Specifically, recency effects appear because the context at the time of the memory test is most similar to the context associated with recent items.
When an item is retrieved at test, it reinstates the context active when that item was studied.
The present study attempted to directly affect reactivated memories through a stress manipulation, and compared the effects of stress on reactivated and nonreactivated components of a declarative memory in a within-subject design.
We presented image pairs that consisted of an image of an animal and an image of an unrelated object.
In CMR2, memory accumulates across multiple experimental lists, and temporal context is used both to focus retrieval on a target list and to censor retrieved information when its match to the current context indicates that it was learned in a non-target list.
Forty-eight hours later, we presented half of the animal images again in an unrelated task to indirectly reactivate the associated object images.
By analyzing the dynamics of the recall process one can quantify the way in which people transition from one recalled word to the next (see Fig. Furthermore, by studying the electrophysiology of the brain while engaged in memory tasks, we can find, for example, regions that show increased or decreased activity when a word is successfully encoded (i.e., later recalled) versus when it is not successfully encoded, known as the subsequent memory effect (see Fig. Two of our ongoing, large-scale data collection projects are the Penn Electrophysiology of Encoding and Retrieval Study (PEERS), a multi-session experiment with young and older adults combining free recall and scalp EEG (a book of these results can be found here); and an effort to collect electrophysiological data on patients with intractable epilepsy (undergoing monitoring with intracranial electrodes at partnering local hospitals) while they participate in a variety of memory and decision-making tasks.
To explain the processes underlying encoding, organization and retrieval of episodic memories, Kahana and colleagues (notably Marc Howard, Sean Polyn, Per Sederberg, and Lynn Lohnas) have developed a class of retrieved-context models.
Our research is focused on neurocomputational mechanisms of human episodic and spatial memory.
Episodic memory refers to memory for events that are embedded in a temporal context.
During recall, the context representation reactivates (through MCF) the features of recently studied items. Hypothesized interactions between prefrontal cortex, temporal cortex, and medial temporal lobe during memory encoding and retrieval predicted by CMR.click to enlarge Fig. CMR2 captures older adults' temporal contiguity deficit. After three lists from the same semantic category, subjects were then presented with a new set of three lists from a different semantic category.