Biomedical subjects

Cary R Savage

Publications and source records attributed to Cary R Savage.

18 recordsLinked to original sources

PubMed2007

Motor inhibition in trichotillomania and obsessive-compulsive disorder.

We investigated motor inhibition abilities in trichotillomania (TTM) and obsessive-compulsive disorder (OCD), two disorders characterized by repetitive, intentionally performed behaviors. Performance in a GoNogo experiment of 25 TTM and 21 OCD participants was compared to the performance of 26 HC participants. In contrast to OCD and HC participants, TTM participants tended to perform either 'fast and inaccurate' (indicating poor motor inhibition) or 'slow and accurate'. TTM participants with poor motor inhibition reported a significantly earlier age of TTM onset than those TTM participants who performed well. There was no evidence for motor inhibition deficits in OCD. Based on our data, a subgroup of TTM sufferers seems to be characterized by motor inhibition deficits.

Adult↗

PubMed2006

Cognitive retraining for organizational impairment in obsessive-compulsive disorder.

Individuals with obsessive-compulsive disorder (OCD) have difficulties in organizing information during encoding associated with subsequent memory impairments. This study was designed to investigate whether impairments in organization in individuals with OCD can be alleviated with cognitive training. Thirty-five OCD subjects and 36 controls copied and recalled the Rey-Osterrieth Complex Figure Test (RCFT) [Osterrieth, P.A., 1944. Le test de copie d'une figure complexe: Contribution a l'étude de la perception et de la memoire (The test of copying a complex figure: A contribution to the study of perception and memory). Archive de Psychologie 30, 286-350.] before being randomly assigned to a training or non-training condition. The training condition was designed to improve the ability to organize complex visuospatial information in a meaningful way. The intervention phase was followed by another copy and recall trial of the RCFT. Both OCD and control subjects who underwent training improved more in organization and memory than subjects who did not receive organizational training, providing evidence that the training procedure was effective. OCD subjects improved more in organizational during encoding than control subjects, irrespective of whether or not they had received training. This suggests that organization impairment in OCD affects primarily the ability to spontaneously utilize strategies when faced with complex, ambiguous information but that the ability to implement such strategies when provided with additional trials is preserved. These findings support a distinction in OCD between failure to utilize a strategy and incapacity to implement a strategy.

Adult↗

PubMed2006

Evidence for reduced cerebellar volumes in trichotillomania.

BACKGROUND: Limited knowledge exists regarding the neurobiology of trichotillomania (TTM). Cerebellum (CBM) volumes were explored, given its role in complex, coordinated motor sequences. METHODS: Morphometric magnetic resonance imaging (MRI) scans were obtained for 14 female subjects with DSM-IV diagnoses of TTM and 12 age-, education-, and gender-matched normal control (NC) participants. Parcellation was performed utilizing a recently developed methodology to measure subterritory volumes of the CBM. Regions were defined based on knowledge of the structural and functional subunits of the CBM. RESULTS: As predicted, significant group differences were reported for CBM raw cortical volumes (p = .008) that survived correction for total brain volume (TBV; p = .037) and head circumference (HC; p = .011). A priori and post hoc group raw volume comparisons for CBM subterritories and functional clusters revealed many significant differences. However, most differences failed to withstand correction for total CBM volumes (TCV). Smaller volumes were consistently reported for the TTM versus NC cohorts. Total Massachusetts General Hospital Hair Pulling Scale (MGHHPS) scores were significantly inversely correlated with left primary sensorimotor cluster volumes (p = .008), with smaller volumes associated with more severe TTM symptoms. CONCLUSIONS: These findings implicate the CBM in the neurobiology of TTM, with reduced subterritory volumes reported for the TTM versus NC groups.

Adolescent↗

PubMed2006

Strategic memory in adults with anorexia nervosa: are there similarities to obsessive compulsive spectrum disorders?

