How are similar objects represented in the brain?, Elita Lee (4413825)
We come across pieces of highly similar information in our daily lives. The hippocampus is known to form nonoverlapping representations of these similar memories to prevent interference. In our current experiment, we aimed to investigate if differentiated representations of similar objects would be consolidated to the cortex after a 24 hour delay. We had participants complete the Mnemonic Similarity Task (MST), where they were asked to identify objects that were repeated or similar looking objects to ones seen before (referred to as “real” and “fake” in our task, respectively), based on what they learned earlier in the task. Correctly identifying a similar object as "fake" rather than "real" suggests successful separation of the similar representations in the hippocampus. Immediately or 24 hours later, participants completed another discrimination task. They were asked to determine if each object presented was the real or fake one. We required speeded responses to target the cortical representations of these objects. We predicted that the 24 hour test group would have higher discrimination test accuracy for objects correctly discriminated during the MST compared to objects that were confused, since they had the chance to consolidate this information. Our current results support this, with the immediate test group showing no difference between objects correctly discriminated and confused (p=0.297), and the 24 hour test group showing better accuracy for objects correctly discriminated compared to confused objects (p=0.001). These results suggest that the consolidation process does help to establish differentiated representations in the cortex.