2) a radio version, and (3) a television version. Third and sixth graders read 1 story and were presented either the television or radio version ofthe other story, counterbalanced for story and order of presentation, A battery of memory and comprehension tests was administered following both the reading and the television or radio conditions. The principal result is that across a range of tasks, performance in the television and reading conditions was not significantly correlated; however, performance in the radio and reading conditions was positively correlated and generally significant. The second important finding is that the absolute levels of performance were similar in the television and reading conditions, and performance was better in both of these conditions than in the radio condition. Hypotheses are discussed to explain why performance in the television condition was not related to reading ability. This research was supported by the National Institute of Education (NIE G-81-0049) and the Haynes Foundation. Portions of these findings were presented at the meeting of the Society for Research in Ghild Development, Detroit, 1983, and the meeting of the Psychonomic Society, San Diego, 1983, We are very grateful to Patricia Greenfield for the use of her materials. We acknowledge the assistance of Mark Runco with the data analysis and Allan Ribbler for data collection. We also appreciate the cooperation of Jack Hassinger, Robert Vislay, and the students and staff at Kingsley,

American Journal on Addictions, 2000

D espite the recent resurgence in methamphetamine (MA) use, there is little evidence concerning w... more D espite the recent resurgence in methamphetamine (MA) use, there is little evidence concerning whether MA affects the cognitive processes of MA users. Although there are extensive anecdotal reports about MA detrimentally affecting the memory of users, there has been little systematic study of MA on cognition or memory. Since at this time cognitive behavioral interventions are used for MA treatment, 1 it is particularly important for providers of these types of treatment to know the cognitive capabilities of the population coming to them for treatment. It is important to distinguish between``the effects of long-term use'' and the``long-term effects'' of MA. The former, which are the topic of this study, are the cognitive effects of using MA over a long period of time. The``long-term effects'' of MA are the effects of using MA that persist over a period of time. Since the MA users participating in this study are still using MA, we will not be able to determine anything about the long-term effects. These are important, and are being addressed by this group, but the focus of this study is the population of MA users who have been using over 6 months and who are still using. The literature to date consists of evidence from animal studies for neurotoxicity associated with repeated exposure to high doses of amphetamine or MA. 2¡6 In contrast to the animal data, many of the studies done with normal adults investigating the effect of MA administration show increases in cognitive abilities. The most consistent results have been found for sleep deprived subjects. Carpenter 7

Journal of Addictive Diseases, 2001

Understanding the association between attention deficit hyperactivity disorder (ADHD) and substan... more Understanding the association between attention deficit hyperactivity disorder (ADHD) and substance abuse, specifically methamphetamine (MA) abuse, is challenging, partly because little is known about the specific constellation of cognitive impairments produced by MA. The present investigation serves to address this relationship by comparing the cognitive performance of MA abusers with ADHD symptomatology (n = 28) and MA abusers without ADHD symptomatology (n = 41) on tests of attention, memory and general intellectual functioning, executive functioning, problem solving, verbal fluency, and abstract thinking. Both MA samples had deficiencies in measures of memory and learning function, psychomotor speed and abstract thinking when compared to a control group (n = 40). Additional deficits were noted on tasks involving executive functioning, attention, and general intellectual functioning in MA abusers with ADHD symptomatology. The preliminary data suggests that executive function deficits and some of the symptoms associated with long-term MA use may be due to the fact that a large proportion of MA addicts had ADHD symptomatology as children.

Journal of Addictive Diseases, 2001

Typical use patterns of methamphetamine (MA) users were examined using self-report measures from ... more Typical use patterns of methamphetamine (MA) users were examined using self-report measures from 120 MA and 63 cocaine users. Twenty (14 MA and 6 cocaine) of the participants also took part in structured interviews designed to provide more specific descriptions of their drug use. The typical MA user uses more than 20 days a month. Use is evenly spaced throughout the day, and although the amount of drug used per day is not different, MA users use fewer times per day than do cocaine users. Fewer of the cocaine users are continuous users, and they use in the evening rather than the daytime. The cocaine pattern of fewer days of use, evening use, and more frequent doses per day fits a picture of recreational use, whereas the all-day-most-days methamphetamine pattern does not.

