Figure 2. The pathophysiology of motor performance in the startle assay. (A-B) Event-history charts depict jump (A) and flight (B) responses of 104 males tested individually every 6 hours between 60d of age and death (see also Figure 1 A). For each fly and each trial responsiveness is indicated by a dash and irresponsiveness by a blank. Insets show overlays of the impairment history (see Figure 1A-C) and the jump/flight responses for a subset of individuals. Note that impairment span was accompanied by a significant reduction in the numbers of jump or flight responses. Four individual flies (F59, F60, F71, F72) were selected as representative case-reports. Fly 59 exhibited paradoxical behavior 18h prior to death and showed no jumping or flight responses during the last 60h of life. Fly 60 showed no impairment and responded with jumping or flight at almost every single trial. Fly 71 was diagnosed with mild climbing impairment and left femur-tibia joint immobility 18 h prior to death. It performed jump but no flight responses. Fly 72 had a defective prothoracic femur-tibia joint and showed multiple climbing defects already 30 hours prior to death. It failed to respond at every late-life trial.