Spatial Working Memory and Saccades

This month I attended the London meeting of the Experimental Psychology Society. I presented preliminary analysis of some eye movement data we recorded whilst people perform a task based upon a widely used computerised neuropsychological test of spatial working memory (Cambridge Cognition Ltd’s CANTAB SWM test).

Spatial working memory refers to the short term storage of information in memory about where things are in space for guiding our behaviour and actions. In the Cantab task “tokens” are hidden under boxes on a screen and participants have to search for them by clicking with a mouse on the boxes and remember where they found the tokens to guide subsequent box selections (as tokens are never hidden under the same location twice). As you can see in the videos here: participants make quite a lot of eye movements in the task! So the challenge has been to make sense of how eye movements are guided. Are they shaped by the memory of where tokens have been found, such that the eyes help to keep track of the route covered? Or do they exclusively plan a search route ahead selecting the next box to be clicked on? Might eye movement measures extracted from the task be useful in assessing memory problems?

thumb2 Our analysis suggests that most eye movements look ahead and select the next box to be clicked on well in advance of the mouse click which reveals its contents. However, particularly in a few participants, the eyes also get drawn back to locations where tokens have already been found, even if they don’t click on the box, indicating that they do actually remember that a token hasnt been found there (see here for a nice example: These subjects were more likely to go on to make lots of actual click errors in the most difficult version of the task though, suggesting eye movements measures may be more sensitive than just mouse clicks.

We have more analysis and work to do with this task and hope to get some people with Parkinsons to do the test as we think they may show subtly different patterns of eye movements in the task to otherwise healthy individuals.

The fingers, not the eyes, have it

Next week we will be presenting our work on orienting to socio-biological cues in children at the 17th European Conference on Eye Movements in Lund, Sweden.

me and eyetrackerAt last years Lincoln Summer Scientist event we asked children to play a game in which they followed a cartoon bee jumping to the left or right with their eyes whilst distracting pictures of arrows, pointing fingers and someone else’s eyes gazing to the left or right were shown in the middle of the screen.  We tracked their eye movements with an Eyelink 1000 eye tracking system and measured how quickly they made saccades to follow the bee.

We found that the youngest children (4-5 year olds) showed a large “congruency” effect for pictures of pointing fingers such that their speed of looking was slowest when the bee jumped in the opposite direction to that in which the hand pointed. Surprisingly, although the pre-schoolers weren’t similarly affected by pictures of eyes and arrows, older fellow summer scientists showed an equally strong congruency effect for all three types of cue (hand, eye and arrows).

The results are potentially very interesting and important in respect to understanding the best ways to direct young children’s attention quickly and effectively in an educational context as well as keeping them away from harm inside or outside of the home, but they might also have more profound implications. Rather than having hard wired “social brain” systems for processing socio-biological stimuli as suggested by some theorists, instead the brain may learn to form fast connections between what we see and what we do in early childhood. It just happens that pointing fingers may be among the first cues children learn to use in this way.

busy bee

We’re looking forward to finding out what other researchers think of our results in Lund and plan to replicate the finding at this years Lincoln Summer Scientists event. The work is carried out in collaboration with Nicola Gregory (Bournemouth University Face Research Centre). The work is part supported by the WESC foundation for Childhood Visual Impairment.



British Oculomotor Group Meeting – Kingston

This week I will be presenting my research on how damage to the prefrontal cortex affects eye movements at the 24th British Oculomotor Group Meeting (BOMG) hosted by the Eye Movements and Cognition Lab at Kingston University.

Whilst at Cambridge University  on Sabbatical in 2009 I was privileged to work with a group of patients with very localised damage affecting the very front of the brain. In most cases this was due to unavoidable collateral damage occurring when a brain tumour had been surgical removed. People with this type of brain injury are often remarkably unaffected by their injury and it can often be quite hard for a psychologist to find tasks that they can’t do perfectly well! But my research found that they made significantly more mistakes when required to switch between rules linking 3 different coloured cues with eye movements towards 3 possible locations (e.g. blue=up, red=left and yellow=right). These videos from my You Tube Eye Movements site show example trials from the task (

MRI scan image





One outstanding question following on from this research is whether this impairment in an artificial computer based task in the psychology lab might have implications for what things people with this type of brain injury can or can’t do in the real world. We often have to make arbitrary connections between what we see and where we look during every day tasks and these patients may find this particularly difficult.

Please feel free to get in touch with me if you are interested in this research for whatever reason and I can tell you more about it.

See also: Research explores rule switching across the life span

Understanding and Improving Functional Vision in Specialist Education

On 25th April I will be speaking at the West of England School and College (WESC) conference on understanding and improving functional vision. I will be giving an overview of my research on the brain systems underlying eye movement control and how they are affected in cases of neurological damage entitled Eye movements, visual attention and the brain.

WESC is a visual impairment specialist school and further education provider in Exeter with an outstanding reputation for excellence and innovation. We are developing an exciting new collaboration to embed visual neuroscience expertise and knowledge in specialist education where to date the emphasis has been upon the role of the eye itself in vision rather than the brain.

Experimental Psychology Society Meeting – Hull 11th-13th April 2012

Two of my former PhD students (Nicola Gregory and Sarah Bate) and ex post-doc (Ben Parris) were among the presenters at this years spring EPS meeting in Hull.

Nicola Gregory’s work described how processing of socio-biological cues is affected following damage to a part of the brain known as the orbitofrontal cortex, while Sarah Bate’s presentation described how people with prosopagnosia (so called “face blindness”) can benefit with treatment using the drug Oxytocin applied using a simple nasal spray. The drug has the effect of making them better at recognising faces they have seen before.

Ben Parris’s work looks at how cognitive function can be influenced through hypnosis. His remarkable results show how the “Stroop effect” (in which people are slower to name the colour of words which spell out another colour e.g. “RED” printed in blue) can be eliminated under certain conditions simply by placing the suggestion in peoples mind that the words are written in an incomprehensible language.

The Conference also included a symposium on associative learning in honour of Geoffrey Hall and an excellent talk on decision making for self and others by University of Lincoln’s own Fenja Ziegla, as well as my own work on rule learning in People with Parkinsons.