Search

We summarize some key features of our comparative and developmental programme at Edinburgh with particular reference to serial ordering and executive control as a window on the growth of cognitive competences in both evolution and development. Based on research on relational rather than associative learning mechanisms, we first argue that nonhuman primates share some core conceptual representations supporting semantic and rational development in humans. Reviewing recent findings from comparative work on seriation and classification, we also show that non-human primates can use ordering mechanisms similar to those that emerge during human development. From theses analyses, we argue that key features of thought and language have strong evolutionary precursors.

We describe experimental techniques based on serial ordering tasks using touch screens, designed to assess memory and high level cognitive organization in human and nonhuman subjects. We demonstrate the applicability of these techniques to a wide range of cognitive competence and executive functioning, illustrating some promising new applications in areas of cognitive dysfunction in humans, specifically Fragile X syndrome and Autistic Spectrum Disorder in children, and Alzheimer’s disease and bipolar disorder in adults. We conclude that these techniques have implications both for work in areas of cognitive remediation, as well as in the promotion of animal models of human cognitive function and executive control.

Nine youngchildren and five tufted capuchin monkeys {Cebus apella) were tested on tasks involving a search for an object hidden within a set of plastic cups. As viewed, the sequences of displacements enabled subjects to eliminate some of the possible locations where the object lay hidden, thereby constraining the search space. Both species deployed principled modes of search, in contrast to a random selection strategy. However, no subject from either group proved able to fully constrain the search on the basis of all of the information conveyed over the full menu of tasks. The reasons for incomplete success are as yet unclear, however failures may be due as much to social limitations as to other forms of error. On that basis we conclude that new paradigms are necessary, designed specifically to evaluate competencies for socially based knowledge on the one hand and self-directed search on the other.

Reports experiments on the symbolic distance effect and related phenomena with six- and nine-year-old children. The effect was obtained for lexical and pictorial input; pictures produced faster responses than words; congruity effects occurred in the pictorial condition. Asymmetry in subjects' capacity to verify statements of relation was found, with older subjects overcoming the asymmetry. (Author/RH)

The 'rational bubble' stance espoused in the target article confounds cultural symbolic achievements with individual cognitive competences. With no explicit role for learning, the core rationale for claiming a major functional discontinuity between humans and other species rests on a hybrid formal model LISA (Learning and Inference with Schemas and Analogies) now overtaken by new models of cognitive growth and new empirical studies within an embodied systems stance.

We argue that Halford et al.'s characterisation of relational complexity offers an unadaptive principle in terms of cognitive economy, that its relation with the empirical evidence is highly selective, and that the task behaviours used in support of a multivector processing space are better described by linear serial processes which do not require n-dimensional mappings for their emergence.