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Biomedical subjects

Susan F Tapert

Publications and source records attributed to Susan F Tapert.

At least 19 recordsLinked to original sources
PubMed2006

Effects of alcohol and combined marijuana and alcohol use during adolescence on hippocampal volume and asymmetry.

BACKGROUND: Converging lines of evidence suggest that the hippocampus may be particularly vulnerable to deleterious effects of alcohol and marijuana use, especially during adolescence. The goal of this study was to examine hippocampal volume and asymmetry in adolescent users of alcohol and marijuana. METHODS: Participants were adolescent (aged 15-18) alcohol (ALC) users (n=16), marijuana and alcohol (MJ+ALC) users (n=26), and demographically similar controls (n=21). Extensive exclusionary criteria included prenatal toxic exposure, left handedness, and psychiatric and neurologic disorders. Substance use, cognitive, and anatomical measures were collected after at least 2 days of abstinence from all substances. RESULTS: Adolescent ALC users demonstrated a significantly different pattern of hippocampal asymmetry (p<.05) and reduced left hippocampal volume (p<.05) compared to MJ+ALC users and non-using controls. Increased alcohol abuse/dependence severity was associated with increased right>left (R>L) asymmetry and smaller left hippocampal volumes while marijuana abuse/dependence was associated with increased L>R asymmetry and larger left hippocampal volumes. Although MJ+ALC users did not differ from controls in asymmetry, functional relationships with verbal learning were found only among controls, among whom greater right than left hippocampal volume was associated with superior performance (p<.05). CONCLUSIONS: Aberrations in hippocampal asymmetry and left hippocampal volumes were found for adolescent heavy drinkers. Further, the functional relationship between hippocampal asymmetry and verbal learning was abnormal among adolescent substance users compared to healthy controls. These findings suggest differential effects of alcohol and combined marijuana and alcohol use on hippocampal morphometry and the relationship between hippocampal asymmetry and verbal learning performance among adolescents.

Adolescent↗
PubMed2006

Age-related changes in prefrontal white matter volume across adolescence.

Past research has suggested that white matter volume increases from childhood to adulthood; however, during adolescence, there is somewhat limited data to support this finding. In the present study, 65 typically developing adolescents underwent structural magnetic resonance imaging. Using magnetic resonance imaging, prefrontal white matter volumes were examined in relation to adolescent age and sex. Surprisingly, results suggested that prefrontal white matter volume decreased during late adolescence, particularly among the female sex. These findings are inconsistent with past research and suggest that perhaps some developmental processes in late adolescence are not yet fully explained. Possible methodological contributions and implications for the current findings are discussed.

Adolescent↗
PubMed2006

Effects of two nights sleep deprivation and two nights recovery sleep on response inhibition.

This study examined the effects of two nights of total sleep deprivation (TSD) and two nights of recovery sleep on response inhibition. Thirty-eight young, healthy adults performed a Go-NoGo task at 14 : 00 after: (1) a normal night of sleep; (2) each of two consecutive nights of TSD; and (3) each of two consecutive nights of recovery sleep; they also performed the task at 05 : 00 during the first night of sleep deprivation. We hypothesized that TSD would lead to an impaired ability to withhold a response that would be reversed with recovery sleep. Subjects did experience a significant increase in false positive responses throughout all of TSD, errors of omission (i.e. missed 'go' targets) were not significant until after the second night of TSD. Both components (withholding a response and automatic responding) of the task returned to baseline levels after one night of recovery sleep. These data suggest that individuals experience difficulty in withholding an inappropriate response during TSD, even when they are able to attend to the incoming stimuli and respond accurately to appropriate stimuli.

Adult↗
PubMed2006

Alcohol attenuates load-related activation during a working memory task: relation to level of response to alcohol.

