• 2024-10-29 Tue

The question is can we bring the language of category theory and verifiable programs to the world of cognitive modeling? To be honest, I rather doubt it, at least in the near term, but I am going to try, and I would love to have some help on this quest, but anyone contemplating it should think long and hard about the trade-offs. It will be an adventure of exploration, fun to be sure, but a risky foundation for a career. The surer path to academic stability will be to grind away in a lab that is exploiting known science to accumulate incrementally new knowledge on a socially important topic. To read more …

• 2024-08-07 Wed

How can you measure someone's prior? Alex Filipowicz, James Danckert, and I thought long and hard about this. We wanted something to reflect an entire distribution and not just a point estimate like the maximum. We also did not want to make assumptions about the shape of the distribution. Since we all have unique life histories it seemed that we should expect individual variation, and not assume consistency for an entire experimental sample. With the help of many others over a few years the paradigm we developed to address these questions took the form of Plinko, another name for Galton's Bean Machine. With writing and analysis help from Peter Diberardino a collection of experiments has just been published in the British Journal of Psychology. We report that people give consistent reports of their priors, they show learning and context effects, and that in adversarial circumstances their distributions converge towards an optimal one. There is of course much more that can be done and the main purpose of this blog post is to advertise the tool. Take a look if you have time and let me know what you think. To read more …

• 2024-08-07 Wed

People have been wondering about this for decades. The direct Bayesian idea would be that after every observation your mental model of the relevant parameters for whatever stochastic event you are interested in gets revised to reflect your most recent evidence. However, in the lab that doesn't seem to be what people do. To read more …

• 2024-05-18 Sat

Hanbin Go and I have spent a lot of the last couple of years trying to come up with ways to probe belief that depart from the conventional subjective probability model. That model is incomplete at best, and probably wrong for many of the most interesting cases: such as when you have to consider counterfactuals or one-off scenarios. We came across the negative ranking theory of Wolfgang Spohn and found it appealing in that it limits much of the computational burden of comparing and updating degrees of belief. But do people actually adhere to this formalism? That has been Hanbin's project for the last few years and he is sharing his first comprehensive overview at this month's (July 2024) Cognitive Science Society meeting in Rotterdam, the Netherlands. Come by and let us know what you think or take a look at the attached poster/paper combo and send us an email. We would love to get feedback on this work. To read more …

• 2024-05-18 Sat

Sixuan Chen has just had accepted at the Canadian Journal of Experimental Psychology her manuscript on the use of statistical structure in maze navigation. This is a condensed and improved account of work detailed in her masters' thesis. Sixuan's work builds on other work from the lab in which we tried to determine whether people have distinct probabilistic representations for various aspects of their environments. Sixuan was interested in spatial behavior and so designed an experiment where mazes were built programmatically. She could manipulate the reliability of local cues and the consistency of the location of the maze goal's, thus having a "local" and "global" probability. She demonstrated that both probabilistic structures independently affected participant choices, but that there was a strong bias to the use of local information even when that policy was sub-optimal. To read more …

• 2024-04-30 Tue

A decade ago an excellent article with an educational reminder of some forgotten history was published by Gallistel and colleagues. The main method was to observe the trial by trial reports of participants estimating the Bernoulli parameter while observing a sequence of "coin flips" with intermittent changes in the underlying, true, parameter. The main conclusion was that participants were not doing trial-by-trial updating, because their reports showed a step-and-hold pattern of updating. What Julia Schirmeister investigated was a possible motor confound, identified by Forsgren in their rebuttal. To read more …

• 2024-04-08 Mon

For some time now Hanbin and I have been interested in the cascade correlation (pdf) neural network architecture. The two of us played with it some using the code that its inventor, Scott Fahlman, made available on line in Lisp (and again, isn't it amazing to use a programming language that you can run out of the box forty years after it was written). To read more …

• 2024-01-19 Fri

How Best to Model a Complex Behavior? I recently had the chance to attend a workshop devoted to reflecting on exactly that problem. It was a wonderful experience. Not just because the topic was interesting, and my fellow attendees were smart and fun people to learn from, but also because the venue fostered an environment that allowed one to exit from the day to day pre-occupations and focus in a sustained way. To read more …

