The excellent and highly interesting commentaries address the following concerns: (1) neuroanatomy and neurophysiology of catatonia; (2) cognitive-motor deficits in catatonia; (3) conceptual issues; (4) general methodology in neuropsychiatric research; and (5) neurophilosophical implications. The specific problems, issues, and aspects raised by the different commentators are grouped under these categories in Table R1 presented below. These five areas of concern are then discussed in the order listed in the five sections of the Response.

Empathy is the phenomenal experience of mirroring ourselves into others. It can be explained in terms of simulations of actions, sensations, and emotions which constitute a shared manifold for intersubjectivity. Simulation, in turn, can be sustained at the subpersonal level by a series of neural mirror matching systems.

Spatial objects may not only be perceived visually but also by touch. We report recent experiments investigating to what extent prior object knowledge acquired in either the haptic or visual sensory modality transfers to a subsequent visual learning task. Results indicate that even mental object representations learnt in one sensory modality may attain a multi-modal quality. These findings seem incompatible with picture-based reasoning schemas but leave open the possibility of modality-specific reasoning mechanisms.

Perruchet & Vinter's article, for all its breadth and scope, has several deep problems: specifically, an eccentric notion of rule, a narrow notion of what it means for a mental instantiation to be abstract, and a failure to take into account fundamental principles of evolutionary biology. While not the only problems, these three are sufficient to seriously weaken their arguments.

We argue that cognitive empathy and other instances of mental state attribution are a byproduct of self-awareness. Evidence is brought to bear on this proposition from comparative psychology, early child development, neuropsychology, and abnormal behavior.

An ethological analysis suggests that effort and protection actions, which are expressions of distress, are comparable with pain expressions. Distress occurs with uncontrollable pain, and the expressions are ritualized pain responses with exaggerated features and lower thresholds. Pain is a sensory-motor feeling state with aversive motivational (hedonic) value. Distress is an emotional state of failure of pain responses to control the pain.

I will argue (contra Carruthers) that accepting natural language as the format of many of our thoughts should entail accepting a version of Whorfian relativism and that, rather than something to be avoided, evidence from bilingual cognition suggests that incorporating this idea into future research would yield further insights into the cognitive functions of natural language.

In recent years we have seen a dramatic shift, in several different areas of communication studies, from an information-theoretic to a dynamic systems paradigm. In an information processing system, communication, whether between cells, mammals, apes, or humans, is said to occur when one organism encodes information into a signal that is transmitted to another organism that decodes the signal. In a dynamic system, all of the elements are continuously interacting with and changing in respect to one another, and an aggregate pattern emerges from this mutual co-action. Whereas the information-processing paradigm looks at communication as a linear, binary sequence of events, the dynamic systems paradigm looks at the relation between behaviors and how the whole configuration changes over time.

One of the most dramatic examples of the significance of shifting from an information processing to a dynamic systems paradigm can be found in the debate over the interpretation of recent advances in ape language research (ALR). To some extent, many of the early ALR studies reinforced the stereotype that animal communication is functional and stimulus bound, precisely because they were based on an information-processing paradigm that promoted a static model of communicative development. But Savage-Rumbaugh's recent results with bonobos has introduced an entirely new dimension into this debate. Shifting the terms of the discussion from an information-processing to a dynamic systems paradigm not only highlights the striking differences between Savage-Rumbaugh's research and earlier ALR studies, but further, it sheds illuminating light on the factors that underpin the development of communication skills in great apes and humans, and the relationship between communicative development and the development of language.

This paper points to the need in ape language research to shift from experimentation to ethnography. We cannot determine what goes on inside the head of an ape when it communicates with a human being, but we can learn about the nature and content of the communication that occurs in such face-to-face interaction. This information is fundamental for establishing a baseline for the abilities of an ape-human common ancestor.

Cognitive mechanisms are based in organisms’biology, and results from biological studies suggest that there is unlikely to be a single mechanism for reorienting or for combining information across modules or domains. Rather, there are likely to be multiple, partly overlapping systems for accomplishing nearly all cognitive and behavioral goals, as is the case for biological mechanisms more generally.

The wealth of important and convergent evidence discussed in the target article contrasts with the poorly conceived theory put forward to explain it. The simulation theory does a better job of explaining how automatic “mirroring” mechanisms might work together with high-level cognitive processes. It also explains what the authors' PAM theory merely stipulates.

Evolutionary explanations of pain expression require modeling social adaptations in a context where the role of health professionals as potential caregivers, conflicts with their status as relative strangers. As signals of help elicitation or of alarm, facial pain displays and responses to displays, particularly in the upper face, are expected to conform to this evolutionarily novel clinical context.

This commentary focuses on four major points: (1) “Tacit knowledge” is not a complete explanation for imagery phenomena, if it is an explanation at all. (2) Similarities and dissimilarities between imagery and perception are entirely consistent with the depictive view. (3) Knowledge about the brain is crucial for settling the debate. (4) It is not clear what sort of theory Pylyshyn advocates.

Perruchet & Vinter's provocative article challenges a series of interesting issues, yet the concept of isomorphism is troublesome for a series of reasons: (1) isomorphism entails some sort of dualism; (2) isomorphism does not entail that a piece of the world is a representation; and (3) it is extremely difficult to provide an explanation about the nature of the relation of isomorphism.

Postulating a variety of mutually isolated thought domains for prelinguistic creatures is both unparsimonious and implausible, requiring unexplained parallel evolution of each separate module. Furthermore, the proposal that domain-general concepts are not accessible without prior exposure to phonetically realized human language utterances cannot be implemented by any concept-acquisition mechanism.

Using a particular formula for quantifying the effortlessness that Perruchet & Vinter suggest accompanies the detection of repetition among a set of representations concurrently in consciousness, it is shown that both the Sternberg function and the Cavanagh function, associated with immediate probed recognition tasks and memory span tasks, can be predicted.

Various techniques have attempted to localize imagery. However, early findings using single cell recordings of human receptive fields during imagery tasks have had little impact. Reports by Marg and his coworkers (1968) found no evidence for imagery in human Area 17, 18, and 19. Single cells from humans suggest later imagery-related activity in hippocampus, amygdala, entorhinal cortex, and parahippocampal gyrus.

Shanker & King argue for a shift in the focus of ape language research from an emphasis on information processing to a dynamic systems approach. We differ from these authors in our understanding of how this “new paradigm” emerged and in our perceptions of its limitations. We see information processing and dynamic systems as complementary approaches in the study of communication.

As a product of natural selection, pain behavior must serve an adaptive function for the species beyond the accurate portrayal of the pain experience. Pain behavior does not simply refer to the pain experience, but promotes survival of the species in various and complex ways. This means that there is no purely respondent or operant pain behavior found in nature.

Attempts to integrate diverse phenomena in terms of common processes are much needed in psychology, but definitional precision is a necessary preliminary to explanation. It is also preferable to use caution in juxtaposing concepts from different realms of discourse.