Research

My current work investigates how humans use frames of reference, how minds plan and learn to plan, behavior programming, dualities of learning and meta/transfer/curriculum learning, and analytic tools for studying minds and models of minds.


Human Parallel Use of Spatial Reference Frames

An academic research experiment series investigating whether humans learn to navigate better with a curriculum in a way that is similar to neural networks. This experiment tested individuals' ability to learn to navigate a maze in a browser. The broader series of experiments investigates the fitness of neural network models of cognition to actual human cognition.

Pathfinder

Frames of Reference for Neural Pathfinding Navigation , 2017, Senior Thesis project with non-authors A. Lampinen and J. McClelland. Full abstract: Two cognitive visuospatial methods for representing object locations are Egocentric refer- ence frames, which place objects relative to a special central entity, and Allocentric reference frames, which place objects on a stationary world. Humans have been shown to selectively use each reference frame, but it is unclear why humans use certain frames in certain situations. This work examines Deep-Q Reinforcement Learning Artificial Neural Networks that solve path-finding navigational puzzles using the two reference frames as models of human neural populations attempting the same puzzles. We provide a computational explanation for why humans generally use egocentric frames for navigational challenges, which is centered around cognitive skill transfer learning. Our results support the plausibility of connectionist cognitive planning as well as indicate the advantages that curriculum learning provides for teaching neural networks to plan effectively.

Upper Left: Sokoban, the primary task challenge. Upper Right: A diagram from part of state space analysis that enables skill reuse in some egocentric frames. Lower Left: A-not-B, a task that exemplifies the human infant cognitive finding that we model.


Modular Internal Attention Network

First Implementation (02/17) and Second Proposal Paper (04/17). Using only tensor operations common to deep learning, a second-order model is proposed that uses a distributed attention over its internal components. By giving the network the ability to selectively use its own resources, the network can reduce catastropic intereference once trained. Aspects of this project are continuing. See this CMU paper for a similar concept.

A diagram of the core structure of the Modular Internal Attention Network.


Multiple Recurrent Attention Network

Inspired by Recurrent Models of Visual Attention, we developed a visual attention model that could process visual input in a way that was biologically-realistically parallel. This project explored 'glimpses', virtual saccades, as internal attentional mechanisms.
Due to a fascinating but unfortunately project-halting bug in provided code, we discovered that neural networks with two weighted outputs that only receive backpropagation signals from one output have the ability to learn internal representations that make effective layerwise random fixed projections of the second output. To our knowledge, this result is absent in literature and is a route for further exploration.

An example of an MRAM model with two attendants and six glimpses learning an MNIST digit.


Normalized Gradient Descent (todo)

See also my other projects, often on related topics.


rho thoughts


[7.13.2021: this section is outdated.]