Investigating human audio-visual object perception with a combination of hypothesis-generating and hypothesis-testing fMRI analysis tools

Primate multisensory object perception involves distributed brain regions. To investigate the network character of these regions of the human brain, we applied data-driven group spatial independent component analysis (ICA) to a functional magnetic resonance imaging (fMRI) data set acquired during a passive audio-visual (AV) experiment with common object stimuli. We labeled three group-level independent component (IC) maps as auditory (A), visual (V), and AV, based on their spatial layouts and activation time courses. The overlap between these IC maps served as definition of a distributed network of multisensory candidate regions including superior temporal, ventral occipito-temporal, posterior parietal and prefrontal regions. During an independent second fMRI experiment, we explicitly tested their involvement in AV integration. Activations in nine out of these twelve regions met the max-criterion (A < AV > V) for multisensory integration. Comparison of this approach with a general linear model-based region-of-interest definition revealed its complementary value for multisensory neuroimaging. In conclusion, we estimated functional networks of uni- and multisensory functional connectivity from one dataset and validated their functional roles in an independent dataset. These findings demonstrate the particular value of ICA for multisensory neuroimaging research and using independent datasets to test hypotheses generated from a data-driven analysis.

Real-time computer-based visual feedback improves visual acuity in downbeat nystagmus - a pilot study.

BACKGROUND Patients with downbeat nystagmus syndrome suffer from oscillopsia, which leads to an unstable visual perception and therefore impaired visual acuity. The aim of this study was to use real-time computer-based visual feedback to compensate for the destabilizing slow phase eye movements. METHODS The patients were sitting in front of a computer screen with the head fixed on a chin rest. The eye movements were recorded by an eye tracking system (EyeSeeCam®). We tested the visual acuity with a fixed Landolt C (static) and during real-time feedback driven condition (dynamic) in gaze straight ahead and (20°) sideward gaze. In the dynamic condition, the Landolt C moved according to the slow phase eye velocity of the downbeat nystagmus. The Shapiro-Wilk test was used to test for normal distribution and one-way ANOVA for comparison. RESULTS Ten patients with downbeat nystagmus were included in the study. Median age was 76 years and the median duration of symptoms was 6.3 years (SD +/- 3.1y). The mean slow phase velocity was moderate during gaze straight ahead (1.44°/s, SD +/- 1.18°/s) and increased significantly in sideward gaze (mean left 3.36°/s; right 3.58°/s). In gaze straight ahead, we found no difference between the static and feedback driven condition. In sideward gaze, visual acuity improved in five out of ten subjects during the feedback-driven condition (p = 0.043). CONCLUSIONS This study provides proof of concept that non-invasive real-time computer-based visual feedback compensates for the SPV in DBN. Therefore, real-time visual feedback may be a promising aid for patients suffering from oscillopsia and impaired text reading on screen. Recent technological advances in the area of virtual reality displays might soon render this approach feasible in fully mobile settings.

Book Review: Regulating Code : Good Governance and Better Regulation in the Information Age

Digital technologies have profoundly changed not only the ways we create, distribute, access, use and re-use information but also many of the governance structures we had in place. Overall, "older" institutions at all governance levels have grappled and often failed to master the multi-faceted and multi-directional issues of the Internet. Regulatory entrepreneurs have yet to discover and fully mobilize the potential of digital technologies as an influential factor impacting upon the regulability of the environment and as a potential regulatory tool in themselves. At the same time, we have seen a deterioration of some public spaces and lower prioritization of public objectives, when strong private commercial interests are at play, such as most tellingly in the field of copyright. Less tangibly, private ordering has taken hold and captured through contracts spaces, previously regulated by public law. Code embedded in technology often replaces law. Non-state action has in general proliferated and put serious pressure upon conventional state-centered, command-and-control models. Under the conditions of this "messy" governance, the provision of key public goods, such as freedom of information, has been made difficult or is indeed jeopardized.The grand question is how can we navigate this complex multi-actor, multi-issue space and secure the attainment of fundamental public interest objectives. This is also the question that Ian Brown and Chris Marsden seek to answer with their book, Regulating Code, as recently published under the "Information Revolution and Global Politics" series of MIT Press. This book review critically assesses the bold effort by Brown and Marsden.

Short structured feedback training is equivalent to a mechanical feedback device in two-rescuer BLS: a randomised simulation study.

