The Mechanics of Embodiment: A Dialogue on Embodiment and Computational Modeling

Embodied theories are increasingly challenging traditional views of cognition by arguing that conceptual representations that constitute our knowledge are grounded in sensory and motor experiences, and processed at this sensorimotor level, rather than being represented and processed abstractly in an amodal conceptual system. Given the established empirical foundation, and the relatively underspecified theories to date, many researchers are extremely interested in embodied cognition but are clamouring for more mechanistic implementations. What is needed at this stage is a push toward explicit computational models that implement sensory-motor grounding as intrinsic to cognitive processes. In this article, six authors from varying backgrounds and approaches address issues concerning the construction of embodied computational models, and illustrate what they view as the critical current and next steps toward mechanistic theories of embodiment. The first part has the form of a dialogue between two fictional characters: Ernest, the �experimenter�, and Mary, the �computational modeller�. The dialogue consists of an interactive sequence of questions, requests for clarification, challenges, and (tentative) answers, and touches the most important aspects of grounded theories that should inform computational modeling and, conversely, the impact that computational modeling could have on embodied theories. The second part of the article discusses the most important open challenges for embodied computational modelling

Spatial representation of described environments: the characteristics of verbal descriptions and the role of physical movement

Recent findings support the assumption that the verbal description of an environment allows the creation of a mental representation of the environment that is functionally equivalent to that deriving from direct perception. Moreover, the verbal descriptions of an environment are commonly used in daily life to communicate with both sighted people in remote environment or visually impaired people. However, many questions on this topic still need to be answered, especially regarding the characteristics of the verbal descriptions and the potential fostering effect of physical movements. Thus, the aim of the present work was to shed light on the role of the physical movements in supporting the verbal descriptions, after a brief examination of some features important for the verbal descriptions. The first part of the manuscript deals with the specific characteristics of the verbal description which could affect the corresponding mental representation. Thus, the influence of the serial position effect on different types of verbal stimuli has been investigated in order to clarify whether people are able to remember all the information provided with a verbal description of an environment or systematically lose information positioned in the central part of the description. Then, the effect of the direction of the verbal description (Clockwise or Counterclockwise) on the recall performance/modality has been considered; I found that people prefers to recall spatial relations that are congruent with the description encoded, extending a well-established effect of memory congruency also to the domain of spatial representation. The second part of the thesis, instead, deals with the influence of physical movement on spatial updating within described environments. Even though several researchers focused on the role of movement in immediate and remote environments, only few of them investigated its role on verbally described environments; moreover, they mainly targeted their studies on imagined movements, rotation and translation, neglecting more ecological movements, such as physical walking. Thus, two separate experiments shed light on the contribution of physical walking compared to both physical and imagined rotation, on spatial updating \u2013 that is, the ability to keep track of the self-to-object relations during observer\u2019s movement. By manipulating the movements required during the encoding of the description or after the description, results suggested different effects of the multisensory pattern of information provided by physical walking on spatial updating, depending on the situation in which the movements were executed. Finally, a third experiment, which used an ecological experimental procedure, examined the effectiveness of the physical exploration of an environment in fostering the development of an adequate spatial representation. In conclusion, the results provide further evidence for the effectiveness of adopting verbal material to describe an environment, and highlight the important role of the physical movements in enhancing people\u2019s ability to successfully interact with the described environments

Credit assignment in multiple goal embodied visuomotor behavior

The intrinsic complexity of the brain can lead one to set aside issues related to its relationships with the body, but the field of embodied cognition emphasizes that understanding brain function at the system level requires one to address the role of the brain-body interface. It has only recently been appreciated that this interface performs huge amounts of computation that does not have to be repeated by the brain, and thus affords the brain great simplifications in its representations. In effect the brain’s abstract states can refer to coded representations of the world created by the body. But even if the brain can communicate with the world through abstractions, the severe speed limitations in its neural circuitry mean that vast amounts of indexing must be performed during development so that appropriate behavioral responses can be rapidly accessed. One way this could happen would be if the brain used a decomposition whereby behavioral primitives could be quickly accessed and combined. This realization motivates our study of independent sensorimotor task solvers, which we call modules, in directing behavior. The issue we focus on herein is how an embodied agent can learn to calibrate such individual visuomotor modules while pursuing multiple goals. The biologically plausible standard for module programming is that of reinforcement given during exploration of the environment. However this formulation contains a substantial issue when sensorimotor modules are used in combination: The credit for their overall performance must be divided amongst them. We show that this problem can be solved and that diverse task combinations are beneficial in learning and not a complication, as usually assumed. Our simulations show that fast algorithms are available that allot credit correctly and are insensitive to measurement noise

Affordances in Psychology, Neuroscience, and Robotics: A Survey

The concept of affordances appeared in psychology during the late 60s as an alternative perspective on the visual perception of the environment. It was revolutionary in the intuition that the way living beings perceive the world is deeply influenced by the actions they are able to perform. Then, across the last 40 years, it has influenced many applied fields, e.g., design, human-computer interaction, computer vision, and robotics. In this paper, we offer a multidisciplinary perspective on the notion of affordances. We first discuss the main definitions and formalizations of the affordance theory, then we report the most significant evidence in psychology and neuroscience that support it, and finally we review the most relevant applications of this concept in robotics