• Hemispheric organization;
  • Encoding-related lateralization;
  • Sensory signature;
  • Visual working memory;
  • Memory search task;
  • Event-related brain potentials (ERPs);
  • Event-related optical signal (EROS)


This paper reports evidence of the existence of multiple and distinct visual memory processes in a memory search task in which a divided field stimulus presentation was used at study (Experiments 1–3) and either a foveal (Experiments 1 and 2) or a lateralized (Experiment 3) stimulus presentation was used at test. These memory processes can be distinguished on the basis of (1) whether or not they are hemispherically organized; and (2) the locus of their underlying brain activity, as evidenced by the scalp distribution of the event-related brain potentials and by the localization of the event-related optical signal that accompany them. These memory effects are discussed in the context of visual form memory.