Hand selection for object grasping is influenced by recent motor history

Action selection processes such as those that underlie decisions about which hand to use for upcoming actions are fundamental to adaptive motor behavior. Previous research has shown that people grasp objects in ways that reflect anticipated task demands, as well as recent movement experience. However, very few studies have addressed the possible influence of recent motor history on hand selection. In the present study, participants grasped and placed objects using either their left or right hand. The results showed shorter response times to initiate successive actions when hand was repeated, even when those actions involved distinct grasp postures and object placement movements to distinct locations. Conversely, no such planning advantage was observed for repeated grasps for successive actions made with opposite hands. The findings are consistent with the idea that choices about which hand to use in the present are influenced by which hand was used in the recent past. When the same hand can be used for successive actions, planning is made more efficient, presumably because the motor parameters that specify which hand to use can be recalled from recent memory rather than formulated anew. The findings indicate that hand selection is sensitive to recent movement experience and provide novel support for computational efficiency accounts of motor history effects.     

Children's imitation of causal action sequences is influenced by statistical and pedagogical evidence

Children are ubiquitous imitators, but how do they decide which actions to imitate? One possibility is that children rationally combine multiple sources of information about which actions are necessary to cause a particular outcome. For instance, children might learn from contingencies between action sequences and outcomes across repeated demonstrations, and they might also use information about the actor’s knowledge state and pedagogical intentions. We define a Bayesian model that predicts children will decide whether to imitate part or all of an action sequence based on both the pattern of statistical evidence and the demonstrator’s pedagogical stance. To test this prediction, we conducted an experiment in which preschool children watched an experimenter repeatedly perform sequences of varying actions followed by an outcome. Children’s imitation of sequences that produced the outcome increased, in some cases resulting in production of shorter sequences of actions that the children had never seen performed in isolation. A second experiment established that children interpret the same statistical evidence differently when it comes from a knowledgeable teacher versus a naïve demonstrator. In particular, in the pedagogical case children are more likely to “overimitate” by reproducing the entire demonstrated sequence. This behavior is consistent with our model’s predictions, and suggests that children attend to both statistical and pedagogical evidence in deciding which actions to imitate, rather than obligately imitating successful action sequences.     

Interference due to shared features between action plans is influenced by working memory span

In this study, we examined the interactions between the action plans that we hold in memory and the actions that we carry out, asking whether the interference due to shared features between action plans is due to selection demands imposed on working memory. Individuals with low and high working memory spans learned arbitrary motor actions in response to two different visual events (A and B), presented in a serial order. They planned a response to the first event (A) and while maintaining this action plan in memory they then executed a speeded response to the second event (B). Afterward, they executed the action plan for the first event (A) maintained in memory. Speeded responses to the second event (B) were delayed when it shared an action feature (feature overlap) with the first event (A), relative to when it did not (no feature overlap). The size of the feature-overlap delay was greater for low-span than for high-span participants. This indicates that interference due to overlapping action plans is greater when fewer working memory resources are available, suggesting that this interference is due to selection demands imposed on working memory. Thus, working memory plays an important role in managing current and upcoming action plans, at least for newly learned tasks. Also, managing multiple action plans is compromised in individuals who have low versus high working memory spans.     

German unification influenced by an unfinished psychosocial history]

The critical form of social psychology presented here is concerned with the modalities and results of German reunification. It proceeds from Freud's insistence on the functional autonomy of psychic dispositions and unconscious forms of identification vis-à-vis the political and economic spheres. With reference to earlier historical experience of the Germans as an "economic nation" the authors suspect that German reunification with the avowed "economistic" priority of establishing the same life conditions in East and West is once again suppressing those problems that are bound up with the post-fascist syndrome handed down from one generation to the next. With a view to casting light on the reunification process and the collective psychic potentials it has released, the authors supplement Freud's mass-psychology approach with Julia Kristeva's outline of a social psychology that hinges on the relationship between cosmopolitanism and the national idea.     

