Concurrent task performance enhances low-level visuomotor learning

The effects of doodling on recall ability

Previous research has documented a positive effect of doodling on individuals’ ability to recall information. However, previous research is limited to structured doodling tasks, such as shading in basic shapes. The present study extends the extant research, and increases the external validity of the previous findings, by considering the effects of multiple forms of doodling on recall. In this experimental study, ninety-three undergraduate participants were randomly assigned to one of 4 conditions (control, structured doodling, unstructured doodling, or note-taking). Participants listened to a fictional dialogue between 2 friends discussing a recent earthquake and then completed a fill-in the blank quiz to test their recall of the conversational information. The results indicated that participants in the unstructured doodling condition performed significantly worse than those in the structured doodling and note-taking condition.

Dual-task practice enhances motor learning: a preliminary investigation

Practicing a motor task under dual-task conditions can be beneficial to motor learning when the secondary task is difficult (Roche et al. in Percept Psychophys 69(4):513-522, 2007) or when it engages similar processes as the primary motor task (Hemond et al. in J Neurosci 30(2):650-654, 2010). The purpose of this pilot study was to determine which factor, difficulty level or engaged processes, of a secondary task is more critical in determining dual-task benefit. Participants practiced a discrete arm task in conjunction with an audio-vocal reaction time (RT) task. We presented two different RT tasks that differed in difficulty, simple versus choice (i.e., more difficult), at two different arm task phases that differed in engaged processes, preparation versus execution, resulting in four dual-task conditions. A simple RT task is thought to predominantly engage motor execution processes, therefore would engage similar processes as the arm movement task when it is presented during the execution phase, while a choice RT task is thought to engage planning processes and therefore would engage similar processes too when it is presented during the preparation phase. Enhanced motor learning was found in those who engaged similar process as the primary task during dual-tasking (i.e., choice RT presented during preparation and simple RT presented during execution). Moreover, those who showed enhanced learning also demonstrated high dual-task cost (poor RT task performance) during practice, indicating that both tasks were taxing the same resource pool possibly due to engaging similar cognitive processes. To further test the relation between dual-task cost and enhanced learning, we delayed the presentation timing of the choice RT task during the preparation phase and the simple RT task during the execution phase in two control experiments. Dual-task cost was reduced in these delayed timing conditions, and the enhanced learning effect was attenuated. Together, our preliminary findings suggest that it is the similarity hypothesis and not the difficulty hypothesis that mediates the enhanced motor learning under dual-task conditions.

Manipulating attentional load in sequence learning through random number generation

Implicit learning is often assumed to be an effortless process. However, some artificial grammar learning and sequence learning studies using dual tasks seem to suggest that attention is essential for implicit learning to occur. This discrepancy probably results from the specific type of secondary task that is used. Different secondary tasks may engage attentional resources differently and therefore may bias performance on the primary task in different ways. Here, we used a random number generation (RNG) task, which may allow for a closer monitoring of a participant's engagement in a secondary task than the popular secondary task in sequence learning studies: tone counting (TC). In the first two experiments, we investigated the interference associated with performing RNG concurrently with a serial reaction time (SRT) task. In a third experiment, we compared the effects of RNG and TC. In all three experiments, we directly evaluated participants' knowledge of the sequence with a subsequent sequence generation task. Sequence learning was consistently observed in all experiments, but was impaired under dual-task conditions. Most importantly, our data suggest that RNG is more demanding and impairs learning to a greater extent than TC. Nevertheless, we failed to observe effects of the secondary task in subsequent sequence generation. Our studies indicate that RNG is a promising task to explore the involvement of attention in the SRT task.

Removing the frontal lobes: the effects of engaging executive functions on perceptual category learning

The present study examined the impact of engaging frontal-mediated working memory processes on implicit and explicit category learning. Two stimulus dimensions were relevant to categorization, but in some conditions, a third, irrelevant dimension was also presented. Results indicated that in both implicit and explicit conditions, the inclusion of the irrelevant dimension impaired performance by increasing the reliance on suboptimal unidimensional strategies. With three-dimensional stimuli, a striking dissociation was observed between implicit and explicit category learning when participants performed a sequential working memory task. With explicit category learning, performance was impaired further, and there was an increased use of suboptimal unidimensional strategies. However, with implicit category learning, the performance impairment decreased, and there was an increased use of optimal strategies. These findings demonstrate the paradoxical situation in which learning can be improved under sequential-task conditions and have important implications for training, decision making, and understanding interactive memory systems.