OBJECTIVE: There is growing interest in the relationship between anorexia nervosa (AN) and obsessive-compulsive (OC) spectrum disorders (e.g., OCD, body dysmorphic disorder [BDD]). Previous neuropsychological investigations of OC spectrum disorders have identified problems with the efficient use of strategy on complex measures of learning and memory. This study evaluated nonverbal strategic memory in AN outpatients using an approach previously applied to OC spectrum disorders. METHOD: Eighteen patients with AN and 19 healthy control participants completed the Rey-Osterrieth Complex Figure Test (RCFT), a widely used measure of nonverbal strategic planning, learning, and memory. RESULTS: Individuals with AN differed significantly from healthy controls in the organizational strategies used to copy the RCFT figure, and they recalled significantly less information on both immediate and delayed testing. Multiple regression analyses indicated that group differences in learning were mediated by copy organizational strategies. CONCLUSION: These results are identical to study findings in OCD and BDD, indicating important shared neuropsychological features among AN and these OC spectrum disorders. As in OCD and BDD, the essential cognitive deficit in AN was impaired use of organizational strategies, which may inform our understanding of the pathophysiology of AN and potentially offer treatment implications.

Adult↗

PubMed2006

Bilateral activation of the prefrontal cortex after strategic semantic cognitive training.

The prefrontal cortex (PFC) has been implicated in the ability to apply semantic organizational strategies during verbal encoding and episodic learning. However, there has been no direct evidence demonstrating which specific areas in the PFC are engaged after cognitive training using semantic organizational strategies in healthy adult human subjects. In this study, we investigated the effects of semantic strategic training on brain activity and changes in behavioral performance, after cognitive training, using functional MRI (fMRI). There was a significant activation in bilateral dorsolateral prefrontal (DLPF) and orbitofrontal (OFC) areas after cognitive training. These results demonstrate the engagement of bilateral DLPF and OFC cortex during strategic memory processes, particularly when mobilization and effort of effective use of strategies are required. The functional adaptations observed here may also shed light on some of the processes underlying recovery with cognitive rehabilitation in patient populations with brain injury.

Adult↗

PubMed2006

Neural mechanisms underlying hyperphagia in Prader-Willi syndrome.

OBJECTIVE: Prader-Willi syndrome (PWS) is a genetic disorder associated with developmental delay, obesity, and obsessive behavior related to food consumption. The most striking symptom of PWS is hyperphagia; as such, PWS may provide important insights into factors leading to overeating and obesity in the general population. We used functional magnetic resonance imaging to study the neural mechanisms underlying responses to visual food stimuli, before and after eating, in individuals with PWS and a healthy weight control (HWC) group. RESEARCH METHODS AND PROCEDURES: Participants were scanned once before (pre-meal) and once after (post-meal) eating a standardized meal. Pictures of food, animals, and blurred control images were presented in a block design format during acquisition of functional magnetic resonance imaging data. RESULTS: Statistical contrasts in the HWC group showed greater activation to food pictures in the pre-meal condition compared with the post-meal condition in the amygdala, orbitofrontal cortex, medial prefrontal cortex (medial PFC), and frontal operculum. In comparison, the PWS group exhibited greater activation to food pictures in the post-meal condition compared with the pre-meal condition in the orbitofrontal cortex, medial PFC, insula, hippocampus, and parahippocampal gyrus. Between-group contrasts in the pre- and post-meal conditions confirmed group differences, with the PWS group showing greater activation than the HWC group after the meal in food motivation networks. DISCUSSION: Results point to distinct neural mechanisms associated with hyperphagia in PWS. After eating a meal, the PWS group showed hyperfunction in limbic and paralimbic regions that drive eating behavior (e.g., the amygdala) and in regions that suppress food intake (e.g., the medial PFC).

Adolescent↗

PubMed2006

Enhanced cue-elicited brain activation in African American compared with Caucasian smokers: an fMRI study.

Current evidence indicates that, although African Americans (AA) are more likely to attempt to quit smoking than Caucasians (CC) in any given year, success rates are lower for AA. However, factors contributing to these differences are not well known. In order to explore potential factors, this study assessed differences in attention to smoking cues between ethnic groups. Participants underwent morning functional magnetic resonance imaging scanning while viewing images of AA models and CC models who were either smoking (smoking cues) or engaging in everyday activities (neutral cues), interspersed with a fixation baseline period. The study was conducted at the Hoglund Brain Imaging Center of the University of Kansas Medical Center in Kansas City, KS. We studied 17 smokers (eight AA, nine CC) after 12-hour abstinence and 17 non-smokers (eight AA, nine CC) matched by age, gender, years of education, and handedness. The AA and CC smoking groups were also matched for number of cigarettes smoked per day. All results are P < 0.01, corrected for whole brain. There was a strong ethnicity by condition interaction among smokers in several a priori regions of interest. AA smokers showed a greater increase in response to smoking (versus neutral cues) than CC smokers in the medial prefrontal cortex, right lateral orbitofrontal cortex, and bilateral ventrolateral prefrontal cortex. In smoking versus baseline contrasts, additional areas of greater activation were found in AA, including the right amygdala and left caudate nucleus. No significant differences in cue-elicited brain activation were found between AA and CC non-smokers. These preliminary findings demonstrate variation in brain activation in response to smoking cues between AA and CC smokers in structures known to be associated with nicotine addiction. Differences in neural response may reflect fundamental differences in attention to smoking cues, which may in turn contribute to differences in effectiveness of nicotine dependence treatments among ethnic populations.