BACKGROUND Resuscitation guidelines encourage the use of cardiopulmonary resuscitation (CPR) feedback devices implying better outcomes after sudden cardiac arrest. Whether effective continuous feedback could also be given verbally by a second rescuer ("human feedback") has not been investigated yet. We, therefore, compared the effect of human feedback to a CPR feedback device. METHODS In an open, prospective, randomised, controlled trial, we compared CPR performance of three groups of medical students in a two-rescuer scenario. Group "sCPR" was taught standard BLS without continuous feedback, serving as control. Group "mfCPR" was taught BLS with mechanical audio-visual feedback (HeartStart MRx with Q-CPR-Technology™). Group "hfCPR" was taught standard BLS with human feedback. Afterwards, 326 medical students performed two-rescuer BLS on a manikin for 8 min. CPR quality parameters, such as "effective compression ratio" (ECR: compressions with correct hand position, depth and complete decompression multiplied by flow-time fraction), and other compression, ventilation and time-related parameters were assessed for all groups. RESULTS ECR was comparable between the hfCPR and the mfCPR group (0.33 vs. 0.35, p = 0.435). The hfCPR group needed less time until starting chest compressions (2 vs. 8 s, p < 0.001) and showed fewer incorrect decompressions (26 vs. 33 %, p = 0.044). On the other hand, absolute hands-off time was higher in the hfCPR group (67 vs. 60 s, p = 0.021). CONCLUSIONS The quality of CPR with human feedback or by using a mechanical audio-visual feedback device was similar. Further studies should investigate whether extended human feedback training could further increase CPR quality at comparable costs for training.

Perception of co-speech gestures in aphasic patients: A visual exploration study during the observation of dyadic conversations.

BACKGROUND Co-speech gestures are part of nonverbal communication during conversations. They either support the verbal message or provide the interlocutor with additional information. Furthermore, they prompt as nonverbal cues the cooperative process of turn taking. In the present study, we investigated the influence of co-speech gestures on the perception of dyadic dialogue in aphasic patients. In particular, we analysed the impact of co-speech gestures on gaze direction (towards speaker or listener) and fixation of body parts. We hypothesized that aphasic patients, who are restricted in verbal comprehension, adapt their visual exploration strategies. METHODS Sixteen aphasic patients and 23 healthy control subjects participated in the study. Visual exploration behaviour was measured by means of a contact-free infrared eye-tracker while subjects were watching videos depicting spontaneous dialogues between two individuals. Cumulative fixation duration and mean fixation duration were calculated for the factors co-speech gesture (present and absent), gaze direction (to the speaker or to the listener), and region of interest (ROI), including hands, face, and body. RESULTS Both aphasic patients and healthy controls mainly fixated the speaker's face. We found a significant co-speech gesture × ROI interaction, indicating that the presence of a co-speech gesture encouraged subjects to look at the speaker. Further, there was a significant gaze direction × ROI × group interaction revealing that aphasic patients showed reduced cumulative fixation duration on the speaker's face compared to healthy controls. CONCLUSION Co-speech gestures guide the observer's attention towards the speaker, the source of semantic input. It is discussed whether an underlying semantic processing deficit or a deficit to integrate audio-visual information may cause aphasic patients to explore less the speaker's face.

The Influence of Pre-stimulus EEG Activity on Reaction Time During a Verbal Sternberg Task is Related to Musical Expertise

Abstract Previous work highlighted the possibility that musical training has an influence on cognitive functioning. The suggested reason for this influence is the strong recruitment of attention, planning, and working memory functions during playing a musical instrument. The purpose of the present work was twofold, namely to evaluate the general relationship between pre-stimulus electrophysiological activity and cognition, and more specifically the influence of musical expertise on working memory functions. With this purpose in mind, we used covariance mapping analyses to evaluate whether pre-stimulus electroencephalographic activity is predictive for reaction time during a visual working memory task (Sternberg paradigm) in musicians and non-musicians. In line with our hypothesis, we replicated previous findings pointing to a general predictive value of pre-stimulus activity for working memory performance. Most importantly, we also provide first evidence for an influence of musical expertise on working memory performance that could distinctively be predicted by pre-stimulus spectral power. Our results open novel perspectives for better comprehending the vast influences of musical expertise on cognition.

