Prenatal folate, homocysteine and vitamin B12 levels and child brain volumes, cognitive development and psychological functioning: the Generation R Study.

Previous studies have suggested that prenatal maternal folate deficiency is associated with reduced prenatal brain growth and psychological problems in offspring. However, little is known about the longer-term impact. The aims of this study were to investigate whether prenatal maternal folate insufficiency, high total homocysteine levels and low vitamin B12 levels are associated with altered brain morphology, cognitive and/or psychological problems in school-aged children. This study was embedded in Generation R, a prospective population-based cohort study. The study sample consisted of 256 Dutch children aged between 6 and 8 years from whom structural brain scans were collected using MRI. The mothers of sixty-two children had insufficient (<8 nmol/l) plasma folate concentrations in early pregnancy. Cognitive development was assessed by the Snijders-Oomen Niet-verbale intelligentietest - Revisie and the NEPSY-II-NL. Psychological problems were assessed at age 6 years using the parent report of the Child Behavior Checklist. Low prenatal folate levels were associated with a smaller total brain volume (B -33·34; 95 % CI -66·7, 0·02; P=050) and predicted poorer performance on the language (B -0·28; 95 % CI -0·52, -0·04; P=0·020) and visuo-spatial domains (B -0·27; 95 % CI -0·50, -0·04; P=0·021). High homocysteine levels (>9·1 µmol/l) predicted poorer performance on the language (B -0·31; 95 % CI -0·56, -0·06; P=0·014) and visuo-spatial domains (B -0·36; 95 % CI -0·60, -0·11; P=0·004). No associations with psychological problems were found. Our findings suggest that folate insufficiency in early pregnancy has a long-lasting, global effect on brain development and is, together with homocysteine levels, associated with poorer cognitive performance.

Food addiction is associated with impaired performance monitoring.

Currently, there is an ongoing debate about whether it is possible to be addicted to food. There are several indications pointing in this direction, but research is scarce. Up to this date it is not exactly known whether this "food addiction" shares common neurocognitive deficits observed in the more classical types of addictions such as substance use disorders (SUDs). One commonly observed finding in SUD patients is that there is an impaired cognitive control. One of the essential components of cognitive control is performance monitoring. In the present study it is studied whether persons with "food addiction" have impaired error monitoring. For this purpose the performance monitoring of persons meeting the criteria for "food addiction" (n=34) according to the Yale Food Addiction Scale (YFAS) were compared with a control group (n=34) while performing an Eriksen flanker task and EEG measurement. Both electrophysiological (ERN and Pe component) and behavioral measures were compared between the two groups. The present study indicates that the "food addicted" persons have reduced ERN and Pe waves. In addition, the "food addiction" group demonstrates a higher number of errors on the flanker task. In general, the results provide indications that persons with a "food addiction" display impaired performance monitoring. These findings provide an indication that food addiction, similar to other addictions, is characterized by impaired cognitive control.

Increased attention and memory for beloved-related information during infatuation: behavioral and electrophysiological data.

Emotionally salient information is well attended and remembered. It has been shown that infatuated individuals have increased attention for their beloved. It is unknown whether this attention bias generalizes to information related to the beloved. Moreover, infatuated individuals report to remember trivial things about their beloved, but this has not yet been tested empirically. In two studies, we tested whether infatuated individuals have increased attention and memory for beloved-related information. In a passive viewing task (Study 1), the late positive potential, an event-related potential (ERP) component reflecting motivated attention, was enhanced for beloved-related vs friend-related words/phrases. In a recognition task (Study 2), memory performance and the frontal and parietal ERP old/new effects, reflecting familiarity and recollection, respectively, were not enhanced for beloved-related compared with friend-related words/phrases. In free recall tasks in both studies, memory was better for beloved-related than friend-related words/phrases. This research reveals that attention and memory are enhanced for beloved-related information. These attention and memory biases for beloved-related information were not due to valence, semantic relatedness, or experience, but to arousal. To conclude, romantic love has profound effects on cognition that play a clear role in daily life.

The role of dopamine in inhibitory control in smokers and non-smokers: a pharmacological fMRI study.

