Flexible shaping: How learning in small steps helps

Humans and animals can perform much more complex tasks than they can acquire using pure trial and error learning. This gap is filled by teaching. One important method of instruction is shaping, in which a teacher decomposes a complete task into sub-components, thereby providing an easier path to learning. Despite its importance, shaping has not been substantially studied in the context of computational modeling of cognitive learning. Here we study the shaping of a hierarchical working memory task using an abstract neural network model as the target learner. Shaping significantly boosts the speed of acquisition of the task compared with conventional training, to a degree that increases with the temporal complexity of the task. Further, it leads to internal representations that are more robust to task manipulations such as reversals. We use the model to investigate some of the elements of successful shaping.     

Applying self-determination theory to understand the motivational impact of cash rewards: New evidence from lab experiments

We investigated, based on self-determination theory (SDT), the impact of the functional meaning of monetary rewards on individuals' motivation and performance and further tested the role of the psychological needs as the underlying mechanism. In two experimental studies, we show that when presented in an autonomy-supportive way, rewards lead participants to experience greater intrinsic motivation, which leads them to perform better, than when monetary rewards are presented in a controlling way. This is mediated by greater psychological need satisfaction, indicating that through greater feelings of competence, autonomy, and relatedness, individuals experience greater intrinsic motivation for the task at hand. Our findings suggest that rewards can have a distinct effect on individuals' motivation and performance depending on whether they take on an autonomy-supportive or controlling meaning, thus providing empirical evidence for the theoretical and practical implications of SDT's concept of functional meaning of rewards. By highlighting the importance of this concept, this research contributes to our understanding of the effectiveness of such rewards in the workplace, suggesting that they can foster employee motivation and performance if organisations present them to employees in an autonomy-supportive way to convey an informational meaning and positively contribute to their psychological need stisfaction.     

Temporal regulation of children with autism spectrum disorder exposed to a differential-reinforcement-of low-rates schedule

This study investigated temporal adjustment of children with autism spectrum disorder under a differential-reinforcement-of-low-rates (DRL) schedule. Sixteen participants, aged 3.2 to 7 years, were exposed to two conditions, DRL 5 s and DRL 20 s. Children participated in 7 sessions in each condition, except for 1 participant who attained the adjustment criteria in the DRL 5-s schedule. Temporal adjustment was measured with the proportion of reinforced interresponse times (IRTs) and the mean IRT. The operant response was a press on a touch screen and the reinforcers were cartoons. IQ and receptive language were measured prior to the DRL sessions. Results showed that the mean proportion of reinforced IRTs was slightly higher in the DRL 5-s schedule. The mean IRT was above the IRT requirement in both conditions. However, substantial individual variability was observed. Children with higher IQ and receptive language scores presented a greater proportion of reinforced IRTs in both conditions. Moreover, participants who adjusted their responses to the DRL 5-s schedule were more likely to adjust responding to the DRL 20-s schedule. This suggests that some children might be more sensitive to reinforcement contingencies than others. This study points at future research in the field of timing in children.     

Contrast of hemispheric lateralization for oro-facial movements between learned attention-getting sounds and species-typical vocalizations in chimpanzees: Extension in a second colony

Studies involving oro-facial asymmetries in nonhuman primates have largely demonstrated a right hemispheric dominance for communicative signals and conveyance of emotional information. A recent study on chimpanzee reported the first evidence of significant left-hemispheric dominance when using attention-getting sounds and rightward bias for species-typical vocalizations (Losin, Russell, Freeman, Meguerditchian, Hopkins & Fitch, 2008). The current study sought to extend the findings from Losin et al. (2008) with additional oro-facial assessment in a new colony of chimpanzees. When combining the two populations, the results indicated a consistent leftward bias for attention-getting sounds and a right lateralization for species-typical vocalizations. Collectively, the results suggest that both voluntary-controlled oro-facial and gestural communication might share the same left-hemispheric specialization and might have coevolved into a single integrated system present in a common hominid ancestor.