BACKGROUND: A low level of response to alcohol is a major risk factor for the development of alcohol dependence, but neural correlates of this marker are unclear. METHOD: Ten healthy volunteers were classified by median split on level of response to alcohol and underwent 2 sessions of functional magnetic resonance imaging following ingestion of a moderate dose of alcohol and a placebo. The blood oxygen level-dependent activation to an event-related visual working memory test was examined. RESULTS: The subjects exhibited longer response latencies and more errors as a function of increasing working memory load and showed a load-dependent increase in activation in dorsolateral prefrontal cortex, posterior parietal cortex, and visual cortex. Alcohol did not affect performance (errors or response latency), but attenuated the working memory load-dependent activation in the dorsolateral prefrontal cortex. During the placebo condition, individuals with a low level of response to alcohol showed greater activation in dorsolateral prefrontal cortex and posterior parietal cortex than those with a high level of response to alcohol. During the alcohol condition, groups showed similar attenuation of load-dependent brain activation in these regions. CONCLUSION: Low-level responders relative to high-level responders exhibited an increased working memory load-dependent activation in dorsolateral prefrontal cortex and posterior parietal cortex when not exposed to alcohol. This increase in brain response was attenuated in low-level responders after ingesting a moderate dose of alcohol.

Adult↗
PubMed2005

Reduced hippocampal volume among adolescents with alcohol use disorders without psychiatric comorbidity.

Studies have suggested that teens with alcohol use disorder (AUD) can demonstrate memory deficits, but the underlying neuroanatomical substrates are unclear. The hippocampus is crucial to intact memory functioning, and it actively develops during adolescence. The current study attempted to replicate and extend previous findings suggesting that adolescents with AUD show smaller hippocampal volumes than healthy adolescents. Manual tracings of bilateral hippocampi were performed on structural magnetic resonance images of 14 adolescents (ages 15 to 17 years) with AUD and 17 healthy comparison teens. Intracranial, white, and gray matter volumes, as well as memory abilities, were also measured. Results revealed that adolescents with AUD had significantly smaller left hippocampal volumes than healthy teens, even after removal of teens with comorbid conduct disorder from the analyses. In contrast the groups did not differ in right hippocampal, intracranial, gray or white matter volumes, or memory performance. Hippocampal volumes were not related to alcohol-consumption rates. These findings indicate that adolescents with AUD, but free from other psychiatric comorbidities, have reduced left hippocampal volume. Because hippocampal volume did not relate to alcohol use characteristics, it is possible that premorbid volumetric differences could account for some of the observed group differences in hippocampal volume.

Adolescent↗
PubMed2005

fMRI response to spatial working memory in adolescents with comorbid marijuana and alcohol use disorders.

Alcohol and marijuana use are prevalent in adolescence, yet the neural impact of concomitant use remains unclear. We previously demonstrated functional magnetic resonance imaging (fMRI) response to spatial working memory (SWM) among teens with alcohol use disorders (AUD) compared to controls, and predicted that adolescents with marijuana and alcohol use disorders would show additional abnormalities. Participants were three groups of 15-17-year-olds: 19 non-abusing controls, 15 AUD teens with limited exposure to drugs, and 15 teens with comorbid marijuana and alcohol use disorders (MAUD) and minimal other drug experience. After >2 days' abstinence, participants performed a SWM task during fMRI acquisition. fMRI brain response patterns differed between groups, despite similar performance on the task. MAUD youths showed less activation in inferior frontal and temporal regions than controls, and more response in other prefrontal regions. Compared to AUD teens, MAUD youths also showed less inferior frontal and temporal activation, but more medial frontal response. Overall, MAUD youths showed different brain response abnormalities than teens with AUD alone, despite relatively short histories of substance involvement. This pattern could suggest compensation for marijuana-related attention and working memory deficits. However, relatively recent use and premorbid features may influence results, and should be examined in future studies.

Adolescent↗
PubMed2005

Gender and adolescent alcohol use disorders on BOLD (blood oxygen level dependent) response to spatial working memory.