Control by reinforcers across time and space: A review of recent choice research

Reinforcers affect behavior. A fundamental assumption has been that reinforcers strengthen the behavior they follow, and that this strengthening may be context‐specific (stimulus control). Less frequently discussed, but just as evident, is the observation that reinforcers have discriminative properties that also guide behavior. We review findings from recent research that approaches choice using nontraditional procedures, with a particular focus on how choice is affected by reinforcers, by time since reinforcers, and by recent sequences of reinforcers. We also discuss how conclusions about these results are impacted by the choice of measurement level and display. Clearly, reinforcers as traditionally considered are conditionally phylogenetically important to animals. However, their effects on behavior may be solely discriminative, and contingent reinforcers may not strengthen behavior. Rather, phylogenetically important stimuli constitute a part of a correlated compound stimulus context consisting of stimuli arising from the organism, from behavior, and from physiologically detected environmental stimuli. Thus, the three‐term contingency may be seen, along with organismic state, as a correlation of stimuli. We suggest that organisms may be seen as natural stimulus‐correlation detectors so that behavioral change affects the overall correlation and directs the organism toward currently appetitive goals and away from potential aversive goals. As a general conclusion, both historical and recent choice research supports the idea that stimulus control, not reinforcer control, may be fundamental.     

Perceived motion is influenced by random dynamic information

Distortions of the local spatial-frequency power spectrum caused by motion blur may be used by the visual system to improve motion analysis (e.g., Barlow and Olshausen, 2004 Journal of Vision 4415-426). We tested this hypothesis by measuring the error of perceived motion direction of moving patterns in the presence of random noncoherent motion manipulated to create different spatial power spectra. The results showed that error increased when the background power spectrum was similar to the motion power spectrum; however, when the background power spectrum had an anisotropy consistent with motion blur, the error was reduced. Shifting the power spectrum away from the motion power spectrum reduced the error.     

Neck posture is influenced by anticipation of stepping

BackgroundPostural deviations such as forward head posture (FHP) are associated with adverse health effects. The causes of these deviations are poorly understood. We hypothesized that anticipating target-directed movement could cause the head to get “ahead of” the body, interfering with optimal head/neck posture, and that the effect may be exacerbated by task difficulty and/or poor inhibitory control.MethodWe assessed posture in 45 healthy young adults standing quietly and when they anticipated walking to place a tray: in a simple condition and in conditions requiring that they bend low or balance an object on the tray. We defined FHP as neck angle relative to torso; we also measured head angle relative to neck and total neck length. We assessed inhibitory control using a Go/No-Go task, Stroop task, and Mindful Attention Awareness Scale (MAAS).ResultsFHP increased when participants anticipated movement, particularly for more difficult movements. Worse Stroop performance and lower MAAS scores correlated with higher FHP. False alarms on the Go/No-Go task correlated with a more extended head relative to the neck and with shortening of the neck when anticipating movement.ConclusionsMaintaining neutral posture may require inhibition of an impulse to put the head forward of the body when anticipating target-directed movement.     

Emotional appraisal is influenced by cardiac afferent information

Influential models highlight the central integration of bodily arousal with emotion. Some emotions, notably disgust, are more closely coupled to visceral state than others. Cardiac baroreceptors, activated at systole within each cardiac cycle, provide short-term visceral feedback. Here we explored how phasic baroreceptor activation may alter the appraisal of brief emotional stimuli and consequent cardiovascular reactions. We used functional MRI (fMRI) to measure brain responses to emotional face stimuli presented before and during cardiac systole. We observed that the processing of emotional stimuli was altered by concurrent natural baroreceptor activation. Specifically, facial expressions of disgust were judged as more intense when presented at systole, and rebound heart rate increases were attenuated after expressions of disgust and happiness. Neural activity within prefrontal cortex correlated with emotionality ratings. Activity within periaqueductal gray matter reflected both emotional ratings and their interaction with cardiac timing. Activity within regions including prefrontal and visual cortices correlated with increases in heart rate evoked by the face stimuli, while orbitofrontal activity reflected both evoked heart rate change and its interaction with cardiac timing. Our findings demonstrate that momentary physiological fluctuations in cardiovascular afferent information (1) influence specific emotional judgments, mediated through regions including the periaqueductal gray matter, and (2) shape evoked autonomic responses through engagement of orbitofrontal cortex. Together these findings highlight the close coupling of visceral and emotional processes and identify neural regions mediating bodily state influences on affective judgment.     

