Visual Attention and Paeleolithic Stone Tools

This month we published a study describing how people direct eye movements during viewing of ancient stone tools. The work was led by Maria Silva Gago, Emiliano Bruner and other researchers from CENIEH University of Burgos Spain together with myself and former Lincoln PhD student Flora Ioannidou (now at University of Aberdeen).

The research used eye tracking and the “mouse click” attention tracking technique to measure which areas of stone tools attracted peoples interest most. High resolution photographs of Paeleolithic hand axes (example right), along with much more ancient (approximate 2 million year old) roughly worked tools (example below) were shown to participants. We found that people’s attention was drawn to the “knapped” surfaces of  tools, as well as areas such as the base where the tool would normally be grasped. This was the case even though participants were just viewing pictures and not handling the objects and weren’t told the objects were tools.

We also ran the images through a computer model which calculated the”salience” of different regions of the images.  Some very influential models of vision suggest that attention is simply attracted to regions that stand out visually from the background (i.e. are more “salient”), but the computer model did not seem to explain our results very well. Instead, we think it was how the different parts of the tool might be grasped and used, rather than just how visually interesting it was, that was directing the viewers’ eyes.

The results support the theory of object-action affordances proposed by James J Gibson in the 1970s. He suggested that the brain very quickly detects features of objects that are relevant for action, priming a tendency for us to carry out the associated action. One possibility is that through evolution our ancestors’ brains became increasingly sophisticated at detecting action affordances in stone objects. This lead in turn to the manufacture of more sophisticated tools with enhanced features designed to activate action affordances. This in turn may have caused further development in the brain’s object-action affordance network in an ongoing process of coevolution between human cognitive capacities and tool complexity.

The full paper is published in the journal Perception and can be read online here.

Some example eye movement sequences recorded in the study are shown below.

“Busy Bee” paper published in Experimental Brain Research

We have a paper published this month in the journal Experimental Brain Research based upon 2 years of data collected at the Lincoln Summer Scientist event which looked at how children’s saccadic eye movements are affected by directional socio-biological cues (see previous posts here and here).

We report results from 137 children who performed a pro-saccade task presented as  a computer game in which they had to keep their eyes on a cartoon bee that jumped unpredictably from the middle to the left or right of a computer screen. The Eyelink II system was used to examine how quickly and accurately the children followed the bee while pictures of arrows and photos of pointing hands and eyes appeared in middle the screen just before the “buzy bee” character moved (see Youtube video).busy bee task

We found that children were distracted by the direction of the pointing pictures such that their eyes were quicker to move towards the cartoon bee when she jumped in the same (Congruent) as opposed to the opposite (Incongruent) direction to the pointing finger, eye or arrow. Interestingly for the youngest group of children (3-5 years) this effect was found most strongly for pointing fingers. Only older children showed the effect for eyes and arrows. The paper makes the case for the view that children have to learn to link what they see in the world around them with the direction of interesting information and events. One of the first “cues” to attention that young children learn may be the direction of an adult’s pointing index finger.

Another interesting finding of the work was that for the youngest group of children when eye gaze cues overlapped with the onset of the peripheral target bee a large proportion of “omission errors” were made such that they missed the target completely and didn’t make a saccade. I was involved in the testing myself at Summer Scientist and I found this feature of young children’s behaviour particularly fascinating. It seems strikingly similar to stimulus “extinction” and ommission errorsneglect seen in adult stroke patients. Rather than just not moving their eyes I think 3-4 year olds didn’t “see” the Bee under these conditions and this is something I’d hope to follow up at future summer Scientist weeks.

The paper is full open access and available here . See here for another recent Experimental Brain Research study I’ve only recently seen by a group in Oslo showing ERP response to finger pointing cues in babies.

A Rewarding Summer of Eye movement Research

Reward and risk on blue road sign with blue sky The Lincoln Eyelink Lab (a.k.a. Lab E1) promises to be a busy place this summer. Undergraduate Research Opportunities Scheme (UROS) students Daniel Richardson and Jade Pickering will be working in the lab between July and August alongside two eye movement researchers from Turkey.

 Daniel Richardson is examining the “neuroeconomics” of reward and eye movements. Together we are developing a task in which participants learn mappings between target stimuli and points rewards. We are interested in whether the learned reward value of stimuli might subtley modify the kinematics (speed and accuracy) of eye movements made towards them.

 Jade Pickering will be assisting with  my investigations of oculomotor and cognitive studies in people with Parkinsons later in the summer as well as collecting some pilot data for the GPSAC project using the Ober saccadometer device.

PhD research student Murat Ozger will be continuing to develop his work on visual attention and eye movements in Crime Scene Investigation settings (see YouTube video).eye

We are also joined by visiting researcher Aycem Ozturk (Dokus Eylul University, Izmir, Turkey) who is in the UK to learn about the Eyelink 1000 system and to further develop her research into oculomotor function in Parkinsons and dementia.

It is exciting for me to be working in such a busy team of researchers this year and I am sure it will be a rewarding summer!

 

GPSAC Research Project Launch Event – 9th April

The General Practice Saccade Assessment Cohort research project (GPSAC) will examine whether a quick, portable and easy to use test of eye movements (saccades) could be used as an all-in-one neurological health check for patients in primary care, capable of detecting early signs of dementia and other brain disorders.  In order to develop the project further it would be useful to get input from local GPs, practice nurses and members of the public on the project idea, design and practical issues facing patients and professionals. 

MRI-scan-of-human-brain-008

With this aim a launch workshop event has been scheduled for spring 2013 which will include a practical demonstration of the saccadometer device, project presentation, lunch and focus group discussions. Travel and other expenses for attendees will be reimbursed.

Date & Time: Tuesday 9th April 2013 11am-2.30 pm

Location: Lincoln Think Tank, Ruston Way, LN6 7FL 

Please contact  me (Tim Hodgson), University of Lincoln to register: email: tlhodgson@lincoln.ac.uk 01522 886159