The Cambrian Explosion and the Origins of Embodied Cognition

Around 540 million years ago there was a sudden, dramatic adaptive radiation known as the Cambrian Explosion. This event marked the origin of almost all of the phyla (major lineages characterized by fundamental body plans) of animals that would ever live on earth, as well the appearance of many notable features such as rigid skeletons and other hard parts, complex jointed appendages, eyes, and brains. This radical evolutionary event has been a major puzzle for evolutionary biologists since Darwin, and while our understanding of it has recently improved with new fossil finds, richer molecular phylogenies, and better grasp of ecological, evolutionary, and developmental processes generally, unanswered questions remain. In this paper I argue that a basic cognitive toolkit for embodied, object-oriented, spatial cognition (what I call Basic Cognitive Embodiment) is a practical necessity for control of a large, mobile, complexly articulated body in space. This hypothesis allows us to relate the complexification of animal bodies to the complexification of perception, cognition and behavior in a way that can help to fill in gaps in our emerging picture of the Cambrian Explosion, as well as shed light on the deep evolutionary origins of the mind

Goal-Directedness, Behavior and Evolution: A Philosophical Investigation

My dissertation explores the conceptual foundations of the behavioral perspective in biology--that is, what it really means to understand a system (such as an animal) as behaving. Behavior is a somewhat fuzzily defined aspect of living systems that is nevertheless of central importance to a variety of approaches in biology. Behavior has to do with what organisms (and perhaps other biological entities) do, rather than what they are (i.e. behavior is different that anatomy or physiology). It is most obviously a category applied to large, mobile animals like the familiar vertebrates (mammals, birds, reptiles, fish, amphibians) and some invertebrates (insects, arachnids, crustaceans, gastropods and cephalopod mollusks). These are the traditional subjects of behavioral biology. However, in the last few decades, a behavioral approach has been applied to plants, single-celled organisms, and groups of animals such as eusocial insect colonies. Moreover, research projects in behavioral robotics and artificial life apply a behavioral perspective to non-living systems. What does it mean to conceive of a system as behaving? What must a system be like to allow this way of thinking to be fruitful for research? My main contribution to solving this puzzle is the development of a dynamical understanding of goal-directedness . My view of goal-directedness is dynamical in that I understand that notion purely in terms of the causal relations within a system and between the system and its environment, rather than in terms of primitively intentional notions, or in terms of evolutionary history. Previous attempts at developing a dynamical understanding of goal-directedness have foundered, but I present a robust solution to the problems that hindered them. I also demonstrate how the dynamical understanding of goal-directedness functions conceptually in contemporary biological research on animal behavior, and how it is crucial for understanding the 'major transitions in evolution', events in which the evolutionary process itself is reorganized, and new levels of structure emerge in the living world

Cognitive function and biological correlates of cognitive performance in schizotypal personality disorder

There is evidence that some schizophrenic patients have deficits on tests of cognitive function, particularly tests of executive function, including the Wisconsin Card Sorting Test (WCST) and the Trail-making Test, Part B. This study was conducted to determine the generalizability of these findings across the schizophrenia spectrum to schizotypal personality disorder (SPD). Forty DSM-III SPD patients, 56 nonschizophrenia-related other personality disorder (OPD) patients, and 32 normal volunteers from two medical centers performed tests of executive function such as the WCST, Trail-making Part B, Stroop Word-Color Test, and Verbal Fluency, as well as tests of more general intellectual functioning such as the Wechsler Intelligence Scale-Revised Vocabulary and Block Design subtests, and Trail-making Part A. SPD patients performed more poorly on the WCST and on Trail-making Part B than did OPD patients or normal subjects; the groups did not differ on tests of general intellectual functioning. SPD patients may share some of the cognitive deficits observed in schizophrenia