• 2023-11-14 Tue

I spend a lot of time listening to podcasts. However, when it comes to neuroscience, and especially theoretical neuroscience, there are not too many to chose from. So, I want to highlight a new podcast that was just announced on the neuroinformatics mailing list. It is organized by Gaute Einevoll and available from many of the usual sources, e.g. apple podcasts. Currently it is free to listen to, but that could change. There is a Patreon page if you want to support the effort. I have listened to a couple of the episodes and look forward to more. To read more …

• 2023-10-27 Fri

For many years now James Danckert and I have been interested in the notion of a mental model, by which we mean, loosely, your model of the world and how it works. In some cases this may be an explicitly statistical model (like in our Rock, Paper, Scissors work), but it doesn't have to be. Somehow we also make inferences about things that are not statistical, e.g. whether to go to graduate school or what country, of the ones we have never visited before, would we most enjoy on our next vacation. To read more …

• 2023-09-05 Tue

For a few years now I have had the pleasure of being part of Chris Striemer's project to expore more the role of the cerbellum in cognition, especially the functional anatomy: what part seems most critical for what functions. Chris has looked attentional effects of cerebellar damage, whether it an be neglect-like, and most recently how it impacts reaching behavior. Although my role has been mostly adjunctive, tracing cerebellar lesions blind to performance, I enjoy the project and encourage you to check out Chris's latest published work. To read more …

• 2023-07-13 Thu

Hanbin Go has been working for the last couple years looking at alternative accounts of how we deal with uncertainty. The traditional account is that we use our subjective probabilities. However, the fact that we are so bad at providing objectively correct probabilities, or estimating randomness, and tricked by so many fallacies suggests that this probabilist account is at the best incomplete. To read more …

• 2023-03-20 Mon

What does that mean: local or global probability? We find that we build up representations of our environments and we use that model to guide our decisions about what to do and what to expect. One type of such models seem to be probabilistic: how likely that X will happen if I do Y or am in state Z? But is this a single construct or do we have multiple representations that get synthesized into action? To read more …

• 2022-05-05 Thu

If you have ever found yourself unable to communicate with a fellow cognitive scientist then this workshop at CogSci 2022 in Toronto is for you. Category Theory could be our theoretical lingua franca, but it is also the mathematical area devoted to the characterization of structure and structure is at the heart of many key concepts in cognitive science such as recursion, composition, and universality. To read more …

• 2022-03-20 Sun

Hanbin's article (which was much of his master's thesis) has just been published in Attention, Perception and Psychophysics. To read more …

• 2021-11-11 Thu

At the end of October, I attended a virtual personal statement workshop hosted by University of Waterloo's Psychology Department Equity, Diversity, and Inclusion (EDI) Working Group. I went into the workshop not knowing what a personal statement was, much less how to write a successful one or even where to start. But by the end of it, I had a clear idea of the steps I needed to take to write one for my future graduate school applications. Through this post, I hope to share what I learn to those who also may benefit from it. To read more …

• 2021-11-09 Tue

This summer, I participated in Neuromatch Academy (NMA) Summer Online school as a TA for Computational Neuroscience (CN) and a student for Deep Learning (DL). It's been several months away since I submitted our group's final DL project for NMA, but what happened those 7 weeks are still vivid today. To read more …

• 2021-10-08 Fri

Sixuan Chen, a masters student working with me as been dealing with the challenges of being a student and conducting research at the University of Waterloo while the pandemic confines her to her home country of China. She has overcome these challenges to get a nice project up and running where participants navigate mazes in the light of local cues (arrows saying go right or go left) and global cues (the exit is likely to be here (or maybe there)). These cues are stochastic and variable and we make the mazes particularly hard by masking the walls of the maze so that the navigation is dependent on the local cues and global goal information only. To read more …

• 2021-10-08 Fri

In 2011 I published a screed against the reification of attention in psychology. Basically, the argument was that attention is not a "thing", and by treating it as such we trick ourselves into thinking we have an explanation when we don't, and we miss out on the opportunity to pursue the real causal mechanisms. To read more …

