Bilingualism and adult differences in inhibitory mechanisms: evidence from a bilingual stroop task

The present investigation examined the functioning of inhibitory mechanisms in younger and older bilinguals using a bilingual version of the Stroop test. The study predicted different patterns of age related decline in inhibitory mechanisms (inter- and intralingual interference) in bilinguals depending on their level of proficiency. Consistent with expectations, older bilinguals were slower when they responded in their non-dominant language. Furthermore, older unbalanced bilinguals showed greater interlingual interference when they responded with their second language to visual stimuli written in their dominant language. Balanced bilinguals showed equivalent interference effects between all conditions. These findings suggest that manipulating two languages may enhance the efficiency of inhibitory mechanisms.     

The role of knowledge of results frequency in learning through observation

The authors examined whether reduced knowledge of results (KR) frequency during observation of a model's performance enhances learning. As they viewed a timing task, observers (n = 54) received KR about the model's performance on each trial (100% KR) or on 1 out of 3 trials (33% KR). Controls (n = 18) received only physical practice; they did not take part in the observation session. The authors also wanted to dissociate the guidance effect of KR during physical practice from the guidance role played by the representation acquired during observation. Therefore, following the observation phase, participants physically performed the task with either the same or a different KR frequency than that experienced during observation. The effects of observation and physical practice on learning were assessed in delayed retention tests. The beneficial effect of reduced KR frequency during observation continued for the following physical practice phases. Possible explanations as to why KR influences observational learning are discussed.     

Shaking hands: Priming by social action effects

In a semi‐naturalistic response–effect compatibility paradigm, participants were given the opportunity to learn that hand‐shaking actions would be followed by social effects (human hand‐shaking stimuli from a third‐person perspective) or inanimate effects (block arrow stimuli). Relative to the actions, these effects appeared on the same or the opposite side of the screen (positional compatibility), and pointed towards or away from the response hand (directional compatibility). After learning, response times indicated a positional compatibility effect for both social and inanimate effects, but a directional compatibility effect occurred only for social action effects. These findings indicate that actions can be represented, not only by their effects on the inanimate world, but also by their effects on the actions of others. They are consistent with ideomotor theory, and with the view that actions are represented by bidirectional response–effect associations. They also have implications with respect to the origins and on‐line control of imitation and the systems supporting imitation.     

Retrieval practice in motor learning

In this study we sought to determine whether testing promotes the generalization of motor skills during the process of encoding and/or consolidation. We used a dynamic arm movement task that required participants to reproduce a spatial-temporal pattern of elbow extensions and flexions with their dominant right arm. Generalization of motor learning was tested by the ability to transfer the original pattern (extrinsic transformation) or the mirrored pattern (intrinsic transformation) to the unpractised left arm. To investigate the testing effects during both encoding and consolidation processing, participants were administered an initial testing session during early practice before being evaluated on a post-practice testing session administered either 10 min (Testing-Encoding group) or 24 hr apart (Testing-Consolidation group), respectively. Control groups were required to perform a post-practice testing session administered after either a 10-min (Control-Encoding group) or 24-hr delay (Control-Consolidation group). The findings revealed that testing produced rapid, within-practice skill improvements, yielding better effector transfer at the 10-min testing for the Testing-Encoding group on both extrinsic and intrinsic transformation tests when compared with the Control-Encoding group. Furthermore, we found better performance for the Testing-Consolidation group at the 24-hr testing for extrinsic and intrinsic transformations of the movement pattern when compared with the Control-Consolidation group. However, our results did not indicate any significant testing advantage on the latent, between-session development of the motor skill representation (i.e., from the 10-min to the 24-hr testing). The testing benefits expressed at the 10-min testing were stabilised but did not extend during the period of consolidation. This indicates that testing contributes to the generalisation of motor skills during encoding but not consolidation.     

Make it real: Belief in occurrence within episodic future thought

While the cognitive and neural bases of episodic future thinking are well documented, questions remain as to what gives the sense that an imagined event belongs to one’s personal future. Capitalizing on previous research on metacognitive appraisals in autobiographical remembering, we propose that episodic future thinking involves, in varying degrees, a subjective belief in the potential occurrence of imagined future events and we explore the nature and determinants of such belief. To this aim, participants provided justifications for belief in occurrence for a series of past and future events. For each event, they also assessed their subjective feelings (belief in occurrence, autonoetic experience, and belief in accuracy) and rated various characteristics of mental representations that might contribute to these feelings. Results showed that belief in the occurrence of future events mostly related to their integration in a broader autobiographical context, especially their relevance to personal goals and their personal plausibility. We also found that belief in occurrence, autonoetic experience, and belief in accuracy represented distinct subjective appraisals of future events, which depended in part on different determinants. Based on these findings, we propose a new theoretical model of subjective feelings associated with episodic future thinking that conceives of belief in occurrence as arising from metacognitive appraisals that shape the sense that imagined events belong to one’s personal future.     

The role of goal-directed behavior in intention attribution in children

In this study, we addressed the question of the nature of the information needed by 13-month-old infants to understand another agent's intentions. In two experiments, an experimenter was either unable or unwilling to give a toy to an infant. Importantly, an implement (a gutter in which the toy could roll down toward the infant) was used to make the experimenter's behavior as similar as possible in the two conditions. When the experimenter remained still in both conditions, infants did not behave differently according to the experimenter's intentions, suggesting that they did not infer them. By contrast, in a second experiment, where the experimenter performed an action directed toward the gutter in both conditions, the infants looked away from the experimental setting more often and longer in the unwilling condition than in the unable condition. They also looked more toward the experimenter in the unable condition than in the unwilling condition. Therefore, we conclude that an agent's intentional attitude can already be inferred by a 13-month-old provided that this intention is concretely shown through a goal-directed action.     

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.     

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.     

Remembering the past and imagining the future in schizophrenia

It has been suggested that patients with schizophrenia experience a distorted sense of continuity of self across time. However, temporal aspects of self-processing have received little empirical attention in schizophrenia. In this study, the authors investigated schizophrenic patients' ability to generate specific mental images of their personal past and future. Results showed that patients recalled fewer specific past events than did healthy controls and were even more impaired in generating specific future events. These deficits were associated with positive symptoms but were not associated with negative symptoms or with performances on verbal fluency tasks. It is suggested that schizophrenic patients' failures to project themselves into specific past and future episodes might be related to difficulties in retrieving contextual details from memory, as well as disturbance of the sense of subjective time.