Today was a momentous day as Siobhan submitted her PhD thesis, “Examining the representation of spatial short term memories through the lens of resource allocation theory”. The main take-home is that spatial short-term memory is best characterised as a flexible resource that is constrained by the amount of cortical space available, as predicted by the cortical maps hypothesis of Franconeri et al., (2013). We’re all very proud of Siobhan, especially as her PhD was profoundly disrupted by the pandemic, and it’s a real testament to her resilience and ability that 2 chapers have already been published (McAteer et al., 2023 in JoV and McAteer et al., 2023 in AP&P) with 2 more under review. It has been a real pleasure to have Siobhan in the lab and we’ve all learned a lot, especially about mixture modelling :-). Siobhan will be leaving us in August to take a postdoc position at Louvain University for the next step in what we’re sure will be a brilliant career. Well done and good luck Siobhan!
McAteer, Siobhan M. and McGregor, Anthony and Smith, Daniel T. (2023) ‘Oculomotor rehearsal in visuospatial working memory.’, Attention, Perception, & Psychophysics, 85 (1). pp. 261-275.
McAteer, Siobhan M. and Ablott, Emma and McGregor, Anthony and Smith, Daniel T. (2023) ‘Dynamic resource allocation in spatial working memory during full and partial report tasks.’, Journal of Vision, 23 (2). p. 10.
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.
People with PSP often experience problems with their vision. A very common issue is a paralysis of the eyes which prevents the person from looking downwards. This vertical gaze paralysis makes it hard to do everyday tasks that usually require looking down; such as reading, using an electronic device (e.g., phone, tablet, or computer keyboard), and cutting up food. One solution that is often recommended is to use light-bending prism glasses, shown in the top figure. These glasses bend light from the lower portion of the visual field so the person can see things they cannot look at directly. In principle this seems like an effective solution that should allow people with PSP to retain some of their independence. However, somewhat surprisingly, there is very little scientific evidence that people with PSP benefit from using prisms. Furthermore, very little is known about how and why people use prism glasses, what kind of instruction or training they are given, and what challenges or issues people with PSP experience when trying to use prisms. To try and start answering these question, Dr Ali Lane and I supervised a research project by two masters students (Dan Ford and James Ireland) in which 35 people with PSP were recruited with the help of the PSP Association to tell us about their experiences of using prism glasses.
The majority of participants (74%) had heard of prism glasses, and of these participants 76% had actually tried them. The most common source of information about prisms was a neuro-ophthalmologist (40%), followed by the PSP association (20%), and the most common source of the prisms themselves was an NHS prescription. When we asked about the kinds of things prisms helped people with the most common response was reading (37% of people), followed by eating (24%), using electronic devices (19%), and watching TV (19%). However, when we asked whether people still used the prisms only 20% of people reported persisting with them. This relatively low adherence may be related to the frequency with which people reported experiencing unpleasant side effects such as disorientation (37.5%) and double vision (19%), and practical problems with the weight and fit with existing eyewear. Overall, 43% of people agreed or strongly agreed that the found the prisms useful, but only 18.5% agreed that they liked the prisms.
The results of our survey indicate that while many people with PSP are aware of prism glasses, there is scope to improve patient knowledge of this rehabilitation aid. Furthermore, while some people find them useful for reading, eating, and using electronic devices, most people with PSP do not appear to benefit from prisms or they find them hard to use. Even those who do find them beneficial do not reliably persist with their use. It is likely that better fitting and more systematic training and practice would improve the usefulness of the prisms and reduce the negative impact of side-effects such disorientation. Indeed, there is evidence from stroke survivors with inattention that training improves adherence and outcomes of prism glasses therapy. However, no such training exists for people with PSP.
It is important to be cautious when drawing conclusions from a relatively small sample, but the findings seem to suggest that current approaches to prism therapy for PSP are, unfortunately, relatively ineffective. We believe this is likely due to a lack of reliable training advice for patients, which results from a dearth of scientific evidence about the optimal way to train people in the fitting and use of prisms for different tasks. The only way to resolve this issue is to conduct more evidence-based research that can establish the optimal way to use prism glasses for the rehabilitation of PSP. We are currently looking for ways to fund more research in the important area and would be interested in hearing from people who are considering studying for a PhD on this topic.
