[Distinctive brain correlates in conscious and unconscious learning: an approach based on sequence learning].
OBJECTIVE
To report on the most recent evidence concerning the neuroanatomical correlates that distinguish conscious and unconscious sequence learning.


METHODS
Sequence-learning tasks are the most widely used test for evaluating learning that takes place with no intention to learn and without awareness of what has been learnt (implicit learning). In these tasks, participants respond to successive stimuli without being told that their run follows a sequence; with practice they improve their performance, even thought they are unable to generate the sequence when directly asked to do so. In this article we review the research that has been carried out to evaluate the performance of neurological patients or that uses neuroimaging techniques to pinpoint the neuroanatomical correlates of learning.


CONCLUSIONS
Studies conducted using functional neuroimaging techniques reveal that conscious learning processes are linked to activity in the anterior cingulate and that there is an important overlap between the structures involved in implicit and explicit learning. Nevertheless, greater differences are seen depending on whether the learning takes place with distractions (in order to prevent subjects from discovering the sequence) or without distractions. These differences can be explained using models that draw a distinction between a dorsal pathway of non-attentional (implicit) learning and a more ventral attentional pathway (which is implicit, or explicit if the sequence is discovered). Studies with neurological patients confirm the involvement of a wide range of structures both in implicit and explicit learning, including the prefrontal lobe, the motor cortex, the temporal lobe, the basal ganglia and the cerebellum. Finally, we present evidence of the functions carried out by each structure.
Vaquero
J M M
JM
Departamento de Psicología Experimental y Fisiología del Comportamento, Facultad de Psicología, Universidad de Granada, Granada, Spain. joaquinm@ugr.es
Jiménez
L
L
D001921:Brain / Q000033:anatomy & histology / Q000502:physiology; D003243:Consciousness / Q000502:physiology*; D006801:Humans; D008959:Models, Neurological; D012691:Serial Learning / Q000502:physiology*; D014474:Unconsciousness