Cultural background shapes spatial reference frame proclivity

Spatial navigation is an essential human skill that is influenced by several factors. The present study investigates how gender, age, and cultural background account for differences in reference frame proclivity and performance in a virtual navigation task. Using an online navigation study, we recorded reaction times, error rates (confusion of turning axis), and reference frame proclivity (egocentric vs. allocentric reference frame) of 1823 participants. Reaction times significantly varied with gender and age, but were only marginally influenced by the cultural background of participants. Error rates were in line with these results and exhibited a significant influence of gender and culture, but not age. Participants’ cultural background significantly influenced reference frame selection; the majority of North-Americans preferred an allocentric strategy, while Latin-Americans preferred an egocentric navigation strategy. European and Asian groups were in between these two extremes. Neither the factor of age nor the factor of gender had a direct impact on participants’ navigation strategies. The strong effects of cultural background on navigation strategies without the influence of gender or age underlines the importance of socialized spatial cognitive processes and argues for socio-economic analysis in studies investigating human navigation.This work was funded by the European research grant: ERC- 2010-AdG #269716 – MULTISENSE, together with the Cognition and Neuroergonomics/Collaborative Technology Alliance #W911NF-10-2-0022

Automatic and Controlled Processing: Implications for Eating Behavior

It is a widely held view that humans have control over their food choices and consumption. However, research also suggests that eating behavior is often triggered by contextual cues and guided by automaticities and habits. Interestingly, the dichotomy between automatic and controlled processing has recently been challenged, suggesting that they may be intertwined. In a large female sample (n = 567), we investigated the hypothesis that task-based and self-reported measures of automatic and controlled processing would interact and impact self-reported eating behavior. Results analyzed via structural equation modeling suggest that automatic, but not controlled processing, during a modified flanker task, including a context-specific proportion congruent (CSPC) manipulation, was inversely associated with self-reported self-control. The influence of self-control on unhealthy eating behavior (i.e., uncontrolled and emotional eating, heightened consumption of fat and sugar) was only indirect via habitual behavior, which itself had a strong direct impact. Unhealthy eating was further associated with real-life outcomes (e.g., body mass index (BMI)). Our findings suggest that eating behavior may indeed be guided primarily by automaticities and habits, whereas self-control might facilitate this association. Having self-control over eating might therefore be most effective by avoiding contextual cues eliciting undesired automatic behavior and establishing habits that serve long-term goals

Automatic and Controlled Processing : Implications for Eating Behavior

It is a widely held view that humans have control over their food choices and consumption. However, research also suggests that eating behavior is often triggered by contextual cues and guided by automaticities and habits. Interestingly, the dichotomy between automatic and controlled processing has recently been challenged, suggesting that they may be intertwined. In a large female sample (n = 567), we investigated the hypothesis that task-based and self-reported measures of automatic and controlled processing would interact and impact self-reported eating behavior. Results analyzed via structural equation modeling suggest that automatic, but not controlled processing, during a modified flanker task, including a context-specific proportion congruent (CSPC) manipulation, was inversely associated with self-reported self-control. The influence of self-control on unhealthy eating behavior (i.e., uncontrolled and emotional eating, heightened consumption of fat and sugar) was only indirect via habitual behavior, which itself had a strong direct impact. Unhealthy eating was further associated with real-life outcomes (e.g., body mass index (BMI)). Our findings suggest that eating behavior may indeed be guided primarily by automaticities and habits, whereas self-control might facilitate this association. Having self-control over eating might therefore be most effective by avoiding contextual cues eliciting undesired automatic behavior and establishing habits that serve long-term goals.Peer reviewe

Learning new sensorimotor contingencies:Effects of long-term use of sensory augmentation on the brain and conscious perception

Theories of embodied cognition propose that perception is shaped by sensory stimuli and by the actions of the organism. Following sensorimotor contingency theory, the mastery of lawful relations between own behavior and resulting changes in sensory signals, called sensorimotor contingencies, is constitutive of conscious perception. Sensorimotor contingency theory predicts that, after training, knowledge relating to new sensorimotor contingencies develops, leading to changes in the activation of sensorimotor systems, and concomitant changes in perception. In the present study, we spell out this hypothesis in detail and investigate whether it is possible to learn new sensorimotor contingencies by sensory augmentation. Specifically, we designed an fMRI compatible sensory augmentation device, the feelSpace belt, which gives orientation information about the direction of magnetic north via vibrotactile stimulation on the waist of participants. In a longitudinal study, participants trained with this belt for seven weeks in natural environment. Our EEG results indicate that training with the belt leads to changes in sleep architecture early in the training phase, compatible with the consolidation of procedural learning as well as increased sensorimotor processing and motor programming. The fMRI results suggest that training entails activity in sensory as well as higher motor centers and brain areas known to be involved in navigation. These neural changes are accompanied with changes in how space and the belt signal are perceived, as well as with increased trust in navigational ability. Thus, our data on physiological processes and subjective experiences are compatible with the hypothesis that new sensorimotor contingencies can be acquired using sensory augmentation

