The neural correlates of implicit and explicit sequence learning: Interacting networks revealed by the process dissociation procedure

Abstract

In two H 2 15O PET scan experiments, we investigated the cerebral correlates of explicit and implicit knowledge in a serial reaction time (SRT) task. To do so, we used a novel application of the Process Dissociation Procedure, a behavioral paradigm that makes it possible to separately assess conscious and unconscious contributions to performance during a subsequent sequence generation task. To manipulate the extent to which the repeating sequential pattern was learned explicitly, we varied the pace of the choice reaction time task-a variable that is known to have differential effects on the extent to which sensitivity to sequence structure involves implicit or explicit knowledge. Results showed that activity in the striatum subtends the implicit component of performance during recollection of a learned sequence, whereas the anterior cingulate/mesial prefrontal cortex (ACC/MPFC) supports the explicit component. Most importantly, we found that the ACC/MPFC exerts control on the activity of the striatum during retrieval of the sequence after explicit learning, whereas the activity of these regions is uncoupled when learning had been essentially implicit. These data suggest that implicit learning processes can be successfully controlled by conscious knowledge when learning is essentially explicit. They also supply further evidence for a partial dissociation between the neural substrates supporting conscious and nonconscious components of performance during recollection of a learned sequence.

Sleep-dependent Neurophysiological Processes in Implicit Sequence Learning

“…Of note, cerebellar activations in Crus I have been also partially associated with the automation of rule-based information, although in the case of low-order rules (Balsters & Ramnani, 2011). Moreover, learning-related activations found over striatal regions (i.e., putamen and caudate nucleus) are in agreement with prior studies that aimed at characterizing the neural correlates of implicit sequence learning using SRTTs (e.g., Destrebecqz et al, 2005;Peigneux et al, 2000).…”

Social cognition and the brain: A meta‐analysis

“…Sequence learning tasks do not require to generate motor sequences, but to respond to observed stimulus sequences with an appropriate response. Perhaps, the most well-known example of a response sequence task is artificial grammar learning [Destrebecqz et al, 2003[Destrebecqz et al, , 2005. Participants respond to the spatial locations of stimuli (e.g., left or right whenever the stimulus appears somewhere left or right on the screen), which are presented in a predictable order or sequence of about 15 locations long.…”

“…After some time, participants may become sensitive to this sequence of responses. Destrebecqz et al (2003Destrebecqz et al ( 2005 measured the participants' brain activation when they are requested to generate the sequence and are consciously aware of it. As shown in Table I and depicted in Figure 2C, these and similar studies identified provide evidence that sequence learning engages the ventral part of the mPFC (100%), although in some studies activation extends to the lateral PFC.…”

Implicit learning seems to come naturally for children with autism, but not for children with specific language impairment: Evidence from behavioral and ERP data

“…Explicit learning relies mainly on the Medial Temporal Lobe, including the hippocampus, with connections to other brain areas such as the prefrontal cortex [e.g., Reber, 2013]. However, it has been found that in some situations the hippocampus is also involved in implicit learning [e.g., Hannula & Greene, 2012; Poldrack & Rodriguez, 2003], and that the neural networks of implicit and explicit learning interact [Destrebecqz et al, 2005; Ullman, 2004]. Thus, the different neural networks involved in implicit and explicit learning can overlap and interact depending on the learning task.…”