Effects of cue prominence and palatability on the drinking behavior of obese and normal humans.

This study examines the effects of cue salience and palatability (water temperature) on the water drinking of obese and normal subjects. Obese subjects drink more than do normal subjects when the water cue is prominent but do not do so when this cue is remote. Palatability does not differentially affect the drinking behavior of obese and normal subjects. These results support the extension to nonfood stimuli of the hypothesis of the hyperreactivity of the obese to prominent cues.     

Natural teeth and cognitive function in humans

A number of neurobiological, psychological and social factors may account for cognitive impairment. In animal studies a relation between dental status and cognitive performance has been found. It is unclear whether such a relation exists for humans. In a first step we compared the performance of 1,351 participants (53% women, 47% men; age M = 54.0) with natural teeth to 487 edentulous participants (59% women, 41% men; age M = 71.3) on 12 cognitive tests. The natural teeth group had a lower mean age, fewer women, more years of education, higher mini-mental state (MMSE), and performed significantly higher on several cognitive tests. In a subsequent analysis, the cognitive performance of a subset of the participants (50-85 years) was examined. In this analysis, 211 had natural dentition and 188 were edentulous. The groups were matched for gender, age, social variables, diseases, stress and MMSE. The cognitive disadvantage of the edentulous group was still apparent. The results suggest that functional natural teeth relate to relatively preserved cognitive functioning in older age.     

Superstitious behavior in humans

Twenty undergraduate students were exposed to single response-independent schedules of reinforcer presentation, fixed-time or variable-time, each with values of 30 and 60 s. The reinforcer was a point on a counter accompanied by a red lamp and a brief buzzer. Three color signals were presented, without consistent relation to reinforcer or to the subjects' behavior. Three large levers were available, but the subjects were not asked to perform any particular behavior. Three of the 20 subjects developed persistent superstitious behavior. One engaged in a pattern of lever-pulling responses that consisted of long pulls after a few short pulls; the second touched many things in the experimental booth; the third showed biased responding called sensory superstition. However, most subjects did not show consistent superstitious behavior. Reinforcers can operate effectively on human behavior even in the absence of a response-reinforcer contingency and can, in some cases, shape stable superstitious patterns. However, superstitious behavior is not a consistent outcome of exposure of human subjects to response-independent reinforcer deliveries.     

Alcohol and cognitive control: implications for regulation of behavior during response conflict

Alcohol intoxication often leads to dysregulated behavior in contexts characterized by conflict between prepotent response tendencies and incompatible alternative responses. Recent research has identified 2 components of an anterior executive attention system that are essential for adaptive behavior when response conflict exists. Event-related potential (ERP) measures of evaluative and regulative cognitive control were collected to determine if impaired executive attention was responsible for observed behavior deficits when intoxicated. Intoxicated participants displayed task performance deficits on incongruent color-naming trials relative to sober controls. Alcohol did not affect P3 magnitude/latency, indicating that timing and integrity of stimulus evaluation remained intact. In contrast, alcohol did reduce frontal components of ERP that index evaluative and regulative cognitive control processes.     

Intrameal eating patterns of obese and nonobese humans.

Two experiments were conducted to test whether the intrameal eating patterns of obese and normal-weight human subjects are different. The first experiment was conducted in a laboratory under the pretense of a taste test. Eating was observed and data were compiled for seven parameters related to eating. The second experiment was conducted under field-study conditions with the subjects unaware of their participation. Few statistically significant differences in eating behavior were observed between obese and normal-weight subjects. These results are in contrast to the majority of previous work.     

Treatment of obsessive-compulsive disorder: cognitive behavior therapy vs. exposure and response prevention

The efficacy of contemporary cognitive therapy for obsessive–compulsive disorder (OCD) has only recently been investigated. The current study compares exposure and response prevention (ERP) and cognitive behavior therapy (CBT) delivered in an individual format. Participants were randomly assigned to the 12 consecutive-week CBT or ERP treatment. Based on 59 treatment completers, there was no significant difference in YBOCS scores between CBT and ERP at post-treatment or at 3-month follow-up. A higher percentage of CBT participants obtained recovered status at post-treatment (67%) and at follow-up (76%), compared to ERP participants (59% and 58%, respectively), but the difference was not significant. Effect sizes (ESs) were used to compare the results of the current study with a previous study conducted at our center that utilized group CBT and ERP treatments, as well as other controlled trials that have compared CBT and ERP. The significance of these results is discussed and a comparison is made with the existing literature.     