Contemporary theoretical models of substance dependence posit that deficits in inhibitory control play an important role in substance dependence. The neural network underlying inhibitory control and its association with substance dependence have been widely investigated. However, the pharmacology of inhibitory control is still insufficiently clear. The aims of the current study were twofold. First, we investigated the role of dopamine in inhibitory control and associated brain activation. Second, the proposed link between dopamine and impaired inhibitory control in nicotine dependence was investigated by comparing smokers and non-smoking controls. Haloperidol (2 mg), a dopamine D2/D3 receptor antagonist, and placebo were administered to 25 smokers and 25 non-smoking controls in a double-blind randomized cross-over design while performing a Go/NoGo task during fMRI scanning. Haloperidol reduced NoGo accuracy and associated brain activation in the ACC, right SFG and left IFG, showing that optimal dopamine levels are crucial to effectively implement inhibitory control. In addition, smokers showed behavioral deficits on the Go/NoGo task as well as hypoactivity in the left IFG, right MFG and ACC after placebo, supporting the hypothesis of a hypoactive prefrontal system in smokers. Haloperidol had a stronger impact on prefrontal brain activation in non-smoking controls compared to smokers, which is in line with the inverted 'U' curve theory of dopamine and cognitive control. The current findings suggest that altered baseline dopamine levels in addicted individuals may contribute to the often observed reduction in inhibitory control in these populations.

Relation of emotional and behavioral problems with body mass index in preschool children: the Generation R study.

OBJECTIVE: Although problem behavior in children and adolescents has frequently been associated with overweight, it is unclear whether this relationship is already present in early childhood. We hypothesized that problem behavior is positively related to body mass index (BMI) in children of preschool age and that eating behavior explains part of this relation. METHODS: The study was embedded in the Generation R Study, a population-based cohort with data available on BMI and problem behavior for 3137 children aged 3 to 4 years. Problem behavior was measured with the child behavior checklist (CBCI), and eating behavior was assessed using the child eating behaviour questionnaire (CEBQ). Linear regression analyses were conducted to assess the association between the CBCI (expressed as z-scores). CEBQ, and BMI standard deviation scores (BMI-SDS), Bootstrapping was used to formally test mediation. RESULTS: Children with higher levels of emotional problems had a lower BMI-SDS after adjustment for relevant covariates (e.g., ß [95% confidence interval {Cl}] for mother report of emotional problems = -0.04 [-0.07, -0.001], father report = -0.04 [-0.08, -0.001]). Behavioral problems were not associated with BMI. Emotional and behavioral problems were not associated with underweight or overweight if studied categorically. The effect estimate for the relation of emotional problems with BMI-SDS attenuated to nonsignificance after adjustment for specific eating behaviors, i.e., they were accounted for by satiety responsiveness, fussiness, and emotional undereating. CONCLUSION: In this population-based study, emotional problems in preschoolers were negatively related to BMI, and this relation was fully explained by food avoidant eating behaviors.

Attentional Processing of Food Cues in Overweight and Obese Individuals.

The incentive sensitization model of obesity hypothesizes that obese individuals in the western world have acquired an enhanced attention bias to food cues, because of the overwhelming exposure to food. This article gives an overview of recent studies regarding attention to food and obesity. In general, an interesting approach-avoidance pattern in food-related attention has been found in overweight/obese individuals in a number of studies. However, it should be noted that study results are contradictory. This might be due to methodological issues, such as the choice of attention measurements, possibly tapping different underlying components of information processing. Although attention research is challenging, researchers are encouraged to further explore important issues, such as the exact circumstances in which obese persons demonstrate enhanced attention to food, the directional relationship between food-related attention bias, overeating and weight gain, and the underlying involvement of the reward system. Knowledge on these issues could help improve treatment programs.

Electrophysiology of appetitive taste and appetitive taste conditioning in humans.

The present study examines two novel aspects of appetitive processing and conditioning: the electrophysiological response to (a) the appetitive taste of a sweet fluid and (b) appetitively/taste conditioned visual stimuli. Event-related potentials (ERPs) were recorded from 32 subjects while they performed a taste conditioning task, in which two symbols were paired with a sweet or a neutral fluid. The results show a clear P1/N1/P2 complex, and a late positive potential (P3) with maxima at right fronto-central electrode sites, in response to the taste stimuli. Of these components particularly the P3 showed robust differences between the sweet and neutral taste. In addition, the electrophysiological response to the taste conditioned stimuli (CS), also showed the expected differences for both P2 and P3 at frontocentral electrodes. The present data demonstrate that the employed paradigm is a useful methodology to study the electrophysiological responses to unconditioned appetitive stimuli. Since appetitive conditioning is assumed to be disturbed in many psychopathological conditions, such as substance dependence, depression and eating disorders, this paradigm could be employed to get more insight in these conditions in humans.

Food-related Stroop interference in obese and normal-weight individuals: behavioral and electrophysiological indices.

