Right Hemisphere Dominance in Visual Statistical Learning (2011)
Matthew E. Roser, József Fiser et al, University of Plymouth, UK, Brandeis University
Scope: examine hemispheric asymmetry in the implicit learning of new visual feature combinations. A split-brain patient and normal control participants viewed multishape scenes presented in either the right or the left visual fields.
Conclusion: Statistical learning of new visual features is dominated by visuospatial processing in the right hemisphere visual statistical learning. Our results are consistent with the view that statistical learning is not only incidental and automatic but also a product of an implicit generation of hypotheses that can be handled in the right hemisphere alone. The current finding adds to the large body of evidence from neurological case studies describing asymmetry of cortical function and, importantly, demonstrates visual statistical learning in the absence of higher conceptual knowledge, thus informing as to the nature of this fundamental process. Moreover, functional imaging of visual statistical learning in neurologically normal participants may reveal an initial reliance on right-hemispheric networks, followed by a transition to more bilateral activity as learning progresses to full conceptual knowledge.
Implicit learning and unconscious knowledge: mental representation, computational mechanisms, and brain structures (1997)
Thomas Goschke, Max-Planck-Institute for Psychological Research, Munich
Scope: comprehensive review and tutorial on the boundary conditions, mechanisms, and brain systems underlying implicit learning, along five major theoretical questions 1) does implicit learning actually lead to unconscious knowledge, and how can it be measured? 2 )does implicit learning require attention or is it automatic? 3) does implicit learning lead to abstract knowledge? 4) what are the computational mechanisms underlying implicit learning? 5) does implicit learning involve specific brain systems?
Conclusion: The evidence on procedural and sequence learning suggests: first, neural structures can be directly modified as a result of processing sensory information or performing some task, and implicit learning may involve modification in brain structures which are also involved in the initial performance of a given task. Secondly, different types of implicit learning depend on modifications in different brain systems. Finally, brain-imaging findings indicate that explicit and implicit modes of learning in the same task are mediated by different networks of brain structures, although the precise anatomy and functional role of these networks remains to be elucidated.