Randomized Controlled Clinical Trial of Blood Glucose Awareness Training (BGAT III) in Switzerland and Germany

Although both diabetes and the efficacy of medical management are international issues, psycho-educational interventions might be culturally bound. Blood Glucose Awareness Training (BGAT) is a psycho-educational program for patients with type 1 diabetes mellitus. It is focused on improving recognition and management of extreme blood glucose levels, and is the best documented American psycho-educational program for this purpose. A randomized controlled clinical trial of BGAT's long-term benefits in a non-American setting has been lacking. One hundred and eleven adults with type 1 diabetes mellitus from Switzerland and Germany participated. After a 6 months baseline assessment, subjects were randomly assigned to receive either 2 months of BGAT (n = 56) or a physician-guided self-help control intervention (n = 55). BGAT improved recognition of low (p = 0.008), high (p = .03), and overall blood glucose (p = 0.001), and reduced frequency of severe hypoglycemia (p = 0.04), without compromising metabolic control. BGAT reduced both the external locus of control (p < 0.02) and fear of hypoglycemia (p < 0.02). BGAT was efficacious in reducing adverse clinical events and achieving clinically desirable goals in a European, as well as American settin

Stress Strengthens Memory of First Impressions of Others' Positive Personality Traits

Encounters with strangers bear potential for social conflict and stress, but also allow the formation of alliances. First impressions of other people play a critical role in the formation of alliances, since they provide a learned base to infer the other's future social attitude. Stress can facilitate emotional memories but it is unknown whether stress strengthens our memory for newly acquired impressions of other people's personality traits. To answer this question, we subjected 60 students (37 females, 23 males) to an impression-formation task, viewing portraits together with brief positive vs. negative behavior descriptions, followed by a 3-min cold pressor stress test or a non-stressful control procedure. The next day, novel and old portraits were paired with single trait adjectives, the old portraits with a trait adjective matching the previous day's behavior description. After a filler task, portraits were presented again and subjects were asked to recall the trait adjective. Cued recall was higher for old (previously implied) than the novel portraits' trait adjectives, indicating validity of the applied test procedures. Overall, recall rate of implied trait adjectives did not differ between the stress and the control group. However, while the control group showed a better memory performance for others' implied negative personality traits, the stress group showed enhanced recall for others' implied positive personality traits. This result indicates that post-learning stress affects consolidation of first impressions in a valence-specific manner. We propose that the stress-induced strengthening of memory of others' positive traits forms an important cue for the formation of alliances in stressful conditions

Cognitive and psychomotor function in hypoglycemia: response error patterns and retest reliability

Hypoglycemia has been shown to impair cognitive and psychomotor function, but it has been unclear which measures are most reliable and sensitive for detecting these effects. In a single-blind repeated measures design, healthy young adults (N=17, 8 male, mean age 27 years) performed three PC-based cognitive and psychomotor function tests: a paced auditory serial addition task (PASAT), an adaptive five-choice reaction time test (CRTT), and a manual tracking test on two occasions 4 weeks apart. In each session, a hyperinsulinemic clamp method was used during a normoglycemic (plasma glucose: 4.7 mmol/l) baseline testing period, followed in one session by a normoglycemic target testing period, and in the other session by a hypoglycemic (2.7 mmol/l) target testing period. All cognitive and psychomotor function measures showed high test-retest reliability (r ranging from.69 to.95) and sensitivity to hypoglycemia (Ptextless.01). A new finding is that on the PASAT, hypoglycemia appears to differentially increase the rate of omission errors more than it increases false responses. Data on PASAT reaction time (RT) are also presented

Effect of water deprivation on cognitive-motor performance in healthy men and women