The primary objective of the present study was to investigate differences in the attentional processing of food-related words in a Stroop task, as assessed by means of behavioral (reaction times) and electrophysiological (P200 and P300 amplitudes) indices, between obese and normal-weight individuals. Results revealed a P200 bias to food-related words in obese participants, which was not seen in normal-weight participants. This indicates that, in an early, automatic stage of information processing, obese participants already tend to engage more attention towards food-related stimuli than to neutral stimuli. With respect to reaction times and P300 scores, as alleged indices of more conscious maintained attention, a general food-related bias was observed, with no between-group differences. Further, in the obese group, significant positive correlations were observed between the food-related reaction time bias, food craving, and external eating, whereas in the normal-weight group, food craving scores correlated positively with P200/P300 amplitude biases. It can be concluded that obese individuals display an enhanced automatic, preconscious attentional processing of food-related stimuli, and this can be regarded as an initial expression of a greater responsiveness to food cues. In the current food-abundant environment, such a heightened food cue-responsiveness might contribute substantially to the tendency to overeat.

Differences in attention to food and food intake between overweight/obese and normal-weight females under conditions of hunger and satiety.

Starting from an addiction model of obesity, the present study examined differences in attention for food-related stimuli and food intake between overweight/obese and normal-weight women under conditions of hunger and satiety. Twenty-six overweight/obese (BMI: 30.00+/-4.62) and 40 normal-weight (BMI: 20.63+/-1.14) females were randomly assigned to a condition of hunger or satiety. Three indexes of attention were employed, all including pictures of food items: an eye-tracking paradigm (gaze direction and duration), a visual probe task (reaction times), and a recording of electrophysiological brain activity (amplitude of the P300 event-related potential). In addition, the acute food intake of participants was assessed using a bogus taste task. In general, an attentional bias towards food pictures was found in all participants. No differences between groups or conditions were observed in the eye-tracking data. The visual probe task revealed an enhanced automatic orientation towards food cues in hungry versus satiated, and in overweight/obese versus normal-weight individuals, but no differences between groups or conditions in maintained attention. The P300 amplitude showed that only in normal-weight participants the intentional allocation of attention to food pictures was enhanced in hunger versus satiety. In hungry overweight/obese participants, the P300 bias for food pictures was not clearly present, although an increased food intake was observed especially in this group. In conclusion, various attention-related tasks yielded various results, suggesting that they measure different underlying processes. Strikingly, overweight/obese individuals appear to automatically direct their attention to food-related stimuli, to a greater extent than normal-weight individuals, particularly when food-deprived. Speculatively, hungry overweight/obese individuals also appear to use cognitive strategies to reduce a maintained attentional bias for food stimuli, perhaps in an attempt to prevent disinhibited food intake. However, in order to draw firm conclusions, replication studies are needed.

Enhanced processing of food-related pictures in female external eaters.

The main purpose of the present study was to investigate differences in the processing of food-related pictures between women with high and low scores on a scale of external eating. Electro-encephalographic brain activity was recorded, while participants were actively exposed to pictures of food items and control pictures. The amplitude of the P300 component of the even-related potentials was used as an index of motivation-related information processing. An enlarged P300 wave to food-related pictures was found in high external eaters as compared to low external eaters at several parieto-occipital electrode positions. No group differences in P300 amplitudes were found to neutral control pictures or pleasant, motivationally salient control pictures. It can be concluded that external eaters display an enhanced attentional processing of food-related information. The findings are discussed within an incentive sensitization model of overeating behavior.

Food cue-elicited brain potentials in obese and healthy-weight individuals.

The main objective of this study was to investigate, by means of event-related potentials (ERPs), whether obese individuals process food-related information differently as compared to normal-weight individuals. Because amplitudes of late positive ERP components (P3, LPP) reflect motivational tendencies, obese participants were expected to display enlarged P3 and LPP amplitudes towards food pictures. Obese and normal-weight adults were exposed to pictures of food and control items, while EEG was recorded. Subjective levels of food craving and hunger were also assessed. While there were no differences in ERP amplitudes between obese and normal-weight individuals, significantly larger P3 and LPP amplitudes were elicited by pictures of food items as compared to control pictures. Positive correlations were found between P3 and LPP amplitudes and self-reported increases of hunger. It was concluded that food-related information is processed differently in the brain as compared to non-food-related information, in a manner that reflects the natural motivational value of food. In the present study, there was no indication of an electrophysiological or subjective hyper-reactivity to food cues in obese adults.

Alcohol selectively reduces brain activity during the affective processing of negative information.

BACKGROUND: Although it has frequently been suggested that alcohol influences emotions such as anxiety and fear through the modulation of affective information processing, few studies addressed this topic using objective measures. OBJECTIVES: The acute effects of alcohol on affective processing of pictorial stimuli were investigated using electrophysiological measures. METHODS: Event-related brain potentials (ERP) resulting from watching pleasant, unpleasant, and neutral pictures were investigated in a group of participants receiving a beverage containing a moderate dose of alcohol (n=26) and a group of participants receiving a nonalcoholic placebo beverage (n=24). Both early [early posterior negativity (EPN)] and late [late positive potential (LPP)] ERP components were employed as index of emotional processing. RESULTS: The results show that alcohol reduced brain activity during watching unpleasant information in a late stage (700-1000 ms). This suggests that alcohol selectively influences the processing of unpleasant information. CONCLUSIONS: The findings are in concordance with theories linking alcohol administration to decreased processing of affective information. The results are discussed in the context of the role of the effect of alcohol on affective information processing, and its relevance to alcoholism.