• 2021-05-11 Tue

Recently Isabella Sewell tackled the details of getting a study on line. This month the fruits of that effort were shared as a poster at the Neuroxchange 2021 undergraduate neuroscience on-line conference. Isabella was doing her undergraduate thesis with co-supervision by James Danckert and myself. James and I are interested in how we revise our models of the world in light of new information. We call this mental model updating, and we know that brain damage in either hemisphere can impair this skill. We have wondered if the two hemispheres might play different roles in this process. One classical division between the roles of the left and right hemispheres is for local and global processing. Isabella took this idea and developed a tool that we might use to probe hemispheric specializations. In her experiment a triangle points either up or down and the participant's task is to predict the direction of the next triangle to be shown. For this task there is a global influence: a long time frame, repeating pattern of up-pointing more likely, alternating with down-pointing more likely. There is also a local bias in which the probability of the direction of the triangle is more likely to repeat. Experimentally you can mix these two biases in whatever proportion you propose. For this first assessment Isabella mixed these two distributions: the repetition probability and the global bias, in equal proportions. She found that participants were influenced by these biases, but in this cohort at least (healthy undergraduates) the local bias was all that we needed to predict partipants' choices. Of course, we have only begun to explore some of the variations possible with this procedure. If you have ideas please feel free to share them with us (or Isabella). And if you want to know what comes next "watch this space." To read more …

• 2021-03-01 Mon

A lot of the last term has been spent developing methods and procedures for moving behavioral studies on line. A lot of the responsibility for this transition has fallen on the shoulders of the graduate and undergraduate students and in the process we have experienced a lack of tutorial, step-by-step material. An undergraduate honors student working with James Danckert and myself, Isabella Sewell, was caught in this bind, and did yeoman's work to get her study up and running this term. Then she decided to compound her efforts by being generous and recording detailed notes on the steps and tools she undertook so that others might have an easier time following her. While much of this will be specific to UWaterloo, and especially our lab group, there is still a lot of good general advice here and therefore we are sharing it here. If you just want to read her advice take a look the pdf. If you think it is something you would like to adapt to your own purposes you can also grab a docx version for editing. Please though remember to credit Isabella if you adapt her work. She put a lot of time and effort into this and deserves the acknowledgement. Thank you Isabella. To read more …

• 2021-02-22 Mon

Earlier I shared a pre-print of some work I had been involved in that was led by Chris Striemer at MacEwan University showing that cerebellar lesions affect particular types of attentional tasks. This work has just been accepted in Cortex. Congratulations to Chris and his student Brandon. You can find the current pretty version at: paper web page To read more …

• 2021-01-07 Thu

Rare when an undergraduate honor's thesis turns into a poster at Psychonomics, but Sungjoon Park (now a graduate student at Texas A&M University) managed to pull it off with a lot of work and effort. In addition to all the research and analysis required of any project he also had to teach himself how to use a new eye tracker I had purchased for the lab (which works great by the way). As the distance/virtual nature of the meeting may have made it hard for people to find the work I am posting it here. If you don't have time to watch the tl;dr is that we used the change in pupil size to explore when a "surprising" event was merely surprising in the statistical - low probability sense - or when it was surprising in a way that gave you new information about the scenario (epistemic surprise). We adapted this task from some fMRI work with the idea that the pupil might be a more accessible way to get at some of the same ideas. In short, it wasn't all that clear whether there is or is not a big difference between these two types of surprise in these data, but as a first step we gained a lot of familiarity with the technique, and both pupilometrics and this simple sort of game/knowledge manipulation seems like it deserves more detailed and systematic experimentation. Let us know what you think. To read more …

• 2020-09-04 Fri

A former psychology graduate student of the University of Waterloo (and a Gold Medal winner at that) has gone on to a successful career in industry. Tanya Jonker has written a long blog post comparing the academic and industrial routes. I think her perspectives should be very useful to any students considering industry as a potential career path. To read more …

• 2020-09-02 Wed

Hanbin Go just recently had his master's thesis accepted. Congratulations Hanbin! To read more …

• 2020-06-30 Tue

• 2019-10-30 Wed

New work with Brandon Craig (University of Calgary) and Chris Striemer (MacEwan University) highlights the effect of cerebellar injury on attentional tasks - primarily on the reflexive, covert orienting measures rather than the voluntary sustained measures. A preprint is available on [BioRxiv](https://www.biorxiv.org/content/10.1101/822635v1). To read more …

