Declarative memory was tested in a study-test task paradigm that has been used previously to study PFC subsequent memory effects in children and adolescents (Fig. 1A) (11, 12, 21). Subjects studied sets of 40 indoor and outdoor scenes, each scene was shown for 3 s, following a 500-ms fixation interval. Subjects were instructed to indicate with a verbal response whether each studied item depicted an indoor or an outdoor scene. Responses were coded as correct or incorrect via offline review of individual audio recordings. A fixation cross remained on screen until a response was provided if none was provided during the 3-s scene presentation epoch. Per-trial RTs were automatically calculated by subtracting the scene onset times from the response onset times. Analysis of electrophysiological data was restricted to correct encoding trials—that is, trials in which scenes were correctly classified as indoor/outdoor, indicating the scenes were properly attended during study. Trials were also considered incorrect if no response was given. A mean of 6 ± 7 trials (range, 0 to 27) per subject were excluded due to incorrect encoding responses.

The memory recognition test included all 40 scenes presented at study, intermixed in a randomized order with 20 new scenes. Each scene remained on screen until a response was given, following a 500-ms fixation pretrial interval. Subjects were instructed to verbalize an old/new judgment of each scene, which was coded as a hit (correct old), miss (new response to old scene), correct rejection (correct new), or false alarm (old response to new scene) via offline review of individual audio recordings. Per-trial RTs were again automatically calculated by subtracting the scene onset times from the response onset times, and trials were excluded if no response was given. Study-test runs were administered in two consecutive cycles of 40 study scenes, followed by 40 studied + 20 new scenes. Half as many new scenes compared with previously studied scenes were introduced in the test phase so that the test remained engaging, and subjects overall responded old and new at roughly equal rates. All subjects completed a short practice run and at least one full study-test run.

On the basis of performance at test, we calculated per subject the hit rate (i.e., number of previously studied scenes that were correctly recognized as old out of all studied scenes) and false alarm rate (number of new scenes presented at test that were incorrectly identified as old out of the number of new scenes presented at test). Recognition accuracy was then calculated as hit rate − false alarm rate, thereby correcting for differences in an individual’s tendency to respond old or new (12, 21).

Note: The content above has been extracted from a research article, so it may not display correctly.



Q&A
Please log in to submit your questions online.
Your question will be posted on the Bio-101 website. We will send your questions to the authors of this protocol and Bio-protocol community members who are experienced with this method. you will be informed using the email address associated with your Bio-protocol account.



We use cookies on this site to enhance your user experience. By using our website, you are agreeing to allow the storage of cookies on your computer.