Category specific knowledge modulate capacity limitations of visual short-term memory

We explore whether expertise can modulate the capacity of visual short-term memory, as some seem to argue that training affects capacity of short-term memory [13] while others are not able to find this modulation [12]. We extend on a previous study [3] by demonstrating expertise effects by investigating different groups of healthy adults. In a whole report paradigm [5] we investigate performance on standardized pictures [11], Latin letters, and Japanese hiragana. Expertise was modulated between groups of novice (Danish university students), trained (Danish university students studying Japanese), and expert observers (Japanese university students). For both the picture and the letter condition we find no performance difference in memory capacity, however, in the critical hiragana condition we demonstrate a systematic difference relating expertise differences between the groups. These results are in line with the theoretical interpretation that visual short-term memory is the sum of the reverberating feedback loops to representations in long-term memory.