• 2019-09-26 Thu

The increase in open access journals and pre-print archives has led to a marked increase in the volume of scientific literature, but I find myself reading less, not more, and reading differently. The constant onslaught of articles with relevant titles and my inability to keep up has led to a sort of learned helplessness. I just don't try as hard as I used to; it feels like, "what is the point?" This feeling of resignation is compounded by what I find when I do pick up an article: one or two experiments; a fragment of an idea; and a presumption that I should have read the author's prior \(n\) articles on the same subject and be willing to wait for the piecemeal roll out the next \(m\). To read more …

• 2019-08-16 Fri

Getting ready to take off for ECVP in Leuven. I have a poster to present that includes some of the last work Christie Haskell Marsh did before she completed her PhD (she now works as senior data scientists with Johnson & Johnson in their Baby Products Division). In addition to Christie's data, there is data collected using virtually the same data collected as a replication. I recorded in the readme for the repo of my Haskell parsing code of all the pain I caused myself, but rarely is the easy way the fun way, or the interesting way, or the educational way or the "moral" way. So, I am back on another painful path trying to make a scientific poster that is reproducible. This isn't about replicability as in "crisis", this is about making a scientific document that clearly documents what you did and how you did it, and that allows others to repeat your analyses exactly as you did them to produce the poster, manuscript, or blog. Unfortunately, the tools that you need to do this require you to work at it and makes it less likely people will do it. If you like making your poster or figures in powerpoint or illustrator I do not know how you will be able to do this. But if you are willing to spend some time, have some patience, and are willing to compromise a bit on your aesthetic vision, it is not too hard to achieve this goal right now. For the poster in Leuven I wrote the poster as an Rnw file. This is a combination of R and nowebformat that allows using R to conduct the analyses and generate the figures while subsequently allowing me to subsequently use LaTeX tools to produce the document I will display. I have done other posters starting with an org file and using org-babel for including the code, but if you are going to have to write a bunch of LaTeX and R anyway the convenience of orgmode is largely absent. Here in short is the basic production line. Do whatever you want to do in RStudio or elsewhere until you have a pretty good idea of the workflow that the poster will need (you can actually include code blocks form other documents, but I did not do that here). Then get to writing your Rnw file. When ready you move over to R and library(knitr) then knit("yourFileName.Rnw"). My current draft of this file is here. The result of this will be a file: yourFileName.tex. You can change that output if you want, but tex is the default. Then you LaTex the file as many times as you need to, with the tools you have set up to get a pdf version. The benefit of this approach is that if you have my data (and I will be posting this some where publically soon) you can start with my raw file and reconstruct the poster. Don't like my analysis? Do your own. You will have the exact code I used available to change. So, this doesn't sound so hard. What is the problem? Well, getting your tools set up. And then there is the fact that if you want to deviate from the established templates or default mode there can be a lot of time on stackoverflow trying to get the tweaks just so. But, it is the right way. Our analyses and our choices should be transparent. Throw away your programs of oppression and free yourself to code your posters. Reproducible scientists of the world unite! To read more …

• 2019-08-16 Fri

It's been an active summer for the lab. We had a visitor from IT Gandhinigar (Samruddhi Damle) who visited on a Shastri Fellowship. We had time to conduct a quick, but interesting project on whether the emotion of a facial expression might alter the perceived contrast of a face the way exogenous cues alter the contrast of a Gabor. I hope to be able to link to a more complete report of this project soon as Sam is preparing it for presentation at a meeting back home in India. To read more …

• 2019-05-10 Fri

Recently, Jack Moffat wrote up a report of his efforts to get the Brian2 Neural Network simulator up and running. He did this using Jupyter notebooks. I thought his efforts might be of use to others, and so I am linking his .ipynb file and the html output here. I would recommend starting with the html page as that gives an overview of what he did and what he found as the pain points. if you decide to try it yourself then download the ipynb file so that you don't have to retype all the code. To read more …

• 2019-03-20 Wed

Brain Day is coming to the University of Waterloo this April 8, 2019. All are welcome. The event is free, and we have a marvelous line up of speakers that will cover the full gamut from philosophy of mind, to human decision making, to computational models and tools for neuroscience. Coffee and refreshments will be available from 8:30, with the talks starting at 9:00 AM. The venue will be in the E7 3343. Look for E7 on the campus interative map. A poster with the schedule for the whole day can be found here. To read more …

