In a left middle area of the superior temporal sulcus, a correlation
between the motivation change ratings and the change in the subsequent
memory contrast indicated that in this region there is a stronger
relationship between activation and subsequent memory when
motivation for the task is higher. The left middle STS may have
been recruited due to the role of this region in speech processing
(Hein and Knight, 2008), which might be engaged when the previously
learned word pairs are being recalled and/or rehearsed. This
strengthening of subsequent memory effects during periods of increased
motivation could indicate that motivation facilitates a stronger
link between retrieval/maintenance of relevant verbal
information during learning and the subsequent ability to accurately
retrieve the correct word association. It is plausible that task-specific
motivation would enhance processing in regions relevant to the processing
of words (e.g., the STS) and the formation of associative
memories (e.g., the parahippocampal gyrus) during our pairedassociate word learning task, since previous research has shown
similar motivation-related increases in task-relevant processing in
cognitive control and visual network