1 Flashcards
What does the HGF do?
Allows the computation of multiple, hierarchically related, precision-weighted PEs when fitted to neurophysiological and behavioural time series.
What does the HGF allow you to achieve?
To investigate with high temporal resolution the neural representation of two crucial quantities: lower-level PEs that update beliefs about stimulus probabilities, and higher-level PEs that update estimates about environmental volatility.
What are you investigating?
The computational underpinning behind the ways in which healthy individuals create and sustain cognitive biases that affect well-being and interpersonal relations.
how will you show this?
For the first time, I propose certain factors (such as intrinsic motivation, emotions or ritualised beliefs) distort the mechanism that assesses the reliability of our prior beliefs, expectations, and incoming sensory evidence. And that this in turn creates self-fuelling biases that affect learning and belief formation by selectively sampling information in ways that support prior belief, and work against the formation of a veridical perception.
what’s predictive processsing?
By this account, we are continually in the process of predicting and explaining away sensory information in relation to our prior expectations whilst assessing the reliability of both sources.
The difference between prediction and sensory information generates a prediction-error signal that is passed up the cortical hierarchy to update beliefs about the expected causes of events - the impact of which is multiplied based on the calculated reliability of the information. Thus, high precision or reliable information has a greater impact on belief, whilst low precision has lessser impact as the information is more unreliable
what is your methodological approach?
I propose a novel methodological approach recording electrophysiological (EEG) responses whilst participants conduct cognitive tasks involving attention and learning under probabilistic uncertainty, subsequently analysing the data using the Hierarchical Gaussian Filter (HGF) computational model.
what is your research question?
Do factors such as intrinsic motivation, anxiety and ritualistic beliefs bias computations of uncertainty and adjust attention and learning processes?
What’s your hypothesis?
The overall hypothesis is that these factors will place greater or lesser precision on prior expectation and sensory input (dependant on the factor – think anxiety reversal) that bias perception and learning. This in turn allows more specific predictions (in every experiment) centred around the Bayes-optimal learning rates developing over the time-course of experiments, about PEs being attenuated (altered in size) and developing over time and as they propagate throughout the brain, and specific predictions about the location of PE neural correlates (being in frontal, occipital, and parietal regions and characterised by gamma oscillations).
what is the impact of your project?
Understanding the mechanisms underlying cognitive biases in healthy individuals that can impact well-being.
Demonstrating the limitations of Bayes-optimal theories to advance our theoretical understanding, but also to further research in clinical cases such as OCD, SCHIZO, DEPRESSION and ANXIETY disorders.
Important to understand how the predictive computations of the brain are calibrated and adjusted in the healthy brain.
Linking anxiety to evolutionary concerns for reducing uncertainty
What are the applications?
Advancing theoretical understanding of both healthy and clinical cases by demonstrating the limitations of Bayes-optimal processing accounts.
Generating research able to devise therapeutic and help based programmes to identify negative cognitive biases which impact people’s lives. For those suffering from anxiety, well-being, depressive or OCD disorders, this research can illuminate what neural computations subserve negative or detrimental thought processes.
How will youanalyse your design? What tests?
Single –trial classification EEG methods / HGF / Permutation tests
Tell us a little bit about your Masters project
Does WM affect error awareness. ERN / Pe / Single trial / PES and Error rates
Can you take us through a timeline of what your planning as the project sounds quite ambitious?
I should have all the skills necessary to begin preparing experiments from September. (?I plan to hone further MATLAB programming skills alongside creating the experiments in psychtoolbox?) – following this, recruitment and testing, analysis and write up of the first experiment will precede the viva upgrade. This will then repeat with the second experiment to the second year review / talk in Sept 2019 – then the 3rd experiment – and the last 6 months in write up.
Where do you see yourself 10 years
research - teaching - emotions affect perceptual inference fmri research (amygdala, insula Cingulate gyrus, orbitofrontal cortex)
Why PhD
History + The PhD represents the next step, where I can apply all the skills and knowledge I have cultivated so far, and focus them entirely on my research whilst learning and teaching others (the ideal environment for me). I am also looking forward to growing as a researcher, communicating with others in the department, and contributing to the development of an active and stimulating research environment.
Why Goldsmiths
the interdisciplinary / academic rigor as well as creative freedom
what skills you bring to Goldsmiths
design and analysis of cognitive psychology experiments, experience with neuroimaging (EEG), advanced quantitative techniques, and the computational approach. I even bring my experience from my 11 years as a professional musician, where I became proficient at creating, writing and collaborating with other professionals, and I honed skills in problem solving whilst creating and designing and programming electronical equipment.
Why are you motivated to undertake this PhD project?
I genuinely enjoy the research process, I find it exciting and fulfilling – but I am also interested in contributing something valuable to our understanding of the computational neuroscience of cognitive biases, attention & learning processes. I am very devoted to cognitive neuroscience, it’s challenging and rewarding intellectually – I would be fortunate and exhilarated at the opportunity to continue working on research I truly love.
What are your thoughts and approaches to teaching?
PhD students run tutorials of around 3 classes, and help cement understanding from lectures and facilitate learning and conversation about lecture and coursework topics.
‘fascinators’ such as an attention grabbing statement or image to generate conversation and interest in the topic.
Moreover, I encourage active learning where students create questions and talk with fellow classmates and myself in order for stimulating discourse/avenues/answers to emerge.
Long term plan?
Extend PhD project by investigating the effect of emotional biases on perceptual inference. And that you could investigate as a Postdoc using fMRI (to access key areas involved in emotional processing & decision-making, e.g amygdala, insula, cingulate gyrus, orbitofrontal cortex).
Relevant Experience/Specific Skills?
Bsc research / summer Jan, / third year -
maria 2 projects - British Academy / Leverhulme / applying computational models of Bayesian inference to investigate motor learning under conditions of uncertainty-EEG
Maria = MATLAB, EEGLab ICA, Bayesian Modelling, Hierarchical Gaussian Filter. I hope to combine all of this experience with my knowledge and creative approach from my experience in music…. Programming / problem solving / determination / attention to detail / high pressure environments and situations.
What are the benefits for the Psychology department?
Developing our reputation as leading researchers using advanced neuroimaging and analysis techniques – and computational;
What skills would you need to improve?
Computational modelling & advanced data analysis /some programming
What teaching experience do you have?
drums
