Sensory-based mechanism for delayed motor intention

Prospective motor learning (PML) can be defined as learning an action to be performed in the future. The privileged retrieval mechanism behind this delayed motor performance remains unknown. From a motor control and learning perspective, we may conceive of two forms of retrieval: a stimulus- and an intention-based control. Retrieval from intention-based control is based on the anticipation of intended sensory effects related to an action in order to select and control the appropriate motor procedure (i.e., the ideomotor mechanism). In contrast, in a stimulus-based control a connection between stimuli-features and their related action-features is stored in the memory and serves as the retrieval mechanism. In this view, action retrieval from external stimuli is based on the detection of events in the environment to perform the intended behaviour (i.e., the sensorimotor mechanism). In this study, we report an advantage in the action retrieval for participants who use an intention-based mode of control in comparison to a stimulus-based control. Furthermore, a control task reveals that the intention-based advantage is specific to PML. Our findings show that PML is benefited by mental anticipation of a sensory effect that is efficiently processed through an ideomotor mechanism to fulfil delayed motor intentions.     

Asymmetric switch-costs and ERPs reveal facial identity dominance over expression

Previous studies on face processing have revealed an asymmetric overlap between identity and expression, as identity is processed irrespective of expression while expression processing partly depends on identity. To investigate whether this relative interaction is caused by dominance of identity over expression, participants performed familiarity and expression judgments during task switching. This paradigm reveals task-set dominance with a paradoxical asymmetric switch-cost (i.e., greater difference between switch and repeat trials when switching toward the dominant task). Event-related potentials (ERPs) were recorded to find the neural signature of the asymmetric cost. As expected, greater switch-cost was shown in the familiarity task with respect to response times, indicating its dominance over the expression task. Moreover, a left-sided ERP correlate of this effect was observed at the level of the frontal N2 component, interpreted as an index of modulations in endogenous executive control. Altogether, these results confirm the overlap between identity and expression during face processing and further indicate their relative dominance.     

The ability of children to delay gratification in an exchange task

The ability to wait for a reward is a necessary capacity for economic transactions. This study is an age-related investigation of children's ability to delay gratification in an exchange task requiring them to wait for a significant reward. We gave 252 children aged 2-4 a small piece of cookie, then offered them an opportunity to wait for a predetermined delay period before exchanging it for a larger one. In a first experiment, the children had to exchange the initial food item for rewards two, four or eight times larger. Results showed that children aged 3-4 years old sustained longer time lags for larger rewards than for smaller rewards. This effect was not found in 2-year-old subjects. In a second experiment, a reward 40 times larger than the initial piece was offered to determine the maximum waiting time that children could sustain. All age groups increased their performances. Older children were more successful at waiting, but some children as young as 2 years old were able to tolerate delays of up to 16 min. Older children who chose to give up waiting earlier than their known capacity demonstrated anticipation skills which had not been seen in younger children, showing that they had anticipated an increase in the time lag, and that they had considered both time and reward value when making their decision. Despite the age effect, we did not establish any limits for delaying gratification in children. This study may have educational implications for dealing with behavioral misconduct, which is known to be related to impulsivity control in young children.     

Evidence for multiple routes in learning to read

We describe a multiple-route model of reading development in which coarse-grained orthographic processing plays a key role in optimizing access to semantics via whole-word orthographic representations. This forms part of the direct orthographic route that gradually replaces phonological recoding during the initial phases of reading acquisition. The model predicts distinct developmental trajectories for pseudo-homophone and transposed-letter effects - two benchmark phenomena associated with phonological recoding and coarse-grained orthographic processing, respectively. Pseudo-homophone effects should decrease over the first years of reading acquisition, whereas transposed-letter effects should initially increase. These predictions were tested in a lexical decision task with 334 children in grades 1-5, and 29 skilled adult readers. In line with the predictions, we found that the pseudo-homophone effect diminished as reading level increased, whereas the transposed-letter effect first increased and then diminished.     