Biological Psychiatry, 2005

Background: Methamphetamine (MA) abusers have cognitive deficits, abnormal metabolic activity and... more Background: Methamphetamine (MA) abusers have cognitive deficits, abnormal metabolic activity and structural deficits in limbic and paralimbic cortices, and reduced hippocampal volume. The links between cognitive impairment and these cerebral abnormalities are not established. Methods: We assessed cerebral glucose metabolism with [F-18]fluorodeoxyglucose positron emission tomography in 17 abstinent (4 to 7 days) methamphetamine users and 16 control subjects performing an auditory vigilance task and obtained structural magnetic resonance brain scans. Regional brain radioactivity served as a marker for relative glucose metabolism. Error rates on the task were related to regional radioactivity and hippocampal morphology Results. Methamphetamine users bad higher error rate than control subjects on the vigilance task. The groups showed different relationships between error rates and relative activity), in the anterior and middle cingulate gyrus and the insula. Whereas the MA user group showed negative correlations involving these regions, the control group showed positive correlations involving the cingulate eScholarship provides open access, scholarly publishing services to the University of California and delivers a dynamic research platform to scholars worldwide. cortex. Across groups, hippocampal metabolic and structural measures were negatively correlated with error rates. Conclusions: Dysfunction in the cingulate and insular cortices of recently abstinent MA abusers contribute to impaired vigilance and other cognitive functions requiring sustained attention. Hippocampal integrity predicts task performance in methamphetamine users as well as control subjects.

Archives of General Psychiatry, 2004

Background: Mood disturbances in methamphetamine (MA) abusers likely influence drug use, but the ... more Background: Mood disturbances in methamphetamine (MA) abusers likely influence drug use, but the neurobiological bases for these problems are poorly understood.

Biological Psychiatry, 2005

Background: Methamphetamine (MA) abusers have cognitive deficits, abnormal metabolic activity and... more Background: Methamphetamine (MA) abusers have cognitive deficits, abnormal metabolic activity and structural deficits in limbic and paralimbic cortices, and reduced hippocampal volume. The links between cognitive impairment and these cerebral abnormalities are not established. Methods: We assessed cerebral glucose metabolism with [F-18]fluorodeoxyglucose positron emission tomography in 17 abstinent (4 to 7 days) methamphetamine users and 16 control subjects performing an auditory vigilance task and obtained structural magnetic resonance brain scans. Regional brain radioactivity served as a marker for relative glucose metabolism. Error rates on the task were related to regional radioactivity and hippocampal morphology Results. Methamphetamine users bad higher error rate than control subjects on the vigilance task. The groups showed different relationships between error rates and relative activity), in the anterior and middle cingulate gyrus and the insula. Whereas the MA user group showed negative correlations involving these regions, the control group showed positive correlations involving the cingulate eScholarship provides open access, scholarly publishing services to the University of California and delivers a dynamic research platform to scholars worldwide. cortex. Across groups, hippocampal metabolic and structural measures were negatively correlated with error rates. Conclusions: Dysfunction in the cingulate and insular cortices of recently abstinent MA abusers contribute to impaired vigilance and other cognitive functions requiring sustained attention. Hippocampal integrity predicts task performance in methamphetamine users as well as control subjects.

Journal of Addictive Diseases, 2001

Forty currently using methamphetamine (MA) abusers, 40 currently using cocaine (COC) abusers, and... more Forty currently using methamphetamine (MA) abusers, 40 currently using cocaine (COC) abusers, and 80 comparison participants who did not use psychostimulants received a cognitive battery and questionnaires covering medical history and stimulant use patterns. Forty comparison participants were matched to the 40 MA users on age, education, ethnicity, and gender. The other 40 comparison participants were matched to the cocaine users on the same variables. This design was chosen because there were significant differences in age and ethnicity between COC and MA users that precluded a direct comparison between the groups. The COC group was older and predominantly African American compared to the predominantly Caucasian MA group. When compared to their matched non-using control groups, both MA and COC abusers were impaired on cognitive measures, but the type and degree of impairments were somewhat different.

