Resting-state brain connectivity after surgical and behavioral weight loss.

OBJECTIVE: Changes in food-cue neural reactivity associated with behavioral and surgical weight loss interventions have been reported. Resting functional connectivity represents tonic neural activity that may contribute to weight loss success. This study explores whether intervention type is associated with differences in functional connectivity after weight loss. METHODS: Fifteen participants with obesity were recruited prior to adjustable gastric banding surgery. Thirteen demographically matched participants with obesity were selected from a separate behavioral diet intervention. Resting-state functional magnetic resonance imaging was collected 3 months after surgery/behavioral intervention. ANOVA was used to examine post-weight loss differences between the two groups in connectivity to seed regions previously identified as showing differential cue-reactivity after weight loss. RESULTS: Following weight loss, behavioral dieters exhibited increased connectivity between left precuneus/superior parietal lobule (SPL) and bilateral insula pre- to postmeal and bariatric patients exhibited decreased connectivity between these regions pre- to postmeal (P(corrected) <0.05). CONCLUSIONS: Behavioral dieters showed increased connectivity pre- to postmeal between a region associated with processing of self-referent information (precuneus/SPL) and a region associated with interoception (insula) whereas bariatric patients showed decreased connectivity between these regions. This may reflect increased attention to hunger signals following surgical procedures and increased attention to satiety signals following behavioral diet interventions.

Visuospatial Memory Improvement after Gamma Ventral Capsulotomy in Treatment Refractory Obsessive-Compulsive Disorder Patients.

Gamma ventral capsulotomy (GVC) radiosurgery is intended to minimize side effects while maintaining the efficacy of traditional thermocoagulation techniques for the treatment of refractory obsessive-compulsive disorder (OCD). Neuropsychological outcomes are not clear based on previous studies and, therefore, we investigated the effects of GVC on cognitive and motor performance. A double-blind, randomized controlled trial (RCT) was conducted with 16 refractory OCD patients allocated to active treatment (n=8) and sham (n=8) groups. A comprehensive neuropsychological evaluation including intellectual functioning, attention, verbal and visuospatial learning and memory, visuospatial perception, inhibitory control, cognitive flexibility, and motor functioning was applied at baseline and one year after the procedure. Secondary analysis included all operated patients: eight from the active group, four from the sham group who were submitted to surgery after blind was broken, and five patients from a previous open pilot study (n=5), totaling 17 patients. In the RCT, visuospatial memory (VSM) performance significantly improved in the active group after GVC (p=0.008), and remained stable in the sham group. Considering all patients operated, there was no decline in cognitive or motor functioning after one year of follow-up. Our initial results after 1 year of follow-up suggests that GVC not only is a safe procedure in terms of neuropsychological functioning but in fact may actually improve certain neuropsychological domains, particularly VSM performance, in treatment refractory OCD patients.

Pre-surgical cortical activation to food pictures is associated with weight loss following bariatric surgery.

BACKGROUND: Recent research suggests that preintervention functional magnetic resonance imaging (fMRI) data may predict weight loss outcomes among patients who participate in a behavioral weight loss plan. No study has examined whether presurgical brain activation can predict outcomes following bariatric surgery. METHOD: The aim of the present study was to determine if brain activations during a presurgical fMRI food-motivation paradigm are associated with weight loss 3 and 6 months following laparoscopic adjustable gastric banding (LAGB). Nineteen participants viewed food and nonfood pictures from a well-established food motivation paradigm during an fMRI scanning session before LAGB surgery. Weight was assessed presurgery and 3 and 6 months postsurgery; data for all participants was available at each time point. fMRI data were analyzed using the BrainVoyager QX statistical package. Whole brain voxelwise correlations of presurgery (food-nonfood) brain activation and weight, corrected for multiple comparisons, were performed to analyze the relationship between presurgical brain activation and subsequent weight loss. The settings were a medical university brain imaging center and 2 surgical weight loss centers in a major metropolitan area. RESULTS: Increased activity in frontal regions associated with cognitive control (medial, middle, superior frontal gyrus) and posterior cingulate cortex was associated with weight loss following LAGB. CONCLUSION: We found that neural activity in previously established regions associated with cognitive and behavioral self-regulation predicts weight loss following bariatric surgery. These preliminary findings highlight the role of neural circuitry in the success and maintenance of weight loss and suggest a possible future use of fMRI in screening LAGB surgery candidates.

