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
We’re delighted to announce that the journal “Cortex” has agreed to host a special issue based around the Symposium on “Cognitive & Motor Processes in Visual Attention” we hosted in Durham earlier this year! The SI will be edited by Dan, Soazig, Stefan and Thomas and is a really exciting opportunity to share work on the relationship between cognition and motor control. The call for papers and SI description is below and is available on the Cortex website . The submission portal will open on 15th February and close on 15th July.
The ability to orient attention in space is fundamental to our ability to successfully interact with our environment, as demonstrated by the profound problems experienced by patients with neuropsychological deficits of attention. Understanding the mechanisms of attentional orienting has been central question in cognitive neuropsychology, and although much progress has been made some important questions remain unanswered. For example, there is broad agreement that there is some relationship between the motor processes involved in the control of eye-movements and the cognitive processes involved in attentional selection. However, the precise nature of this relationship remains controversial, with some scholars arguing for an almost complete functional overlap, others arguing for complete functional dissociation and a variety of views between these poles. Furthermore, the interplay between visuospatial working memory, visuospatial attention and oculomotor control is not well understood, despite great progress in understanding the neural and cognitive mechanisms of each individual processes. Finally, it is not clear to what extent the theoretical advances in understanding the interactions between spatial attention and oculomotor control can be used inform the development of new therapies for neuropsychological disorders such as hemianopia and neglect. This special issue will bring together empirical and review articles that offer new insights into the functional role of attentional and motor systems in cognitive processes, and/or seek to apply the principles that govern the relationship between attention, memory and motor control to solving applied questions relating to the clinical diagnosis and rehabilitation of neuropsychological disorders.
This week our Psychology seminar was given by Dr Bianca de Haan from Brunel University, who came to explain her research on attentional selection in multi target displays. Bianca and I shared an office as PhD students in Nottingham in the early noughties, so I was delighted to have the chance to catch up with her, show off our labs in Durham and hear about her current research. In her talk Bianca presented a series of studies exploring the mechanisms by which we are able to select more than one item in a scene (e.g. when we are required to track multiple moving objects when driving). She began by telling everyone I spent most of my time as a PhD student playing Championship Manager (which is only partly true), then kicked off the science with a study of patients with right brain damage who present with visual extinction, which is their tendency to ignore the leftmost of two simultaneously presented stimuli. She showed that these extinction effects also affected subliminally presented cues. Interestingly, other patients with right brain damage but no extinction also showed disrupted subliminal cueing, indicating that extinction is caused by combination of reduced sensory processing and reduced attentional capacity. I found this quite a striking result, and when Sozaig and I compared notes afterwards we both had the same thought; how do these patients perform when the response is a saccade, not a button press? Bianca then used data from series of neuroimaging studies to argue that the Intraparietal Sulcus is the key anatomical correlate for multi-target selection, and showed that theta-burst TMS over IPS disrupted multi-target selection by reducing the availability of VSWM resources. Interestingly, TMS over TPJ had no effect on selection, despite this region frequently being identified as the locus of extinction by neuropsychological studies. She reflected on some possible reasons for this discrepancy between the neuroimaging and neuropsychological data, concluding that ‘that’s science for you!’. From a theoretical point of view, Bianca’s work is rooted in the Biased Competition view of attention, and during the questions she seemed sceptical of other approaches such as Premotor Theory, although of course there are regions in IPS which code eye-movements. There was also some lively discussion of the nature of the relationship between attention and visuospatial working memory, which Bianca argued were largely the same thing. Overall the talk was very accessible and perfectly pitched for our mixed audience of masters students, PhD students and staff, as was evident by the number of questions at the end. Following the seminar I gave Bianca a quick tour and showed off the Oculomotor Lab, after which Soazig met with her to discuss the MotorBias project. Later in the afternoon we strolled down to the Victoria Inn for Psychology Drinks, then had dinner in the Tapas Factory. I’m really grateful to Bianca for coming up and giving such a thought-provoking seminar which filled my head with lots of ideas for new studies, if only we could find some people with visual extinction…
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.
