Poster C70, Sunday, March 25, 1:00-3:00 pm, Exhibit Hall C
Cortical oscillations underlying strict and lax decision criteria in recognition memory
Charlie Nettles1, Evan Layher2, Justin Kantner1, Michael B. Miller2; 1California State University, Northridge, 2University of California, Santa Barbara
Most theories of recognition memory assume that people reach recognition decisions by establishing a criterion reflecting the amount of memory evidence necessary to judge a test probe as previously studied (“old”). The decision criterion can be manipulated, such that individuals are induced to respond “old” only when probes are associated with a large amount of memory evidence (a “strict” or conservative criterion) or on the basis of relatively little memory evidence (a “lax” or liberal criterion). Research with patient populations and neuroimaging work are consistent with the idea that maintaining a strict decision criterion is more demanding of frontal cortical regions than maintaining a lax criterion. We hypothesize that when an individual is compelled to adopt a strict recognition criterion, s/he must engage cognitive control processes that suppress prepotent “old” judgments and support cautious responding. If so, strict and lax decision states should be associated with differing patterns of cortical oscillations. We collected EEG recordings while manipulating participants’ decision states via a “security patrol” recognition paradigm in which old-new discrimination was minimal and shifts between lax and strict criteria were necessary to avoid critical misses (letting dangerous people go free) or false alarms (harming innocent people), respectively. Theta power following hits (versus correct rejections) was higher during strict than lax test blocks at frontal channels, while the results for alpha power were mixed. We also observed differences in baseline activity on strict versus lax test blocks, potentially reflecting the global maintenance of these two decision states.
Topic Area: LONG-TERM MEMORY: Episodic