Jim Davies

As a belief source, testimony has long been held by theorists of the mind to play a deeply important role in human cognition. It is unclear, however, just why testimony has been afforded such cognitive importance. We distinguish three suggestions on the matter: the number claim, which takes testimony’s cognitive importance to be a function of the number of beliefs it typically yields, relative to other belief sources; the reliability claim, which ties the importance of testimony to its relative truth-conduciveness; and the scope claim, according to which testimony’s importance is a function of its relative representational power, non-numerically conceived. After laying out these three suggestions, we go on to argue that there is little hope of grounding testimony’s cognitive importance in either the number claim or the reliability claim. We conclude with a tentative exploration of the basis and plausibility of the scope claim.

Population-level biomedical research has become crucial to the health system’s ability to improve the health of the population. This form of research raises a number of well-documented ethical concerns, perhaps the most significant of which is the inability of the researcher to obtain fully informed specific consent from participants. Two proposed technical solutions to this problem of consent in large-scale biomedical research that have become increasingly popular are meta-consent and dynamic consent. We critically examine the ethical and practical credentials of these proposals and find them lacking. We suggest that the consent problem is not solved by adopting a technology driven approach grounded in a notion of ‘specific’ consent but by taking seriously the role of research governance in combination with broader conceptions of consent. In our view, these approaches misconstrue the rightful location of authority in the way in which population-level biomedical research activities are structured and organized. We conclude by showing how and why the authority for determining the nature and shape of choice making about participation ought not to lie with individual participants, but rather with the researchers and the research governance process, and that this necessarily leads to the endorsement of a fully articulated broad consent approach.

Many mental phenomena involve thinking about people who do not exist. Imagined characters appear in planning, dreams, fantasizing, imaginary companions, bereavement hallucinations, auditory verbal hallucinations, and as characters created in fictional narratives by authors. Sometimes these imagined persons are felt to be completely under our control, as when one fantasizes about having a great time at a party. Other times, characters feel as though they are outside of our conscious control. Dream characters, for example, are experienced by dreamers as autonomous entities, and often do things that frighten and surprise dreamers. Some imagined persons, such as characters in fiction, start off under conscious control of the author, but over time, can appear to gain an illusion of independent agency. I propose an explanation for different autonomy attributions: characters are by default non-autonomous, unless their personalities are well-practiced. Characters become autonomous because modeling their thinking has become automatized, like many other well-practiced activities.

An incoherent visualization is when aspects of different senses of a word are present in the same visualization. We describe and implement a new model of creating contextual coherence in the visual imagination called Coherencer, based on the SOILIE model of imagination. We show that Coherencer is able to generate scene descriptions that are more coherent than SOILIE's original approach as well as a parallel connectionist algorithm that is considered competitive in the literature on general coherence. We also show that co-occurrence probabilities are a better association representation than holographic vectors and that better models of coherence improve the resulting output independent of the association type that is used. Theoretically, we show that Coherencer is consistent with other models of cognitive generation. In particular, Coherencer is a similar, but more cognitively plausible model than the C3 model of concept combination created by Costello and Keane. We show that Coherencer is also consistent with both the modal schematic indices of perceptual symbol systems theory and the amodal contextual constraints of Thagard's theory of coherence. Finally, we describe how Coherencer is consistent with contemporary research on the hippocampus, and we show evidence that the process of making a visualization coherent is serial.

Visual analogy is believed to be important in human problem solving. Yet, there are few computational models of visual analogy. In this paper, we present a preliminary computational model of visual analogy in problem solving. The model is instantiated in a computer program, called Galatea, which uses a language for representing and transferring visual information called Privlan. We describe how the computational model can account for a small slice of a cognitive-historical analysis of Maxwell’s reasoning about electromagnetism.