Processing and Integration of Sensory Information in Spatial Navigation

As nomads, humanity constantly moved and relocated for hundred thousands of years. Thereby, individuals or small groups of people had to navigate over very long distances in order to survive. As a result, successful spatial navigation was one of the key cognitive abilities, which ensured our survival. Although navigation has nowadays become less life-threatening, exploring our environment and efficiently navigating between places are still very important aspects in our everyday life. However, in order to be able to navigate efficiently, our brain has to perform a series of spatial cognitive operations. This dissertation is structured into three sections, which explore these cognitive operations from three different perspectives. In the first section I will elaborate about the role of reference frames in human spatial navigation. Specifically, in an online navigation study (study one) I will show that humans have distinct but stable reference frame proclivities. Furthermore, this study demonstrates the existence of a spatial strategy, in which the preference to use a particular reference frame is dependent on the axis of rotation (horizontal vs. vertical). In a follow-up study (study two) I will then analyze the factors underlying performance differences in navigation, as well as individual preferences using one or another spatial strategy. Interestingly, the results suggest that performance measures (reaction time and error rate) are influenced mostly by the factors gender and age. However, even more importantly, I will show that the prevalent factor, which influences the choice for an individual navigation strategy, is the cultural background of the participant. This underlines the importance of socio-economic aspects in human spatial navigation. In the second part of this thesis I will then discuss aspects of learning and memorizing spatial information. In this respect, the alignment study (study three) will show that humans are able to recall object-to-object relations (e.g. how to get from A to B) in a very brief time, indicating that such information is directly stored in memory. This supports an embodied (action-oriented) perspective of human spatial cognition. Following this approach, in the feelSpace study (study four) I will then investigate the long-term training effects with a sensory augmentation device. Most importantly, the respective results will demonstrate substantial changes in the subjective perception of space, in sleep stage architecture, and in neural oscillations during sleep. In the third and last section I will describe the importance of multimodal processes in spatial cognitive operations. Most importantly, in the platform study (study five) I will combine the topics of sensory augmentation and Bayesian cue combination. The results of this study show that untrained adult participants alternate rather than integrate between augmented and native sensory information. Interestingly, this alternation is based on a subjective evaluation of cue reliability. In summary, this thesis will present relevant and new findings for better understanding spatial strategy formation, learning and representing spatial relations in memory, and multimodal cue combination. An important and overarching aspect of this thesis is the characterization of individual differences in the context of human spatial navigation. Specifically, my research revealed individual differences in three areas: First, in utilizing egocentric or allocentric reference frames for spatial updating, second in individualized qualitative changes of space perception during long-term sensory augmentation, and third, in preferences to use native or augmented information in a cue combination task. Most importantly, I will provide a better definition and understanding of these individual differences, by combining qualitative and quantitative measures and using latest technologies such as online data recordings and interactive experimental setups. In fact, in the real world, humans are very active beings who follow individualized spatial cognitive strategies. Studying such interactive and individualized behavior will ultimately lead to more coherent and meaningful insights within the human sciences

Auditory Information Supports the Learning Transfer from L2 to L3 Tonal Languages

While the acquisition of three or more languages becomes steadily more important in modern societies, the underlying cognitive and linguistic processes of multi-linguistic language acquisition are not well understood. This study investigates how a formerly acquired second language (L2) can facilitate the acquisition of a third language (L3). Thirty-two native German speakers with proficient knowledge in either a tonal L2 (Chinese) or a non-tonal L2 (English) learned vocabulary of a tonal L3 (Thai), while the information of the target L3 was either presented visually or both visually and auditorily. Additional auditory information improved later recognition of L3 vocabulary for participants with a tonal L2 (Chinese) but not for those with a non-tonal L2 (English). These results suggest that the L2 to L3 learning transfer can be improved when the similarities between both languages, such as tonal information, are accentuated in the learning process