AIMS: To determine how alcohol use differentially affects brain functioning in male and female adolescents. METHODS: Adolescents with alcohol use disorders (AUDs; 7 female, 11 male) and control adolescents without AUDs (9 female, 12 male), aged 14-17 years, performed spatial working memory and vigilance tasks during functional magnetic resonance imaging. RESULTS: Gender, AUD and their interaction were significantly associated with brain activation patterns to the tasks. There were interactions in the superior frontal, superior temporal, cingulate and fusiform regions, in which female and male adolescents with AUDs showed a different brain response from each other and control subjects. Overall, female adolescents with AUDs showed a greater departure from normal activation patterns than male adolescents with AUD. CONCLUSIONS: Adolescent alcohol involvement may affect male and female brains differently, and adolescent females may be somewhat more vulnerable to adverse alcohol effects. With continued drinking, these adolescents may be at an increased risk for behavioural deficits.

Adolescent↗
PubMed2005

Neural activation patterns of methamphetamine-dependent subjects during decision making predict relapse.

CONTEXT: Relapse is a common clinical problem in individuals with substance dependence. Previous studies have implicated a multifactorial process underlying relapse; however, the contribution of specific neural substrates has not yet been examined. OBJECTIVE: To determine whether results from functional magnetic resonance imaging (fMRI) shortly after drug cessation could predict relapse in stimulant-dependent individuals. PARTICIPANTS AND DESIGN: Treatment-seeking methamphetamine-dependent males (N = 46) underwent fMRI 3 to 4 weeks after cessation of drug use. Of the 40 subjects who were followed up a median of 370 days, 18 relapsed and 22 did not. MAIN OUTCOME MEASURE: Blood oxygen level-dependent fMRI activation during a simple 2-choice prediction task. RESULTS: The fMRI activation patterns in right insular, posterior cingulate, and temporal cortex obtained early in recovery correctly predicted 20 of 22 subjects who did not relapse and 17 of 18 subjects who did. A Cox regression analysis revealed that the combination of right middle frontal gyrus, middle temporal gyrus, and posterior cingulate activation best predicted the time to relapse. CONCLUSION: To our knowledge, this is the first investigation to show that fMRI can be used to predict relapse in substance-dependent individuals.

Adult↗
PubMed2005

fMRI reveals alteration of spatial working memory networks across adolescence.

Recent studies have described neuromaturation and cognitive development across the lifespan, yet few neuroimaging studies have investigated task-related alterations in brain activity during adolescence. We used functional magnetic resonance imaging (fMRI) to examine brain response to a spatial working memory (SWM) task in 49 typically developing adolescents (25 females and 24 males; ages 12-17). No gender or age differences were found for task performance during SWM. However, age was positively associated with SWM brain response in left prefrontal and bilateral inferior posterior parietal regions. Age was negatively associated with SWM activation in bilateral superior parietal cortex. Gender was significantly associated with SWM response; females demonstrated diminished anterior cingulate activation and males demonstrated greater response in frontopolar cortex than females. Our findings indicate that the frontal and parietal neural networks involved in spatial working memory change over the adolescent age range and are further influenced by gender. These changes may represent evolving mnemonic strategies subserved by ongoing adolescent brain development.

Adolescent↗
PubMed2005

Neuropsychological predictors of BOLD response during a spatial working memory task in adolescents: what can performance tell us about fMRI response patterns?

The relationship between standardized neuropsychological test performance and functional magnetic resonance imaging (fMRI) response during cognitive tasks is largely unknown. This exploratory investigation examined the relationship between neuropsychological test performance and fMRI response to a spatial working memory (SWM) task among 49 typically developing adolescents. Participants were administered a variety of neuropsychological tests in the domains of working memory, visuospatial skills, executive functioning, attention, learning and memory, visuomotor skills and processing speed, and language functioning. Neuropsychological domain scores were used to predict fMRI response during a SWM task. Results suggest that in many brain regions, neuropsychological performance negatively predicts fMRI response, suggesting that those teens with better neuropsychological abilities required fewer neural resources to adequately perform the task. This study provides further understanding of how neuropsychological abilities relate to neural activity during fMRI tasks, and provides an important link between neuropsychological and fMRI research.

Adolescent↗
PubMed2005

Adolescence: booze, brains, and behavior.