Biological Psychiatry, 2005

Archives of General Psychiatry, 2004

Background: Mood disturbances in methamphetamine (MA) abusers likely influence drug use, but the ... more Background: Mood disturbances in methamphetamine (MA) abusers likely influence drug use, but the neurobiological bases for these problems are poorly understood. Objective: To assess regional brain function and its possible relationships with negative affect in newly abstinent MA abusers. Design: Two groups were compared by measures of mood and cerebral glucose metabolism ([ 18 F]fluorodeoxyglucose positron emission tomography) during performance of a vigilance task. Setting: Participants were recruited from the general community to a research center. Participants: Seventeen abstaining (4-7 days) MA abusers (6 women) were compared with 18 control subjects (8 women). Main Outcome Measures: Self-reports of depressive symptoms and anxiety were measured, as were global and relative glucose metabolism in the orbitofrontal, cingulate, lateral prefrontal, and insular cortices and the amygdala, striatum, and cerebellum.

Journal of Addictive Diseases, 2001

Understanding the association between attention deficit hyperactivity disorder (ADHD) and substan... more Understanding the association between attention deficit hyperactivity disorder (ADHD) and substance abuse, specifically methamphetamine (MA) abuse, is challenging, partly because little is known about the specific constellation of cognitive impairments produced by MA. The present investigation serves to address this relationship by comparing the cognitive performance of MA abusers with ADHD symptomatology (n = 28) and MA abusers without ADHD symptomatology (n = 41) on tests of attention, memory and general intellectual functioning, executive functioning, problem solving, verbal fluency, and abstract thinking. Both MA samples had deficiencies in measures of memory and learning function, psychomotor speed and abstract thinking when compared to a control group (n = 40). Additional deficits were noted on tasks involving executive functioning, attention, and general intellectual functioning in MA abusers with ADHD symptomatology. The preliminary data suggests that executive function deficits and some of the symptoms associated with long-term MA use may be due to the fact that a large proportion of MA addicts had ADHD symptomatology as children.

This study tested effects of smoking history and withdrawal using two cognitive tasks: N-Back Tas... more This study tested effects of smoking history and withdrawal using two cognitive tasks: N-Back Task (working memory), Stroop Color Word Interference Task (selective attention, response inhibition). The N-Back Task included three conditions: 0-back (respond when an “X” appears), 1-back (respond when the letter matches the preceding one), 2-back (respond when it matches the letter 2-back in the sequence), 3-back (respond

Difficulty in focusing attention is a feature of the nicotine withdrawal syndrome; and alleviatio... more Difficulty in focusing attention is a feature of the nicotine withdrawal syndrome; and alleviation of this problem by cigarette smoking can undermine attempts to quit. Understanding the neural bases for deficits in focused attention and the effect of acute smoking in abstinent smokers may help tailor the design of treatments for smoking cessation. We tested smokers and nonsmokers (n =

Compared to nonsmokers individuals who smoke cigarettes perform differently on working memory tas... more Compared to nonsmokers individuals who smoke cigarettes perform differently on working memory tasks such as the N-Back task. Here we paired fMRI (BOLD) with this task to assess the neural correlates of this task as a function of smoking status. Two groups (smokers & nonsmokers n=8 3 females/group 20-54 yr) were tested in the afternoon. Smoking ad libitum was allowed

Psychology and Aging, 1992

Measures of spatial cognition, neighborhood knowledge, and neighborhood use from the research des... more Measures of spatial cognition, neighborhood knowledge, and neighborhood use from the research described by Walsh, Krauss, and Regnier (1981) were examined to determine if laboratory tests of spatial cognition were significant predictors of older adults' use of their neighborhoods. The overall results show that laboratory-based measures of spatial cognition and subjects' knowledge of their neighborhoods are both significant predictors of their use of neighborhood goods and services. The ability to learn and remember the location and orientation of objects, when contextual cues were not provided at test, was more predictive of the participants' neighborhood use than either the participants' number of years in the neighborhood or their mobility. Spatial memory as measured by the Educational Testing Service Building Memory task predicted neighborhood knowledge, which was predictive of neighborhood use.