Winning and losing: differences in reward and punishment sensitivity between smokers and nonsmokers.

BACKGROUND: Smokers show increased brain activation in reward processing regions in response to smoking-related cues, yet few studies have examined secondary rewards not associated with smoking (i.e., money). Inconsistencies exist in the studies that do examine secondary rewards with some studies showing increased brain activation in reward processing brain regions, while others show decreased activation or no difference in activation between smokers and nonsmokers. AIMS: The goal of the current study is to see if smokers process the evaluation and delivery of equally salient real world rewards similarly or differently than nonsmokers. METHODS: The current study employed functional magnetic resonance imaging (fMRI) to examine brain responses in smokers and nonsmokers during the evaluation and delivery of monetary gains and losses. RESULTS: In comparison to nonsmokers, smokers showed increased activation in the ventromedial prefrontal cortex to the evaluation of anticipated monetary losses and the brain response. Moreover, smokers compared to nonsmokers showed decreased activation in the inferior frontal gyrus to the delivery of expected monetary gains. Brain activations to both the evaluation of anticipated monetary losses and the delivery of expected monetary gains correlated with increased self-reported smoking craving to relieve negative withdrawal symptoms and craving related to positive aspects of smoking, respectively. DISCUSSION: Together these results indicate that smokers are hyperresponsive to the evaluation of anticipated punishment and hyporesponsive to the delivery of expected rewards. Although further research is needed, this hypersensitivity to punishments coupled with increased craving may negatively impact quit attempts as smokers anticipate the negative withdrawal symptoms associated with quitting.

Brain regions supporting verbal memory improvement in healthy older subjects / Regiões do cérebro relacionadas à melhora da memória verbal em idosos saudáveis

Despite growing interest in developing cognitive training interventions to minimize the aging cognitive decline process, no studies have attempted to explore which brain regions support the application of semantic strategies during verbal memory encoding. Our aim was to investigate the behavioral performance and brain correlates of these strategies in elderly individuals using fMRI in healthy older subjects. Method Subjects were scanned twice on the same day, before and after, directed instructions to apply semantic strategies during the encoding of word lists. Results Improved memory performance associated to increased semantic strategy application and brain activity in the left inferior and middle and right medial superior prefrontal cortex were found after the directed instructions. There was also reduced activation in areas related to strategy mobilization. Conclusion Improved memory performance in older subjects after the application of semantic strategies was associated with functional brain reorganization involving regions inside and outside the typical memory network. .

Apesar do crescente interesse em intervenções de treinamento cognitivo para minimizar o declínio cognitivo do envelhecimento, nenhum estudo explorou quais regiões do cérebro estão relacionadas à aplicação de estratégias semânticas durante a codificação da memória verbal. Nosso objetivo foi investigar o comportamento e correlatos cerebrais associados a essas estratégias usando fMRI em idosos saudáveis. Método Os sujeitos foram examinados no mesmo dia, antes e depois, de instruções dirigidas para aplicar estratégias semânticas durante a codificação de palavras. Resultados Melhora da memória relacionada ao uso de estratégias semânticas e aumento da atividade no córtex prefrontal inferior e medial esquerdo e medial superior direito foram encontrados após as instruções. Também houve redução de ativação em áreas de mobilização de estratégias. Conclusão A melhora da memória em idosos após o uso de estratégias semânticas estava associada à reorganização cerebral funcional envolvendo regiões dentro e fora da rede de áreas cerebrais típicas da memória. .