The modified Trait and State Food-Cravings Questionnaires: development and validation of a general index of food craving.

In the present study, the multidimensional Trait and State Food Cravings Questionnaires (FCQ-T and FCQ-S), as developed by Cepeda-Benito, Gleaves, Williams, and Erath, [2000. The development and validation of the State and Trait Food Cravings Questionnaires. Behavior Therapy, 31, 151-173], were modified in order to construct an index of general food craving instead of specific food craving. The factor structure, validity and reliability of the modified questionnaires, renamed as the Trait and State General Food Cravings Questionnaires (G-FCQ-T and G-FCQ-S), were investigated in three separate studies. Firstly, exploratory factor analyses were conducted, which yielded a G-FCQ-T with a four-factor structure, that was considerably shorter as compared to the original (nine-factor) FCQ-T, and a G-FCQ-S of which the factor structure was highly comparable to the original FCQ-S. Secondly, in an attempt to replicate the factor structures of the G-FCQ-T and the G-FCQ-S as found in Study 1, confirmative factor analyses were performed. Results indicated adequate fits for both questionnaires. In addition, the test-retest reliability of both versions was satisfactory and an analysis of the construct validity generally revealed the expected results. In Study 3, the validity of the state version of the G-FCQ was further investigated by relating scores on this questionnaire to indices of food deprivation and satiation. Results indicated that the G-FCQ-S indeed measures food craving as a variable state, which is influenced by situational and temporal variables. Altogether, it can be concluded that the G-FCQ-T and G-FCQ-S are both reliable and valid measures of general trait-like and state-dependent food craving.

Effect of hedonic tone on event-related potential measures of cognitive processing.

Anhedonia, the inability to experience pleasure, is a core feature of several psychiatric disorders such as schizophrenia, depression, and substance dependence. Furthermore, it has been suggested that anhedonia is an important predictor of schizophrenia. Anhedonia has been associated with information-processing deficits, especially attentional deficits, which may predispose for schizophrenia. In the present study, event-related potentials (ERPs) were used to examine the influence of hedonic tone on information-processing characteristics in a sample of healthy individuals. Thirty-five healthy subjects were divided into two groups based on their scores on the Snaith-Hamilton Pleasure Scale (SHAPS). Cognitive functions were measured during an active visual oddball paradigm. It was found that both early, middle and late ERP components of subjects with low levels of hedonic tone were attenuated compared with ERPs of subjects with high levels of hedonic tone. These findings suggest that decreased hedonic tone is associated with reductions in both automatic and effortful cognitive processing of relevant stimuli. Consequences of these findings for the vulnerability to psychopathology are discussed.

Effect of green tea on resting energy expenditure and substrate oxidation during weight loss in overweight females.

We assessed the effect of ingestion of green tea (GT) extract along with a low-energy diet (LED) on resting energy expenditure (REE), substrate oxidation and body weight as GT has been shown to increase energy expenditure and fat oxidation in the short term in both animals and people. Forty-six overweight women (BMI 27.6 (sd 1.8) kg/m2) were fed in energy balance from day 1 to day 3, followed by a LED with GT (1125 mg tea catechins +225 mg caffeine/d) or placebo (PLAC) from day 4 to day 87. Caffeine intake was standardised to 300 mg/d. Energy expenditure was measured on days 4 and 32. Reductions in weight (4.19 (sd 2.0) kg PLAC, 4.21 (sd 2.7) kg GT), BMI, waist:hip ratio, fat mass and fat-free mass were not statistically different between treatments. REE as a function of fat-free mass and fat mass was significantly reduced over 32 d in the PLAC group (P<0.05) but not in the GT group. Dietary restraint increased over time (P<0.001) in both groups, whereas disinhibition and general hunger decreased (P<0.05). The GT group became more hungry over time and less thirsty, and showed increased prospective food consumption compared with PLAC (P<0.05). Taken together, the ingestion of GT along with a LED had no additional benefit for any measures of body weight or body composition. Although the decrease in REE as a function of fat-free mass and fat mass was not significant with GT treatment, whereas it was with PLAC treatment, no significant effect of treatment over time was seen, suggesting that a robust limitation of REE reduction during a LED was not achieved by GT.