Chemosensory function and food perception is affected in COPD, but unrelated to sarcopenia risk.

BACKGROUND & AIMS: Patients with advanced COPD often have difficulty maintaining sufficient dietary intake. Chemosensory function influences food choice and intake but is often overlooked in dietary assessment and intervention strategies. This study aimed to assess differences in chemosensory function and hedonic evaluation of food between patients with COPD and age- and gender-matched healthy controls. Additionally, a possible association between increased risk of sarcopenia or frailty and chemosensory impairments was explored. METHODS: We recruited 53 COPD patients (34 males, mean age 66.6 ± 7.6 years) and 53 controls (25 males, mean age 68.4 ± 5.7 years). Chemosensory function was assessed using a smell threshold, smell identification (Sniffin' Sticks, Burghart) and taste recognition test (Taste Strips, Burghart) and through self-report. Sensory properties (appearance, smell, taste, mouthfeel) of four standardized food products were evaluated on 9-point hedonic rating scales. Sarcopenia risk was assessed with the SARC-F. RESULTS: The COPD group scored lower on both the smell (p = 0.026 for threshold, p = 0.001 for identification) and taste recognition tests (p < 0.001) and also reported more smell and taste impairments (p < 0.001) compared to controls. Hedonic evaluation of food items' appearance (p = 0.009) and smell (p = 0.033) was lower in COPD patients. Within the COPD group, risk of sarcopenia was not associated with chemosensory function. CONCLUSION: This study demonstrates that COPD patients have poorer chemosensory function and experience more impairments compared to controls. COPD patients also tend to evaluate foods less positive than do their controls but within COPD patients, sarcopenia risk is not associated with chemosensory function.

Sensory-specific satiety for a food is unaffected by the ad libitum intake of other foods during a meal. Is SSS subject to dishabituation?

Sensory-specific satiety (SSS) is defined as a decrease in the pleasantness of a specific food that has just been eaten to satiation, while other non-eaten foods remain pleasant. The objectives of this study were the following: (1) to investigate whether SSS for a food is affected by the ad libitum intake of other foods presented sequentially during a meal, (2) to compare the development of SSS when foods are presented simultaneously or sequentially during a meal, and (3) to examine whether SSS is modified when foods are presented in an unusual order within a meal. Twelve participants participated in three tasting sessions. In session A, SSS for protein-, fat- and carbohydrate-rich sandwiches was measured after the ad libitum consumption of single type of each of these foods. In session B, SSS was measured for the same three foods consumed ad libitum but presented simultaneously. Session C was identical to session A, except that the presentation order of the three foods was reversed. The results indicate that once SSS for a given food is reached, the ad libitum consumption of other foods with different sensory characteristics does not decrease SSS, regardless of the order in which the foods are presented. Once reached, SSS is thus not subject to dishabituation during a meal.

Reward activity in satiated overweight women is decreased during unbiased viewing but increased when imagining taste: an event-related fMRI study.

OBJECTIVE: The aim of this functional magnetic resonance imaging (fMRI) study was to investigate reward-related brain activity in satiated overweight and healthy-weight participants in response to high-calorie palatable food pictures, when viewing the pictures without prior instructions (called unbiased viewing) versus imagining the taste of the shown pictures (called taste imagination). We predicted that neural activation in brain reward regions would be greater in overweight participants than in healthy-weight ones and that this difference between groups would be strongest during unbiased viewing. METHOD: Neural activation was measured using fMRI in 14 overweight (mean body mass index (BMI): 29.8 kg m(-2)) and 15 healthy-weight (mean BMI: 21.1 kg m(-2)) participants who were satiated, in response to palatable and unpalatable high-calorie and low-calorie food pictures, presented in an event-related design during two conditions: unbiased viewing (no prior instructions) versus taste imagination. RESULTS: A group × condition interaction was found in 14 brain regions involved in food reward processing during the presentation of high-calorie palatable food stimuli. During the taste imagination condition, neural activation in these regions was greater in the overweight participants than in the healthy-weight ones. Contrary to our expectations, the opposite pattern was observed during unbiased viewing: activation in reward regions in the overweight participants was reduced compared with the healthy-weight ones. In all brain reward regions except for the left amygdala, the group × condition interaction was specific to high-calorie palatable food stimuli. CONCLUSION: Greater reward activity in the overweight participants compared with the control group when imagining taste may represent an increased reward response induced by high-calorie palatable food. During unbiased viewing, reduced reward activation in the overweight participants compared with those with a healthy weight may reflect avoidance of high-calorie palatable food stimuli. Taken together, this pattern of activation may reflect ambivalence in the overweight group between desire for (in the taste imagination condition) and avoidance of (in the unbiased viewing condition) high-calorie palatable food stimuli.

