Maria and Dan at the Durham PSPA meeting at the Bay Horse
The last couple of months have seen significant progress with the PSP project and some important milestones for Siobhan’s PhD. We’ve been delighted to have seen a big increase in people volunteering for the PSP project, and I’m pleased to say we are now at 20 participants, which means we are slightly ahead of schedule. We’re particularly grateful to the wonderful research nurses in James Cook, Gateshead and Sunderland for their efforts to recruit people, and to the local PSPA co-ordinators who have helped publicise the study. We still need people to take part, especially for our age matched control group, so please get in touch if you are interested. We also had a very nice meeting with Maria from the County Durham PSPA, who let Alexis and I update the group on progress with the project and pitch some ideas for new research projects. They gave us quite a grilling, but the feedback was extremely valuable!
Siobhan at the graduating with her PhD at the winter congregation in Durham cathedral
It was also lovely to catch up with Siobhan, who returned to Durham to graduate her PhD at Durham Cathedral. It was a very proud day! There was more good news from Siobhan, as the 3rd paper from her PhD was accepted and appeared in Vision Research on the last day of the year. The paper shows that measuring VSWM capacity with mouse pointing produces a rather different pattern of resource allocation than measuring with finger pointing (imprecision asymptotes at set sizes larger than 2, rather than monotonically increasing), we think because of the additional visuomotor transformations required by mouse pointing. You can read all about it here: Precision in spatial working memory examined with mouse pointing – ScienceDirect
It has been a busy summer for the MotorBias project with lots of progress on several projects. Alexis’ main focus has been the Dunhill Medical Trust project on Attention and Memory in PSP and Parkinsons’ disease, which reached a notable milestone when we reached our recruitment target of 27 for the Parkinsons group. This excellent achievement is thanks due to the fantastic efforts of Susan Wilson at Sunderland Royal and Bryony Storey at Gateshead who have provided us with a steady stream of willing volunteers, and of course the participants themselves whose time and effort we are very grateful for! Dan has also been busy with the PSP project, running very some very informative PPI sessions with Susan at Sunderland Royal to get feedback on the potential for a project exploring prism use in PSP.
Another highlight of the summer was the Federation of European Neuropsychology Societies 2023, where we were fortunate to be joined by Prof Chrystalina Antonaides and Dr Luca Wollenberg in the city of Thessalonki for a symposium on “Visual cognition and oculomotor control in neurodegenerative disease” organized by Dan and Thomas. Alexis presented a preliminary analysis of the visual search tasks, reporting that people with PSP find visual searh significantly more challenging than people with Parkinsons’ disease. Chrystalina outlined her recent advances in using measures of oculomotor control to track progression of Parkinson’s disease and Luca who explained his exciting research showing decoupling of attention and saccades after training. Although unfortunately Prof Trevor Crawford wasn’t able to join as planned, the symposium produced lively discussion in the session and at the symposium dinner afterwards. We’re very hopeful that some the seeds of ideas planted over dinner and well watered with Greek beer will grow into future collaborations!
Overall the conference was very good with some some thought provoking keynotes. Alfredo Spagna gave a particularly compelling talk arguing against a functional role for V1 in mental imagery. Unfortunately the poster sessions were a great disappointment. Posters were electronic, but with only three display screens it was impossible to browse the posters at leisure, which is one of the great pleasures of a conference. It also severely limited the time Dan had to present the results of the VSWM and social cognition tasks, which was very frustrating. You can see the poster at the bottom of this page.
Other notable events during the summer included Siobhan getting a new job with Dr Robert Hardwick in Leuven, Belgium, a new publication from in PLOSONE in which Dan demonstrated the existence of a presaccadic perceptual impairment at the post-saccadic location of the blindspot (Smith Beierholm & Avery 2023), Shuzhe completing her masters project looking at the effect of varying cue spatial frequency on the temporal profile of exogenous attention, and Soazig submitting a paper on eye-movements and aesthetic appreciation to JoV. With the start of term imminent we’re looking forward to welcoming a our new cohort of UG and masters students and getting on with more exciting projects.
