Infant manual exploration of composite substrates

Everyday environments, even small regions within reach, vary dramatically in terms of material composition. Adapting one's manual behavior to such transitions can be considered to be an important element of skilled action. To investigate the origins of this ability, we presented 8-month-olds (n=24) and 10-month-olds (n=24) hard or soft objects on a composite tabletop substrate that was half rigid and half flexible. Results indicated infants explored the objects selectively and geared their manual behaviors, with or without an object in hand, to the particular substrate they contacted. More broadly, the study suggests that infant manual exploration is flexible even in the face of abrupt transitions in material structure. Such flexibility may support early attempts at problem solving and tool use.     

Conflict in the kitchen: Contextual modulation of responsiveness to affordances

Recently, human behavior has been considered the product of continuous interactions between perception, cognition and action in which “affordances” (action possibilities the environment has to offer) play an important role. Converging evidence suggests that multiple action possibilities simultaneously compete for further processing, while external and internal factors (e.g., incoming sensory information, predictions) bias this competition. In the present study we used a stop-task to investigate whether context is able to modulate the strength of the responsiveness to affordances. We therefore placed participants in an actual kitchen and workshop during electroencephalographic recordings. A faster response to context congruent objects demonstrated that the direct surrounding is able to affect responsiveness to affordances. In addition, when responses needed to be withheld, context congruent objects evoked greater response conflict as indicated by an enhanced N2 Event Related Potential (ERP) component.     

药物成瘾行为的脑机制及其研究进展

药物成瘾是脑内相关核团和细胞在药物反复作用下发生适应性变化的时间依赖过程。成瘾的适应性学说从ｃＡＭＰ水平调节、阿片和多巴胺受体与Ｇ蛋白家族耦联等方面,为成瘾形成机制提供了最基本的生物学范畴的理论解释。实验证据在一定程度上揭示了从给药到耐受、敏感、依赖,再到撤药症状的生物变化过程。然而,阐明从急性给药到特殊脑区持续性的适应机制仍然是当前成瘾研究最具挑战性的目标之一。     

Keeping the driver in the loop in conditionally automated driving: A perception-action theory approach

In this paper we investigated if keeping the driver in the perception–action loop during automated driving can improve take-over behavior from conditionally automated driving. To meet this aim, we designed an experiment in which visual exposure (perception) and manual control exposure (action) were manipulated. In a dynamic driving simulator experiment, participants (n = 88) performed a non-driving related task either in a head-up display in the windshield (high visual exposure) or on a head-down display near the gear shift (low visual exposure). While driving, participants were either in an intermittent control-mode with four noncritical take-over situations (high manual control exposure), or in a continuous automation-mode throughout the ride (low manual control exposure). In all conditions, a critical take-over had to be carried out after an approximately 13 min ride. Measurements of take-over behavior showed that only high visual exposure had an effect on hands-on reaction time measurements. Both visual exposure and manual control exposure had small to medium sized main effects on time to system deactivation, the maximum velocity of the steering wheel, and the standard deviation of the steering wheel angle. The combined high visual – and high manual control exposure condition led to 0.55 s faster reaction time and 37% less steering variability in comparison to the worst case low visual – and low manual control exposure condition. Together, results corroborate that maintaining visual exposure and manual control exposure during automated driving can be efficacious and suggest that their positive effects are additive.     

Tracing the size,reach, impact,and breadth of positive psychology

This study quantitatively assessed the size, disciplinary reach, impact, and topic breadth of positive psychology (PP), in order to provide a comprehensive evaluation of the growth and significance of the field. Over 1.7?million documents in 700 PsycINFO ^® journals covering the fields of psychology, psychiatry, neuroscience, management, business, public health, and sport science were analyzed using semantic and bibliographic methods. Results indicate that PP covers many different research topics from a diverse range of disciplines, and that PP literature has been growing rapidly in significance. Over 18,000 documents were identified as belonging to PP, with 2300 published in 2011. These documents represent over 4% of PsycINFO ^® documents within the data-set published that year, and make PP close to the median size of all disciplines listed in the Thomson Reuters Journal Citation Reports ^®, Social Sciences Edition. The aggregate impact factor for PP in 2011 was 2.64.     

A Perception-Action Coupling Type of Control in Long Jumping

The authors' goal was to identify the control mechanisms used by long jumpers (N = 6) to precisely position their foot at the board. In addition to the intertrial method usually used in previous research, an original method based on a trial-by-trial analysis was also implemented. If the approach to the board in long jumping encompasses two distinct sequences separated by a key step that marks the initiation of visual control, then a trial-by-trial analysis should reveal those sequences, regardless of the amount of adjustment: The step number at which regulation is initiated should be the same irrespective of the amount of adjustment. If, in contrast, a perception-action coupling mechanism operates, then the step number at which regulation is initiated should be a function of the amount of adjustment: A linear relation between those 2 variables should emerge. The results of the present study are compatible with continuous control mechanisms based on a perception-action coupling.     

Bilateral Transfer in Tapping Skill in the Absence of Peripheral Information

Bilateral transfer in a fast tapping task was investigated under normal (+FB) and reduced (-FB) feedback conditions, in the -FB experiment 36 Ss were assigned to 3 groups: preferred (PH) to non-preferred (NPH) shift; NPH to PH; and alternating trials of PH and NPH. With + FB 2 further groups of 12 Ss transferred PH to NPH or NPH to PH. 8 preshift and 8 postshift trials were given. The alternating group had 8 PH and 8 NPH trials. In preshift performance increment was found in ail groups except in +FB with NPH. With +FB some facilitation in transfer was obtained for the NPH; under -FB marked positive transfer was found for the PH. Alternating PH and NPH performance conformed to preshift levels. Results were discussed in terms of differential central control processes for the two hands.     

The dynamics of standing balance

The control of standing is a complicated task that involves the action of muscles distributed over the whole body. Forces arising from gravity, external events or our own actions all tend to disturb the unstable equilibrium that preserves posture. For the central nervous system the problem of standing can be cast in terms of finding appropriate relations among body segments to maintain the desired position of the body as a whole with respect to the environment. In this review we evaluate some recent discoveries on the effects of predictable and unpredictable perturbations, and the role of perceptual information, attention and cognitive processes in the control of upright stance.     

A response binding effect in visual short-term memory

The current study aimed to investigate the effect of action on the preservation of stored feature bindings. Prior research suggests that stimuli presented after a memory array can disrupt the feature bindings of memory array items. Here, we conducted three experiments to examine whether response to targets disrupts feature bindings. Two of four letters (A, B, C, D) were presented in a memory array, and were followed by a second array containing a single target letter. After either identifying or localizing the target letter, participants were required to report the identity or location of the memory array items. There was a deficit in memory performance involving spatial repetition when participants were required to localize targets, and involving identity repetition when participants were required to identify targets. We conclude that response codes are fundamentally linked to stimulus representations, and can affect retrieval from visual working memory.     

The GROOP effect: groups mimic group actions

Research on perception–action links has focused on an interpersonal level, demonstrating effects of observing individual actions on performance. The present study investigated perception–action matching at an inter-group level. Pairs of participants responded to hand movements that were performed by two individuals who used one hand each or they responded to hand movements performed by an individual who used both hands. Apart from the difference in the number of observed agents, the observed hand movements were identical. If co-actors form action plans that specify the actions to be performed jointly, then participants should have a stronger tendency to mimic group actions than individual actions. Confirming this prediction, the results showed larger mimicry effects when groups responded to group actions than when groups responded to otherwise identical individual actions. This suggests that representations of joint tasks modulate automatic perception–action links and facilitate mimicry at an inter-group level.