Infant learning is influenced by local spurious generalizations

In previous work, 11‐month‐old infants were able to learn rules about the relation of the consonants in CVCV words from just four examples. The rules involved phonetic feature relations (same voicing or same place of articulation), and infants' learning was impeded when pairs of words allowed alternative possible generalizations (e.g. two words both contained the specific consonants p and t). Experiment 1 asked whether a small number of such spurious generalizations found in a randomly ordered list of 24 different words would also impede learning. It did – infants showed no sign of learning the rule. To ask whether it was the overall set of words or their order that prevented learning, Experiment 2 reordered the words to avoid local spurious generalizations. Infants showed robust learning. Infants thus appear to entertain spurious generalizations based on small, local subsets of stimuli. The results support a characterization of infants as incremental rather than batch learners.     

Post-error slowing is influenced by cognitive control demand

Post-error slowing (PES) has been shown to reflect a control failure due to automatic attentional capture by the error. Here we aimed to assess whether PES also involves an increase in cognitive control. Using a cued-task-switching paradigm (Experiment 1) and a Stroop task (Experiment 2), the demand for top down control was manipulated. In Experiment 1, one group received dimension cues indicating the relevant stimulus dimension (e.g., “number”) without specifying the response-category-to-key mapping, hence requiring considerable top down control. Another group was shown mapping cues providing information regarding both the relevant task identity and its category-to-key mapping (e.g., “one three”), requiring less top down control, and the last group received both types of cues, intermixed. In Experiment 2, one group performed a pure incongruent Stroop condition (name ink color of incongruent color names, high control demand), and another group received a pure neutral Stroop condition (name color patches, low control demand). In Experiment 2a, participants received the two conditions, intermixed. A larger PES was observed with dimension cues as compared with mapping cues, and with incongruent Stroop stimuli as compared to neutral stimuli, but not when the conditions were intermixed. These findings reveal that PES is influenced by the control demands that characterize the given block-wide experimental context and show that proactive cognitive control is involved in PES.     

Visual short-term memory is influenced by haptic perception

The present study investigated whether and how visual memory and haptic perception are related. Participants were required to compare a visual reference velocity with a visual test velocity separated by a 4-s interval. During the retention interval, a fast or slow hand movement was performed. Although the hand movement was not visible, effects of the speed of the distracting body movement occurred. Slow movements resulted in a lowering of the represented visual velocity, whereas fast movements heightened the represented velocity. Subsequent experiments extended the effect to body movements that differed from the visual motion and ruled out the possibility that the effect was due to changes in visual perception or interference from semantic, verbal, and acoustic memory codes. Perhaps haptic velocity information and visual velocity information stored in short-term memory are blended.     

“动手不动口”：手部动作与语言进化的关系

语言进化是进化心理学研究领域的重要问题。镜像系统假说、工具制造假说与传授假说从不同角度对手部动作与语言进化间的关系进行了解释, 三种假说都认为人类语言起源于手部动作经验。相关实证研究发现：手语与口语具有一致性特征、语言与手部动作具有共同的神经基础、手势发展可以预测语言发展水平以及手势可以提高工具制造知识的传播效率, 这些研究为三种假说的具体观点提供了实证支持。未来该领域的研究需要关注手势语与口语在进化中的发展关系, 以及人类语言进化与其他认知特征的进化关系。     

The open-object illusion: size perception is greatly influenced by object boundaries

This study presents a new powerful visual illusion, in which simple “open” objects—ones with missing boundaries—are perceived as bigger than the same size, fully “closed” objects. In a series of experiments that employed a continuous-response adjustment procedure, it was found that the lack of vertical boundaries inflated the perceived width of an object, whereas the lack of horizontal boundaries inflated its perceived length. The effect was highly robust and it was replicated across different stimulus types and experimental parameters, with almost all observers exhibiting a strong effect. In contrast to the overestimation of the size of an object due to missing boundaries, the inclusion of inner boundaries within an object caused observers to underestimate its size, suggesting that filled space sometimes shrinks, rather than inflates, the perceived size of an object. The open-object illusion bears practical implications for graphics and design as well as important theoretical implications. Specifically, it indicates that the perception of an object’s area is not veridical but rather critically depends on contour closure. It is suggested that the visual system extends the missing boundaries of open contour objects, which results in an overestimation of the object’s size.     

