H Number of wall approaches as indicator of poor coping with the test and non-spatial strategy choice (ANOVA: genotype F1,26=18.31 p=0.0002, age F2,26=4.486 p=0.0212, age x genotype F2,26=7.068 p=0.0035). Number of wall approaches increased with age in controls and was prematurely increased in mutants at 9- and 14-months. 