Comparing three CPR feedback devices and standard BLS in a single rescuer scenario: a randomised simulation study

BACKGROUND Efficiently performed basic life support (BLS) after cardiac arrest is proven to be effective. However, cardiopulmonary resuscitation (CPR) is strenuous and rescuers' performance declines rapidly over time. Audio-visual feedback devices reporting CPR quality may prevent this decline. We aimed to investigate the effect of various CPR feedback devices on CPR quality. METHODS In this open, prospective, randomised, controlled trial we compared three CPR feedback devices (PocketCPR, CPRmeter, iPhone app PocketCPR) with standard BLS without feedback in a simulated scenario. 240 trained medical students performed single rescuer BLS on a manikin for 8min. Effective compression (compressions with correct depth, pressure point and sufficient decompression) as well as compression rate, flow time fraction and ventilation parameters were compared between the four groups. RESULTS Study participants using the PocketCPR performed 17±19% effective compressions compared to 32±28% with CPRmeter, 25±27% with the iPhone app PocketCPR, and 35±30% applying standard BLS (PocketCPR vs. CPRmeter p=0.007, PocketCPR vs. standard BLS p=0.001, others: ns). PocketCPR and CPRmeter prevented a decline in effective compression over time, but overall performance in the PocketCPR group was considerably inferior to standard BLS. Compression depth and rate were within the range recommended in the guidelines in all groups. CONCLUSION While we found differences between the investigated CPR feedback devices, overall BLS quality was suboptimal in all groups. Surprisingly, effective compression was not improved by any CPR feedback device compared to standard BLS. All feedback devices caused substantial delay in starting CPR, which may worsen outcome.

Perception of co-speech gestures in aphasic patients: A visual exploration study during the observation of dyadic conversations

Background: Co-speech gestures are part of nonverbal communication during conversations. They either support the verbal message or provide the interlocutor with additional information. Furthermore, they prompt as nonverbal cues the cooperative process of turn taking. In the present study, we investigated the influence of co-speech gestures on the perception of dyadic dialogue in aphasic patients. In particular, we analysed the impact of co-speech gestures on gaze direction (towards speaker or listener) and fixation of body parts. We hypothesized that aphasic patients, who are restricted in verbal comprehension, adapt their visual exploration strategies. Methods: Sixteen aphasic patients and 23 healthy control subjects participated in the study. Visual exploration behaviour was measured by means of a contact-free infrared eye-tracker while subjects were watching videos depicting spontaneous dialogues between two individuals. Cumulative fixation duration and mean fixation duration were calculated for the factors co-speech gesture (present and absent), gaze direction (to the speaker or to the listener), and region of interest (ROI), including hands, face, and body. Results: Both aphasic patients and healthy controls mainly fixated the speaker’s face. We found a significant co-speech gesture x ROI interaction, indicating that the presence of a co-speech gesture encouraged subjects to look at the speaker. Further, there was a significant gaze direction x ROI x group interaction revealing that aphasic patients showed reduced cumulative fixation duration on the speaker’s face compared to healthy controls. Conclusion: Co-speech gestures guide the observer’s attention towards the speaker, the source of semantic input. It is discussed whether an underlying semantic processing deficit or a deficit to integrate audio-visual information may cause aphasic patients to explore less the speaker’s face. Keywords: Gestures, visual exploration, dialogue, aphasia, apraxia, eye movements

Internet video telephony allows speech reading by deaf individuals and improves speech perception by cochlear implant users

OBJECTIVE To analyze speech reading through Internet video calls by profoundly hearing-impaired individuals and cochlear implant (CI) users. METHODS Speech reading skills of 14 deaf adults and 21 CI users were assessed using the Hochmair Schulz Moser (HSM) sentence test. We presented video simulations using different video resolutions (1280 × 720, 640 × 480, 320 × 240, 160 × 120 px), frame rates (30, 20, 10, 7, 5 frames per second (fps)), speech velocities (three different speakers), webcameras (Logitech Pro9000, C600 and C500) and image/sound delays (0-500 ms). All video simulations were presented with and without sound and in two screen sizes. Additionally, scores for live Skype™ video connection and live face-to-face communication were assessed. RESULTS Higher frame rate (>7 fps), higher camera resolution (>640 × 480 px) and shorter picture/sound delay (<100 ms) were associated with increased speech perception scores. Scores were strongly dependent on the speaker but were not influenced by physical properties of the camera optics or the full screen mode. There is a significant median gain of +8.5%pts (p = 0.009) in speech perception for all 21 CI-users if visual cues are additionally shown. CI users with poor open set speech perception scores (n = 11) showed the greatest benefit under combined audio-visual presentation (median speech perception +11.8%pts, p = 0.032). CONCLUSION Webcameras have the potential to improve telecommunication of hearing-impaired individuals.