The interactive effect of hunger and impulsivity on food intake and purchase in a virtual supermarket.

OBJECTIVE: It has been shown repeatedly that impulsivity, obesity and food intake are related; obese people are more impulsive than lean people and impulsive people eat more than less impulsive people. The relation between impulsivity and food intake might be state dependent; hunger motivates food seeking behaviour and food consumption, especially of high caloric food. Difficulties to overrule automatic behavioural tendencies might make impulsive people more susceptible to the effects of hunger on food selection. Therefore, they are expected to increase their intake more than low impulsive people when feeling hungry. STUDY 1: Fifty-seven female participants were randomly assigned to a hunger or sated condition. Response inhibition (a measure of impulsivity) and food intake were measured. Results show that impulsive participants ate significantly more, but only when feeling hungry. STUDY 2: Ninety-four undergraduate students participated. Hunger, response inhibition and the purchase of food in a virtual supermarket were measured. The same interaction was found: impulsive participants bought most calories, especially from snack food, but only when feeling hungry. CONCLUSION: Hunger and impulsivity interact in their influence on consumption. These data suggest that reducing hunger during calorie restricting diets is important for successful weight loss, particularly for the impulsive dieters.

The environment influences whether high-fat foods are associated with palatable or with unhealthy.

This study investigated whether relatively automatic evaluations of food differ between situations and between obese people and lean controls. These evaluations were assessed in the affective priming paradigm (APP) -- a response latency based measure for associations. In Experiment 1, we either focused participants (33 obese and 26 lean controls) on the palatability (restaurant condition) or on the healthiness (health condition) of food, prior to the APP. Independent of weight-status, relatively automatic evaluations of food were based on palatability in the restaurant condition, and on health in the health condition. So, the current focus of attention can shape the way foods are evaluated relatively automatically. In Experiment 2, craving was induced in participants (27 obese and 29 lean controls). Unexpectedly, the craving induction did not achieve its goal of focusing on the palatability of food in general, but just for low-fat foods, possibly because of the health-emphasizing environment -- a hospital. Interestingly, obese people showed a stronger palatability priming effect with increasing levels of initial craving. For normal weight controls the effect was in the same direction, but missed significance. In our environment, palatability of food may be too salient, and health may not be salient enough, influencing automatic food-evaluations.

Effects of trazodone on EEG sleep and clinical state in major depression.

The effects of the antidepressant trazodone on clinical state and on EEG sleep in eight outpatients with a major depressive disorder were investigated in a single blind study. A medication period of 5 weeks was preceded and followed by one week placebo treatment. Five subjects showed a positive treatment response. Trazodone did not influence sleep continuity and slow wave sleep, but did suppress REM sleep significantly. A significant increase of REM sleep latency was also found. These results are in contrast with earlier reports on trazodone's effects on EEG sleep but are in accordance with the general finding that antidepressants influence REM sleep characteristics without necessarily affecting sleep continuity.

A controlled study of temporal lobe structure volumes and P300 responses in schizophrenic patients with persistent auditory hallucinations.

