Cognition Intervention Study Dortmund (CogniDO)

• Tonic Alertness (Mean Reaction Time) [ Time Frame: Participants were tested twice with one week wash out (1h after having/skipping lunch) ] [ Designated as safety issue: No ]
  Mean reaction time to response to a simple visual stimulus without a preceding warning signal
  
  
• Tonic Alertness (Deviation of Reaction Time) [ Time Frame: Participants were tested twice with one week wash out (1h after having/skipping lunch) ] [ Designated as safety issue: No ]
  Deviation of reaction time --> logarithmic standard deviation of the reaction times
  
  
• Tonic Alertness (Commission Errors) [ Time Frame: Participants were tested twice with one week wash out (1h after having/skipping lunch) ] [ Designated as safety issue: No ]
  Reactions when no stimulus had been presented
  
  
• Tonic Alertness (Omission Errors) [ Time Frame: Participants were tested twice with one week wash out (1h after having/skipping lunch) ] [ Designated as safety issue: No ]
  Stimuli to which no reaction follows within 1.5s
  
  
• Immediate Block Span [ Time Frame: Participants were tested twice with one week wash out (1h after having/skipping lunch) ] [ Designated as safety issue: No ]
  Longest sequence correctly reproduced in at least two of three items (the test is a task of reproducing prescribed sequences from two to eight blocks)
  
  
• Incorrect Immediate Block Span [ Time Frame: Participants were tested twice with one week wash out (1h after having/skipping lunch) ] [ Designated as safety issue: No ]
  Number of sequences incorrectly reproduced
  
  
• Correct Immediate Block Span [ Time Frame: Participants were tested twice with one week wash out (1h after having/skipping lunch) ] [ Designated as safety issue: No ]
  Number of sequences correctly reproduced
  
  
• Sequencing Errors [ Time Frame: Participants were tested twice with one week wash out (1h after having/skipping lunch) ] [ Designated as safety issue: No ]
  Sequences including all the blocks of a prescribed sequence, but in the wrong order
  
  
• Reactions [ Time Frame: Participants were tested twice with one week wash out (1h after having/skipping lunch) ] [ Designated as safety issue: No ]
  Number of total reactions (Subjects have to decide whether a displayed figure is identical with one of four figures shown or not)
  
  
• Percentage Incorrect Reactions [ Time Frame: Participants were tested twice with one week wash out (1h after having/skipping lunch) ] [ Designated as safety issue: No ]
  Percentage of incorrect reactions
  
  
• Number Correct Reactions [ Time Frame: Participants were tested twice with one week wash out (1h after having/skipping lunch) ] [ Designated as safety issue: No ]
  Number of correct reactions
  
  
• Incorrect Reactions [ Time Frame: Participants were tested twice with one week wash out (1h after having/skipping lunch) ] [ Designated as safety issue: No ]
  Number of incorrect reactions
  
  
• Mean Time Correct Reactions [ Time Frame: Participants were tested twice with one week wash out (1h after having/skipping lunch) ] [ Designated as safety issue: No ]
  Mean time to react correctly
  
  
• Mean Time Incorrect Reactions [ Time Frame: Participants were tested twice with one week wash out (1h after having/skipping lunch) ] [ Designated as safety issue: No ]
  Mean time to react incorrectly
  
  

Because of cerebral particularities, children may react sensitive to short-term variations of nutrient supply. Therefore, an optimised composition of meals at nutritionally favourable mealtime should be considered for optimal cognitive performance. The increasing implementation of all-day schools in Germany requires the children's catering at school. However, also the number of 'meal skippers' is increasing among children. Thus, the effect of skipping of the midday meal at school on cognitive functioning is examined in this experimental cross-over trial.

As prior intake of food can have an influence on the physiological effect of test meal, the children's dietary intake in the morning is standardized. The intervention is integrated in the usual everyday school life:

9.15 a.m. standardized snack within the frame of the regular break, 9.45 a.m. to 12.25 p.m. everyday school life, 12.25 p.m. either lunch (control) or only a non-caloric beverage (intervention of 'skipping meal'), 12.45 p.m. to 1.15 p.m. regular lunch break, 1.15 p.m. computerized tests of cognitive functioning, 2 p.m. lunch for the 'skipping meal'-group.

Parameters of cognition with relevance to everyday school life are measured by a computerized test battery of the 'Wiener Testsystem'. Usual eating behaviour, sleep behaviour, physical activity, parental education and migration background are determined as control variables by questionnaires for children, parents and teachers. Beside the Body Mass Index, the individual IQ is measured by a paper-pencil-test.