• 2018-08-28 Tue

The group has just had an article published in Frontiers on Statistical Learning Impairments as a Consequence of Stroke. The original goal of the research was to assess whether people with right hemisphere strokes might have more trouble updating a statistical model of language than participants with left hemisphere damage. Along the way things got more interesting and murkier. We ended up running many variants and including older and younger controls. So there are a lot of data, and they are available for you to look at too. To read more …

• 2018-08-27 Mon

A recent article in the New York Times by Casey Schwartz discusses the challenges in paying attention. One fact mentioned there is that our terminology may be faulty and its usage impeding our progress. I therefore appreciate Ms. Schwartz giving some attention to my position published back in 2011 that we reify the term attention to our scientific detriment. At least one alternative approach, which might explain a lot but not all of "attention", is that we are sensitive to the statistical structure of our environment and tuned to experience, from which tuning emerges attentional effects. I look forward to reading more on this topic from Ms. Schwartz. To read more …

• 2018-05-03 Thu

• 2018-04-11 Wed

• 2018-02-23 Fri

Brain Day is coming to the University of Waterloo this April 6, 2018. All are welcome. The event is free, and we have a marvelous line up of speakers that will cover the full gamut from philosophy of mind, to human decision making, to computational models and tools for neuroscience. The first talk will begin at 9:00 AM (with coffee available before). The venue will be in the main lecture hall on the main floor of EV3 on the University of Waterloo campus. To read more …

• 2018-01-20 Sat

Introductory note: Derek Besner recently circulated some informal advice to the graduate students in our department. I thought there was a lot of wisdome there, and wanted a wider audience to have access to it. With Prof. Besner's permission, the advice is republished here. – Britt Anderson To read more …

• 2017-12-05 Tue

• 2017-08-22 Tue

Introductory note: I asked Sherif, now a Research Scientist with Amazon and who I worked with during his undergraduate and graduate years at UWloo to share some advice on what he wished he knew back then. I hope this may help be of help to others considering psychology for undergraduate or graduate study. – Britt Anderson To read more …

• 2017-08-16 Wed

While superficially similiar, attending to features (color, orientation, etc.) is associated with distinct behavioural effects, as compared to attending to a location. In Jabar & Anderson (2017), we showed that a similiar distinction exists for probability. While orientation probability affected perceptual precision, spatial probabilty did not. To read more …

• 2017-07-29 Sat

As an undergraduate student, no one really tells you how to transition from "ambitious, yet confused" to "feeling accomplished, but still slightly confused". You want to feel prepared for the next step, whether that's graduate school or your first "real job", but there's still that undeniable grey area in between that must be navigated. Speaking from personal experience, I can say with confidence that the most important step in this transition is to define your comfort zone, and then take one step outside of that. It was in this zone of slightly-uncomfortable that I made connections, explored my interests, and gained valuable skills that helped me come out of my undergraduate degree feeling like I had gained more than just a fancy piece of paper. To read more …

• 2017-07-20 Thu

In Jabar & Anderson (2015), we saw that orientation probability affected perceptual precision, and based on the data, we hypothesized that this was due to V1 tuning changes. We thought of a way to test that hypothesis by looking at the C1 ERP potential, which is thought to index early V1 activity. As it turns out, the electrophysiological data is concordant with our specific hypothesis. To read more …

• 2017-03-28 Tue

Classically, attention has been associated with a network of cortical sites that often include areas like the right parietal lobe, the frontal eye fields, and the superior temporal gyrus. Subcortical sites mentioned include the pulvinar - the thalmus's big mystery - and the superior colliculi. And up to a few decades, the cerebellum was dismissively relegated to motor function. However, the cerebellum has been making a come back for a while now with an ever enlarging recognition of its role in cognitive functions, perhaps most successfully in learning. Under the leadership of Chris Striemer of MacEwan University and the able support of his student Brandon Craig, we at Waterloo have had the chance to participate in a study examining the effect of cerebellar lesions on attentional functioning. This work is still on going, but preliminary findings were presented by Chris at the annual meeting of the Cognitive Neuroscience Society in San Francisco this month (March 2017). The principal result so far has been an association of lateral cerebellar damage with changes in inhibition of return. Look for more findings in this space next year. For more details, feel free to contact Chris. A link to the poster is here. To read more …