The latest paper from Siobhan’s PhD work, published in Journal of Vision, suggests so. In this study, we examined the serial position effect in spatial working memory using a continuous report task to explore how sources of recall error change across different positions in a sequence. We compared the sources of recall error in full and partial report tasks. The key take-home for this paper is that the serial position effect in precision in spatial working memory depends on whether a full sequence or only one item from that sequence is recalled. We found that when a full sequence is recalled, items presented early in this sequence are recalled more precisely than subsequent items (primacy effect). In contrast, when only a single item is to be recalled, this serial position effect is reduced and reversed. This finding reconciles previously contradictory findings in visuospatial working memory, where differences in the nature of the recall task appeared to determine whether a recency or primacy effect was observed. The key data are captured in the figure below:
Mean imprecision for whole report (sequential presentation mode only) and single probe tasks as a function of serial position at each set size. Error bars represent the standard error of the mean.
This finding is important because it suggests that the primacy effect in the whole report task results from accumulation of noise/error due to performing multiple goal-directed actions during recall, whereas only a single action was required in the partial report task. Additionally, this finding has important implications for models of capacity, and suggests that spatial STM is flexible and dynamic, with resource allocation being determined by the nature of the recall task.
The PSP Association were kind enough to publish a short article about our new Dunhill Medical Trust project exploring “Can tests of cognitive function help diagnose PSP?”. You can also read the article with a nice picture here (page 15)
I first heard about PSP as a graduate student when I read a paper describing an unusual and devastating disease characterised by paralysis of the eyes. The paper reported a striking result: people with PSP had a problem moving attention that was not experienced by people with Parkinson’s disease. At the time I was doing my doctoral research and the result seemed to have profound implications for our theoretical understanding of attention. I didn’t realise at this time was that it might also be important for the purposes of diagnosis. I was keen to explore how PSP affected attention further, but unfortunately due to the rarity of the condition we had no luck finding participants. At this point end I moved on to working with stroke survivors. However, as my career progressed I often thought about the condition, and one day happened to mention it to Dr Neil Archibald, consultant neurologist at James Cook University Hospital. He had a particular interest in PSP and was keen to collaborate. He put me in touch with the PSP Association, and together we ran a workshop with patients, carers, clinicians and academics to generate research ideas.
One issue that was important to everyone was diagnosis. Because PSP is rare and shares many symptoms with Parkinson’s disease, a great many PSP patients are misdiagnosed. This is distressing to patients and carers and can lead to unnecessary prescription of medications with potentially harmful side effects. Out of the workshop emerged an idea for a pilot study comparing mental functions such as attention and memory in people with PSP and Parkinson’s disease, with the long- term aim of evaluating whether such tests could be useful for diagnosis. Over the next 2 years we recruited a group people with PSP and another group of people with Parkinson’s disease. We asked them to do computer tasks that tested their eye-movements, attention and short-term memory. The results of the pilot study were clear: People with PSP could not make any up or down eye-movements, and their left and right eye-movements were also affected. Importantly, we found impairments in attention and memory that seemed to correlate with the eye-movement problems. These results were very promising, and the Dunhill Medical Trust subsequently agreed to fund a 3-year project designed to develop a more complete understanding of how PSP affects visual cognition. This project will begin next year, and we hope it will bring us a step closer to finding a cheap, effective and reliable tool for the early diagnosis of PSP.
Last week Soazig and I co-organised a workshop to mark the end of our 3-year ORA collaboration with Stefan van der Stigchel and Thomas Schenk, and here are a few reflections on how things went.
Left to right: Dan Smith, Teuni ten Brink, Trevor Crawford, Stefan van der Stigchel, Joris Elshout, Anna Grubert, Soazig Casteau, Nina Hanning, Laure Pisella, Therese Collins, Martin Rolfs, Karin Ludwig, Chris Olivers, Marissa Carrasco , Paul Butler
The workshop kicked off on Wednesday with the arrival with many of our invited speakers and our two keynotes. The only event we had planned was a meal in the evening at a local tapas restaurant. There was a minor but rather stressful hiccup when it emerged that our booking had mysteriously vanished, but Soazig sorted out another restaurant (she got the owner to find us something!) while I fussed around our gang of 12 visitors. Fortunately, the evening was warm, there was lots of catching-up to do and the new restaurant was just a couple of minutes’ walk away so nobody seemed to mind too much. After dinner most people went back to the accommodation at Stephenson College, while I scoured Durham city centre with Marisa and Thomas looking for plug adaptors. Sadly, our hunt was in vain; unlike New York and Munich, Durham isn’t really a 24 hour city!