Whether mental performance is affected by slowly progressive moderate dehydration induced by water deprivation has not been examined previously. Therefore, objective and subjective cognitive-motor function was examined in 16 volunteers (8 females, 8 males, mean age: 26 yr) twice, once after 24 h of water deprivation and once during normal water intake (randomized cross-over design; 7-day interval). Water deprivation resulted in a 2.6% decrease in body weight. Neither cognitive-motor function estimated by a paced auditory serial addition task, an adaptive 5-choice reaction time test, a manual tracking test, and a Stroop word-color conflict test nor neurophysiological function assessed by auditory event-related potentials P300 (oddball paradigm) differed (P textgreater 0.1) between the water deprivation and the control study. However, subjective ratings of mental performance changed significantly toward increased tiredness (+1.0 points) and reduced alertness (-0.9 points on a 5-point scale; both: P textless 0.05), and higher levels of perceived effort (+27 mm) and concentration (+28 mm on a 100-mm scale; both: P textless 0.05) necessary for test accomplishment during dehydration. Several reaction time-based responses revealed significant interactions between gender and dehydration, with prolonged reaction time in women but shortened in men after water deprivation (Stroop word-color conflict test, reaction time in women: +26 ms, in men: -36 ms, P textless 0.01; paced auditory serial addition task, reaction time in women +58 ms, in men -31 ms, P = 0.05). In conclusion, cognitive-motor function is preserved during water deprivation in young humans up to a moderate dehydration level of 2.6% of body weight. Sexual dimorphism for reaction time-based performance is present. Increased subjective task-related effort suggests that healthy volunteers exhibit cognitive compensating mechanisms for increased tiredness and reduced alertness during slowly progressive moderate dehydration

Selective processing of food words during insulin-induced hypoglycemia in healthy humans

RATIONALE: Hypoglycemia leads to undernutrition of the brain. Favoring selective processing of food stimuli would be an adaptive cognitive strategy. However, hypoglycemia is known to impair several aspects of cognitive function, and it is unknown whether selective cognitive processing of food stimuli occurs during insulin-induced hypoglycemia. METHODS: In a single-blind repeated measures design, healthy young adults (n=12, six female, mean age 28 years; mean body mass index 22.5 kg/m(2)) performed a standard Stroop word-color test, as well as a variant with food words designed to detect selective processing of food cues. Two sessions were scheduled with a 4-week interval. In each session, a hyperinsulinemic clamp method produced a normoglycemic (plasma glucose: 4.7 mmol/l) period, followed on 1 day by a hypoglycemic (2.7 mmol/l) testing period, and on the other day a second normoglycemic testing period (counterbalanced order). RESULTS: Color naming verbal reaction time (RT) increased during hypoglycemia (Ptextless0.0001). The extent of the Stroop cognitive interference was independent of plasma glucose level. The key finding is that RT for food words increased more than for non-food control words (Ptextless0.004), and this effect was not predicted by hunger ratings. CONCLUSIONS: Our data provide new evidence that during hypoglycemia, attention is directed selectively to food-relevant stimuli. The results are discussed in terms of adaptation

Prepulse inhibition of the human startle eye blink response by visual food cues

We present a new paradigm to investigate cognitive processing of food cues. The study assessed if pictures of food induce prepulse inhibition (PPI) of startle eye blink, and if any such effect is sensitive to food deprivation. In a balanced cross-over design, 16 healthy male volunteers (mean age: 29 years) were tested on 2 days 1 week apart, either after a period of normal food intake (NFI) or after a 24 h period of food restriction (RFI). On each experimental day, 80 control and 20 food pictures (slides) were displayed. Noise stimuli were presented 250 ms after slide onset. Startle responses were assessed by EMG recordings of the right M. orbicularis oculi. Startle elicited during dark inter-slide periods served as control responses to calculate PPI effects. The arousing content of each picture was rated by all subjects at the end of the session. The perceived arousal effect of control slides was strongly related to their PPI effect; no impact of food access status on this association was detectable. After NFI, food slides significantly induced PPI of startle (mean: -14.5%). After RFI, arousal ratings for food pictures increased but PPI did not. These results are evidence for a pre-attentive mechanism operative in the processing of visual food cues