  We analyse the electroencephalogram signals in the beta band of working
memory representation recorded from young healthy volunteers performing several
different Visual Short-Term Memory (VSTM) tasks which have proven useful in the
assessment of clinical and preclinical Alzheimer's disease. We compare network
analysis using Maximum Spanning Trees (MSTs) with network analysis obtained
using 20% and 25% connection thresholds on the VSTM data. MSTs are a promising
method of network analysis negating the more classical use of thresholds which
are so far chosen arbitrarily. However, we find that the threshold analyses
outperforms MSTs for detection of functional network differences. Particularly,
MSTs fail to find any significant differences. Further, the thresholds detect
significant differences between shape and shape-colour binding tasks when these
are tested in the left side of the display screen, but no such differences are
detected when these tasks are tested for in the right side of the display
screen. This provides evidence that contralateral activity is a significant
factor in sensitivity for detection of cognitive task differences.