Adult↗

PubMed2005

Brain correlates of negative and positive visuospatial priming in adults.

A balance of inhibitory and facilitatory mechanisms is essential for efficient and goal-directed behaviors. These mechanisms may go awry in several neuropsychiatric disorders characterized by uncontrolled, repetitive behaviors. The visuospatial priming paradigm is a well-established probe of inhibition and facilitation that has been used to demonstrate behavioral deficits in patients with Tourette syndrome and obsessive-compulsive disorder. However, the brain correlates of this visuospatial priming paradigm are not yet well established. In the present study, we used a visuospatial priming paradigm and event-related functional MRI, to probe inhibitory and facilitatory brain mechanisms in healthy adult women. When subjects performed the negative priming (i.e., inhibitory) task, several regions of the prefrontal cortex were selectively activated relative to the neutral condition. Non-overlapping regions of the prefrontal cortex were deactivated in the positive priming condition. These results support the notion that the prefrontal cortex is involved in both inhibitory and facilitatory processing and demonstrate that this visuospatial priming task shares brain correlates with other positive and negative priming tasks. In conjunction with functional MRI, this visuospatial priming task may be useful for studying the pathophysiology of neuropsychiatric disorders in which deficient inhibitory processing or excessive facilitation is a feature.

Adolescent↗

PubMed2005

Neural mechanisms underlying food motivation in children and adolescents.

Dramatic increases in childhood obesity necessitate a more complete understanding of neural mechanisms of hunger and satiation in pediatric populations. In this study, normal weight children and adolescents underwent functional magnetic resonance imaging (fMRI) scanning before and after eating a meal. Participants showed increased activation to visual food stimuli in the amygdala, medial frontal/orbitofrontal cortex, and insula in the pre-meal condition; no regions of interest responded in the post-meal condition. These results closely parallel previous findings in adults. In addition, we found evidence for habituation to food stimuli in the amygdala within the pre-meal session. These findings provide evidence that normal patterns of neural activity related to food motivation begin in childhood. Results have implications for obese children and adults, who may have abnormal hunger and satiation mechanisms.

Adolescent↗

PubMed2005

Visuospatial abilities, memory, and executive functioning in trichotillomania and obsessive-compulsive disorder.

Few studies have compared neuropsychological functioning in trichotillomania (TTM) and obsessive-compulsive disorder (OCD). In OCD, most studies suggest abnormal visuospatial abilities, memory, and executive functioning. We compared 23 TTM, 21 OCD and 26 healthy control individuals on neuropsychological tasks assessing these abilities. Neither the TTM nor the OCD groups suffered from generalized neuropsychological deficits compared to the healthy control group. TTM participants showed increased perseveration on the Object Alternation Task suggesting difficulties with response flexibility. OCD participants showed impaired ability to learn from feedback on the Wisconsin Card Sorting Test. Other executive functions, as well as memory and visuospatial abilities were unimpaired in TTM and OCD. Our data suggest that TTM and OCD are characterized by different patterns of neuropsychological dysfunction.

Adult↗

PubMed2005

Functional neuroimaging and cognitive rehabilitation for people with traumatic brain injury.

Cognitive deficits are a common consequence of traumatic brain injury. Although such deficits are amenable to rehabilitation, methods for individualizing cognitive interventions are still unrefined. Functional neuroimaging methods such as positron emission tomography and functional magnetic resonance imaging are emerging as possible technologies for measuring and monitoring the cerebral consequences of plasticity associated with brain injury and for evaluating the effectiveness of rehabilitation interventions. Functional neuroimaging may even enable more customized and efficient selection, design, or adaptation of individual cognitive rehabilitation programs. We review the current literature on functional neuroimaging after traumatic brain injury, relating these findings to cognitive rehabilitation. Overall, functional neuroimaging after traumatic brain injury has shown reliable differences in brain activity within several regions of frontal cortex, partly but not uniformly consistent with neuropsychological and structural findings in traumatic brain injury. We also outline a number of promising research opportunities for applying functional neuroimaging in traumatic brain injury settings, along with associated challenges.

