4. General discussion
The two experiments of the present study featured nonmanipulative
memory tasks, where abstract symbols had to be
placed onto two-dimensional grids following a given pattern. The
tasks of Experiment 1 included 9 different symbols to be placed on
a 3 3 grid; the tasks of Experiment 2 were more difficult, as they
included 12 symbols to be placed on a 4 3 grid. Performance in
these task was measured by (a) accuracy score (number of symbols
correctly placed), (b) time on task, and (c) efficiency measure (accuracy
vs. self-reported cognitive effort). Both experiments
compared performance between conditions according to a 2
(hands: no-hands vs. with-hands) 2 (presentation: statics vs.
animation) factorial design