Potential of Subliminal Perception

We propose to employ subliminal techniques as encouraging approach to provide the driver with (noncritical) driving related information without dissipating available attention resources. The notion that stimuli presented below conscious awareness could influence cognition is not new - Peirce and Jastrow were the first reported in 1884 that people could perceive small differences in pressure to the skin without conscious awareness of different sensations. Moreover, it is well known that certain subliminal cues can facilitate certain behaviors. For example, store chains sprays fragrances with a subtle influence outside their stores to attract customers, background music in shopping malls is said to increase sales by subliminally stimulating shoppers, and millions of people buy subliminal audiotapes to help them lose weight or increase their assertiveness.

In this workshop, we will pick up on these ideas and put them into an automotive context. The central objective is to provoke an active debate on the adequacy of information provided below active awareness as well as to discuss potential problems as this is "highly risky research". Subliminal information processing raises elementary questions like
  • "How good is the mind at extracting meaning from stimuli of which one is not consciously aware?"
  • "How to measure the positive effect of subliminal information cues?" or
  • "How something presented subliminally would persuade a driver if he/she did not consciously attend to it?" (as it is generally accepted that such stimuli are weak and often presented at very low intensity)

To answer these questions we would like to invite researchers to take part in an in-depth discussion of this timely, relevant, and important field of investigation to - in case of supported positive effects - increase road safety and/or improve driving performance. We assume that a broader knowledge of subliminal perception and persuasion would have much potential also to improve driver-vehicle interaction. It has to be pointed out, however, that this is high risk research and it cannot be taken for granted at all that answers can be found to the stated research questions. The fact that subliminal information pose high danger for driver, passengers, and other road participants (if used in real traffic and for driving related information) has to be emphasized when defining/conducting experiments in the wild.

Topics of Interest

Potential topics to be covered in position papers and discussed at the workshop include, but are not limited to

  • Taxonomy (definition, terminology) of terms implicit, subliminal, supraliminal, priming, conscious, preconscious.
  • Philosophy or rationale for the use of subliminal interfaces.
  • How to reduce "risk" in subliminal interfaces?
  • Socio technical issues, e.g., social acceptance and/or aversion/repulsion about this type of technology?
  • How fast do people perceive information presented in a subliminal way? Is it fast enough to be used in a vehicular setting?
  • Is the perceived information difficult to interpret?
  • Is there an influence on individual differences like age, gender, intelligence, characteristics, abilities and disabilities, cognitive style, cultural differences, etc.?
  • Evaluation techniques for the perception of subliminal information
  • What, if any, is the impact of information communicated subliminally to further information submitted explicitly?
  • What differences in "dual information presentation" using subconscious and conscious channels can be discovered?
  • Is a replacement of consciousness by subliminally delivered information directly results in an increase in road safety?
  • Is a impact of subliminally delivered information discoverable on the cognitive load or perceived workload (e.g., NASA TLX)?
  • What are appropriate subliminal techniques for workload reduction while driving? More specific,
    1. Unobtrusive way of drivers' state detection (e.g., facial expression detection, grip strength detection, etc.),
    2. Subliminal display of drivers' state or adaptive interfaces (dynamically changing contents and/or formats of visual display, sonification (of EEG, alpha wave), etc.),
    3. Mitigation or regulation interfaces (speech-based interfaces or driving coach, mitigation using music, fragrances, etc.)
  • Subliminal interfaces for the automotive domain (head-up displays, vibro-tactile transducers, olfactory stimulation, brain-computer interfaces (BCI))
  • What are characteristics of subliminally delivered information (e.g., reachable bandwidth, natural bounds, complexity of information, speed of perception, appropriate modalities, strength/duration/frequency of subliminal interaction)?
  • Potential of subliminal cues to guide a driver to the right course of action or to a specific emotional state?