乾敏郎
Properties of visual memory for block patterns
Abstract:Several characteristics of short-term visual memory (STVM) were specified through a series of experments, by using block patterns (BPs) of varying complexity. In experiment I, the characteristics of its acquisition process were examined through a recall task. The recall rate at a single glance (exposure time less than 0.3 sec.) is more than 90% for 3-by-3, and 4-by-4-L BPs. For 4-by-4-H BP, an improvement in recall rate was not found even when exposure time was increased to 2.4 sec. The
recall rate for 6-by-6-H, 7-by-7, and 8-by-8 BPs did not change even when the exposure time was increased to 9 sec. In experiment II, the characteristics of the STVM decay process were examined using a recall task. Though a difference between 4-by-4-L and 4-by-4-H was found in the
acquisition rate, one for the forgetting rate was not found. No decay was
found for 6-by-6 BPs. Furthermore, the information obtained during a
short duration was not forgotten for 4-by-4, and 6-by-6 BPs. It was
concluded from these results that: 1) The acquisitoin rate into STVM
depends upon figural complexity. 2) The forgetting rate does not depend
upon figural complexity. 3) The limit of STVM was between 3-by-3, and
4-by-4-L BPs. 4) The recall performance for 6-by-6 BPs reflects the
information stored in long-term visual memory. Although the acquisition rate
into STVM depended upon figural complexity, it appeared in Experiment IV
that the number of subpatterns into which subjects segmented BPs when
memorizing them was highly correlated with rated fugural complexity. It
also appeared that the number of memory chunks estimated from the data of
inter-recall-interval was not correlated with the complexity. Finally, a
process model for visual memory for block patterns was proposed.