• 2017-01-24 Tue

Probability effects tend to resemble ones obtained with traditional 'attentional' manipulations. Cued or probable objects are detected faster and more accurately. This goes beyond simple detection tasks. Even in perceptual estimation tasks, both spatial exogenous cuing Anderson & Druker (2013) and orientation probability (Anderson, 2014; Jabar & Anderson, 2015) improve precision. To read more …

• 2016-11-08 Tue

Our group will be presenting a couple of posters at this year's Society for Neuroscience conference. Do swing by the posters if you get the chance! To read more …

• 2016-09-29 Thu

Our group has been designing and writing experiments in Python for the better part of a decade now. And an absolutely critical library for getting us started was Jon Pierce's PsychoPy. However, in the last few years the emphasis has moved to developing and supporting a gui interface to the library's functions. This is obviously a boon for many psychologists, but I wonder if it has the effect of keeping from them learning how to code, by allowing them to do most, but often not all, of what they wanted to do? This was what I saw with E-prime users. They would think of the experiment they wanted to do, realize they couldn't do it in E-prime, and then implement a nearest neighbor approximation, which often wasn't that near-by. We shouldn't let the software determine what experiments we run. We should run the experiments dictated by our scientitific needs. In this day, everyone needs to have some rudimentary coding competency so that they don't feel trapped by the drop-down box options of their favorite plug and play tool. If GUIs help bridge the fear chasm that separates many psychologists from doing this, great, but I wonder if it really does? To read more …

• 2016-09-02 Fri

We live in an age of technology. New computers. New tools (MEG/fMRI). And new algorithms. It can easily lead one to believe that innovative research for Cog Neuro questions mainly depend on hardware and infrastructure. However it is good to remember that our goal is to puzzle out the workings of people's minds, and that means that "people" are actually the most important resource. To read more …

• 2016-08-26 Fri

We recently published a review article in the Canadian Journal of Experimental Psychology that highlights evidence we, in collaboration with the Danckert Attention Group, and others have garnered to suggest a critical involvement of the right hemisphere in mental model updating. To read more …

• 2016-06-30 Thu

To read more …

• 2016-06-02 Thu

Following up from Part 1, when are detection tasks useful? To read more …

• 2016-05-31 Tue

Cognitive experiments commonly utilize some kind of detection paradigm. These usually involve forced choices (hit button A when you see/think about X, hit button B for Y). Such tasks neccessarily requires decision-making, which arguably could contaminate effects. To read more …

• 2016-05-26 Thu

• 2016-05-05 Thu

Some of the language that is used to describe memory mechanisms sounds a lot like the language used to describe attention. And some of the methods used to study memory are similar to the methods used to study attention. Is this just a professional accident where a common community leads to similar terms and tools? Or is this a reflection that there are some deeper, functional dependencies? This became a live question for me when I read this paper by Liu & Becker that used a procedure very similar to one that I had used with a, then, graduate student: Michael Druker. When I had the chance to work with Christie Haskell it seemed like an excellent chance to re-visit this issue. In our recently published paper, Christie and I replicated the work of Liu & Becker, and compared memory effects to cueing effects. Some interesting results (and careful reviewers) led us eventually to a series of five experiments. We looked at the effect of simultaneous and sequential presentations of targets with and without cues, where the cues could be informative or not, valid or not, and preceded either the first or second stimulus when stimuli were shown sequentially. Some simple mixture model fitting also comes into play. We do find the memory effects seem to be most prominently on the likehood of guessing whereas the attentional effects for informative cues are more at the level of response precision. For uninformative cues, guessing again seems to be the locus. When a cue means something you get more precise responses. There may be more to mine from these data and this approach, and we welcome any comments or feedback. To read more …

• 2016-04-23 Sat

How does 'attention' affect perceptual processing? Does it alter the way even early visual processing works? In Jabar & Anderson (2015), we hypothesized that exposure to probablistic stimuli can result in V1 neurons being tuned differently, and that this is what drives differences in perceptual precision. But are such low-level mechanisms enough to cause the changes we see at the behavioural level? To read more …

