Ed Oneil (University of Toronto as Scarborough) and Melanie Sekeres, Post Doctoral Fellow, Rotman Research Institute at Baycrest
Ed Oneil Title: The Role of Perirhinal Cortex in the Perception and Recognition of Faces
Melanie Sekeres Title: From Neurons to Networks: Brain Activation Predicted by the Transformation Theory of
Ebbinghaus Empire Series 2013-2014
Abstract (Ed Oneil): The prevailing view of medial temporal lobe (MTL) functioning holds that its structures are dedicated to long-term declarative memory processing. Recent evidence challenges this view, suggesting that perirhinal cortex (PrC), which interfaces the MTL with the ventral visual pathway, supports highly integrated object representations critical for perceptual as well as for memory-based discriminations. Here, I will review a series of fMRI studies conducted in healthy individuals that examined the role of PrC in perceptual and mnemonic discriminations of faces. My findings challenge the view that mnemonic demands are the sole determinant of PrC involvement in face processing, and point to a broader representational role of PrC in the support of face discrimination.
Abstract (Melanie Sekeres): The Transformation Theory of memory consolidation proposes that rich contextual and episodic memories are initially dependent on the hippocampus, but as the memory consolidates, a memory trace also becomes represented in the cortex. The cortical version of the memory is not a precise copy of the initial hippocampal memory, but rather a more general 'schematic' or 'gist-like' version, retaining the general features, but not the precise details of the memory. Recall of the rich contextual details of the original memory is thought to always depend on the hippocampus. Building on our rodent lesion studies, my current studies are further exploring these ideas to investigate how the passage of time affects the quality and the neural representation of episodic (or episodic-like) memory in the healthy human and rodent brain. My talk will focus on the following questions: 1) When you recall an event shortly after encoding it, is the recall of precise contextual detail accompanied by high hippocampal activity? 2) As a memory ages and the recall of the event loses detail, does the prefrontal cortex show increased activation? 3) Can a brief reminder of the event reinstate the recall of rich perceptual/contextual detail and a return to high hippocampal activation?
I will present converging evidence from a series of studies in both humans and animals investigating how memory precision for rich contextual details declines over time, while the gist of the memory is retained, and present some preliminary results on the neural activation patterns associated with this memory transformation based on immediate-early gene imaging in the rodent, and fMRI results in humans.
For further information please contact Christopher Honey at firstname.lastname@example.org.