My interests are in the evolution of the brain, particularly in hominids, along with the presumed coevolution of cognition (of various kinds) responsible for these changes.  My research has three main foci related to these interests.  First, I have investigated brain/behavior associations, using high resolution MRI to quantify neuroanatomical variability, and diverse neurospsychological, linguistic, and general behavioral (e.g., "sociality") tasks to quantify cognitive variability in normal humans.  In collaboration with Dr. James Gee (U. Penn) I have been applying morphometric registration algorithms originally developed in the context of functional brain imaging to quantify variability in anatomy on a voxel-by-voxel basis.  This research sits at the intersection of neuroanatomy and cognitive psychology, within an evolutionary biological framework.  Allied with this is a project attempting to determine brain activity during stone tool manufacturing using new optical imaging techniques.

Second, I have been investigating the quantitative differences in brain anatomy between humans and other primates, with the goal being to fully understand exactly what has to be explained in hominid brain evolution.  This work has involved image processing of MRI's of an array of primates and humans.  I have also done research on the scaling relationships of brain size with various components of body mass across mammals, and am interested in the extent to which phylogenetic inertia (in which the evolution of one organ system is tied together with the evolution of another system) is empirically demonstrable.  In addition to the work with MRI, Dr. Janet Monge, Dr. James Gee and I have been comparing endocast morphology of extant human and ape skulls, again using voxel-based registration methods.  As part of this, Janet and I developed the Open Research Scan Archive, which has involved obtaining high-resolution CT scans of human and primate crania and making these accessible for research worldwide.  Ultimately, the archive will include other types of scans as well (e.g., MRI of primate brains).  A number of projects have begun on images in this archive (see the website for examples).

Third, I have done work attempting to model aspects of cognitive evolution using agent-based computer simulations.  The focus here has been on the evolution of language, specifically the interplay between semantic and syntactic evolution, as well as the fossil anatomical evidence relevant to the origin and evolution of language.  The goal is to determine if language universals are the result of functional constraints, rather than evolved, innate, species-specific, dedicated brain modules (which I have argued is evolutionarily suspect).

I am also interested in the extent to which neural net computing models are a reasonable model for how the brain works: To what extent do they mimic what our own brains are really doing, and to what extent do our brains actually work in an analogous fashion?

Here are some of the things I have published relevant to these topics.  Further details of my research can be found on my Lab's website.