The talks began after lunch the following day. Most of our delegates spent the morning walking up and down Cardiac Hill (we sit at the top of quite a steep hill) to get ‘proper coffee’ from the Calman café, while and we rushed around putting up signs and poster boards and getting the registration desk ready. We were very fortunate to be assisted by Ellie, who was on a work experience placement from a local school. As the morning progressed I spent more and more time schmoozing people as they arrived, while Soazig and Ellie got people organised, and by 12:20 we were ready to go. After a few words from me (no fire drill, directions to the loos, etc) Marisa Carrasco gave our first keynote which outlined some important dissociations between presaccadic attention and covert attention in terms of their effects on response gain and tuning in the visual system. There was also some impressive new research on covert orienting within the fovea. The take-home from this seemed to be that endogenous covert orienting could occur simultaneously with but independently of microsaccadic eye-movements. I enjoyed this very much until it also transpired that a similar dissociation was observed for exogenous orienting! The ‘kilotrials’ approach (where they count trials in thousands, not tens or hundreds) is one I find hugely impressive, but I do wonder about the effect this volume of practice has on psychological processes which are known to be sensitive to learning, such as attention. The remainder of this session comprised talks from Martin Rolfs, who argued that the primary function of presaccadic attention was to serve perceptual continuity, Casimir Ludwig, who elegantly argued that current models of saccade control that rely on race models do not adequately account for the effects of foveal load on saccade latency, and Trevor Crawford, who described deficits of saccade control and working memory in Alzhiemers disease that seem to offer an important early marker for the disease. Trevor’s talk also included some footage of visuomotor actions (AD patients making a cup of tea). It was striking how normal the eye-movement of these patients were when performing a well practiced, real world task, compared to the profound deficits observed under lab conditions. He concluded by cautioning us to consider to what extent the ‘deficits’ we observe in our clever lab-based experiments reflect the functional impairments experienced by patients.
After a coffee break our second session got underway with a talk from Nina Hanning, who presented some impressive data from her PhD research and argued against our proposal that exogenous, covert orienting is tied to the oculomotor system (you can read a more extensive discussion of her paper here). We didn’t get much of a chance to discuss this in the session but had a very good chat about it at the conference dinner later in the day. Therese Collins then gave a talk on the reference frame of action prediction, followed by a bit of change of pace in which Anna Grubert give a hugely entertaining and informative talk on the time-course of activation of search templates, which seem to be flexibly activated in the 600ms or so leading to the expected onset of a search array. As a special treat Stefan gave us an overview of the recent debate about how to interpret the finding that attention is not allocated to the endpoint of saccades that land between a target and distractor. Luca Wollenberg had his say too, and much like the discussion between Nina and myself, everything was very civilised. The day ended with a poster session and drinks reception, followed by dinner at St. Hilde & St. Bede College, where we had a veggie starter, roast chicken & veg, cheesecake then coffee. There was lots of wine, but no beer much to the disgruntlement of our German colleagues!
Day two was thankfully a bit cooler than day 1, and the focus was much more on neuropsychological aspects of attention and eye movements. Laure Pisella gave a lovely talk outlining a number of dissociations between presaccadic attention and covert attention in patients with parietal lobe lesions, which was followed by a very detailed study of transsaccadic memory in patients with right parietal brain damage from Teuni ten Brink. Contrary to previous reports, these patients had no specific problem with transsaccadic memory, although there was a global reduction in spatial memory performance. Monika Harvey then gave a very thought-provoking talk on the use of tDCS in and RCT trial for neurorehabilitation of neglect. The key message was that although patients tolerated tDCS well (and in fact were quite keen to receive it) it was really hard to recruit to the trial which required 10 in-hospital sessions, and ultimately the tDCS didn’t seem to greatly potentiate the therapy. I found this a really important result, as there is often a big song and dance about the therapeutic potential for tDCS, and Monika’s work sounded a welcome note of caution about the efficacy and feasibility of tDCS interventions. The final act of this session was a keynote from Chris Olivers, who gave a riveting talk outlining a computational account of the role visual working memory in the control of action that really got the audience thinking and was much discussed in the lunch break.