You can learn more about our other research into attention and memory in PSP here
We’re all very excited about EPS online next week. We’ve got posters from Dan, Soazig and Siobhan uploaded to the OSF site and presentations from Siobhan and Dan (whose talk is much too long at 8mins, but some just people love the sound of thier own voice 😉 ). It’ll be our first online conference so not really sure what to expect, but hopefully we can foward to some lively discussions!
Soazig’s poster describes some work we did with an excellent group of dissertation students, whose project explored the impact of holding things in WM on presaccadic attention. The take-home here is that we got some nice interference effects, suggesting some shared control between presaccadic attention and VWM: https://osf.io/djrvz/
Siobhan’s poster outlines the first complete experiment from her PhD, which was a conceptual replication of Schneegans & Bayes (2016) study that argued for a resource model of spatial working memory. She replicated the basic finding, but the devil is in the detail, as excluding trials with eye-movements produces some interesting changes to the modelling https://osf.io/nphqv/
Dan’s poster argues that a classic claim in cognitive psychology (that eogenous attention gradually accumulates at a cued location) is probably wrong, and instead argues that exogenous attention is fully deployed by at least 30ms after cue onset https://osf.io/tn3gz/
Finally, if you’re interested in social attention you should check out Dr Emma Morgan’s poster showing how autistic traits modulate the effects of mental state attribution on gaze cueing /https://osf.io/ud2yz/.
Hope you enjoy our posters and talks, we’ll be available for discussion via twitter if you have any questions: @AttentionLab, @SoazigCasteau, @SiobhanMcateer4
Coronavirus has meant many of our projects have ground to a halt, but in spite of the disruption we’ve been pressing on by moving some research online. Something we’re delighted to be making progress with is Dan Ford and James Ireland’s MSc project, which explores the use of prism glasses by people with Progressive Supranuclear Palsy (PSP). People with PSP often have problems looking downwards, which makes it hard for them to see what is happening in the lower visual field. Many everyday tasks like eating, reading and using a computer rely on being able to look down into the lower part of the visual field, which makes them very difficult for people with PSP. Prism glasses bend the light so that that the lower visual field can be seen without having to move the eyes. They are cheap and easy to use, so appear to have great potential as a compensatory tool. They are widely used to treat other neurological disorders which affect vision, such has hemispatial neglect and hemianopia.
However, prisms do have some disadvantages. For example, they can be heavy and it takes time to get used to the way they change how the world looks. Furthermore, nobody really knows how useful they are or how widely used they are because nobody has asked people with PSP. Dan and James’s project aims to start answering this important issue by surveying people with PSP about their attitudes towards, and experiences of, using prism glasses. It’s one of the first surveys of its kind and we’re hoping that the results will help us better understand how people use prisms, whether they find them useful, and/or the problems or impediments that people experience when using prism glasses. If you have PSP and would like to take part the questionnaire can be found here:
Dan and James are being supervised by Dr Alison Lane and the project is a collaboration with the PSP Association. You can find out more about Dr Ali Lane’s research on neurorehabilitation on her homepage.
If you are interested, some of our related research can be found here:
Smith, D.T. & Archibald, N. (2018). Visual Search in Progressive Supranuclear Palsy. In Processes of Visuo-spatial Attention and Working Memory. Hodgson, T. Berlin, Heidelberg: Springer. 305-324.
memories through the lens of resource allocation theory”. The main take-home is that spatial short-term memory is best characterised as a flexible resource that is constrained by the amount of cortical space available, as predicted by the cortical maps hypothesis of Franconeri et al., (2013). We’re all very proud of Siobhan, especially as her PhD was profoundly disrupted by the pandemic, and it’s a real testament to her resilience and ability that 2 chapers have already been published (McAteer et al., 2023 in JoV and McAteer et al., 2023 in AP&P) with 2 more under review. It has been a real pleasure to have Siobhan in the lab and we’ve all learned a lot, especially about mixture modelling :-). Siobhan will be leaving us in August to take a postdoc position at Louvain University for the next step in what we’re sure will be a brilliant career. Well done and good luck Siobhan!
downwards, which makes it hard for them to see what is happening in the lower visual field. Many everyday tasks like eating, reading and using a computer rely on being able to look down into the lower part of the visual field, which makes them very difficult for people with PSP. Prism glasses bend the light so that that the lower visual field can be seen without having to move the eyes. They are cheap and easy to use, so appear to have great potential as a compensatory tool. They are widely used to treat other neurological disorders which affect vision, such has hemispatial neglect and