The development of interindividual sharing of knowledge and beliefs in 5- to 9-year-old children

The authors studied the evolution of interindividual intentionality in children and showed that the sharing of knowledge and beliefs requires more complex operations than those involved in usual false-belief tasks. The authors conducted 3 experiments on 380 children (aged 5 years, 0 months to 9 years, 6 months). They assessed the children's ability to attribute to a character an intended action that was compatible with the belief held by another character interacting with that character. The observed lag in performances is explained both in terms of information processing and at the Piagetian concrete operational level.     

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

In two H2(15)O 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.     

Can inhibition resolve retrieval competition through the control of spreading activation?

Two experiments are reported in which the mechanisms underlying retrieval-induced forgetting for complex prose materials were investigated, using the independent probe technique pioneered by Anderson and Spellman (1995). These experiments provide additional empirical evidence in support of an inhibitory account of memory. Specifically, evidence emerged not only for the inhibition of nonpracticed items from practiced sets (i.e., first-order effects), but also for the inhibition of items from nonpracticed sets that were semantically related to practiced items in practiced sets (i.e., cross-category effects) and for items from nonpracticed sets that were semantically related to nonpracticed items in practiced sets (ie., second-order effects). These findings are considered in terms of Anderson and Spellman's model of inhibitory processing. We also outline an alternative inhibitory interpretation. Specifically, we consider how inhibition may function as a way of controlling the spread of activation and what implications this may have for the flexibility and adaptiveness of memory.