In the final session Soazig gave a brief outline of some of key ideas we had set out to test out in the ORA grant, then discussed two key experiments in which we showed that exogenous covert attention is constrained by the oculomotor range. This caused some discussion between Marisa, Nina and ourselves, as to how to reconcile our different findings, which has yet to be resolved. Karin Ludwig then presented data from a trial using gaze-contingent changes in visual scenes to treat spatial neglect, followed by Joris Elshout who argued that patients with visual neglect present a dissociation between presaccadic attention, which was largely preserved, and covert attention, which was severely impaired. This talk closed the meeting, and there was just enough time for a team photo before everyone went on their way.
Overall, I feel like the meeting was a big success (based on lots of people saying lots of nice things), but boy was it tiring! I think my favourite part was the poster session and conference dinner. It seemed to me that this was where all the really interesting conversations took place, and I certainly got a huge amount from the chat I had with Stefan and Nina about how to reconcile our different experimental data. I must admit to also being really thrilled to meet Chris Olivers and Marisa Carrasco. In particular Marisa is someone whose work I am rather in awe of and I had felt rather nervous about meeting with her. It was a delight to find that she was so down-to-earth and she really set the tone for what I think was a friendly, informal but also very high quality meeting.
A few last observations in no particular order
We put everyone up in Stephenson College. It was cheap and cheerful (except for Thomas, whose shower was broken), and within walking distance of the conference venue. I had worried that this type of accommodation might be a bit low-rent for our very eminent speakers, but everyone seemed happy with it. I actually really enjoyed the communal breakfast at long banqueting tables, it felt a bit like reliving my days as an undergrad!
We didn’t get as many PhD students as I would have liked, perhaps because we clashed with the EPS meeting in Bournemouth. It might also be because we relied mainly on advertising the meeting on VisionList, CVNET and Twitter. If I was doing this sort of thing again I would definitely explore the possibility of promoting the meeting via societies like the EPS and BPS.
We did conference folders with a pen, notepad and schedule. Lots of people didn’t bother with the pack, so in future I’d consider just provide a pen & a schedule when people register, or maybe nothing at all.
We over-catered, especially on the wine and nibbles for the poster session. We had ~50 people and we would probably have been better ordering for ~30. We didn’t get much advice on how much food was appropriate for 50 people, so we wasted quite a lot of food and cash. I’m not sure how this can be resolved, but there must be some good resources somewhere that can help with catering budgets.
Germans like good coffee and beer and are very happy to let you know about these preferences. Next time round I’d offer much less wine and more beer (alcoholic and non-alcoholic) at the poster session.
It’s at least a 2 person job. I was really grateful to Soazig for co-organising the meeting, and she in fact did all the hard stuff like chasing people for abstracts, organising the food and troubleshooting during the meeting (she found fans, printed posters, booked restaurants, taxi’s & tours, sourced plugs & adaptors and no doubt all sorts of other things I don’t know about).
It’s expensive. Even with relatively budget accommodation our meeting will probably come in at >6k. We included funds for the meeting in the grant (thank you ESRC!) but we still needed some extra financial support from the Durham Psychology Department, for which I am also very grateful.
I first heard about PSP as a graduate student when I read a paper describing an unusual and devastating disease characterised by paralysis of the eyes. The paper reported a striking result: people with PSP had a problem moving attention that was not experienced by people with Parkinson’s disease. At the time I was doing my doctoral research and the result seemed to have profound implications for our theoretical understanding of attention. I didn’t realise at this time was that it might also be important for the purposes of diagnosis. I was keen to explore how PSP affected attention further, but unfortunately due to the rarity of the condition we had no luck finding participants. At this point end I moved on to working with stroke survivors. However, as my career progressed I often thought about the condition, and one day happened to mention it to Dr Neil Archibald, consultant neurologist at James Cook University Hospital. He had a particular interest in PSP and was keen to collaborate. He put me in touch with the PSP Association, and together we ran a workshop with patients, carers, clinicians and academics to generate research ideas.