I'm interested in a number of different topics within computational and cognitive neuroscience. Firstly, I'm intrigued by human memory, especially in the visual and auditory domains. Once we understand exactly how memories are encoded, stored, and recalled, I'm interested to know if we could then augment these processes. You could imagine a world where we are able to "back up" our memories to the cloud, and even share our memories with others.
It also fascinates me how we process and perceive visual and auditory information concurrently. Often, we use information received in the auditory domain to help us process a visual cue, and vice versa. Although this sometimes leads to negative biases, I wonder if it can be utilized in a way that enhances information uptake — perhaps for use in a learning environment. Additionally, I'm interested in using imaging techniques such as fMRI and MEG to combine my experience with crossmodal correspondences with memory research. The advent of machine learning and computer vision also presents many interesting opportunities to combine with neuroscientific data which I'm eager to explore.
Although I've switched fields, I've kept my love for Astrophysics! I enjoy reading the latest news, and hope someday I'll have the opportunity to research supernovae once more.
Neural Correlates of Crossmodal Correspondence Between Pitch and Visual Motion
Supervisor: Prof Joydeep Bhattacharya FRSA
Our senses are not independent entities — instead, they work together to build our realities. When one sense influences another, we call this phenomenon crossmodal correspondence. I studied a particular crossmodal correspondence in which an ascending/descending pitch as well as the spoken words "up"/"down" (auditory domain) were able to bias perception of visual motion (visual domain).
I designed and conducted an EEG experiment in which the participant judged the direction of motion of an ambiguous (same upwards and downwards components) moving grating whilst listening to the auditory stimuli. Using behavioural and ERP analysis, I showed that auditory stimuli were enough to bias people's perception of visual motion — an ascending tone caused more people to perceive upwards motion. This was the first time that this effect was studied using brain imaging techniques.
You can read my MSc thesis here or take a look at my poster for the behavioural data here.
Anvil Hack 2018:
While at Goldsmiths, I participated in a number of different hackathons including Anvil Hack. During this event, I worked in a team of 3 to make a platform that allows you to convert text into a form that was much more quickly readable. We were inspired by this advert by Honda. Perhaps in the future, devices that use this technology might be commonplace.
Realistic MHD Modeling of Wind-Driven Processes in Cataclysmic Variable-Like Binaries
Supervisors: Dr Cecilia Garraffo and Dr Jeremy Drake
When main sequence stars such as our Sun orbit a star known as a white dwarf, they can form something called a cataclysmic variable-like binary. The charged ions contained within the magnetic fields of these stars creates a complex wind structure as the two bodies orbit each other. When this wind structure decouples from the system it carries away mass and angular momentum, which impacts how the stars spin and how their orbits evolve. Using 3-D magnetohydrodynamic simulations, I explored the effects of orbital separation and magnetic field configuration on these mass and angular momentum loss rates for binary systems.
The current models don't include the magnetic fields of the stars. It was hypothesized that including the magnetic field of the white dwarf in the binary system could alter these rates. I found that when including these magnetic fields, the mass and angular momentum loss rates dropped by factors of 4 and 6 respectively, suggesting that the current models for these systems should be amended to include the magnetic field.
You can read my MPhys thesis here or watch a 20-min video of my thesis defense given at the Harvard-Smithsonian Center for Astrophysics High Energy Seminar here.
Hack @ Brown 2017:
Saguaro: An open source, extensible home automation platform
I attended a hackathon at Brown University where I worked within a team of 5 to design and build an IOT platform called Saguaro. Saguaro allows hardware devices to be controlled by a simple web interface.
Activating hardware in your home — lights, windows, anything you can run a wire to — is as simple as pushing a button. Additionally, Saguaro learns your schedule, and over time will be able to anticipate your actions and automate your home for you.
You can learn more about this project here.
Bottom image credit: Lynette Cook / extrasolar.spaceart.org
Computing Project #1:
Planetary Orbits Around Binary Star Systems
Incredibly, almost half of the star systems that we see in the sky contain multiple stars! This project aimed to simulate planetary orbits around a binary star system. This is important to study because such simulations could be used to detect habitable planets outside our solar system (exoplanets). For life to exist, the planet on which it occurs must keep a stable orbit over long time-scales.
To find stable orbits, I used a Runge-Kutta approach to solve the differential equations involved in such a 3-body system and tested various initial velocities and separations. I found many different p- and s-type orbits (the two species of stable planetary orbit), as well as some chaotic orbits, and discovered whether they possessed a habitable zone where the planet could sustain life.
You can read my report on this project here.
Computing Project #2:
The Structure of White Dwarf Stars
White dwarf (WD) stars are extremely dense objects — the only thing preventing them from collapsing into a black hole is a force called electron degeneracy pressure, which has to do with the fact that electrons cannot be close enough to occupy the same energy state. They are very important within astronomy and appear in many areas of study, including galaxy formation, stellar evolution, and supernovae. Since over 95% of the stars we observe will end their lives as WDs, knowing how they function and how their parameters behave is crucial.
In this project, I created a model for determining the mass-radius variation in WDs, and ultimately found the critical mass of a WD (Chandrasekhar limit), beyond which the electron degeneracy pressure can no longer support the star and it must collapse into a neutron star or a black hole.
You can read more about this project here.
BAE Systems Project:
Submarine Drag Reduction Study
Before I started university I spent a summer internship at BAE Systems Maritime completing a project focusing on how to reduce physical drag on the new class of nuclear submarines.
I investigated how changes to the bow, control surfaces, fins, and body of the submarine would affect the hydrodynamics of the submarine. I also investigated if it would be possible to inject polymers or micro-bubbles to change the way the water flowed over the submarine's surface. Finally, I looked into more radical solutions such as supercavitation — a technology used in some underwater missiles that involves boiling the water in front of the supercavitating body to reduce friction drag.
You can read the original report for this project here.
Copyright © 2018 Alex Lascelles.