Symbols and material signs in the debate on human origins

This chapter delves into the issues of symbolization and material signification as they have been conceived in the literature on human origins, focusing on three interrelated questions found at the crux of the debate on behavioral and cognitive “modernity:” firstly, how did material objects signify in prehistoric times? Secondly, how were material signs created at that point in time? And thirdly, how did material signs and human minds evolve and change over time? These questions about the nature, emergence, and evolution of material signification have been addressed in very different ways by two broad schools of thought. The symbolocentric paradigm, which for long was the favored approach, treats material signs in linguistic terms, attributes their creation to predefined mental templates harbored by symbolically and linguistically capable brains, and sees their evolution as an adaptive response to selective pressures. Contrastingly, a more recent approach defines material signs primarily based on their material qualities and relations, ascribes their creation to the anchoring of cognitive projections onto these physical manifestations, and approaches their evolution as an ontogenetic process driven by the prolonged engagement between humans and things. Opting for the latter way of thinking, this chapter evaluates the theoretical assumptions of the traditional approach, and sketches the materially sensitive dictates of Peircean semiotics and the Material Engagement Theory. As we suggest, the emphasis of these chronologically distant, but philosophically proximate frameworks on the ontological primacy of process and situated engagement, allows them to shed new light on the origins of mind and material semiosis.

Culture, Cognition, and Pedagogy

This chapter begins with identification of paradigmatic shifts in the discourse of cognitive psychology. A ‘person-in-context’ approach is advanced which assumes that culture is a constituent of mind and asserts that knowledge is constructed by the knower. These constructions begin as personal or idiosyncratic. As learners are social beings these constructions are socially shared. In the process, the diversity and incongruence between constructions and the pluralistic nature of knowledge are recognized. People function as a community and move towards a shared understanding. This is a significant ontogenetic process in the life of any learner. Therefore, this ontogeny needs to be reflected in the approaches to pedagogy. The chapter critically analyses current research in the field of cognition and pedagogy and highlights the future directions of research. Also, the implications of this research for the future of education are indicated.

Evidence that gastropod torsion is driven by asymmetric cell proliferation activated by TGF-β signalling

Gastropods are characterized by their asymmetric bodyplan, which develops through a unique ontogenetic process called ‘torsion’. Despite several intensive studies, the driving force of torsion remains to be determined. Although torsion was traditionally believed to be driven by contraction of the retractor muscle connecting the foot and the shell, some recent reports cast doubt on that idea. Here, we report that torsion is accompanied by left–right asymmetric cell proliferation in the mantle epithelium in the limpet Nipponacmea fuscoviridis . Furthermore, we found that pharmacological inhibition of the transforming growth factor-β (TGF-β) signalling pathway, including that of Nodal, blocked torsion. We confirmed that the blocking was brought about through failure of the activation of cell proliferation in the right-hand side of the mantle epithelium, while the retractor muscle apparently developed normally. These results suggest that limpet torsion is driven by left–right asymmetric cell proliferation in the mantle epithelium, induced by the TGF-β pathway.

Detailed Analyses of Ganzfeld Phenomena as Perceptual Events in Stimulus-Reductive Situations

Experiment 1 reexamined in detail conscious experiences in Ganzfeld situations with homogeneous light (red, green, or blue). Subjects were instructed to report everything, including phenomena attributed to the external world (colour, brightness, space) and those of the self (somatosensory experience, body movement, and emotion). The reports were richer in the red-light condition. Naïve subjects reported a larger variety of events than sophisticated subjects. In Experiment 2 pupillary responses were recorded while the subjects were exposed to a Ganzfeld at two different levels of illumination. Pupillary size for high illumination decreased with time and then recovered to the initial level, while for low illumination it remained constant. Subjective brightness correlated with pupillary size. Experiment 3 revealed a temporal pattern of spatial events. The findings obtained are discussed in relation to the ontogenetic process of visual space perception and emotion.

Regression equations between body and head measurements in the broad-snouted caiman (Caiman latirostris)

In the present study, regression equations between body and head length measurements for the broad-snouted caiman (Caiman latirostris) are presented. Age and sex are discussed as sources of variation for allometric models. Four body-length, fourteen head-length, and ten ratio variables were taken from wild and captive animals. With the exception of body mass, log-transformation did not improve the regression equations. Besides helping to estimate body-size from head dimensions, the regression equations stressed skull shape changes during the ontogenetic process. All age-dependent variables are also size-dependent (and consequently dependent on growth rate), which is possibly related to the difficulty in predicting age of crocodilians based on single variable growth curves. Sexual dimorphism was detected in the allometric growth of cranium but not in the mandible, which may be evolutionarily related to the visual recognition of gender when individuals exhibit only the top of their heads above the surface of the water, a usual crocodilian behavior.

The inheritance and innateness of grammars. Myrna Gopnik (Ed.). New York: Oxford University Press, 1997. Pp. 232.

What could possibly be innate? John Morton asked this question in a symposium on psycholinguistics in 1969 (Morton, 1970), and, as this book makes clear, he was certainly not the last to ask it. The Inheritance and Innateness of Grammars is one of the most recent manifestations of our fascination with the question of just what it is that makes it possible for humans – and only humans – to learn language as we know it. The book is the product of a conference that was held at Simon Fraser University in Vancouver in 1993. Nine chapters present work by authors whose expertise includes such topics as speech perception, neurobiology, sign language, language impairment, and, of course, developmental psycholinguistics. Although the word “inheritance” in the title can be understood to refer to genetics, it would have been helpful if the authors had provided their definitions of the term “innateness.” In its primary sense, innate means inborn or present at birth, but clearly no one is arguing that language itself is present at birth, although most would agree that some capacities that may underlie language can be demonstrated in very young infants. Eric Lenneberg provided one definition of innateness in his book, Biological Foundations of Language (1967), which may be what some authors have in mind since his work is frequently referenced: Animals may be thought of as functioning like machines. Their inner structure is not the result of accidental circumstances. The machine unfolds during development, and the internal structure is programmed onto the ontogenetic process. Let us call the internal structure innate mechanisms and the modes of operation that are determined by these mechanisms innate behavior. (p. 220)