Interactions between perception and action in a reaction task with overlapping S-R assignments

 We have used a novel task to study relationships between perception and action. Four experiments studied stimulus-response (S-R) relationships under conditions in which stimuli and responses were functionally unrelated (i.e., not assigned to each other by instruction) and merely overlapped in time. On each trial, participants carried out movements on a graphic tablet while observing motions displayed on a computer screen. The movement on trial n was specified by the motion observed on the previous trial n-1, whereas the motion observed on trial n specified the movement to be performed on trial n+1. Results showed that stimulus motion had a contrast-like impact on response movement. Watching a small motion while performing a medium-sized movement increased movement size, whereas watching a large motion led to a decrease (Experiment 1). Further experiments showed that the contrast pattern was not affected by the mode of motion presentation (Experiment 2), or by the interval between motion and movement execution (Experiment 3). Contrast was also observed in the reverse direction, i.e., from action to perception (Experiment 4). We propose that the contrast effect is due to a mechanism for selective code modification. This mechanism acts to increase the distinctiveness of simultaneously activated perception and action codes in a common representational domain. Received: 11 July 2000 / Accepted: 4 March 2001     

Baby do–baby see!: How action production influences action perception in infants

With a series of four experiments we show that self-produced actions influence infants’ perception of actions performed by others. After having played with an object, 7–11-month-olds simultaneously watched two videos presenting adults who act on either the same object or a different one. The 9- and 11-month-old preferred to watch the same-object video indicating an influence of action production on action perception at this age. Follow-up studies showed that this influence was restricted to object-related actions. Agentive experience enhanced interest in actions with objects, but not in watching objects or persons per se. These findings indicate that infants are not only interested in acting on objects themselves, but that this experience increases their interest in the actions of other people with the same object.     

The Normativity Challenge: Cultural Psychology Provides the Real Threat to Virtue Ethics

Situationists argue that virtue ethics is empirically untenable, since traditional virtue ethicists postulate broad, efficacious character traits, and social psychology suggests that such traits do not exist. I argue that prominent philosophical replies to this challenge do not succeed. But cross-cultural research gives reason to postulate character traits, and this undermines the situationist critique. There is, however, another empirical challenge to virtue ethics that is harder to escape. Character traits are culturally informed, as are our ideals of what traits are virtuous, and our ideals of what qualifies as well-being. If virtues and well-being are culturally constructed ideals, then the standard strategy for grounding the normativity of virtue ethics in human nature is undermined.     

Assimilation and contrast: the two sides of specific interference between action and perception

Perception and action have long been treated as relatively independent and serial processes. More recent views, however, consider perception and action as relying on a common set of processes and/or representations. The present paper will focus on a variety of specific (content-based) perception–action interactions that have been taken as support for such views. In particular, the following aspects will be considered: direction of influence (perception on action vs. action on perception), temporal type (concurrent vs. non-concurrent), functional relation (related/unrelated), and type of movements (biological vs. non-biological). Different extant models of the perception-action interface are discussed and a classification schema proposed that tries to explain when contrast and when assimilation effects will arise.     

Mad and glad: Musically induced emotions have divergent impact on morals

Moral judgments can be positive or negative: we can judge action as good or wrong. Here we show that good judgments and wrong judgments are influenced by incidental emotions. Using instrumental music as an induction method, we show that anger, but not happiness, increases the tendency to judge actions as wrong (Experiment 1). We also show that happiness increases the tendency to praise actions as both good and obligatory, while anger reduces these judgments (Experiment 2). These findings extend the literature on emotions and moral judgment by demonstrating impact of anger and happiness, and by contrasting goodness and wrongness in their emotional valence. The findings also show that music can have a significant impact on moral judgment. This is important because music is a highly prevalent situational variable. The use of instrumental music may have advantages over other induction techniques because it does not carry specific semantic cues that might encourage people to think about morality.     

Trial-to-trial sequential dependencies in a social and non-social Simon task

Recent research has shown that joint-action effects in a social Simon task provide a good index of action co-representation. The present study aimed to specify the mechanisms underlying joint action by considering trial-to-trial transitions. Using non-social stimuli, we assigned a Simon task to two participants. Each was responsible for only one of two possible responses. This task was performed alone (Individual go/nogo task) and in cooperation with another person who was sitting alongside (Joint go/nogo task). As a further control task, we added a Standard Simon task. Replicating previous findings (Sebanz et al. in Cognition 88:B11-B21, 2003), we found no spatial compatibility effect in the Individual go/nogo task but we did find one in the Joint go/nogo task. A more detailed analysis showed that a sequential modulation of the Simon effect was present in both the Joint and the Individual go/nogo tasks. We found reliable Simon effects in trials following Simon compatible trials not only in the Joint go/nogo task but also to a somewhat smaller extent in the Individual go/nogo task. For both these go/nogo tasks, sequential modulation effects were stronger for nogo/go transitions than for go/go transitions. This suggests that low-level feature binding and repetition mechanisms contribute to the social Simon effect related to the specific requirement not to respond on nogo trials.     

Movement observation affects movement execution in a simple response task

The present study was designed to examine the hypothesis that stimulus-response arrangements with high ideomotor compatibility lead to substantial compatibility effects even in simple response tasks. In Experiment 1, participants executed pre-instructed finger movements in response to compatible and incompatible finger movements. A pronounced reaction time advantage was found for compatible as compared to incompatible trials. Experiment 2 revealed a much smaller compatibility effect for less ideomotor-compatible object movements compared to finger movements. Experiment 3 presented normal stimuli (hand upright) and flipped stimuli (hand upside-down). Two components were found to contribute to the compatibility effect, a dynamic spatial compatibility component (related to movement directions) and an ideomotor component (related to movement types). The implications of these results for theories about stimulus-response compatibility (SRC) as well as for theories about imitation are discussed.     

How two share a task: corepresenting stimulus-response mappings

Previous research has shown that individuals unintentionally adjust their behavior to others by mimicking others' actions and by synchronizing their actions with others. This study investigated whether individuals form a representation of a coactor's task when the context does not require interpersonal coordination. Pairs of participants performed a reaction time (RT) task alongside each other, responding to 2 different dimensions of the same stimulus. Results showed that each actor's performance was influenced by the other's task. RTs on trials that required a response from both participants were slowed compared with trials that required only a response from 1 actor. Similar results were observed when each participant knew the other's task but could not observe the other's actions. These findings provide evidence that shared task representations are formed in social settings that do not require interpersonal coordination and emerge as a consequence of how a social situation is conceptualized.