• 2016-04-05 Tue

• 2016-02-25 Thu

"If the only tool you have is a hammer, you tend to see every problem as a nail." - Abraham Maslow To read more …

• 2016-01-14 Thu

Congratulations to Elisabeth Stöttinger on being selected for one of the few, and highly competitive, Elise Richter Fellowships. Elisabeth has been working as a post-doctoral researcher with James Danckert and myself on our updating project (see this post for some details on our recent work). Elisabeth is in the process of transitioning to a position at the University of Salzburg, Austria, but fortunately we will still have her around for a few more months. To read more …

• 2015-11-26 Thu

Some of the language that is used to describe memory mechanisms sounds a lot like the language used to describe attention. And some of the methods used to study memory are similar to the methods used to study attention. Is this just a professional accident where a common community leads to similar terms and tools? Or is this a reflection that there are some deeper, functional dependencies? This became a live question for me when I read this paper by Liu & Becker that used a procedure very similar to one that I had used with a, then, graduate student: Michael Druker. When I had the chance to work with Christie Haskell it seemed like an excellent chance to re-visit this issue. In our recently published paper, Christie and I replicated the work of Liu & Becker, and compared memory effects to cueing effects. Some interesting results (and careful reviewers) led us eventually to a series of five experiments. We looked at the effect of simultaneous and sequential presentations of targets with and without cues, where the cues could be informative or not, valid or not, and preceded either the first or second stimulus when stimuli were shown sequentially. Some simple mixture model fitting also comes into play. We do find the memory effects seem to be most prominently on the likehood of guessing whereas the attentional effects for informative cues are more at the level of response precision. For uninformative cues, guessing again seems to be the locus. When a cue means something you get more precise responses. There may be more to mine from these data and this approach, and we welcome any comments or feedback. To read more …

• 2015-11-12 Thu

Listening recently to a SuchThatCast podcast I came across a discussion about whether Psychology is really a science (ever since Kant the Philosophers seem to be piling on). It contains the following observations from Selmer Bringsjord: To read more …

• 2015-11-05 Thu

What happens in your brain when you experience those "Aha" moments? We may not be there yet, but our recent article on the updating of conscious representations takes us a step in that direction. This fMRI study, led by Elisabeth Stöttinger, grew out of the interest that my collaborator James Danckert and I have in the phenomenon of "updating." By updating we mean the revision of your model of your environment. We have looked at this in a variety of domains, and now, here, we probe it by functional imaging. In this paper we used the morphing, ambiguous figure data set that we have developed, normed, and made freely available (the details were published in Behavior Research Methods). To read more …

• 2015-11-01 Sun

During graduate school, at least in Cognitive Psychology, it is often the case that the only two career trajectories that you hear discussed and advertised are academia and teaching. Nearing the end of my PhD, I realized I wasn't interested in either of those two paths and had to do a lot of research to determine what kinds of things a Cognitive Psychologist can do in industry. It was during this search that I discovered the massively expanding field of Data Science. To read more …

• 2015-10-30 Fri

Manipulating the probability of events creates a host of behavioural changes. In Jabar & Anderson (2015), we highlight that probable orientations are robustly linked to better perceptual precision. We also advanced a hypothesis: Perhaps the result of probability learning is to change the neural tuning of visual processing neurons, leading to these precision changes. To read more …

• 2015-10-28 Wed

I am currently in Paris, France working with Etienne Koechlin at the École normale supérieure (ENS) on a project aimed at understanding the consequences of specific forms of brain damage on decision making processes. The goal of this post is to give a little background on some of the work we've done so far, and a description of the project I'm working on in Paris. To read more …

• 2015-09-15 Tue

This is a bit off the usual content of this blog, which is to feature activities and news of interest to our research group, but I just couldn't find another forum for this piece, and I wanted to do something to promote these ideas. I think they are a good desiderata of academic work. In his The Problems of Philosophy, Bertrand Russell writes the following: To read more …