This article represents the proceedings of a symposium at the 2004 Research Society on Alcoholism meeting in Vancouver, British Columbia, Canada, organized and chaired by Peter M. Monti and Fulton T. Crews. The presentations and presenters were (1) Introduction, by Peter M. Monti; (2) Adolescent Binge Drinking Causes Life-Long Changes in Brain, by Fulton T. Crews and Kim Nixon; (3) Functional Neuroimaging Studies in Human Adolescent Drinkers, by Susan F. Tapert; (4) Abnormal Emotional Reactivity as a Risk Factor for Alcoholism, by Robert Miranda, Jr.; (5) Alcohol-Induced Memory Impairments, Including Blackouts, and the Changing Adolescent Brain, by Aaron M. White and H. Scott Swartzwelder; and (6) Discussion, by Kenneth Sher.

Adolescent↗
PubMed2004

fMRI BOLD response to alcohol stimuli in alcohol dependent young women.

BACKGROUND: Cue reactivity in alcohol dependent adults has revealed autonomic, cognitive, and neural responses to alcohol-related stimuli that differ from those of nonabusers. Cue reactivity and craving responses have not been studied in youth. METHOD: Alcohol-dependent young women (n=8) and female light social drinkers (n=9) ages 18-24 were administered an alcohol cue reactivity task during functional magnetic resonance imaging (fMRI) to examine brain response to alcohol-related words. RESULTS: Alcohol dependent young women demonstrated significantly more blood oxygen level dependent (BOLD) response than nonabusers during alcohol word presentation trials relative to neutral word trials in subcallosal, anterior cingulate, left prefrontal, and bilateral insular regions (P<.025). However, controls showed greater response to alcohol words in some right hemisphere cortical regions. Increased craving after cue exposure correlated with increased subcallosal cortex BOLD response to alcohol cues (r=.87) among alcohol dependent subjects. CONCLUSIONS: This pilot study corroborates previous reports of increased limbic and frontal response to substance cues and extends these findings to young alcohol dependent women. This limbic reaction may underlie the elevated physiological response and altered cognitive reactions to alcohol stimuli that are observed in alcohol dependent individuals.

Adolescent↗
PubMed2004

Trend detection via temporal difference model predicts inferior prefrontal cortex activation during acquisition of advantageous action selection.

The process of accurately predicting which actions are associated with advantageous versus disadvantageous outcomes is an important function of daily life. An integral part of this process is being able to detect when the association between an action and an outcome changes. This investigation examined the hypothesis that the inferior prefrontal cortex is critical for the detection of trends and that a trend process derived from the temporal difference model accomplishes this detection. Nineteen normal right-handed volunteers completed 120 4-s trials of a Rock Paper Scissors (RPS) task during functional magnetic resonance imaging. Subjects acquired the selection of advantageous actions during the RPS task. Activations in the medial frontal gyrus (BA 10), left ventrolateral frontal gyrus (BA 11/47), and left pallidum were significantly higher during trials in which subjects acquired the advantageous action. The time course of individually derived trend detection functions was found to be time-locked to the hemodynamic changes in the inferior frontal gyrus. These findings are consistent with the hypothesis that the inferior prefrontal cortex computes a trend from previously experienced action-outcome sequences based on a value function derived from the temporal difference model.

Association Learning↗
PubMed2004

Neurocognitive ability in adults coping with alcohol and drug relapse temptations.

Coping is important for preventing relapse, but may be utilized differently depending on the individual's level of cognitive functioning. Impaired reasoning, attention, and memory are commonly observed in alcohol-dependent individuals. This study describes the prospective relationship between neuropsychological functioning and utilization of coping strategies in predicting outcome one year after discharge from an inpatient alcohol treatment program. Male veterans (n = 43) hospitalized in an alcohol treatment facility were given structured interviews, coping questionnaires, and neuropsychological testing, and were followed three and 12 months after discharge. Neuropsychological ability moderated the relationship between coping and drinking outcomes one year after treatment. This was particularly true for patients with better neurocognitive functioning. Specifically, patients with higher neurocognitive performances and more maladaptive coping responses, such as self-blame, had a greater percentage of drinking days at follow-up. Alcohol-dependent adults with good neuropsychological functioning may be able to benefit more from coping skills training. For those with neuropsychological deficits, coping skills training may need to take cognitive limitations into consideration.