Memory & Cognition, 1987

sis is the semantic integration of visual information with the simultaneously presented auditory/... more sis is the semantic integration of visual information with the simultaneously presented auditory/verbal material. Consistent with this model, young children find the visual information on television more salient and memorable than the audio material (Pezdek & Stevens, 1984), and children use the visually presented information to guide their comprehension of auditorily presented material (Pezdek & Hartman, 1983).

Child Development, 1984

This study compares the relationship between comprehension and memory for text and television, an... more This study compares the relationship between comprehension and memory for text and television, and comprehension and memory for text and radio, 2 stories were edited to create 3 matched versions of each-(1) a storybook with pictures, (2) a radio version, and (3) a television version. Third and sixth graders read 1 story and were presented either the television or radio version ofthe other story, counterbalanced for story and order of presentation, A battery of memory and comprehension tests was administered following both the reading and the television or radio conditions. The principal result is that across a range of tasks, performance in the television and reading conditions was not significantly correlated; however, performance in the radio and reading conditions was positively correlated and generally significant. The second important finding is that the absolute levels of performance were similar in the television and reading conditions, and performance was better in both of these conditions than in the radio condition. Hypotheses are discussed to explain why performance in the television condition was not related to reading ability. This research was supported by the National Institute of Education (NIE G-81-0049) and the Haynes Foundation. Portions of these findings were presented at the meeting of the Society for Research in Ghild Development, Detroit, 1983, and the meeting of the Psychonomic Society, San Diego, 1983, We are very grateful to Patricia Greenfield for the use of her materials. We acknowledge the assistance of Mark Runco with the data analysis and Allan Ribbler for data collection. We also appreciate the cooperation of Jack Hassinger, Robert Vislay, and the students and staff at Kingsley,

American Journal on Addictions, 2000

D espite the recent resurgence in methamphetamine (MA) use, there is little evidence concerning w... more D espite the recent resurgence in methamphetamine (MA) use, there is little evidence concerning whether MA affects the cognitive processes of MA users. Although there are extensive anecdotal reports about MA detrimentally affecting the memory of users, there has been little systematic study of MA on cognition or memory. Since at this time cognitive behavioral interventions are used for MA treatment, 1 it is particularly important for providers of these types of treatment to know the cognitive capabilities of the population coming to them for treatment. It is important to distinguish between``the effects of long-term use'' and the``long-term effects'' of MA. The former, which are the topic of this study, are the cognitive effects of using MA over a long period of time. The``long-term effects'' of MA are the effects of using MA that persist over a period of time. Since the MA users participating in this study are still using MA, we will not be able to determine anything about the long-term effects. These are important, and are being addressed by this group, but the focus of this study is the population of MA users who have been using over 6 months and who are still using. The literature to date consists of evidence from animal studies for neurotoxicity associated with repeated exposure to high doses of amphetamine or MA. 2¡6 In contrast to the animal data, many of the studies done with normal adults investigating the effect of MA administration show increases in cognitive abilities. The most consistent results have been found for sleep deprived subjects. Carpenter 7

Journal of Addictive Diseases, 2001

Understanding the association between attention deficit hyperactivity disorder (ADHD) and substan... more Understanding the association between attention deficit hyperactivity disorder (ADHD) and substance abuse, specifically methamphetamine (MA) abuse, is challenging, partly because little is known about the specific constellation of cognitive impairments produced by MA. The present investigation serves to address this relationship by comparing the cognitive performance of MA abusers with ADHD symptomatology (n = 28) and MA abusers without ADHD symptomatology (n = 41) on tests of attention, memory and general intellectual functioning, executive functioning, problem solving, verbal fluency, and abstract thinking. Both MA samples had deficiencies in measures of memory and learning function, psychomotor speed and abstract thinking when compared to a control group (n = 40). Additional deficits were noted on tasks involving executive functioning, attention, and general intellectual functioning in MA abusers with ADHD symptomatology. The preliminary data suggests that executive function deficits and some of the symptoms associated with long-term MA use may be due to the fact that a large proportion of MA addicts had ADHD symptomatology as children.

