With regard to social-cognitive deficits in autism and psychosis, Crespi & Badcock's (C&B's) theory does not incorporate the developmental context of the disorders. We propose that there is significant overlap in social-cognitive impairments, but that the exact manifestation of social-cognitive deficits is highly dependent on the dynamics of cognitive development and hence different in autism as compared to psychosis.

Crespi & Badcock (C&B) have presented a novel view that the influence of genomic imprinting causes diametrically opposite disorders: namely, psychoses and autism. I propose an extended hypothesis that while genomic imprinting is likely to have an influence on the pathogenesis of psychoses and autism, it might contribute to phenomenological antithesis between as well as within these disorders.

Crespi & Badcock (C&B) hypothesize that psychosis and autism represent opposite poles of human social cognition. I briefly outline how computational models of cognitive brain function may be used as a resource to further develop and experimentally test hypotheses concerning “autism-psychosis spectrum disorders.”1

Augmenting and supplementing the arguments of Crespi & Badcock (C&B), I show that digit ratio (2D:4D), a putative marker of prenatal androgen action, indeed appears differentially altered in autism-spectrum disorders (lower/masculinized) versus schizophrenic-spectrum disorders (higher/feminized). Consistent with C&B's framework, some evidence (substantial heritability, assortative mating, sex-specific familial transmission) points to possible sex chromosome and imprinted genes effects on 2D:4D expression.

The commentaries on our target article, “Psychosis and Autism as Diametrical Disorders of the Social Brain,” reflect the multidisciplinary yet highly fragmented state of current studies of human social cognition. Progress in our understanding of the human social brain must come from studies that integrate across diverse analytic levels, using conceptual frameworks grounded in evolutionary biology.

Neuroconstructivism: How the Brain Constructs Cognition proposes a unifying framework for the study of cognitive development that brings together (1) constructivism (which views development as the progressive elaboration of increasingly complex structures), (2) cognitive neuroscience (which aims to understand the neural mechanisms underlying behavior), and (3) computational modeling (which proposes formal and explicit specifications of information processing). The guiding principle of our approach is context dependence, within and (in contrast to Marr [1982]) between levels of organization. We propose that three mechanisms guide the emergence of representations: competition, cooperation, and chronotopy; which themselves allow for two central processes: proactivity and progressive specialization. We suggest that the main outcome of development is partial representations, distributed across distinct functional circuits. This framework is derived by examining development at the level of single neurons, brain systems, and whole organisms. We use the terms encellment, embrainment, and embodiment to describe the higher-level contextual influences that act at each of these levels of organization. To illustrate these mechanisms in operation we provide case studies in early visual perception, infant habituation, phonological development, and object representations in infancy. Three further case studies are concerned with interactions between levels of explanation: social development, atypical development and within that, developmental dyslexia. We conclude that cognitive development arises from a dynamic, contextual change in embodied neural structures leading to partial representations across multiple brain regions and timescales, in response to proactively specified physical and social environment.

I offer a simple method for further investigating the Interactive Specialization framework, and some data that may or may not be compatible with the approach, depending on the precise meaning of “specialization.” Findings from my lab indicate that, while networks of brain areas cooperate in specialized ways to support cognitive functions, individual brain areas participate in many such networks, in different cognitive domains.

An attractive feature of Neuroconstructivism, Vol. I: How the Brain Constructs Cognition is its emphasis on the active role of the individual in neural and behavioural development and the importance of the interplay with the environment. Certain aspects of development are omitted, however, such as specializations for the distinctive ecologies of infancy and childhood and the scaffolding-like features of behaviour seen during development. It was also a pity that so little credit was given to many scientists who have contributed to just those aspects of development on which the authors focus.

Mareschal and his colleagues argue that cognition consists of partial representations emerging from organismic constraints placed on information processing through development. However, any notion of constraints must consider multiple sensory modalities, and their gradual integration across development. Multisensory integration constitutes one important way in which developmental constraints may lead to enriched representations that serve more than immediate behavioural goals.

From our deep interest in the neuroconstructivist framework, we would like to comment on two fundamental aspects of Mareschal et al.'s work: the role of neuroconstructivism for clinical work with people suffering from developmental disorders; and the relation between the process of progressive specialization and the increasing abstraction of representations in development.

Neuroconstructivism, Vol. 1: How the Brain Constructs Cognition implies that brain functioning depends on biofeedback and ecological trajectories. Using the building blocks of Boolean algebra known as logic gates and models of distributed control systems, I suggest that levels of regulatory states are responsible for optimal, pathological, and developmental processes. I include the impact of regulatory and nonregulatory functions on structural development.

The authors of this commentary concur with the viewpoint presented by Mareschal et al. (2007a; 2007b) concerning the relevance of neurological data when theorizing about cognitive development. However, we argue here that Mareschal et al. fail to consider adequately the relevance of reorganizational brain events occurring through adolescence and early adulthood, especially regarding the prefrontal cortex and the ontogeny of executive functioning. In addition, evidence from the lifespan neurodevelopmental literature indicates that increased activity of neural networks may signify less efficient processing. This observation is of potential relevance when considering the neurological changes associated with cognitive development during childhood and adolescence.

This book is an excellent manifesto for future work in child development. It presents a multidisciplinary approach that clearly demonstrates the value of integrating modeling, neuroscience, and behavior to explore the mechanisms underlying development and to show how internal context-dependent representations arise and are modified during development. Its only major flaw is to have given short shrift to the study of the role of genetics on development.

Neurocostructivism aims to illustrate and explain cognitive development in relation to the underlying neural structures, with the help of computational models. This enterprise should be grounded both in the evolutionary and in the developmental perspectives. In both, selection plays a fundamental role in the construction of neural and cognitive structures.

Neuroconstructivism is a hybrid of two incompatible philosophical traditions: a radical idealism insisting upon the free activity of the Subject; and a radical materialistic anthropomorphism, which ascribes inherent properties of humans (e.g., the ability to construct) to nonhuman objects or body parts (e.g., the brain). The two traditions can be combined only by obscuring or confusing the basic notions.

Neuroconstructivism (Mareschal et al. 2007a) provides a useful framework for how to integrate research from different levels of analysis to model the multidimensional dynamics of development. However, the authors overlook the topic of meaning, a fundamental feature of cognition and subjective experience and also downplay the nonlinear nature of developmental causality. Neuroconstructivism is overly optimistic on the point of how well current computational models can address the challenge of complexity in developmental science.

Neuroconstructivism (Mareschal et al. 2007a) heralds a departure from the standard “associationism” that has dominated the English speaking cognitive and neuroscience community for generations. Its central concept is context dependency: encellment, embrainment, embodiment and ensocioment. This reviewer welcomes the breath of fresh air in overcoming the “deconstructions” of postmodernism. The program is carried out with a carefully selected sample of empirical evidence with an emphasis on development. This review points to some of the books' strengths and shortcomings, and adds a few observations that carry the program further.

Neuroconstructivist modeling can be usefully extended with algorithms that build their own topology and recruit existing knowledge, effectively constructing a hierarchy of network modules. Possible benefits include allowing abilities to emerge naturally, in a way that affords objective study, deeper insights, and more rapid progress, and provides more serious consideration of the implications of constructivism.

In this response, we consider four main issues arising from the commentaries to the target article. These include further details of the theory of interactive specialization, the relationship between neuroconstructivism and selectionism, the implications of neuroconstructivism for the notion of representation, and the role of genetics in theories of development. We conclude by stressing the importance of multidisciplinary approaches in the future study of cognitive development and by identifying the directions in which neuroconstructivism can expand in the Twenty-first Century.