Bayesian Alternation during Tactile Augmentation

A large number of studies suggest that the integration of multisensory signals by humans is well-described by Bayesian principles. However, there are very few reports about cue combination between a native and an augmented sense. In particular, we asked the question whether adult participants are able to integrate an augmented sensory cue with existing native sensory information. Hence for the purpose of this study, we build a tactile augmentation device. Consequently, we compared different hypotheses of how untrained adult participants combine information from a native and an augmented sense. In a two-interval forced choice (2 IFC) task, while subjects were blindfolded and seated on a rotating platform, our sensory augmentation device translated information on whole body yaw rotation to tactile stimulation. Three conditions were realized: tactile stimulation only (augmented condition), rotation only (native condition), and both augmented and native information (bimodal condition). Participants had to choose one out of two consecutive rotations with higher angular rotation. For the analysis, we fitted the participants' responses with a probit model and calculated the just notable difference (JND). Then, we compared several models for predicting bimodal from unimodal responses. An objective Bayesian alternation model yielded a better prediction (χred2 = 1.67) than the Bayesian integration model (χred2 = 4.34). Slightly higher accuracy showed a non-Bayesian winner takes all (WTA) model (χred2 = 1.64), which either used only native or only augmented values per subject for prediction. However, the performance of the Bayesian alternation model could be substantially improved (χred2 = 1.09) utilizing subjective weights obtained by a questionnaire. As a result, the subjective Bayesian alternation model predicted bimodal performance most accurately among all tested models. These results suggest that information from augmented and existing sensory modalities in untrained humans is combined via a subjective Bayesian alternation process. Therefore, we conclude that behavior in our bimodal condition is explained better by top down-subjective weighting than by bottom-up weighting based upon objective cue reliability

Different strategies for spatial updating in yaw and pitch path integration

Research in spatial navigation revealed the existence of discrete strategies defined by the use of distinct reference frames during virtual path integration. The present study investigated the distribution of these navigation strategies as a function of gender, video gaming experience, and self-estimates of spatial navigation abilities in a population of 300 subjects. Participants watched videos of virtual passages through a star-field with one turn in either the horizontal (yaw) or the vertical (pitch) axis. At the end of a passage they selected one out of four homing arrows to indicate the initial starting location. To solve the task, participants could employ two discrete strategies, navigating within either an egocentric or an allocentric reference frame. The majority of valid subjects (232/260) consistently used the same strategy in more than 75% of all trials. With that approach 33.1% of all participants were classified as Turners (using an egocentric reference frame on both axes) and 46.5% as Nonturners (using an allocentric reference frame on both axes). 9.2% of all participants consistently used an egocentric reference frame in the yaw plane but an allocentric reference frame in the pitch plane (Switcher). Investigating the influence of gender on navigation strategies revealed that females predominantly used the Nonturner strategy while males used both the Turner and the Nonturner strategy with comparable probabilities. Other than expected, video gaming experience did not influence strategy use. Based on a strong quantitative basis with the sample size about an order of magnitude larger than in typical psychophysical studies these results demonstrate that most people reliably use one out of three possible navigation strategies (Turners, Nonturners, Switchers) for spatial updating and provides a sound estimate of how those strategies are distributed within the general population

Automatic and Controlled Processing: Implications for Eating Behavior

It is a widely held view that humans have control over their food choices and consumption. However, research also suggests that eating behavior is often triggered by contextual cues and guided by automaticities and habits. Interestingly, the dichotomy between automatic and controlled processing has recently been challenged, suggesting that they may be intertwined. In a large female sample (n = 567), we investigated the hypothesis that task-based and self-reported measures of automatic and controlled processing would interact and impact self-reported eating behavior. Results analyzed via structural equation modeling suggest that automatic, but not controlled processing, during a modified flanker task, including a context-specific proportion congruent (CSPC) manipulation, was inversely associated with self-reported self-control. The influence of self-control on unhealthy eating behavior (i.e., uncontrolled and emotional eating, heightened consumption of fat and sugar) was only indirect via habitual behavior, which itself had a strong direct impact. Unhealthy eating was further associated with real-life outcomes (e.g., body mass index (BMI)). Our findings suggest that eating behavior may indeed be guided primarily by automaticities and habits, whereas self-control might facilitate this association. Having self-control over eating might therefore be most effective by avoiding contextual cues eliciting undesired automatic behavior and establishing habits that serve long-term goals

Automatic and Controlled Processing: Implications for Eating Behavior

It is a widely held view that humans have control over their food choices and consumption. However, research also suggests that eating behavior is often triggered by contextual cues and guided by automaticities and habits. Interestingly, the dichotomy between automatic and controlled processing has recently been challenged, suggesting that they may be intertwined. In a large female sample (n = 567), we investigated the hypothesis that task-based and self-reported measures of automatic and controlled processing would interact and impact self-reported eating behavior. Results analyzed via structural equation modeling suggest that automatic, but not controlled processing, during a modified flanker task, including a context-specific proportion congruent (CSPC) manipulation, was inversely associated with self-reported self-control. The influence of self-control on unhealthy eating behavior (i.e., uncontrolled and emotional eating, heightened consumption of fat and sugar) was only indirect via habitual behavior, which itself had a strong direct impact. Unhealthy eating was further associated with real-life outcomes (e.g., body mass index (BMI)). Our findings suggest that eating behavior may indeed be guided primarily by automaticities and habits, whereas self-control might facilitate this association. Having self-control over eating might therefore be most effective by avoiding contextual cues eliciting undesired automatic behavior and establishing habits that serve long-term goals