Branding and a child's brain: an fMRI study of neural responses to logos.

Branding and advertising have a powerful effect on both familiarity and preference for products, yet no neuroimaging studies have examined neural response to logos in children. Food advertising is particularly pervasive and effective in manipulating choices in children. The purpose of this study was to examine how healthy children's brains respond to common food and other logos. A pilot validation study was first conducted with 32 children to select the most culturally familiar logos, and to match food and non-food logos on valence and intensity. A new sample of 17 healthy weight children were then scanned using functional magnetic resonance imaging. Food logos compared to baseline were associated with increased activation in orbitofrontal cortex and inferior prefrontal cortex. Compared to non-food logos, food logos elicited increased activation in posterior cingulate cortex. Results confirmed that food logos activate some brain regions in children known to be associated with motivation. This marks the first study in children to examine brain responses to culturally familiar logos. Considering the pervasiveness of advertising, research should further investigate how children respond at the neural level to marketing.

A comparison of functional brain changes associated with surgical versus behavioral weight loss.

OBJECTIVE: Few studies have examined brain changes in response to effective weight loss; none have compared different methods of weight-loss intervention. Functional brain changes associated with a behavioral weight loss intervention to those associated with bariatric surgery were compared. DESIGN AND METHODS: Fifteen obese participants were recruited prior to adjustable gastric banding surgery and 16 obese participants were recruited prior to a behavioral diet intervention. Groups were matched for demographics and amount of weight lost. Functional magnetic resonance imaging scans (visual food motivation paradigm while hungry and following a meal) were conducted before and 12 weeks after surgery/behavioral intervention. RESULTS: When compared to bariatric patients in the premeal analyses, behavioral dieters showed increased activation to food images in right medial prefrontal cortex (PFC) and left precuneus following weight loss. When compared to behavioral dieters, bariatric patients showed increased activation in bilateral temporal cortex following weight loss. CONCLUSIONS: Behavioral dieters showed increased responses to food cues in medial PFC-a region associated with valuation and processing of self-referent information-when compared to bariatric patients. Bariatric patients showed increased responses to food cues in brain regions associated with higher level perception-when compared to behavioral dieters. The method of weight loss determines unique changes in brain function.

Evening hyperphagia and food motivation: a preliminary study of neural mechanisms.

Evening hyperphagia (EH; consumption of ≥25% of total daily calories after the evening meal) is a circadian delay in the pattern of daily food intake and is a core criterion of night eating syndrome (Allison et al., 2010). This preliminary study examined the brain response to food cues using functional magnetic resonance imaging (fMRI) in seven obese adults with EH compared to seven obese adults without EH. When contrasting food to non-food and blurry baseline images pre-meal, groups differed in brain activation in the inferior frontal gyrus, precentral gyrus, cingulate gyrus, superior temporal gyrus and cerebellum. At post meal, groups differed in brain activation in the fusiform gyrus, inferior frontal gyrus, inferior parietal lobule and the cerebellum. Significant interactions between time (pre-meal, post-meal) and group (EH, control) when contrasting food to non-food images were also noted in the inferior frontal gyrus and the superior temporal gyrus. Further research is necessary to replicate these findings and determine if they have a mechanistic role in the development of circadian delayed eating behavior in obese adults with EH.

Semantic strategy training increases memory performance and brain activity in patients with prefrontal cortex lesions.

OBJECTIVE: Memory deficit is a frequent cognitive disorder following acquired prefrontal cortex lesions. In the present study, we investigated the brain correlates of a short semantic strategy training and memory performance of patients with distinct prefrontal cortex lesions using fMRI and cognitive tests. METHODS: Twenty-one adult patients with post-acute prefrontal cortex (PFC) lesions, twelve with left dorsolateral PFC (LPFC) and nine with bilateral orbitofrontal cortex (BOFC) were assessed before and after a short cognitive semantic training using a verbal memory encoding paradigm during scanning and neuropsychological tests outside the scanner. RESULTS: After the semantic strategy training both groups of patients showed significant behavioral improvement in verbal memory recall and use of semantic strategies. In the LPFC group, greater activity in left inferior and medial frontal gyrus, precentral gyrus and insula was found after training. For the BOFC group, a greater activation was found in the left parietal cortex, right cingulated and precuneus after training. CONCLUSION: The activation of these specific areas in the memory and executive networks following cognitive training was associated to compensatory brain mechanisms and application of the semantic strategy.

