Psychonomic Bulletin & Review

, Volume 3, Issue 2, pp 135–148

PET studies of encoding and retrieval: The HERA model


DOI: 10.3758/BF03212412

Cite this article as:
Nyberg, L., Cabeza, R. & Tulving, E. Psychonomic Bulletin & Review (1996) 3: 135. doi:10.3758/BF03212412


We review positron emission tomography (PET) studies whose results converge on the hemispheric encoding/retrieval asymmetry (HERA) model of the involvement of prefrontal cortical regions in the processes of human memory. The model holds that the left prefrontal cortex is differentially more involved in retrieval of information from semantic memory, and in simultaneously encoding novel aspects of the retrieved information into episodic memory, than is the right prefrontal cortex. The right prefrontal cortex, on the other hand, is differentially more involved in episodic memory retrieval than is the left prefrontal cortex. This general pattern holds for different kinds of information (e.g., verbal materials, pictures, faces) and a variety of conditions of encoding and retrieval.

Download to read the full article text

Copyright information

© Psychonomic Society, Inc 1996

Authors and Affiliations

  1. 1.Rotman Research Institute of Baycrest CentreUniversity of TorontoNorth YorkCanada
  2. 2.Department of PsychologyUmeå UniversityUmeåSweden