Following a Postdoctoral Fellowship at the University of Western Ontario's Rotman Institute of Philosophy, I am working as a Senior Policy Associate at the University of Toronto's Mowat Centre. I held a previous Postdoc at the Centre for Integrative Neuroscience and Max Planck Institute for Biological Cybernetics in Tuebingen, Germany, where I worked on body perception using behavioural experiments and Virtual Reality. I got my PhD from the University of Pittsburgh in History & Philosophy of Science. I have a MSc in Computer Science from the University of Toronto, where I worked on the effects of biased datasets in machine learning. I also have worked as an open source web developer, textile artist, and writer.
My research concerns questions in general philosophy of science including explanation, causation, discovery, and modeling, applied primarily to problems in psychology, neuroscience, and psychiatry. I have published about attention, mechanistic explanation, computational models, and classification in psychiatry.
I also engage in scientific research, primarily in body perception, medical reasoning, and machine learning, and have a growing interest in using philosophical analysis to inform scientific practice and public policy, especially in matters concerning mental health, maternal health, and privacy.
Historians emphasize how choices of model organisms are made on pragmatic grounds or due to contingent factors, while many scientists and philosophers claim that model organisms ought to be chosen based on phylogenetic relatedness. I examine a variety of examples of model organism, including plants, and argue that i) phylogenetic relatedness is a poor guide for choosing model organisms, and ii) in many cases the apparently pragmatic factors guiding model choice have an epistemic character.
Mechanistic and mathematical explanations are made out to be distinct types of explanation with rather different properties. Whether the relation between explanandum and explanans is symmetric or not is taken to be one important difference. I suggest that both types of expanation can be either symmetric or asymmetric, depending on the possible interventions we can do on the system, and the properties of the relation. It is the possibility of interventions that determines wheher the relation is causal or not. In nearly all the interesting cases of scientific explanation, mathematical and mechanistic explanation need to work together.
Scientists treat abstractions like network structures or populations as though they are important bearers of causal powers. Philosophers tend to think of abstractions like these as mere representations, which are not the sorts of things that can be causes. This project looks at the history of metaphysics to examine the reasons why we think of concrete universals as contradictions in terms, and to carve out a metaphysical option that might better express scientists' views. This is a joint project with .
Idealization in Computational Models
In a chapter about Explanation and Connectionist Models, forthcoming (2018) in The Routledge Handbook of the Computational Mind, I outline the computational modeling methods used in cognitive science, and contrast them with the simulation methods used in the physical sciences, as well as with the more detailed brain simulations sometimes used in neuroscience. I argue that connectionist models of cognition explain by instantiating idealized neural models, and demonstrating their properties.
In a paper under review, I argue that the Parallel Distributed Procesing (PDP) Research Group's approach to connectionist modeling in the 1980s to 1990s was largely misunderstood. I reinterpret both the textual evidence and the models they produced to show that realistic physiological detail was never their goal, despite some rhetoric that suggested this. Rather, although the idea hadn't yet been described and given a vocabulary in philosophy of science, what the PDP group were doing was creating idealized models, and using them as tools for discovering multi-level mechanistic explanations of cognition.
Body Perception in Psychiatry
In a paper in Synthese (online 2017), I demonstrate that treatment and research of Anorexia Nervosa (AN) largely overlook one of its three diagnostic criteria---a disturbance of body perception---despite evidence that this symptom might be central to AN etiology and treatment outcomes. I review the history of revisions to the Eating Disorders category of the Diagnostic and Statistical Manual of Mental Disorders (DSM). This history suggests that the assumption that AN is an Eating Disorder may be responsible for AN's body perception symptoms being overlooked, and perhaps also partly responsible for AN's tragically high relapse and mortality rates. I propose a change to the DSM taxonomy allowing for disorders to be listed under multiple categories.
With several , I worked on a series of experiments investigating whether the Rubber-Hand Illusion (RHI) paradigm might be useful for changing perceptions of the size of one's body. In the first study, using Virtual Reality, we induced a full body RHI on healthy participants, effectively changing their perceptions of the size of their bodies, at least in the short term. This study was published in PLOS One in 2014. Another group recently showed that this effect can be maintained for several hours in both participants with AN and healthy controls, suggesting that it might be a useful paradigm for treating the disturbance of body perception in AN.
