Document Detail

A parametric investigation of pattern separation processes in the medial temporal lobe.
MedLine Citation:
PMID:  22993425     Owner:  NLM     Status:  In-Data-Review    
The hippocampus is thought to be involved in memory formation and consolidation, with computational models proposing the process of pattern separation as a means for encoding overlapping memories. Previous research has used semantically related targets and lures to investigate hippocampal responses to mnemonic interference. Here, we attempted to define the response function of the human hippocampus and its inputs during pattern separation by parametrically varying target-lure similarity in a continuous recognition task. We also investigated the effect of task demands (intentional vs incidental encoding) on pattern separation processes. We collected functional magnetic resonance imaging data while participants were shown a series of objects. In the intentional paradigm, participants identified objects as "new" (novel stimuli), "old" (exact repetitions), or "rotated" (previously seen objects that were subsequently rotated by varied degrees). In the incidental paradigm, participants were shown the same stimuli but identified objects as "toy" or "not toy." Activation in the hippocampus was best fit with a power function, consistent with predictions made by computational models of pattern separation processes in the hippocampus. The degree of pattern separation was driven by the information most relevant to the task: pattern separation was seen in the left hippocampus when semantic information was more important to the task and seen in the right hippocampus when spatial information was more important. We also present data illustrating that top-down processes modulate activity in the ventral visual processing stream.
Sarah E Motley; C Brock Kirwan
Related Documents :
10083945 - Repressed memories. when are they real? how are they false?
24202815 - Mental comparisons for ordered information on abstract and concrete dimensions.
12818955 - Implicit memory varies as a function of hypnotic electroencephalogram stage in surgical...
23586355 - An effect of age on implicit memory that is not due to explicit contamination: implicat...
1580815 - 'fatigue' in patients with multiple sclerosis. motor pathway conduction and event-relat...
17499175 - Does tool-related fmri activity within the intraparietal sulcus reflect the plan to grasp?
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  The Journal of neuroscience : the official journal of the Society for Neuroscience     Volume:  32     ISSN:  1529-2401     ISO Abbreviation:  J. Neurosci.     Publication Date:  2012 Sep 
Date Detail:
Created Date:  2012-09-20     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  8102140     Medline TA:  J Neurosci     Country:  United States    
Other Details:
Languages:  eng     Pagination:  13076-84     Citation Subset:  IM    
Departments of Physiology and Developmental Biology and Psychology and Neuroscience Center, Brigham Young University, Provo, Utah 84602.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  GABAergic inhibition of histaminergic neurons regulates active waking but not the sleep-wake switch ...
Next Document:  A role for silent synapses in the development of the pathway from layer 2/3 to 5 pyramidal cells in ...