Zero the hero: Evidence for involvement of the ventromedial prefrontal cortex in affective bias for free items.

Recent evidence from psycho-economics shows that when the price of an item decreases to the extent that it becomes available for free, one can observe a remarkable increase of subjective utility toward this item. This phenomenon, which is not observed for any other price but zero, has been termed the zero-price effect (ZPE). The ZPE is attributed to an affective heuristic where the positive affect elicited by the free status of an item provides a mental shortcut biasing choice towards that item. Given that the ZPE relies on affective processing, a key role of the ventromedial prefrontal cortex (vmPFC) has been proposed, yet neuroscientific studies of the ZPE remain scarce. This study aimed to explore the role of the vmPFC in the ZPE using a novel, within-subject assessment in participants with either an acquired (lesion patients) or degenerative (behavioural-variant frontotemporal dementia patients) lesion of the vmPFC, and age-matched healthy controls. All participants were asked to make a series of choices between pairs of items that varied in price. One choice trial involved an equal decrease of both item prices, such that one of the items was priced zero. In contrast to controls, patients with both vmPFC-lesion and behavioural-variant frontotemporal dementia showed marked reductions in zero-related changes of preference in pairs of gift-cards, but not for pairs of food items. Our findings suggest that affective evaluations driving the ZPE are altered in patients with focal or degenerative damage to the vmPFC. This supports the notion of a key role of the vmPFC in the ZPE and, more generally, the importance of this region in value-based affective decision-making. Our findings also highlight the potential utility of affective heuristic tasks in future clinical assessments.

Perception, attention, and working memory are disproportionately impaired in dementia with Lewy bodies compared with Alzheimer's disease.

OBJECTIVE: To test the hypotheses that visuoperceptual and attentional ability are disproportionately impaired in patients having dementia with Lewy Bodies (DLB) compared with Alzheimer's disease (AD). METHODS: A comprehensive battery of neuropsychological tasks designed to assess working, episodic, and semantic memory, and visuoperceptual and attentional functions was given to groups of patients with DLB (n=10) and AD (n=9), matched for age, education, and mini mental state examination (MMSE), and to normal controls (n=17). RESULTS: Both patient groups performed equally poorly on tests of episodic and semantic memory with the exception of immediate and delayed story recall, which was worse in the AD group. Digit span was by contrast spared in AD. The most striking differences were on tests of visuoperceptual/spatial ability and attention. Whereas patients with AD performed normally on several subtests of the visual object and space perception battery, the DLB group showed substantial impairments. In keeping with previous studies, the AD group showed deficits in selective attention and set shifting, but patients with DLB were more impaired on virtually every test of attention with deficits in sustained, selective, and divided attention. CONCLUSIONS: Patients with DLB have substantially greater impairment of attention, working memory, and visuoperceptual ability than patients with AD matched for overall dementia severity. Semantic memory seems to be equally affected in DLB and AD, unlike episodic memory, which is worse in AD. These findings may have relevance for our understanding of the genesis of visual hallucinations, and the differential diagnosis of AD and DLB.

Ventilatory function and winter fresh fruit consumption in a random sample of British adults.

The relation between ventilatory function and the reported frequency of consumption of fresh fruit and fruit juice was studied among 1502 lifelong non-smokers and 1357 current smokers aged 18-69 with no history of chronic respiratory disease. Forced expiratory volume in one second (FEV1) was assessed by turbine spirometry. As winter fruit consumption was more widely dispersed than summer consumption and few subjects ate fruit more frequently in the winter, winter fruit consumption was taken as an indicator of habitual (year round) consumption. After adjustment for sex, age, height, cigarette consumption, region of residence, and household socioeconomic group, FEV1 was associated with winter fruit consumption. The mean adjusted FEV1 among those who never drank fresh fruit juice and ate fresh fruit less than once a week during the winter was 78 ml lower (95% confidence interval 24-132 ml) than the mean for the other subjects. A similar difference was found in all age-sex groups and among both current smokers and lifelong non-smokers. Antioxidant and other actions of vitamin C may protect against pulmonary emphysema, or reduce bronchoconstrictor responses to environmental pollutants.

Some regional variations in dietary patterns in a random sample of British adults.

Comparison was made of the reported frequency of consumption or choice of 30 food items by 8860 adults in the 11 standard regions of Great Britain, with the use of log-linear analysis to allow for the age, sex, social class and smoking habit variations between the regions. The South-East was taken as the base region against which the others were compared. The number of food items for which there were significant differences from the South-East were Scotland 23, North 25, North-West and Yorkshire/Humberside 20, Wales 19, West Midlands 15, East Midlands 10, East Anglia 8, South-West 7 and Greater London 9. Overall the findings confirm a North/South trend in relation to eating habits, even when demographic and smoking-habit variations are taken into account, with the frequent consumption of many fruit and vegetable products being much less common and of several high-fat foods (chips, processed meats and fried food) more common in Scotland, Wales and the northern part of England. In most regions there was a significantly lower frequency of consumption of fresh fruit, fruit juice, 'brown' bread, pasta/rice, poultry, skimmed/semi-skimmed milk, light desserts and nuts, and a higher consumption of red meat, fish and fried food than in the South-East.

A comparison of the diets of non-smokers and smokers.

Dietary data, mostly in the form of the frequency of consumption of foods, from the 9003 respondents in the Health and Lifestyle Survey were used to compare lifetime non-smokers with light, heavy and ex-smokers, taking account of age and social class. Non-smokers, of both sexes, were significantly more likely than smokers to consume, frequently, fresh fruit in summer and winter, fruit juice, cooked and canned fruit, salads in summer and winter, breakfast cereals, cakes, biscuits, puddings, pasta, poultry, light desserts and preserves. They were also more likely to choose 'brown' bread, semi- or skimmed milk, low fat or polyunsaturated spread and to eat breakfast. Smokers were likely to consume chips and processed meats frequently, to drink more alcohol, more cups of tea and coffee and take sugar in these beverages. The differences from the non-smokers were more marked in the heavy smokers. Ex-smokers only differed from non-smokers in consuming more alcohol, tea and coffee, and nuts, in consuming cakes and soft drinks less frequently and in being more likely to choose skimmed or semi-skimmed milk. The results extend previous findings, and suggest that the eating patterns of non-smokers are more in line with current dietary recommendations than those of light smokers or, more particularly, heavy smokers.