Journal of Addictive Diseases, 2001

Typical use patterns of methamphetamine (MA) users were examined using self-report measures from ... more Typical use patterns of methamphetamine (MA) users were examined using self-report measures from 120 MA and 63 cocaine users. Twenty (14 MA and 6 cocaine) of the participants also took part in structured interviews designed to provide more specific descriptions of their drug use. The typical MA user uses more than 20 days a month. Use is evenly spaced throughout the day, and although the amount of drug used per day is not different, MA users use fewer times per day than do cocaine users. Fewer of the cocaine users are continuous users, and they use in the evening rather than the daytime. The cocaine pattern of fewer days of use, evening use, and more frequent doses per day fits a picture of recreational use, whereas the all-day-most-days methamphetamine pattern does not.

Biological Psychiatry, 2005

Background: Methamphetamine (MA) abusers have cognitive deficits, abnormal metabolic activity and... more Background: Methamphetamine (MA) abusers have cognitive deficits, abnormal metabolic activity and structural deficits in limbic and paralimbic cortices, and reduced hippocampal volume. The links between cognitive impairment and these cerebral abnormalities are not established. Methods: We assessed cerebral glucose metabolism with [F-18]fluorodeoxyglucose positron emission tomography in 17 abstinent (4 to 7 days) methamphetamine users and 16 control subjects performing an auditory vigilance task and obtained structural magnetic resonance brain scans. Regional brain radioactivity served as a marker for relative glucose metabolism. Error rates on the task were related to regional radioactivity and hippocampal morphology Results. Methamphetamine users bad higher error rate than control subjects on the vigilance task. The groups showed different relationships between error rates and relative activity), in the anterior and middle cingulate gyrus and the insula. Whereas the MA user group showed negative correlations involving these regions, the control group showed positive correlations involving the cingulate eScholarship provides open access, scholarly publishing services to the University of California and delivers a dynamic research platform to scholars worldwide. cortex. Across groups, hippocampal metabolic and structural measures were negatively correlated with error rates. Conclusions: Dysfunction in the cingulate and insular cortices of recently abstinent MA abusers contribute to impaired vigilance and other cognitive functions requiring sustained attention. Hippocampal integrity predicts task performance in methamphetamine users as well as control subjects.

Archives of General Psychiatry, 2004

Background: Mood disturbances in methamphetamine (MA) abusers likely influence drug use, but the ... more Background: Mood disturbances in methamphetamine (MA) abusers likely influence drug use, but the neurobiological bases for these problems are poorly understood.

Biological Psychiatry, 2005

Background: Methamphetamine (MA) abusers have cognitive deficits, abnormal metabolic activity and... more Background: Methamphetamine (MA) abusers have cognitive deficits, abnormal metabolic activity and structural deficits in limbic and paralimbic cortices, and reduced hippocampal volume. The links between cognitive impairment and these cerebral abnormalities are not established. Methods: We assessed cerebral glucose metabolism with [F-18]fluorodeoxyglucose positron emission tomography in 17 abstinent (4 to 7 days) methamphetamine users and 16 control subjects performing an auditory vigilance task and obtained structural magnetic resonance brain scans. Regional brain radioactivity served as a marker for relative glucose metabolism. Error rates on the task were related to regional radioactivity and hippocampal morphology Results. Methamphetamine users bad higher error rate than control subjects on the vigilance task. The groups showed different relationships between error rates and relative activity), in the anterior and middle cingulate gyrus and the insula. Whereas the MA user group showed negative correlations involving these regions, the control group showed positive correlations involving the cingulate eScholarship provides open access, scholarly publishing services to the University of California and delivers a dynamic research platform to scholars worldwide. cortex. Across groups, hippocampal metabolic and structural measures were negatively correlated with error rates. Conclusions: Dysfunction in the cingulate and insular cortices of recently abstinent MA abusers contribute to impaired vigilance and other cognitive functions requiring sustained attention. Hippocampal integrity predicts task performance in methamphetamine users as well as control subjects.