Centre for Cognitive Neuroscience and Cognitive Systems

CCNCS Seminar Details

Breakthrough Percepts - Subliminal Salience Search, Brain Computer Interaction and Deception Detection on the Fringe of Awareness

Speaker: Howard Bowman
Date/Time: Wednesday 18 December 2013, 4.15pm
Location: Woolf College W1-SR6.


We use the term Subliminal Salience Search (SSS) to describe humans' extraordinary capacity to preconsciously "locate" stimuli that are, in a broad sense, salient to them [Bowman et al, 2013]. Although often not framed in these terms, there are many demonstrations of SSS, e.g. classic "pop-out" visual search. But a particularly compelling demonstration is in Rapid Serial Visual Presentation (RSVP), in which the vast majority of stimuli presented are not consciously perceived (hence the term subliminal), but ones that are salient breakthrough into consciousness and are perceived (hence the term search). In addition, we now have an electrophysiological correlate of such perceptual events - a P3 component is only present when a stimulus is consciously perceived. This gives us a way to determine what a participant's brain selects, either on the basis of task set or intrinsic salience, from scalp recorded EEG.

We will discuss some of the theoretical issues associated with subliminal salience search and how models, such as the Simultaneous Type/ Serial Token model [Bowman & Wyble, 2007], explain it. But then our main focus will be on application of EEG-marked SSS in deception detection [Bowman et al, 2013] and brain-computer interaction [Chennu et al, 2013]. We will particularly focus on the former of these and our recent demonstration that our fringe/ P3-Rapid identity detector is resilient against countermeasures, e.g. artificially elevating the response to the control stimulus.

Bowman, H. and Wyble, B. (2007) The Simultaneous Type, Serial Token Model of Temporal Attention and Working Memory. Psychological Review, 114 (1). pp. 38-70. ISSN 0033-295X.

Bowman, H. and Filetti, M. and Janssen, D.P. et al. (2013) Subliminal Salience Search Illustrated: EEG Identity and Deception Detection on the Fringe of Awareness. PLoS ONE, 8 (1). pp. 1-21. ISSN 1932-6203.

Chennu, Srivas and Alsufyani, Abdulmajeed and Filetti, Marco et al. (2013) The cost of space independence in P300-BCI spellers. Journal of NeuroEngineering and Rehabilitation, 10 (82). pp. 1-13. ISSN 1743-0003.

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Centre for Cognitive Science and Cognitive Systems, School of Psychology, University of Kent, Canterbury, Kent CT2 7NP

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Last Updated: 24/05/2013