Recent studies of cerebral pathology in patients with schizophrenia have focused on symptomatological and electrophysiological correlates of reduced temporal lobe structure volumes. Volume deficits of the left superior temporal gyrus have been correlated with auditory hallucinations as well as to left-sided P300 amplitude reduction. However, caution is needed to interpret correlational data as evidence of a specific relationship. Therefore, a controlled study was undertaken on schizophrenic patients with and without auditory hallucinations. MRI-defined volumes of the left superior temporal gyrus and other temporal lobe structures were quantified from 3-mm coronal slices in 15 schizophrenic patients with chronic auditory hallucinations (hallucinators), 15 schizophrenic patients without auditory hallucinations (nonhallucinators) and 17 healthy controls. In all subjects a simple oddball paradigm was used to elicit P300 responses at temporal and centro-parietal electrode sites. No evidence was found for volume reductions of temporal lobe structures in the combined patient group compared with controls, or in the hallucinators compared with the nonhallucinators. The patients did show left P300 amplitude reduction compared with controls, particularly in the hallucinator group. Correlations between volumes of left temporal lobe structures and left P300 amplitudes were low and not significant. The results of the present study do not indicate that auditory hallucinations and associated abnormal electrophysiological activity are the consequence of atrophy of localized temporal lobe structures. However, replication in a larger sample of subjects is needed before firm conclusions can be drawn.

Factors affecting context specificity of appetitive conditioned responding.

The present experiment contributes to the identification of factors affecting magnitude of context specificity of simple appetitive conditioned responding. Rats were first trained to associate an auditory and a visual stimulus with food. Each of these stimuli was consistently presented in a distinctive environmental context. Groups of rats differed only in the number of conditioning trials. At test, all groups received trials on which each of the stimuli was presented either in the same context as used during training, or in the different context. Rats made significantly fewer food-magazine visits on different-context trials than on same-context trials only under the conditions that the stimulus tested was the auditory stimulus, which generally elicited a stronger conditioned response (CR) than did the visual stimulus, and the animals had received a relatively small number of conditioning trials. Apparently, magnitude of context specificity is affected by factors determining the strength of the appetitive conditioned response to the target stimulus.

Cognitive performance in relation to MRI temporal lobe volume in schizophrenic patients and healthy control subjects.

The aim of this study was to identify whether specific deficits in cognitive processing are present in schizophrenia and whether these are related to the volume of temporal and limbic structures. Twenty-seven schizophrenic outpatients were compared with 19 matched control subjects. Compared with control subjects, patients performed complex tasks disproportionately worse than they performed simple tasks. No group differences were found with regard to temporal and limbic volume. Volume of the parahippocampal gyrus was correlated with cognitive performance. The findings are interpreted as evidence for a dysfunction in the maintenance of task-relevant information and the inhibition of irrelevant information.

Emotional reactivity to daily life stress in psychosis and affective disorder: an experience sampling study.

OBJECTIVE: To investigate the emotional reactivity to small disturbances in daily life in patients with non-affective psychosis (NAP), bipolar disorder (BD) and major depression [major depressive disorder (MDD)]. METHOD: Forty-two patients with NAP, 38 with BD, 46 with MDD, and 49 healthy controls were studied with the experience sampling method to assess (i) appraised subjective stress of small disturbances in daily life and (ii) emotional reactivity, reflected in changes in positive affect (PA) and negative affect (NA). RESULTS: Multilevel regression analyses showed an increase in NA in MDD, a decrease in PA in BD and both an increase in NA and a decrease in PA in NAP in association with the subjectively stressful situations, compared with the control subjects. CONCLUSION: Individuals with NAP, MDD and BD display differences in emotional stress reactivity. Type of mood disorder may exert a pathoplastic effect on emotional reactivity in individuals with MDD and BD. Individuals with NAP may be most vulnerable to the effects of daily life stress.