By Karolyn Webb
School of Psychology & Sport Science
Anglia Ruskin University, Cambridge, UK
Anglia Ruskin University’s Experimental Psychology provision is mostly powered by E-Prime – as a Technician in the School of Psychology and Sport Science, it is the most flexible, user-friendly and powerful tool in my arsenal. We train undergraduates on its use throughout the academic year but equally, we create highly complex, bespoke programs with our lecturers and research students.
For my own PhD research, E-Prime is essential not only for the presentation of stimuli but also for controlling external peripherals and guaranteeing timing. My research concerns the role of experience in driving and the impact of this on driving performance – driving and road usage involves a level of risk that many would not accept in other activities – almost 1,800 people will die on UK roads this year (Department of Transport, 2017). My aim is to investigate the underlying human factors that contribute to driving performance and ultimately, to design interventions that reduce the skill gap between novice and experienced drivers.
As part of this research, I am using EEG to analyse brain activity during hazard perception and risk analysis tasks. As EEG involves traditionally static stimuli, in order to eliminate ocular artefacts and to have accurate event markers to produce a stereotyped Event Related Potential (ERP), I was faced with the option of reducing ecological validity by using static imagery or finding another approach. I turned to other areas in psychology for an alternative methodology and stumbled across the use of Eye Fixation Related Potentials (EFRP) in the reading literature. Reading suffers the same issues as driving in that looking at single words presented in the centre of the screen is not “reading” (Baccino, 2012).
The lab has evolved over the space of a year, as we moved in to our purpose built Science Centre – this allowed us to bring in newer equipment and software.
The current lab set up uses two high-powered custom built PCs with hardware from Tobii Pro, Brain Products GmbH and AD Instruments, providing us with a battery of tools to comprehensively measure a variety of cognitive and physical responses. Running on the stimulus PC is E-Prime 3.0 and Tobii Pro Lab, and I am using a Tobii TX-300 and a customised Tobii I-VT filter to reduce noise in the eye tracking data.
The AD Instruments PowerLab is connected to the Acquisition PC, as well as the Brain Products EEG equipment. This consists of two BrainAmp amplifiers and an ActiCap 64 Channel cap. AD Instruments’ LabChart Pro collects data relating to Galvanic Skin Resistance (GSR), heart rate, respiration rate and skin temperature. We use BrainVision Recorder to capture EEG data and a combination of BrainVision Recorder and the Matlab plugins, EEGLab and EYE-EEG to combine eye tracking data with EEG data.
The jewel in the crown, however, is E-Prime 3.0. E-Prime 3.0 allows us to control and connect all manner of external peripherals. We use the E-Prime Extensions for Tobii Pro to integrate the eye tracker into our research, and the EET’s allow us to mark data with precise timing and accuracy using a local server on the stimulus PC. At present, we script the EEG triggers the old fashioned way but intend to upgrade to the E-Prime Extensions for Brain Products on the basis of how simple the EETs are to integrate. The PowerLab 4/35 is connected to E-Prime through its digital input socket using an AD Instruments E-Prime cable. In this instance, we use Task Events to send trigger information to LabChart Pro.
The current research using this set-up is a replication of the official UK Driving and Motorcyle Hazard Perception test (See here for the official DVSA guide: https://www.youtube.com/watch?v=SdQRkmdhwJs). This involves participants watching a rendered driving scene where they must press a button when they observe an evolving hazard. An evolving hazard is one that requires the driver to take evasive action, either slowing down or altering their direction. If participants identify the hazard within a specific scoring window, they will be awarded 5 points through to 1 point. Participants are allowed to press the “Hazard” button as many times as they like – all of which is necessary to record.
Most of the custom programming was easily achieved using E-Basic inline scripts, with the main structure of the experiment simply constructed using e-objects.
The aim of my research is to compare stereotyped responses to perceived hazards between novice and experienced drivers and to also compare physiological measures between these two groups. The basic set-up should be able to support other EEG studies that use non-static or interactive stimuli such as in computer gaming research.