Brain Injuries↗

PubMed2005

Spontaneous and directed application of verbal learning strategies in bipolar disorder and obsessive-compulsive disorder.

OBJECTIVES: Individuals with bipolar disorder exhibit neuropsychological impairments when they are euthymic (neither depressed nor manic). One of the most consistently reported cognitive problems in euthymic individuals with bipolar disorder is impairment in verbal episodic memory. Recent findings suggest that episodic memory difficulties in these individuals are attributable to difficulties using organizational strategies during encoding. The purpose of the present study was (i) to investigate whether difficulties using organizational strategies in bipolar disorder are due to a failure in spontaneously initiating verbal organization strategies or are due to difficulties implementing such strategies, and (ii) to compare the characteristics of verbal organizational impairment in bipolar disorder with those observed in individuals with obsessive-compulsive disorder (OCD). METHODS: Study participants were 20 individuals with bipolar I disorder (BP-I), 20 individuals with OCD, and 20 healthy control participants matched for age, gender, and education. Participants completed a verbal encoding paradigm that involved spontaneous and directed use of verbal organization strategies during encoding of word lists. RESULTS: Compared with control subjects, both BP-I and OCD participants showed impaired verbal organization in the spontaneous encoding condition. In the directed encoding condition, OCD patients organized the word lists as well as control participants whereas BP-I participants exhibited lower verbal organization than both control and OCD participants. OCD and BP-I participants' free recall performance did not differ from that of control participants in the spontaneous encoding condition. In the directed encoding condition, BP-I participants recalled fewer words than OCD or control participants. CONCLUSIONS: Episodic memory difficulties in OCD are associated with difficulties spontaneously initiating verbal organization strategies during encoding whereas the ability to implement verbal organization when instructed to do so is preserved. BP-I participants, on the other hand, exhibit difficulties in both spontaneously initiating verbal organization strategies and in the ability to implement such strategies when instructed to do so.

Adult↗

PubMed2004

Actual and perceived memory deficits in individuals with compulsive hoarding.

Memory problems have been hypothesized to underlie compulsive hoarding behavior [Frost and Hartl, 1996: Behav Res Ther 34:341-350]. This study examined memory performance, memory confidence, and memory beliefs in 22 individuals with severe hoarding symptoms and 24 matched normal control subjects. Participants were administered two measures of learning and memory that required strategic planning and organization for successful performance: the Rey-Osterrieth Complex Figure Test (RCFT) and California Verbal Learning Test (CVLT). Self-reports of memory confidence, perceived consequences of forgetting, importance of remembering, and need to keep possessions in sight also were assessed. In comparison to controls, participants with compulsive hoarding recalled less information on delayed recall of the RCFT and CVLT and used less effective organizational strategies on the RCFT but not the CVLT. Hoarders also reported significantly less confidence in their memory, more catastrophic assessments of the consequences of forgetting, and a stronger desire to keep possessions in sight. Results provide initial evidence of learning and memory impairment and poor memory confidence in subjects with compulsive hoarding.

Adult↗

PubMed2004

Cognitive and neurobiological findings in obsessive-compulsive disorder.

The behavioral disturbances seen in OCD patients likely are related to abnormalities in the frontal striatal systems, with complex involvement of other brain regions. This is suggested by data from various modalities. Executive deficits are seen on neuropsychological assessments, which may contribute to poor performance on tasks designed to test other domains. Studies of neurological illness in which obsessive and compulsive symptoms are seen with increased frequency and results of neuroimaging studies are also indicative of frontal-striatal dysfunction. Some neuroimaging studies specifically implicate the OFC, along with other regions such as the anterior cingulate cortex and caudate nucleus. Data from studies of neurological soft signs are less specific and suggest pathology that may be common to other psychiatric conditions, such as schizophrenia. Although data from these various modalities do not give clear guidance on treatment, future work may show usefulness of adding these assessments to a clinical evaluation,especially with respect to predicting treatment response in subtypes of OCD.