Practice makes transfer of motor skills imperfect

We investigated the practice-effects on motor skill transfer and the associated representational memory changes that occur during the within-practice and between-practice phases. In two experiments, participants produced extension–flexion movements with their dominant right arm for a limited or prolonged practice session arranged in either a single- or multi-session format. We tested the ability of participants to transfer the original pattern (extrinsic transformation) or the mirrored one (intrinsic transformation) to the non-dominant left arm, 10?min and 24?h after the practice sessions. Results showed that practice induces rapid motor skill improvements that are non-transferable irrespective of the amount of acquisition trials. Furthermore, the extrinsic component of the skill develops early and remains the dominant coding system during practice. Conversely, we found distinct between-practice memory changes: a limited practice induces an off-line development of the extrinsic component, whereas a prolonged practice session subserves the off-line development of the intrinsic component (Experiment 2). We provided further evidence that the long-term representation of the motor skill also depends on the nature of the practice session itself: the parsing of practice into multiple sessions narrows the effector-transfer capacities in comparison to a single session (Experiment 1). These findings yield theoretical and practical implications that are discussed in the context of recent motor skill learning models.     

Tracking the construction of episodic future thoughts

The ability to mentally simulate possible futures (episodic future thinking) is of fundamental importance for various aspects of human cognition and behavior, but precisely how humans construct mental representations of future events is still essentially unknown. We suggest that episodic future thoughts consist of transitory patterns of activation over knowledge structures at different levels of specificity, with general knowledge about the personal future (i.e., personal semantic information and anticipated general events) providing a context or frame for retrieving, integrating, and interpreting episodic details. In line with this hypothesis, Study 1 showed that the construction of episodic future thoughts is frequently a protracted generative process in which general personal knowledge is accessed before episodic details. We then explored in more detail the nature of this general personal knowledge and tested the hypothesis that it is mainly organized in terms of personal goals. Study 2 showed that cuing participants with knowledge about personal goals increased the ease of future event production during a fluency task. Study 3 further demonstrated that cuing participants with their personal goals facilitated access to episodic details during the imagination of future events. Taken together, these findings indicate that general personal knowledge and, in particular, knowledge about personal goals plays an important role in the construction of episodic future thoughts.     

How emotional pictures influence visuospatial binding in short-term memory in ageing and Alzheimer’s disease?

The present study examines the prediction that emotion can facilitate short-term memory. Nevertheless, emotion also recruits attention to process information, thereby disrupting short-term memory when tasks involve high attentional resources. In this way, we aimed to determine whether there is a differential influence of emotional information on short-term memory in ageing and Alzheimer's disease (AD). Fourteen patients with mild AD, 14 healthy older participants (NC), and 14 younger adults (YA) performed two tasks. In the first task, involving visual short-term memory, participants were asked to remember a picture among four different pictures (negative or neutral) following a brief delay. The second task, a binding memory task, required the recognition by participants of a picture according to its spatial location. The attentional cost involved was higher than for the first task. The pattern of results showed that visual memory performance was better for negative stimuli than for neutral ones, irrespective of the group. In contrast, binding memory performance was essentially poorer for the location of negative pictures in the NC group, and for the location of both negative and neutral stimuli in the AD group, in comparison to the YA group. Taken together, these results show that emotion has beneficial effects on visual short-term memory in ageing and AD. In contrast, emotion does not improve their performances in the binding condition.     

Verbal irony processing: How do contrast and humour correlate?

Verbal irony relies on contrast, that is, incongruity between the situational context and the ironic assertion. But is the degree of contrast related to the perceived humorousness of ironic comments? We answered this question by conducting two experiments. In the first experiment, participants were asked to read a list of sentence pairs (ironic or control) and judge the extent to which the meaning of the first sentence contrasted with that of the second. In the second experiment, participants were invited to rate the humorousness of ironic comments compared with their literal counterparts. Results showed that ironic remarks were rated as more contrasting and more humorous than their literal counterparts, but that humour only emerged from a moderate contrast.     

Conscious awareness of action potentiates sensorimotor learning

Many everyday skills are unconsciously learned through repetitions of the same behaviour by binding independent motor acts into unified sets of actions. However, our ability to be consciously aware of producing newly and highly trained motor skills raises the question of the role played by conscious awareness of action upon skill acquisition. In this study we strengthened conscious awareness of self-produced sequential finger movements by way of asking participants to judge their performance in terms of maximal fluency after each trial. Control conditions in which participants did not make any judgment or performance-unrelated judgments were also included. Findings indicate that conscious awareness of action, enhanced via subjective appraisal of motor efficiency, potentiates sensorimotor learning and skilful motor production in optimising the processing and sequencing of action units, as compared to the control groups. The current work lends support to the claim that the learning and skilful expression of sensorimotor behaviours might be grounded upon our ability to be consciously aware of our own motor capability and efficiency.