Adaptation, Psychological↗
PubMed2004

Blood oxygen level dependent response and spatial working memory in adolescents with alcohol use disorders.

BACKGROUND: Previous studies have suggested neural disruption and reorganization in young and older adults with alcohol use disorders (AUD). However, it remains unclear at what age and when in the progression of AUD changes in brain functioning might occur. METHODS: Alcohol use disordered (n = 15) and nonabusing (n = 19) boys and girls aged 15 to 17 were recruited from local high schools. Functional magnetic resonance imaging data were collected after a minimum of 5 days' abstinence as participants performed spatial working memory and simple motor tasks. RESULTS: Adolescents with AUD showed greater brain response to the spatial working memory task in bilateral parietal cortices and diminished response in other regions, including the left precentral gyrus and bilateral cerebellar areas (clusters > or =943 microl; p < 0.05), although groups did not differ on behavioral measures of task performance. No brain response differences were observed during a simple finger-tapping task. The degree of abnormality was greater for teens who reported experiencing more withdrawal or hangover symptoms and who consumed more alcohol. CONCLUSIONS: Adolescents with AUD show abnormalities in brain response to a spatial working memory task, despite adequate performance, suggesting that subtle neuronal reorganization may occur early in the course of AUD.

Adolescent↗
PubMed2004

Adolescence and the trajectory of alcohol use: basic to clinical studies.

Emerging findings from developmentally focused research indicates subtle but important neurocognitive disadvantages among adolescents with alcohol-use disorders (AUD) as compared to teens without AUD. Even after 3 weeks of abstinence AUD youth display a 10% decrement in delayed memory functions. Neuropsychological testing of youth followed at 4 and 8 years demonstrates that heavy drinking during adolescence is associated with diminished retrieval of verbal and nonverbal material, and poorer performance on tests requiring attention skills. Alcohol withdrawal over the teen years appears to uniquely contribute to deterioration in functioning in visuospatial tasks. Brain imaging studies suggest reduced hippocampal volumes, white matter microstructure irregularities, brain response abnormalities while performing challenging cognitive tasks, and enhanced brain response when viewing alcohol cues (i.e., alcohol advertisements) among adolescents with AUD. Family characteristics such as history of alcoholism and socioeconomic status as well as personal features, including adolescent psychopathology, gender, and age of onset must be carefully considered when investigating the influence of teenage drinking on neurocognition. Further research is needed to understand how age at onset of drinking and duration of abstinence at the time of assessment affect cognitive findings. Longitudinal studies are needed to clarify neuromaturational changes associated with early alcohol exposure and patterns of resiliency. Although the magnitude of alcohol-related effects observed in adolescents' neurocognition is relatively modest, the implications are major given the prevalence of alcohol involvement, and the important educational, occupational, and social transitions that occur during adolescence.

Adolescent↗
PubMed2004

An FMRI study of response inhibition in youths with a family history of alcoholism.

Disinhibition among alcoholics may precede or result from alcohol use disorders (AUDs). It remains unclear how disinhibition might contribute to AUD risk among youths with a family history of alcoholism (FHP). We used functional magnetic resonance imaging (fMRI) to explore inhibition-related neural risk factors for AUD. Participants were 12- to 14-year-old nondrinkers, including 12 FHP youths and 14 youths with no family history of alcoholism (FHN). Youths performed a go/no-go task during fMRI acquisition. At a conservative threshold, FHN youths showed less inhibitory response than FHP youths in the left middle frontal gyrus, despite similar task performance between groups. Using a more liberal threshold, FHP youths also demonstrated less response in additional frontal regions. These preliminary findings suggest that FHP youths show less inhibitory frontal response than FHN youths. Altered neural activation among FHP youths may underlie subsequent disinhibition and could be related to the AUD risk.

Adolescent↗