Blog

Hinting Cache Decorator Types

gist

Recently, I encountered a python function that I didn’t want to modify, but whose output I wanted cached. Providing typehints for this seemed a bit complicated, so I’m…

How to store a NIfTI as a TFRecord

gist

A recent project required sending brain images to TensorFlow. Unfortunately, the data exceeded memory and so during training would need to be read from the disk. Poking…

Spurious Serial Dependencies

research

I’m working on a project involving serial dependence. The project involves disentangling a dependence on the previous orientation from a dependence on the previous response.…

New England GAN

A friend recently moved away from Western Mass, so I wanted to send them a gift to help remind them of the area. I also happened to want to learn a bit more about Generative…

counterbalanced continuous designs with eulerian walks

experiments

Many experiments require counterbalancing sequences of trials. For example, I’m currently running an experiment on serial dependence¹. In my experiment, participants report…

thoughts on eye movement

Visual perception research has produced many illusions. Stare at a waterfall for a minute, then look away and the whole world appears in motion, traveling upwards (Addams 1834…

Half of a parameter

dissertation

Science produces models that provide parsimonious descriptions of the world. In cognitive psychology, models regularly compete to explain a few phenomena. But models can…

Staircases for Thresholds, Part 2

dissertation

In last week’s post, I discussed how some experiments in cognitive psychology require researchers to pick a differently intense stimulus for each participant. In particular…

Staircases for Thresholds

dissertation

Performing any experiment on cognition requires deciding which stimuli to use. Some experiments require participants to make many errors, requiring the stimuli to be…

Forward encoding model

Functional magnetic resonance imaging records brain activity with spatially distinct voxels, but this segmentation will be misaligned with a brain’s meaningful boundaries.…

Modulations to tuning functions can bias evidence accumulation

dissertation

Perceptual decisions can be deconstructed with evidence accumulation models. These models formalize expectations about how participants behave, when that behavior involves…

serial dependence reflects a preference for low variability

dissertation

One framework for understanding perception casts it as inference: just as a statistician uncovers noisy data to uncover patterns, an organism perceives when it converts…

derivative of gaussian for serial dependence

dissertation

Cognitive experiments can require participants to complete hundreds of trials, but completing so many trials invariably alters participants’ behavior. Their behavior late in…

an overview of population receptive field mapping

dissertation

Perceiving the world requires representing the world in neural tissue. A neuron is tuned to perceivable information when different values of that information cause the…

Serial Dependence

dissertation

Objects in the visual environment move suddenly and erratically, and visual perception must be sensitive to the changes that are important. But each saccade and head tilt…

Circular Diffusion Model of Response Times

Many cognitive experiments involve asking participants to answer questions that require circular responses (Figure 1). What was the color of the shape you just saw? In which…

eyetracking with eyelink in psychtoolbox, now with oop

experiments

I’ve started trying out MATLAB’s OOP after mounting suspicion that the way I’d been coding experiments basically involved making something that looked and behaved like an…

Basic Importance Sampling for Variance Reduction

comps

This post attempts to provide a brief intro to importance sampling, presenting a relatively simple situation in which importance sampling enables a speedup in Monte Carlo by…

Anonymizing MTurk WorkerIDs

experiments

It may be the case that Amazon Mechanical Turk WorkerIDs are not anonymous. Lease et al., 2013 describe at length how personally identifying information may be exposed when…

eyetracking with eyelink in psychtoolbox

experiments

UPDATE: I now think that the examples I’ve presented here obscure the interface with Eyelink. Much cleaner to use MATLAB’s object oriented programming. This is covered in ano…