RESUMEN
Previous studies on task sharing propose that a representation of the co-actor's task share is generated when two actors share a common task. An important function of co-representation seems to lie in the anticipation of others' upcoming actions, which is essential for one's own action planning, as it enables the rapid selection of an appropriate response. We utilized measures of lateralized motor activation, the lateralized readiness potential (LRP), in a task sharing paradigm to address the questions (1) whether the generation of a co-representation involves motor activity in the non-acting person when it is other agent's turn to respond, and (2) whether co-representation of the other's task share is generated from one's own egocentric perspective or from the perspective of the actor (allocentric). Results showed that although it was the other agent's turn to respond, the motor system of the non-acting person was activated prior to the other's response. Furthermore, motor activity was based on egocentric spatial properties. The findings support the tight functional coupling between one's own actions and actions produced by others, suggesting that the involvement of the motor system is crucial for social interaction.
Asunto(s)
Corteza Cerebral/fisiología , Variación Contingente Negativa/fisiología , Conducta Cooperativa , Relaciones Interpersonales , Actividad Motora , Adulto , Electroencefalografía , Electromiografía , Femenino , Humanos , Masculino , Pruebas Neuropsicológicas , Tiempo de Reacción/fisiologíaRESUMEN
In recent years, researchers have made many new discoveries in the field of social interaction and have attempted to understand the mechanisms of interpersonal coordination. This research is marked by two streams: On the one hand, there are attempts to explain spontaneous, incidental interpersonal coordination in terms of the behavioral dynamics perspective, and on the other, to explain instructed, intentional interpersonal coordination in terms of joint action. Other paradigms fall somewhere between incidental and intentional coordination, e.g. task sharing paradigms. The present study has two major objectives. First, we wanted to explore to what extent a dyadic scenario for bimanual coordination mimics typical signatures of bimanual coordination performance as obtained in the classical individual scenario. Second, if such mimicking is obtained, we wanted to investigate the kind of information on which the coordination between the two individuals may be grounded. To do so, we used a bimanual aiming task, which enabled us to assess measurements of two levels of coordination: global (operating over longer periods of time) and local (operating on each particular trial). In Experiment 1, this task was performed in an individual and in a dyadic setting. In the dyadic scenario, we observed strong global coordination and weak local coordination. In Experiment 2, we replicated this pattern and showed that different kinds of feedback had no impact on interpersonal coordination. Based on these findings, we propose that interpersonal coordination in a non-rhythmic choice response task is based on weak interpersonal coordination.
Asunto(s)
Conducta Cooperativa , Relaciones Interpersonales , Desempeño Psicomotor , Adulto , Atención , Femenino , Humanos , Masculino , Estimulación Luminosa , Tiempo de ReacciónRESUMEN
OBJECTIVE: This study investigated whether kinesthetic and/or visual imagery could alter the contingent negative variation (CNV) for patients with Parkinson's disease (PD). METHODS: The CNV was recorded in six patients with PD and seven controls before and after a 10min block of imagery. There were two types of imagery employed: kinesthetic and visual, which were evaluated on separate days. RESULTS: The global field power (GFP) of the late CNV did not change after the visual imagery for either group, nor was there a significant difference between the groups. In contrast, kinesthetic imagery resulted in significant group differences pre-, versus post-imagery GFPs, which was not present prior to performing the kinesthetic imagery task. In patients with PD, the CNV amplitudes post-, relative to pre-kinesthetic imagery, increased over the dorsolateral prefrontal regions and decreased in the ipsilateral parietal regions. There were no such changes in controls. CONCLUSIONS: A 10-min session of kinesthetic imagery enhanced the GFP amplitude of the late CNV for patients but not for controls. SIGNIFICANCE: While the study needs to be replicated with a greater number of participants, the results suggest that kinesthetic imagery may be a promising tool for investigations into motor changes, and may potentially be employed therapeutically, in patients with Parkinson's disease.
Asunto(s)
Encéfalo/fisiopatología , Imaginación/fisiología , Enfermedad de Parkinson/fisiopatología , Desempeño Psicomotor/fisiología , Anciano , Anciano de 80 o más Años , Electroencefalografía , Electromiografía , Potenciales Evocados Auditivos/fisiología , Femenino , Humanos , MasculinoRESUMEN
The present study examines differences in functional cerebral asymmetries modulated by gonadal steroid hormones during the menstrual cycle in women. Twenty-one right-handed women with regular menstrual cycles performed a double-stream rapid serial visual presentation (RSVP) task, with one stream in each visual field, during the low steroid menses and the high steroid midluteal phase. They were required to detect a target item, and then a probe item, each of which could appear in either stream. If the probe item appeared 200 ms after the target, detection of the probe was impaired-a phenomenon known as the "attentional blink." This occurred in both streams in the midluteal phase, but only in the right visual field during menses. Thus low steroid levels appeared to restrict the attentional blink to the left hemisphere, while high levels of estradiol and progesterone in the midluteal phase appeared to reduce functional asymmetries by selectively increasing the attentional blink in the right hemisphere. This effect appears to be mediated by estradiol rather than progesterone, and it is compatible with the assumption of a hormone-related suppression of right hemisphere functions during the midluteal phase.
Asunto(s)
Atención/fisiología , Parpadeo/fisiología , Encéfalo/metabolismo , Estradiol/metabolismo , Lateralidad Funcional/fisiología , Progesterona/fisiología , Adulto , Femenino , Humanos , Ciclo Menstrual/fisiología , Campos Visuales/fisiologíaRESUMEN
The attentional blink (AB) refers to a decrement in detecting the occurrence of a probe item if it closely follows a previous target item in rapid serial visual presentation (RSVP). In the present study we presented target and probe stimuli in two parallel RSVP streams, one in each visual field, in order to address the question of whether the AB might differ between the cerebral hemispheres. The characteristic AB, with reduced detection of the probe at post-target Lags 2-5, but no such deficit at Lag 1 (Lag 1 sparing), was observed when target and probe were both in the right visual field. When they were both presented in the left visual field the AB was attenuated. When the target and probe were in opposite visual fields, probe detection was again reduced when it was in the left visual field, and there was no Lag 1 sparing. The left-visual-field advantage in performing the AB task may reflect a general right-hemispheric specialization for attentional processing.