We read with great interest the recent PNAS paper by Hanning and colleagues, in which they use a variant of Craighero et al’s Eye Abduction paradigm to test the proposal that exogenous covert attention is constrained by the oculomotor range (Smith & Schenk 2012; Casteau & Smith 2019). If you’re not familiar with the paradigm, figure A illustrates the setup. The idea is that by abducting the eye by ~35-40 degrees it is possible to present stimuli at locations that can be seen but cannot be reached with a saccadic eye-movement. This neat procedure decouples perception and oculomotor control, and in 2012 we showed that peripheral cues beyond the oculomotor range did not summon attention (Smith, Rorden & Schenk 2012).
In the Hanning version of the task participants are shown 4 channels of noise, 3 within the range of eye-movements and one beyond. One of the locations is cued for 50ms, and 100ms later a probe appears in one of the channels for 50ms. Participants must report the orientation of the probe with button press. People are really bad at this task, and accuracy is only above chance at the cued location. Critically, this attentional facilitation for the cued location is observed even when the cued channel is beyond the range of eye-movements, contrary to our previous findings. Hanning and colleagues argue this is problematic for premotor theory, and argue the data are more consistent with selection-for-action models like VAM. They conclude that covert, exogenous orienting of attention is not constrained by the range of eye-movements, contrary to our previous findings.
The paper is beautifully presented, the experiment is cleverly designed and on first inspection these data look clear cut. There can be no doubt that the peripheral cues are producing enhanced target detection. So, do we need to abandon our position that covert, exogenous orienting is dependent on oculomotor activation? Perhaps not yet. Hannings’ data are convincing, but as they note in their paper, there are considerable differences in the stimuli used in our lab (e.g. Smith et al., 2012, Casteau & Smith 2018), by Craighero et al., (2012) and by Michalczyk et al., (2018) that show an effect of eye-abduction on covert attention, and those used by Hanning and colleagues. One potentially crucial difference is the difficulty of the task. Hannings’ task is extremely difficult. In fact, it is impossible to accurately discriminate the target unless it is attended (See fig 2b: dprime is ~0 at all uncued locations – you can see the task for yourself here). To understand why this is a problem we need to first consider the rationale for using a non-predictive peripheral cueing task. The reason typically given is that a non-predictive cue gives the participant no incentive to endogenously attend to the cued location, so allows a ‘pure’ measure of exogenous attention. This rationale makes sense when the task is simple detection task or a speeded discrimination, because the participant detects the target regardless of whether or not it appears at the cued location, and the differences emerge in the speed of target detection. However, this rationale does not hold true when the task is so difficult that the target is never detected at uncued locations. Why? Because under these conditions the cue is highly informative from the perspective of the participant; they only ever perceive a target when they attend a cued location, and never detect targets at uncued locations (a similar issue is found in the change blindness literature- see Smith & Schenk 2010). It therefore makes complete sense for participants to adopt an attentional set of ‘endogenously attend cued location’ in order to correctly perform the task. We know that endogenous shifts of attention can be observed at short SOAs, for example in Muller & Rabbit (1989) seminal study there is a beneficial effect of endogenous attention at 100ms SOA, and Tipples (2002) has shown a similar effect for arrows. It therefore seems likely that the peripheral cue used by Hanning et al., engaged both endogenous and exogenous attention, and it was the endogenous component of attention that produced the attentional benefit. If participants are endogenously attending the cued location, the results are in fact in exact accordance with our previous findings and those of Klein and colleagues (1980;1994), which were that endogenous orienting is independent of oculomotor control. A less critical, but still noteworthy issue is that the sample is rather small (n=6 in the critical covert attention task). In contrast, papers showing impaired exogenous attention beyond the oculomotor range tend to have larger samples (N= ~20-25), so there is also a risk that this study was somewhat underpowered to detect the interaction of interest. Hanning et al., also make the valid point that previous studies using eye-abduction did not establish the range of eye-movements for their participants. However, in our 2018 paper we measured each participants own oculomotor range, and again showed a selective deficit for covert exogenous attention at locations beyond the range of eye-movements when the eye was centred in its orbit .