Brain↗

PubMed2004

Episodic memory impairment in bipolar disorder and obsessive-compulsive disorder: the role of memory strategies.

BACKGROUND: There is evidence that individuals with bipolar disorder exhibit neuropsychological impairments not only during mood episodes but also when they are euthymic. One of the most consistently reported cognitive problems in euthymic individuals with bipolar disorder is an impairment in verbal episodic memory. Verbal learning and memory depend on individuals' ability to organize verbal information appropriately during learning. The purpose of the present study was (i) to determine whether episodic memory impairment in euthymic individuals with bipolar disorder is mediated by impairments in organization of verbal information during learning and (ii) to compare the characteristics of memory impairment in bipolar disorder with that previously found in obsessive-compulsive disorder (OCD). METHODS: Study participants were 30 individuals with DSM-IV bipolar I disorder (BP-I), 30 individuals with DSM-IV OCD and 30 normal control participants matched for age, gender and education. Participants completed the California Verbal Learning Test (CVLT), a well-established measure of verbal learning and memory that enables assessment of verbal organization strategies during learning. RESULTS: Compared with control subjects, both BP-I and OCD participants showed impaired performance in long-delayed free recall and verbal organization strategies during learning. BP-I participants showed greater long-delay free recall difficulties but not greater verbal organization difficulties during learning than OCD participants. For OCD participants, the long-delay recall impairment was mediated by difficulties using verbal organizational strategies during learning. In contrast, the group difference in long-delayed free recall between BP-I and control participants remained significant even when semantic clustering was introduced as a mediator. This indicated that BP-I participants' long-delayed free recall difficulties were mediated to a lesser extent by difficulties using verbal organizational strategies than for OCD participants. CONCLUSIONS: Verbal episodic memory problems in individuals with bipolar I disorder and OCD are mediated to different degrees by difficulties using semantic clustering encoding strategies compared with control participants.

Adult↗

PubMed2003

Relation of neurological soft signs to nonverbal memory performance in obsessive-compulsive disorder.

Few studies have examined the relation between neurological soft signs (NSS) and neuropsychological performance in Obsessive-Compulsive Disorder (OCD). Thirty outpatients with primary OCD and 30 matched normal controls were administered the Cambridge Neurological Inventory and the Rey-Osterrieth Complex Figure Test (RCFT). A series of multiple regression models tested the relationship between NSS and performance on the RCFT. Patients presented significantly more neurological soft signs than controls on both sides of the body, and were impaired on the free recall and organization scores of the RCFT. Nonverbal memory deficits in OCD were predicted independently by organizational strategies during the copy condition of the RCFT, and neurological soft signs. There might be at least two variables independently mediating nonverbal memory deficits in OCD: (1) a cognitive organization and planning component, and (2) a complex motor regulatory component.

Adult↗

PubMed2002

A study of parallel implicit and explicit information processing in patients with obsessive-compulsive disorder.

OBJECTIVE: This study examined implicit sequence learning in patients with obsessive-compulsive disorder (OCD) under dual-task conditions. Frontal-striatal networks support implicit learning and are implicated in the pathophysiology of OCD. Neuroimaging data suggest that during implicit learning, OCD patients use neural systems normally active during explicit learning to compensate for striatal dysfunction. METHOD: The authors examined implicit sequence learning in 25 OCD patients and 25 healthy comparison subjects using a dual-task paradigm, with subjects simultaneously engaged in an explicit memory task and an implicit learning task. They predicted that implicit learning in OCD subjects would be disrupted because concurrent explicit information-processing demands would prevent use of compensatory processes. RESULTS: OCD patients failed to show evidence of implicit learning and exhibited a significant deficit in comparison with healthy subjects. CONCLUSIONS: These results are consistent with the hypothesis that concurrent explicit and implicit information-processing demands interfere with implicit learning in OCD patients.

Attention↗

PubMedDate not supplied

The neural network basis for abnormalities of attention and executive function in major depressive disorder: implications for application of the medical disease model to psychiatric disorders.

The deficits in attention and executive function characteristic of major depressive disorder (MDD) are reviewed. The networks underlying attention and executive function, the neuropsychological tests commonly used to evaluate these domains, and the neuroanatomy of MDD are also discussed. A neural network approach to the attentional and executive function deficits of MDD has ramifications for hypothesis-guided research, the cognitive model of depression, and application of the medical disease model to psychiatric disorders.

Attention↗