4.5 Conclusion
The STP approach is a reliable and valid method to measure peak
amplitude and latencies in single trials in the speeded flanker task.
The averaged ERP approach is useful in certain situations such as when
the components of interest are stable across individuals, and when there
is little interest in individual differences or change over time.
However, if there is variability across individuals or when trying to
examine changes over time, the STP approach would provide valuable
information about brain activity. Contrary to the assumptions often made
to justify averaging across trials, the present study shows that the
peaks in the single trial are large enough to be measured, that the
brain’s response to a stimulus is not invariant, and systematically
changes occur over successive trials. While the STP approach is not the
only way to measure single trial data, it is a parsimonious way of
measuring ERP components at the trial level that can be easily
replicated and interpreted by ERP researchers across labs.