Hand dominance, attention, and the choice between responses

Thirty pairs of matched right- and left-handed subjects carried out a serial C.RT task involving reaches between 2.4 cm square contact grids set at 2.4 cm intervals in a horizontal line. In one condition they responded with the right hand alone, in a second with the left and in a third they had to choose between hands on each trial responding to left side grids with the left hand and to right side grids with the right.

All subjects took longer to respond when they had to choose between hands than when they used either hand alone. In the one-hand conditions neither group showed any effect of hand dominance. When choices had to be made between hands both groups responded faster with their dominant than with their nondominant hands.

Analysis of the results was undertaken in terms of two hypothetical systems of instructions which might control machines designed to carry out similar tasks. It is concluded that in some tasks hand dominance can be described in terms of an attentional bias towards the field of operation of one effector rather than another. In the present task the effects of such possible attentional biases were shown not to interact with other effects, such as the facilitation of successive responses by repeated use of the same limb. These latter effects seem to depend on processes underlying execution of responses rather than choices between responding limbs.     

Acquisition of abstract concepts is influenced by emotional valence

There is considerable lack of evidence concerning the linguistic and cognitive skills underpinning abstract vocabulary acquisition. The present study considers the role of emotional valence in providing an embodied learning experience in which to anchor abstract meanings. First, analyses of adult ratings of age‐of‐acquisition, concreteness and valence demonstrate that abstract words acquired early tend to be emotionally valenced. Second, auditory Lexical Decision accuracies of children aged 6–7, 8–9, and 10–11 years (n = 20 per group) complement these analyses, demonstrating that emotional valence facilitates processing of abstract words, but not concrete. These findings provide the first evidence that young, school‐aged children are sensitive to emotional valence and that this facilitates acquisition of abstract words.     

Gaze cueing elicited by emotional faces is influenced by affective context

When we observe someone shift their gaze to a peripheral event or object, a corresponding shift in our own attention often follows. This social orienting response, joint attention, has been studied in the laboratory using the gaze cueing paradigm. Here, we investigate the combined influence of the emotional content displayed in two critical components of a joint attention episode: The facial expression of the cue face, and the affective nature of the to-be-localized target object. Hence, we presented participants with happy and disgusted faces as cueing stimuli, and neutral (Experiment 1), pleasant and unpleasant (Experiment 2) pictures as target stimuli. The findings demonstrate an effect of ‘emotional context’ confined to participants viewing pleasant pictures. Specifically, gaze cueing was boosted when the emotion of the gazing face (i.e., happy) matched that of the targets (pleasant). Demonstrating modulation by emotional context highlights the vital flexibility that a successful joint attention system requires in order to assist our navigation of the social world.     

Suboptimal choice by dogs: when less is better than more

The less is more effect, an example of an affect heuristic, can be shown in humans when they give greater value to a set of six baseball cards in perfect condition, than to the same set of six perfect cards together with three additional cards each with some value but in fair condition. A similar effect has been reported in monkeys which will eat both grapes and cucumbers but prefer grapes, when they prefer a single grape over a single grape plus a slice of cucumber. In the present experiment, we tested the less is more effect with a nonprimate but social species, dogs. We used dogs that would eat a slice of carrot and a slice of cheese but preferred the cheese. When we then gave them a choice between a slice of cheese and a slice of cheese plus a slice of carrot, most dogs preferred the single slice of cheese. Thus, the less is more effect appears to occur in several species.     

And All is Always Now: Contemplations on Artistic Talent

This paper aims to suggest the notion of layers of dying, as a metaphorical discussion of states that call for the breakdown of opposites and a unification in the form of a lived experience. Artistic talent is seen as a personal capacity to sustain such a state and transform it into a communicative form that is accessible to us all. Winnicott, in his “fear of breakdown” paper is a main source of influence, along with Bion who encouraged the articulation of “stray thoughts.”