Jan van Erp

EEG-Based Navigation from a Human Factors Perspective

In this chapter we discuss Brain-Computer Interfaces (BCIs) as navigation devices from a Human Factors point of view. We argue that navigation is more than only steering a car or a wheelchair. It involves three levels: planning, steering and control, linked to cognition, perception and sensation, respectively. We structure the existing BCIs along those three levels. Most existing BCIs focus on the steering level of navigation. This is a remarkable observation from a Human Factors perspective because steering requires a very specific subclass of control devices that have a high bandwidth and a very low latency like joysticks or steering wheels; requirements that can not be met with current BCIs. We recommend exploring the potential of BCIs for the planning level, e.g. to select a route, and for the control level, e.g. based on possible collision-related potentials.

Aging and Sensitivity to Illusory Target Motion With or Without Secondary Tasks

Older individuals seem to find it more difficult to ignore inaccurate sensory cues than younger individuals. We examined whether this could be quantified using an interception task. Twenty healthy young adults (age 18-34) and twenty-four healthy older adults (age 60-82) were asked to tap on discs that were moving downwards on a screen with their finger. Moving the background to the left made the discs appear to move more to the right. Moving the background to the right made them appear to move more to the left. The discs disappeared before the finger reached the screen, so participants had to anticipate how the target would continue to move. We examined how misjudging the discs motion when the background moves influenced tapping. Participants received veridical feedback about their performance, so their sensitivity to the illusory motion indicates to what extent they could ignore the task-irrelevant visual information. We expected older adults to be more sensitive to the illusion than younger adults. To investigate whether sensorimotor or cognitive load would increase this sensitivity, we also asked participants to do the task while standing on foam or counting tones. Background motion influenced older adults more than younger adults. The secondary tasks did not increase the backgrounds influence. Older adults might be more sensitive to the moving background because they find it more difficult to ignore irrelevant sensory information in general, but they may rely more on vision because they have less reliable proprioceptive and vestibular information.

Are food cinemagraphs more yummy than stills

Cinemagraphs are a new medium that is intermediate between photographs and videos: most of the frame is static, while some details are animated in a seamless loop. Given their vivid appearance we expected that food cinemagraphs evoke stronger affective and appetitive responses than their static counterparts (stills). In this study we measured the Liking (affective) and Wanting (appetitive) responses to both cinemagraphs and stills representing a wide range of different food products. Our results show that food cinemagraphs only slightly increase Wanting scores and do not affect Liking scores, compared to similar stills. Although we found no main effect of image dynamics on Liking, we did observe a significant effect for some individual food items. However, the effects of image dynamics on Liking and Wanting appeared to be product specific: for some products dynamic images were scored higher on Liking or Wanting, while static images were scored higher for other products. This suggests that image dynamics intensifies subjective Liking and Wanting judgements but does not alter their polarity. Further research is needed to resolve this issue.

Graphical uncertainty representations for ensemble predictions

We investigated how different graphical representations convey the underlying uncertainty distribution in ensemble predictions. In ensemble predictions, a set of forecasts is produced, indicating the range of possible future states. Adopting a use case from life sciences, we asked non-expert participants to compare ensemble predictions of the growth distribution of individual children to that of the normal population. For each individual child, the historical growth data of a set of 20 of its best matching peers was adopted as the ensemble prediction of the child’s growth curve. The ensemble growth predictions were plotted in seven different graphical formats (an ensemble plot, depicting all 20 forecasts and six summary representations, depicting the peer group mean and standard deviation). These graphs were plotted on a population chart with a given mean and variance. For comparison, we included a representation showing only the initial part of the growth curve without any future predictions. For 3u2009months old children that were measured at four occasions since birth, participants predicted their length at the age of 2u2009years. They compared their prediction to either (1) the population mean or to (2) a “normal” population range (the meanu2009±u20092(standard deviation)). Our results show that the interpretation of a given uncertainty visualization depends on its visual characteristics, on the type of estimate required and on the user’s numeracy. Numeracy correlates negatively with bias (mean response error) magnitude (i.e. people with lower numeracy show larger response bias). Compared to the summary plots that yield a substantial overestimation of probabilities, and the No-prediction representation that results in quite variable predictions, the Ensemble representation consistently shows a lower probability estimation, resulting in the smallest overall response bias. The current results suggest that an Ensemble or “spaghetti plot” representation may be the best choice for communicating the uncertainty in ensemble predictions to non-expert users.

Methods for Evaluating Emotions Evoked by Food Experiences: A Literature Review

Besides sensory characteristics of food, food-evoked emotion is a crucial factor in predicting consumers food preference and therefore in developing new products. Many measures have been developed to assess food-evoked emotions. The aim of this literature review is (i) to give an exhaustive overview of measures used in current research and (ii) to categorize these methods along measurement level (physiological, behavioral, and cognitive) and emotional processing level (unconscious sensory, perceptual/early cognitive, and conscious/decision making) level. This 3 × 3 categorization may help researchers to compile a set of complementary measures (“toolbox”) for their studies. We included 101 peer-reviewed articles that evaluate consumers emotions and were published between 1997 and 2016, providing us with 59 different measures. More than 60% of these measures are based on self-reported, subjective ratings and questionnaires (cognitive measurement level) and assess the conscious/decision-making level of emotional processing. This multitude of measures and their overrepresentation in a single category hinders the comparison of results across studies and building a complete multi-faceted picture of food-evoked emotions. We recommend (1) to use widely applied, validated measures only, (2) to refrain from using (highly correlated) measures from the same category but use measures from different categories instead, preferably covering all three emotional processing levels, and (3) to acquire and share simultaneously collected physiological, behavioral, and cognitive datasets to improve the predictive power of food choice and other models.

Effects of aging on illusory target motion in a hitting task.

Age-related changes in multisensory integration (MSI, brain integration of multiple unisensory signals) were investigated. Accurate MSI is a key component of successful aging and crucial to perform activities of daily living (ADLs). Previous research suggests that with aging, different sources of sensory information are not properly weighted anymore. Twenty healthy younger (YA, age 18-34) and twenty-four healthy older adults (OA, age 60-82) were asked to hit discs moving downwards on a screen with their index finger. Illusory direction of motion was included (moving a checkerboard-like background either to the left or right). The discs disappeared before the screen was reached. Experimental conditions were: sitting (baseline), standing on foam (balance task), and sitting while doing a cognitive dual task (counting task). Participants hit the disc more to the right for left background motion compared to right background motion, conforming the illusory effect. OA show a larger effect of the illusion compared to YA in the baseline and balance conditions (p=.036 and p=.047, respectively). The same tendency was shown in the counting condition. Overall, background motion had a greater influence on the counting condition compared to the other conditions (p=.005 for YA and p=.009 for OA). No significant differences were found for the summed reaction and movement time, and no correlations between hitting performance and results of clinical pretests were found. We conclude that OA are more affected by the background motion than YA, which supports the idea that OA do not weigh information properly. Our finding that a cognitive dual task increases the illusion effect in both groups of participants suggests that cognitive resources are required for proper weighting, which may be a problem for OA. Future research will include OA with ADLs difficulties in order to develop a toolkit for early detection of MSI problems in the elderly population.