Ehrsson, Holmes, and Passingham (2005) introduced a non-visual version of the RHI. I ran an experiment demonstrating that participants can induce a similar tactile version of the RHI on their own body, without guidance from an experimenter. We compare active (subject controlling the brush) and passive (experimenter controlling the brush) touch on objective and subjective messures of the RHI. Preliminary analysis of the results shows i) subjects can independently induce a tactile RHI on their own body, and ii) the active variant of the RHI is stronger than the passive version. These results suggest a way of developing home therapies that might help modify the disturbance of body image characteristic of Anorexia Nervosa.
Mechanistic Explanation in Neuroscience
My dissertation was about how to integrate explanations in cognitive psychology and neuroscience. I defended a non-hierarchical view of the relations between models pitched at different levels of grain and abstraction. On this account, each model might express only some of the causes at play, or part of the mechanism. Multiple models do not fit together neatly like pieces of a puzzle or mosaic, but instead partially overlap in patchy ways.
In a paper published in Synthese (2016), I argued against popular accounts of integration that suggest that psychology and neuroscience can be seamlessly integrated by taking psychological explanations to be sketches of neural mechanisms.
In a paper co-authored with , we used several historical case studies in neuroanatomy, and neurophysiology to illustrate how explanations develop from sketchy, primitive ideas to detailed mechanistic accounts. We highlighted several issues that have not received adequate attention elsewhere, including how top-down and bottom-up methods need to be combined in order to discover how structure and function relate; alternatives to the unrealistic expectation that explanations in neuroscience will all fit into a neat hierarchy of levels; and how the use of model organisms and varying experimental protocols complicates this research. This paper just came out (2017) in The Routledge Handbook of Mechanisms and Mechanical Philosophy.
In a paper for Peter Machamer's Festschrift (2017, Springer), I examine the notion of a mechanism schema. Peter has suggested that Piaget's theory of child development was his inspiration for mechanism schemata. I compare mechanism schemata to Piagetian schemata to draw out some features of mechanism schemata that have been overlooked in the new mechanist literature.
History of Anatomy and Physiology
In this paper I expand on the suggestion by a few scholars that contrary to popular opinion, Camillo Golgi did not in fact question the main tenet of the Neuron Doctrine after Santiago Ramon y Cajal's results were known. I trace the accusation that Golgi embarrassed himself at the Nobel Prize ceremony back to exactly one source: Cajal's autobiography. I examine in detail the early work of both and discover that Golgi was much more concerned with physiology and Cajal much more with anatomy. This difference in their research questions, as well as a difference in which brain systems each studied explains their real disagreement.
William Harvey is widely considered the founder of experimental physiology, although there is no clear story about why that is, and the disciplinary boundaries between anatomy and physiology did not shift until much later. In this paper I argue that although Harvey called his experiments anatomical, and claimed to follow an Aristotelian method, he unwittingly ushered in modern physiology by practicing a new kind of science. This new practice mixed investigations of causes with anatomcal investigations, and left behind the teleological speculations that used to be called physiology.
Attention and Consciousness
In my philosophy MA paper, I argued that some of the troubling homuncular thinking that once pervaded work on consciousness has been shifted onto the notion of execitve attention. I critiqued the common practice of equivocating between attention as the source or reason for more focused processing of some stimuli, and attention as that focused processing itself. This paper was shortlisted for an essay prize for junior scholars sponsored by the European Science Foundation (alongside papers by graduating PhDs and postdocs), and was published in PSYCHE in 2009, accompanied by a commentary by Andy Clark.
After several years teaching at the University of Toronto, in the Cognitive Science program, I am taking a break from teaching. I have also taught in philosophy, history and philosophy of science, computer science, and neuroscience departments.
Select Courses Taught
The following is a list of select courses I have taught with links to syllabi and course materials. A complete list can be found on my CV.
The full list of my presentations is available in my CV.