Finding a voice - Nollywood inspired filmmaking practices in Switzerland

Under the name Nollywood a unique video film industry has developed in Nigeria in the last few decades, which now forms one of the world’s biggest entertainment industries. With its focus on stories reflecting „the values, desires and fears” (Haynes 2007: 133) of African viewers and its particular way of production, Nollywood brings „lived practices and its representation together in ways that make the films deeply accessible and entirely familiar to their audience“ (Marston et al. 2007: 57). In doing so, Nollywood shows its spectators new postcolonial forms of performative self‐expression and becomes a point of reference for a wide range of people. However, Nollywood not only excites a large number of viewers inside and outside Nigeria, it also inspires some of them to become active themselves and make their own films. This effect of Nigerian filmmaking can be found in many parts of sub‐Saharan Africa as well as in African diasporas all over the world – including Switzerland (Mooser 2011: 63‐66). As a source of inspiration, Nollywood and its unconventional ways of filmmaking offer African migrants a benchmark that meets their wish to express themselves as minority group in a foreign country. As Appadurai (1996: 53), Ginsburg (2003: 78) and Marks (2000: 21) assume, filmmakers with a migratory background have a specific need to express themselves through media. As minority group members in their country of residence they not only wish to reflect upon their situation within the diaspora and illustrate their everyday struggles as foreigners, but to also express their own views and ideas in order to challenge dominant public opinion (Ginsburg 2003: 78). They attempt to “talk back to the structures of power” (2003: 78) they live in. In this process, their audio-visual works become a means of response and “an answering echo to a previous presentation or representation” (Mitchell 1994: 421). The American art historian Mitchell, therefore, suggests interpreting representation as “the relay mechanism in exchange of power, value, and publicity” (1994: 420). This desire of interacting with the local public has also been expressed during a film project of African, mainly Nigerian, first-generation migrants in Switzerland I am currently partnering in. Several cast and crew members have expressed feelings of being under-represented, even misrepresented, in the dominant Swiss media discourse. In order to create a form of exchange and give themselves a voice, they consequently produce a Nollywood inspired film and wish to present it to the society they live in. My partnership in this on‐going film production (which forms the foundation of my PhD field study) allows me to observe and experience this process. By employing qualitative media anthropological methods and in particular Performance Ethnography, I seek to find out more about the ways African migrants represent themselves as a community through audio‐visual media and the effect the transnational use of Nollywood has on their form of self‐representations as well as the ways they express themselves.

Retraining of interjoint arm coordination after stroke using robot-assisted time-independent functional training

We have developed a haptic-based approach for retraining of interjoint coordination following stroke called time-independent functional training (TIFT) and implemented this mode in the ARMin III robotic exoskeleton. The ARMin III robot was developed by Drs. Robert Riener and Tobias Nef at the Swiss Federal Institute of Technology Zurich (Eidgenossische Technische Hochschule Zurich, or ETH Zurich), in Zurich, Switzerland. In the TIFT mode, the robot maintains arm movements within the proper kinematic trajectory via haptic walls at each joint. These arm movements focus training of interjoint coordination with highly intuitive real-time feedback of performance; arm movements advance within the trajectory only if their movement coordination is correct. In initial testing, 37 nondisabled subjects received a single session of learning of a complex pattern. Subjects were randomized to TIFT or visual demonstration or moved along with the robot as it moved though the pattern (time-dependent [TD] training). We examined visual demonstration to separate the effects of action observation on motor learning from the effects of the two haptic guidance methods. During these training trials, TIFT subjects reduced error and interaction forces between the robot and arm, while TD subject performance did not change. All groups showed significant learning of the trajectory during unassisted recall trials, but we observed no difference in learning between groups, possibly because this learning task is dominated by vision. Further testing in stroke populations is warranted.

Comparison of real-time polymerase chain reaction and DNA-strip technology in microbiological evaluation of periodontitis treatment

The impact of a semiquantitative commercially available test based on DNA-strip technology (microIDent®, Hain Lifescience, Nehren, Germany) on diagnosis and treatment of severe chronic periodontitis of 25 periodontitis patients was evaluated in comparison with a quantitative in-house real-time PCR. Subgingival plaque samples were collected at baseline as well as at 3, 6, and 12 months later. After extracting DNA, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, and several other periodontopathogens were determined by both methods. The results obtained by DNA-strip technology were analyzed semiquantitatively and additionally quantitatively by densitometry. The results for the 4 major periodontopathogenic bacterial species correlated significantly between the 2 methods. Samples detecting a high bacterial load by one method and negative by the other were always found in less than 2% of the total samples. Both technologies showed the impact of treatment on microflora. Especially the semiquantitative DNA-strip technology clearly analyzed the different loads of periodontopathogens after therapy and is useful in microbial diagnostics for patients in dental practices.