Table 2. Distribution of trials.

(tested in random order).

Recall delay time	No secondary task	Non-spatial-memory task	Spatial-memory task
	3focustrials
0s	2 other fwd-translation trials	0 trials *	0 trials *
	3 bwd-translation trials
	3focustrials
2s	2 other fwd-translation trials	0 trials *	0 trials *
	3 bwd-translation trials
	3focustrials	3focustrials	3focustrials
5s	2 other fwd-translation trials	2 other fwd-translation trials	2 other fwd-translation trials
	3 bwd-translation trials	3 bwd-translation trials	3 bwd-translation trials
	3focustrials	3focustrials	3focustrials
10s	2 other fwd-translation trials	2 other fwd-translation trials	2 other fwd-translation trials
	3 bwd-translation trials	3 bwd-translation trials	3 bwd-translation trials
	4 catch trials	4 catch trials	4 catch trials

Note: “Focus trials” = trials included in the analyses:

   - forward platform translation (backward falling motion); handhold at 33% shoulder-width from mid-line

Additional trials included to increase unpredictability:

   - “other fwd-translation trials” = forward platform translation (backward falling motion); handhold at one of the three other handhold positions (see Figure 1 inset)

   - “bwd-translation trials” = backward platform translation (forward falling motion); handhold at any of the four handhold positions

   - “catch trials” = no platform motion (to deter anticipatory reactions); handhold at any of the four handhold positions

* Recall-delay interval not long enough to permit the secondary cognitive tasks to be performed.