Title
Object knowledge during entry-level categorization is activated and modified by implicit memory after 200 ms.
Abstract
The timing of activating memory about visual objects is important for theories of human cognition but largely unknown, especially for tasks like entry level categorization that activate semantic memory. We tested an implicit memory-categorization “equivalence” hypothesis of multiple memory systems theory that a cortical system that stores structural knowledge to support entry level categorization also stores long-term, perceptual implicit memory, resulting in priming of this knowledge. Event-related brain potentials (ERPs) were recorded to impoverished pictures of new and repeated objects that were similar in perceptual properties but differed in categorization success. The cortical dynamics of object knowledge were defined using categorization ratings and naming. As predicted, rating, naming, and repetition effects on a frontocentral N350 show that implicit memory modifies the object knowledge network supporting categorization. This ERP is a complex of components between 200 and 500 ms indexing temporally overlapping substates from more perceptual to more conceptual knowledge. A frontopolar N350 subcomponent defines the first substate of a process of object model selection from occipitotemporal cortex based on shape similarity, and indicates that implicit memory in this system is greater with better categorization success. Afterwards, parietal positivity and a slow wave index secondary, post-model selection processes, like evaluating the success of a decision or memory match, and working memory for overt report, respectively. Altogether, ERP findings support the equivalence hypothesis and a two-state interactive account of visual object knowledge, and delineate the timing of multiple memory systems.
Year
DOI
Venue
2009
10.1016/j.neuroimage.2008.09.061
NeuroImage
Keywords
Field
DocType
working memory,indexation,semantic memory,model selection,human cognition,implicit memory,object model
Semantic memory,Categorization,Explicit memory,Iconic memory,Visual short-term memory,Implicit memory,Psychology,Visual memory,Cognitive psychology,Spatial memory
Journal
Volume
Issue
ISSN
44
4
1053-8119
Citations 
PageRank 
References 
7
0.99
15
Authors
2
Name
Order
Citations
PageRank
Haline E. Schendan1637.73
Stephen M. Maher270.99