Changes in brain activation to food pictures after adjustable gastric banding.

BACKGROUND: Adjustable gastric banding is an effective weight-loss treatment, but little is known about the neural mechanisms underlying weight loss. The purpose of the present study was to determine whether gastric banding affects brain function in regions previously implicated in food motivation, reward, and cognitive control. The setting for the study was the University of Missouri-Kansas City, Department of Psychology; Hoglund Brain Imaging Center, University of Kansas Medical Center; and private practice in the United States. METHODS: Ten obese participants were recruited before adjustable gastric banding surgery (mean body mass index before surgery 40.6 ± 1.96 kg/m2). Their mean body mass index at 12 weeks after surgery was 36.1 ± 2.32 kg/m2, with a mean percentage of excess weight loss of 25.21% ± 8.41%. Functional magnetic resonance imaging scans were conducted before and 12 weeks after adjustable gastric banding surgery. At each assessment point, the participants completed questionnaires assessing food motivation and were scanned while hungry (before eating) and immediately after a standardized meal (after eating). During the functional magnetic resonance imaging scans, the participants viewed food pictures, nonfood pictures (animals), and blurred baseline control pictures. The functional magnetic resonance imaging data were analyzed using BrainVoyager QX. RESULTS: After surgery, the participants reported significantly less food motivation and more cognitive restraint. The participants also showed decreased brain activation to food versus nonfood pictures in regions implicated in food motivation and reward, including the parahippocampus, medial prefrontal cortex, insula, and inferior frontal gyrus. In contrast, they demonstrated increased activation to food versus nonfood pictures in anterior prefrontal cortex, a region implicated in cognitive control and inhibition. CONCLUSION: This is the first study to examine the functional brain changes after gastric banding surgery and 1 of the first studies to longitudinally examine neural changes associated with weight loss. These results have provided preliminary evidence that adjustable gastric banding alters brain function in regions known to regulate reward and cognitive control.

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).

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.

Diferenças fenomenológicas surgidas com comportamentos repetitivos no transtorno obsessivo-compulsivo e na síndrome de Gilles de la Tourette / Phenomenological differences appearing with repetitive behaviours in obsessive-compulsive disorder and Gilles de la Tourette's syndrome

Retrospectiva. O transtorno obsessivo-compulsivo (TOC) é heterogênio, com algumas formas relacionadas à Síndrome de Gilles de la Tourette (SGT). Este é um estudo fenomenológico destinado a investigar a natureza desses possíveis subtipos de TOC e a relaçäo entre TOC e SGT. Método. Avaliamos 20 pacientes adultos ambulatoriais com TOC, 21 com SGT, e 20 com TOC + SGT, utilizando uma entrevista semi-estruturada para avaliar os fenômenos cognitivos, sensoriais e autonômicos, precedentes aos comportamentos repetitivos. Resultados. Foram relatados mais fenômenos cognitivos e ansiedade autonômica e menos fenômenos sensoriais no TOC que na SGT. Assim como no grupo de SGT, também no grupo de TOC e SGT foram relatados mais fenômenos sensoriais e menos cogniçöes que no grupo TOC. Conclusöes. A presença ou ausência de fenômenos cognitivos, fenômenos sensoriais e ansiedade autonômica distinguem os comportamentos repetitivos em pacientes com TOC daqueles com TOC + SGT, e SGT. Essas experiências subjetivas podem ser úteis em subclassificar o TOC e podem representar preditores válidos de prognóstico e resposta ao tratamento