• 2015-09-09 Wed

James Danckert and I have been working together for sometime now on the concept of updating. Suggested by our experiences with people with right brain injury (often with neglect, but not always), we began to conceive of a deficit in the ability to recognize that environmental contingencies had changed, and to update one's model of the environment accordingly. We have since done a series of studies on control and brain damaged volunteers showing that just such a deficit is prevalent after brain injury, and we have begun to work out some of the cortical network that supports it at both computational and anatomical levels. To read more …

• 2015-08-31 Mon

I recently got the chance to see a talk at the Centre for Theoretical Neuroscience (CTN) by renowned computer engineer Dr. Steve Furber. Dr. Furber is probably best known for his involvement in developing the ARM microprocessor, the chip that's responsible for the many of the tablets and smartphones we use everyday. He has since moved to the University of Manchester where he has been building biologically inspired computer hardware. To read more …

• 2015-08-20 Thu

Unfortunately a family emergency has forced me to cancel my trip to ECVP 2015. This is too bad for a number of reasons, but especially because I was looking forward to comments and feedback on the poster describing my work on the controversial issue of whether cueing actually causes contrast enhancement. The answer I find (and which I am in the process of writing up now - let me know if you would like to see the draft manuscript) is that the answer is yes and no. It depends on how you elicit the contrast report. It seems like this is an example of a "multiple drafts model." To read more …

• 2015-07-13 Mon

It is clear we learn to expect what is probable, but does that knowledge impact on the precision of our perceptual judgements - do we become more precise in our reports of the probable range of feature space? Or do we just develop a bias to respond more quickly? To read more …

• 2015-06-03 Wed

The Group is on its way to Ottawa for CSBBCS 2015. We have four posters that will be presented over the weekend. Alex is continuing his decision based work with some interesting new ideas, and sharpened by his recent presentation at the Paris symposium. Syaheed and I have been working hard to understand how different modalities of attention (spatial and featural) respond to probability cues, and exactly what the effect is on performance. Is it mostly about precision, or does the shape of the error distribution also change? With Christie I have been looking at the reward side of things, again with an interest in shape changes. For us, it isn't only a question of whether errors become generally smaller, but is there an inevitable trade-off between increasing the proportion of small errors at the expense of having to suffer some great big whopping errors. Lastly, I have continued my work (with the help of a variety of undergraduates over the last couple of years) of looking at how exogenous cues might alter appearance. It was inspired by the Carrasco, Ling, and Read article of 2004. My conclusion is that attention both does, and does not, alter appearance. It depends on how you ask the question, and to my mind seems consistent with a multiple drafts account of conscious perception. All out posters are on the conference page. We look forward to comments and critiques. To read more …

• 2015-05-03 Sun

I went to this conference last year, and it was a great experience. Excellent lectures. Wonderful venue. Single track. In addition, there was an ample opportunity to meet and visit with the other attendees, and there was the added advantage that you could pop around the corner at lunch to see the Curie's House or the older section of the Salpêtrière. To read more …

• 2015-03-31 Tue

We recently published in Frontiers in Psychology a collaboration with the Besner and Danckert laboratories on changing functional connectivity with task demands. To read more …

• 2015-02-11 Wed

This is an area that has come up relatively recently in the lab. On evaluating some of our data from an orientation estimation task that we use a lot we found interesting changes in the shapes of error distributions. This increase in kurtosis seems to have some real opportunity to provide some insight into mechanisms of probability effects on attention. We have one recent article in press at Journal of Vision (manuscript copy on this page), and Syaheed Jabar's master thesis (and the manuscript in preparation) have additional details. To read more …

• 2015-02-10 Tue

There has been a lot of activity on "updating"; work done in collaboration with James Danckert and the DAAG lab. We have been doing work to identify cortical structures active at the moment of a perceptual updating event, as well as exploring a novel behavioral task that is giving us a lot of data for probing the probabilistic cues that weight evidence for or against an environmental change. Elisabeth Stöttinger headed up the fMRI task, while Alex Filipowicz is leading the Plinko Team. Most of this work is still in the poster phase. You can find links to those on the Conferences page. To read more …

• 2015-02-09 Mon

I find many psychological undergraduates are interested in computational modelling, but that there is not a lot of literature or texts to help them get started. To try and improve that, I took the notes from a seminar I have taught over the last few years, and wrote a textbook. It is is published by SAGE. Take a look and let me know what you think. To read more …