Cognitive modelling 3: the importance of a script

One of the key things we must avoid is mess and confusion. In the last post I briefly covered one possible template for a research project. One of the reasons why cognitive modelling projects might be a little tricky is because you are not just using an off the shelf software package. For example, if […]

Cognitive modelling 2: project structure

What we definitely want to do is avoid confusion and mess. Having a clear project structure and workflow has many advantages. While there is no one single correct way to organise a project, putting a bit of thought into it, and learning from past projects can help a lot. This is the workflow that works for […]

Cognitive modelling 1: programming problems

This is the first post in a series exploring programming practice in cognitive modelling. While I have over a decade of experience in cognitive modelling, I am in no way an expert and have no formal computer science training. I am not an authority on this, I am feeling my way. Comments welcome. This post may […]

Bayesian accounts of covert selective attention: a tutorial review

I am very happy to announce my new tutorial review paper. Vincent, B. T. (2015) Bayesian accounts of covert selective attention: a tutorial review, Attention, Perception, & Psychophysics, 77(4), 1013-1032. If you do not have an institutional subscription to Attention, Perception, & Psychophysics, Springer allow me to self-archive my author-accepted manuscript (legal). Get the preprints here: [manuscript pdf], [supplementary pdf]. The final publication […]

Plotting posterior predictive distributions

I’ve just released a small bit of Matlab code on GitHub which helps automate the job of plotting posterior predictive distributions. If you are inferring posterior distributions of parameters of a 1D function (e.g. y=mx+c) then this code will plot the posterior predictive distribution for you. This should be handy for you to eyeball how well a model […]

How do we use the past to predict the future in oculomotor search?

When we conduct visual search for an item of interest we can not only ask ‘what looks like my target’ but we can also ask ‘where do I expect the target to be?’ In a forthcoming paper in the journal Vision Research I asked: how do we use our past experience to construct predictions of where a […]

The prominence of behavioural biases in eye guidance

Abstract When attempting to understand where people look during scene perception, researchers typically focus on the relative contributions of low- and high-level cues. Computational models of the contribution of low-level features to fixation selection, with modifications to incorporate top-down sources of information have been abundant in recent research. However, we are still some way from […]

Systematic tendencies in scene viewing

Abstract While many current models of scene perception debate the relative roles of low- and high- level factors in eye guidance, systematic tendencies in how the eyes move may be infor- mative. We consider how each saccade and fixation is influenced by that which preceded or followed it, during free inspection of images of natural […]

Investigating a space-variant weighted salience account of visual selection

Abstract Weighted salience models are a popular framework for image-driven visual attentional processes. These models operate by: sampling the visual environment; calculating feature maps; combining them in a weighted sum and using this to determine where the eye will fixate next. We examine these stages in turn. We find that a biologically plausible non-uniform retinal […]

Is the early visual system optimised to be energy efficient?

Abstract This paper demonstrates that a representation which balances natural image encoding with metabolic energy efficiency shows many similarities to the neural organisation observed in the early visual system. A simple linear model was constructed that learned receptive fields by optimally balancing information coding with metabolic expense for an entire visual field in a 2-stage […]

Synaptic energy efficiency in retinal processing

Abstract Recent work suggests that the visual system may represent early visual information in an energy efficient manner [Nature 381 (1996); Nature, 381 (1996) 607; Neural Comput. 3 (2001) 799; Curr. Opin. Neurobiol. 11 (2001) 475]. This paper applies the idea of energy efficient representations to understand retinal processing, and provides evidence that centre surround […]