Making and breaking habits: Revisiting the definitions and behavioral factors that influence habits in animals

Habits have garnered significant interest in studies of associative learning and maladaptive behavior. However, habit research has faced scrutiny and challenges related to the definitions and methods. Differences in the conceptualizations of habits between animal and human studies create difficulties for translational research. Here, we review the definitions and commonly used methods for studying habits in animals and humans and discuss potential alternative ways to assess habits, such as automaticity. To better understand habits, we then focus on the behavioral factors that have been shown to make or break habits in animals, as well as potential mechanisms underlying the influence of these factors. We discuss the evidence that habitual and goal-directed systems learn in parallel and that they seem to interact in competitive and cooperative manners. Finally, we draw parallels between habitual responding and compulsive drug seeking in animals to delineate the similarities and differences in these behaviors.     

Palatability of food as a factor influencing obese and normal-weight children''s eating habits

The type and amount of food leftover from school lunches by normal-weight and obese elementary school children was examined for its similarity to the pattern reported by Krassner et al. (1979) in a study of normal-weight and obese college students. In this study 102 observations of children between the ages of 9–11, were taken over eight lunch periods in their school cafeteria. Overall, the normal-weight children left only slightly more food uneaten than did the obese children. However, when food palatability was examined, it was found that normal-weight children left over twice as much palatable food as did obese children. Children did not differ on the amount of unpalatable food left uneaten.

These results suggest that Krassner et al.'s observation that obese adults leave less food on their plates may be extended to children and, further, that like obese adults, obese children may be more influenced by the palatability of food than their normal-weight peers.     

Effects of minimal exercise and cognitive behavior modification on adherence, emotion change, self-image, and physical change in obese women

The present investigation tested a 12-wk. treatment protocol which employed low intensity cardiovascular and resistance exercise as well as cognitive-behavior modification on 13 obese, previously sedentary women. Separate analyses were conducted on program maintenance, emotional change, and physiological change. Although self motivation was lower in the treatment group than in the control group (n=35), measures of exercise maintenance were significantly higher. Analyses within the treatment group only indicated significant improvements in measures of State Anxiety, Depression, Anger, Fatigue, Tension, and Vigor, also Health Evaluation, Body Area Satisfaction, and heightened Overweight Preoccupation, over the 12 weeks. Their feelings after individual bouts of exercise indicated significantly increased Positive Engagement, Revitalization, and Tranquility, and reduced Physical Exhaustion. Maximum volume of oxygen uptake (VO2max) significantly increased (2nd to 10th percentile), but not resting heart rate. No significant correlation was found between cardiorespiratory change and change in scores on depression and anxiety. No significant association was found between physiological change and change in body image. Preliminary evaluation of the minimal exercise treatment was given. The need to replicate findings with larger and different samples was emphasized.     

Environmental stimulation, parental nurturance and cognitive development in humans

The effects of environmental stimulation and parental nurturance on brain development have been studied extensively in animals. Much less is known about the relations between childhood experience and cognitive development in humans. Using a longitudinally collected data set with ecologically valid in-home measures of childhood experience and later in-laboratory behavioral measures of cognitive ability, we were able to test hypotheses concerning the effects of environmental stimulation and parental nurturance. A double dissociation was found: On the one hand, there was a selective relation between parental nurturance and memory development, consistent with the animal literature on maternal buffering of stress hormone effects on hippocampal development. On the other hand, there was a selective relation between environmental stimulation and language development. The relevance of these findings to socioeconomic gradients in cognitive ability is discussed.     

The neurotic paradox and self-punitive behavior in humans

Human subjects learned a key-pressing response in order to avoid or escape shock. The reinforcement contingencies were then changed to punishment or to regular nonpunished extinction. The locus of shock onset and offset was systematically varied during the punishment phase. More subjects reported awarencess of the change in the nonpunished extinction group. By inference, the punished groups responded more, and thus the results appear analogous to animal studies on vicious circle, self-punitive responding. Discriminability of change from acquisition to extinction appeared to affect detection of the change.     

The eating behavior of obese and nonobese women

Sixty-one obese, normal weight and thin women were observed for 30 minutes as they consumed a free-choice lunch in a quasi-naturalistic setting. Their behavior was unobtrusively quantified in terms of microbehavior (mouthfulls, chews, drinks and pauses) and of the macrobehavior (type and amount of food consumed and total active eating or drinking time). Information on subject and environmental variables are also reported. Observed behavior was analyzed as comparative group totals and as patterns of behavior over time. Comparison of group totals showed that: (a) there were no differences in types of food or number of calories consumed between the three groups, (b) no differences were found between the eating behavior of the normal weight and the obese and (c) the obese women spent less time actively eating, less time chewing and more time drinking than did the thinnest group. Pattern analysis revealed a decrease in all responses over time but showed no significant pattern difference between groups.