To briefly summarize, Hanning et al., show that a peripheral cue produces attentional facilitation beyond the EOMR. The evidence for this effect is very clear, and we do not dispute that participants did indeed covertly orient to the cued location. However, we do dispute the claim that this shift of attention is exogenous in nature. Rather, we believe it is more likely that participants endogenously oriented to the peripheral cue because it was the only way to successful complete the task, and that the improved performance at the cued location is caused by this endogenous shift of attention. We agree with the conclusion that the data are problematic for premotor theory, but only because they show that endogenous orienting is possible to locations that cannot become the goal of a saccade.
We asked Hanning & colleagues if they would like to reply to our comment, and will add it here ASAP if they do. Nina will be joining us in Durham for our workshop and we’re looking forward to some lively discussions! (there are still some places if you fancy joining us)
References
Casteau, S.; Smith, D.T. Covert attention beyond the range of eye-movements: Evidence for a dissociation between exogenous and endogenous orienting. Cortex [Google Scholar] [CrossRef]
Craighero, L.; Nascimben, M.; Fadiga, L. Eye position affects orienting of visuospatial attention. Biol.2004, 14, 331–333. [Google Scholar] [CrossRef]
Hanning, N., Szinte, M,. & Deubel H. Visual attention is not limited to the oculomotor range. Proceedings of the National Academy of Sciences 2019, 116 (19) 9665-9670; DOI: 10.1073/pnas.1813465116
Klein, R.M. Does oculomotor readiness mediate cognitive control of visual attention? Perform. 1980, 8, 259–276. [Google Scholar]
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This week our Psychology seminar was given by Dr Bianca de Haan from Brunel University, who came to explain her research on attentional selection in multi target displays. Bianca and I shared an office as PhD students in Nottingham in the early noughties, so I was delighted to have the chance to catch up with her, show off our labs in Durham and hear about her current research. In her talk Bianca presented a series of studies exploring the mechanisms by which we are able to select more than one item in a scene (e.g. when we are required to track multiple moving objects when driving). She began by telling everyone I spent most of my time as a PhD student playing Championship Manager (which is only partly true), then kicked off the science with a study of patients with right brain damage who present with visual extinction, which is their tendency to ignore the leftmost of two simultaneously presented stimuli. She showed that these extinction effects also affected subliminally presented cues. Interestingly, other patients with right brain damage but no extinction also showed disrupted subliminal cueing, indicating that extinction is caused by combination of reduced sensory processing and reduced attentional capacity. I found this quite a striking result, and when Sozaig and I compared notes afterwards we both had the same thought; how do these patients perform when the response is a saccade, not a button press? Bianca then used data from series of neuroimaging studies to argue that the Intraparietal Sulcus is the key anatomical correlate for multi-target selection, and showed that theta-burst TMS over IPS disrupted multi-target selection by reducing the availability of VSWM resources. Interestingly, TMS over TPJ had no effect on selection, despite this region frequently being identified as the locus of extinction by neuropsychological studies. She reflected on some possible reasons for this discrepancy between the neuroimaging and neuropsychological data, concluding that ‘that’s science for you!’. From a theoretical point of view, Bianca’s work is rooted in the Biased Competition view of attention, and during the questions she seemed sceptical of other approaches such as Premotor Theory, although of course there are regions in IPS which code eye-movements. There was also some lively discussion of the nature of the relationship between attention and visuospatial working memory, which Bianca argued were largely the same thing. Overall the talk was very accessible and perfectly pitched for our mixed audience of masters students, PhD students and staff, as was evident by the number of questions at the end. Following the seminar I gave Bianca a quick tour and showed off the Oculomotor Lab, after which Soazig met with her to discuss the MotorBias project. Later in the afternoon we strolled down to the Victoria Inn for Psychology Drinks, then had dinner in the Tapas Factory. I’m really grateful to Bianca for coming up and giving such a thought-provoking seminar which filled my head with lots of ideas for new studies, if only we could find some people with visual extinction…
