| |
Abstract:
Numerous studies on recognition memory have established a
left parietal ERP old/new effect, i.e. a larger positive-going
shift (in an interval from 400 to about 900 ms after stimulus
onset) for correctly recognized old items (hits), than for
correctly rejected new items (correct rejections). This left
parietal effect has been attributed to activity modulated by the
medial temporal lobe, an idea consistent with evidence that
hippocampal activity increases as a function of retrieval success.
This interpretation suggests that the left parietal effect should
vary as a function of confidence. The present study investigated
the effect of retrieval confidence on the left parietal effect. In
the study phase, the participants first classified low-frequency
words as living/nonliving, and in the test-phase classified words
as old/new using a scale from definitely old to definitely new. The
standard left parietal ERP old/new effect was found, but, in
addition, we observed that confidence had a strong modulatory
effect: The positive shift was significantly reduced for
low-confidence judgements, and the reduction was larger for hits
than for correct rejections.
|
