Papers by Harold Bekkering

NeuroImage, 2008
Lately, neuroscience is showing a great interest in examining the functional and neural mechanism... more Lately, neuroscience is showing a great interest in examining the functional and neural mechanisms which support action observation and understanding. Recent studies have suggested that our motor skills crucially affect the way in which we perceive the actions generated by others, by showing stronger motor resonance for observation of actions that are established in one's motor repertoire. In the present study we extend previous findings that were based on expert motor skills in adults to the natural development of actions in infants. To investigate the effect of natural motor experience on motor resonance during action observation, 14-to 16-month-old infants' EEG was recorded during observation of action videos. Stronger mu-and betadesynchronizations were found for observation of crawling compared to walking videos and the size of the effect was strongly related to the infant's own crawling experience. This suggests that already early in life one's own action experience is closely related to how actions of others are perceived.

In analyses of the motor system, two hierarchies are often posited: The first – the action hierar... more In analyses of the motor system, two hierarchies are often posited: The first – the action hierarchy – is a decomposition of an action into sub-actions and sub-sub-actions. The second – the control hierarchy – is a postulated hierarchy in the neural control processes that are supposed to bring about the action. A general assumption in cognitive neuroscience is that these two hierarchies are internally consistent and provide complementary descriptions of neuronal control processes. In this essay, we suggest that neither offers a complete explanation and that they cannot be reconciled in a logical or conceptually coherent way. Furthermore, neither pays proper attention to the dynamics and temporal aspects of neural control processes. We will explore an alternative hierarchical organization in which causality is inherent in the dynamics over time. Specifically, high levels of the hierarchy encode more stable (goal-related) representations, while lower levels represent more transient (actions and motor acts) kinematics. If employed properly, a hierarchy based on this latter principle of temporal extension is not subject to the problems that plague the traditional accounts.

Social …, Jan 1, 2011
The discovery of mirror neurons in monkeys, and the finding of motor activity during action obser... more The discovery of mirror neurons in monkeys, and the finding of motor activity during action observation in humans are generally regarded to support motor theories of action understanding. These theories take motor resonance to be essential in the understanding of observed actions and the inference of action goals. However, the notions of “resonance,” “action understanding,” and “action goal” appear to be used ambiguously in the literature. A survey of the literature on mirror neurons and motor resonance yields two different interpretations of the term “resonance,” three different interpretations of action understanding, and again three different interpretations of what the goal of an action is. This entails that, unless it is specified what interpretation is used, the meaning of any statement about the relation between these concepts can differ to a great extent. By discussing an experiment we will show that more precise definitions and use of the concepts will allow for better assessments of motor theories of action understanding and hence a more fruitful scientific debate. Lastly, we will provide an example of how the discussed experimental setup could be adapted to test other interpretations of the concepts.

Philosophical …, Jan 1, 2011
Single cell recordings in monkeys provide strong evidence for an important role of the motor syst... more Single cell recordings in monkeys provide strong evidence for an important role of the motor system in action understanding. This evidence is backed up by data from studies of the (human) mirror neuron system using neuroimaging or TMS techniques, and behavioral experiments. Although the data acquired from single cell recordings are generally considered to be robust, several debates have shown that the interpretation of these data is far from straightforward. We will show that research based on single-cell recordings allows for unlimited content attribution to mirror neurons. We will argue that a theoretical analysis of the mirroring process, combined with behavioral and brain studies, can provide the necessary limitations. A complexity analysis of the type of processing attributed to the mirror neuron system can help formulate restrictions on what mirroring is and what cognitive functions could, in principle, be explained by a mirror mechanism. We argue that processing at higher levels of abstraction needs assistance of non-mirroring processes to such an extent that subsuming the processes needed to infer goals from actions under the label ‘mirroring’ is not warranted.
Proceedings of the …, Jan 1, 1783
The discovery of mirror neurons in the 1990s has led to much excitement in the cognitive neurosci... more The discovery of mirror neurons in the 1990s has led to much excitement in the cognitive neurosciences. After the initial discovery more and more abilities have been attributed to these neurons. As mirror neurons are commonly viewed as vehicles of representation, we analyze the increasingly wider representational role mirror neurons play and argue for a principled distinction between mirror and non-mirror neurons.
Brain and Cognition, Jan 1, 2003

Developmental science, 2000
We used imitation as a tool for investigating how young children code action. The study was desig... more We used imitation as a tool for investigating how young children code action. The study was designed to examine the errors children make in re-enacting manual gestures they see. Thirty-two 3-year-old children served as subjects. Each child was shown 24 gestures, generated by systematically crossing four factors: visual monitoring, spatial endpoint, movement path, and number of hands. The results showed no difference as a function of whether the children could visually monitor their own responses. Interestingly, children made significantly more errors when the adult's action terminated on a body part than they did when the same movement terminated near the body part. There were also significantly more errors when the demonstrated act involved crossing midline than when it did not, and more errors when it involved one hand rather than two hands. Our hypothesis is that human acts are coded in terms of goals. The goals are hierarchically organized, and because young children have difficulty simultaneously integrating multiple goals into one act they often re-enact the goals that are ranked higher, which leads to the errors observed. We argue that imitation is an active reconstruction of perceived events and taps cognitive processing. We suggest that the goal-based imitation in 3-year-olds is a natural developmental outgrowth of the perceptual± motor mapping and goal-directed coding of human acts found in infancy.

The Quarterly journal of experimental psychology. A, Human experimental psychology, 2004
Theories in motor control suggest that the parameters specified during the planning of goaldirect... more Theories in motor control suggest that the parameters specified during the planning of goaldirected hand movements to a visual target are defined in spatial parameters like direction and amplitude. Recent findings in the visual attention literature, however, argue widely for early object-based selection processes. The present experiments were designed to examine the contributions of object-based and space-based selection processes to the preparation time of goaldirected pointing movements. Therefore, a cue was presented at a specific location. The question addressed was whether the initiation of responses to uncued target stimuli could benefit from being either within the same object (object based) or presented at the same direction (space based). Experiment 1 replicated earlier findings of object-based benefits for non-goal-directed responses. Experiment 2 confirmed earlier findings of space-based benefits for goal-directed hand pointing movements. In Experiments 3 and 4, space-based and object-based manipulations were combined while requiring goal-directed hand pointing movements. The results clearly favour the notion that the selection processes for goal-directed pointing movements are primarily object based. Implications for theories on selective attention and action planning are discussed.
Progress in brain research, 2002

Psychological science, 2002
The influence of action intentions on visual selection processes was investigated in a visual sea... more The influence of action intentions on visual selection processes was investigated in a visual search paradigm. A predefined target object with a certain orientation and color was presented among distractors, and subjects had to either look and point at the target or look at and grasp the target. Target selection processes prior to the first saccadic eye movement were modulated by the different action intentions. Specifically, fewer saccades to objects with the wrong orientation were made in the grasping condition than in the pointing condition, whereas the number of saccades to an object with the wrong color was the same in the two conditions. Saccadic latencies were similar under the different task conditions, so the results cannot be explained by a speedaccuracy trade-off. The results suggest that a specific action intention, such as grasping, can enhance visual processing of action-relevant features, such as orientation. Together, the findings support the view that visual attention can be best understood as a selection-for-action mechanism.
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Papers by Harold Bekkering