Positive Technology Journal

From Pink Tentacle

Artist Pyocotan has developed “Noriko-san,” a sleep mask with an electronic scrolling display that communicates the wearer’s destination to fellow passengers.

A learning theory for reward-modulated spike-timing-dependent plasticity with application to biofeedback.

PLoS Comput Biol. 2008 Oct;4(10):e1000180

Authors: Legenstein R, Pecevski D, Maass W

Reward-modulated spike-timing-dependent plasticity (STDP) has recently emerged as a candidate for a learning rule that could explain how behaviorally relevant adaptive changes in complex networks of spiking neurons could be achieved in a self-organizing manner through local synaptic plasticity. However, the capabilities and limitations of this learning rule could so far only be tested through computer simulations. This article provides tools for an analytic treatment of reward-modulated STDP, which allows us to predict under which conditions reward-modulated STDP will achieve a desired learning effect. These analytical results imply that neurons can learn through reward-modulated STDP to classify not only spatial but also temporal firing patterns of presynaptic neurons. They also can learn to respond to specific presynaptic firing patterns with particular spike patterns. Finally, the resulting learning theory predicts that even difficult credit-assignment problems, where it is very hard to tell which synaptic weights should be modified in order to increase the global reward for the system, can be solved in a self-organizing manner through reward-modulated STDP. This yields an explanation for a fundamental experimental result on biofeedback in monkeys by Fetz and Baker. In this experiment monkeys were rewarded for increasing the firing rate of a particular neuron in the cortex and were able to solve this extremely difficult credit assignment problem. Our model for this experiment relies on a combination of reward-modulated STDP with variable spontaneous firing activity. Hence it also provides a possible functional explanation for trial-to-trial variability, which is characteristic for cortical networks of neurons but has no analogue in currently existing artificial computing systems. In addition our model demonstrates that reward-modulated STDP can be applied to all synapses in a large recurrent neural network without endangering the stability of the network dynamics.

Sleep-related improvements in motor learning following mental practice.

Brain Cogn. 2008 Oct 4;

Authors: Debarnot U, Creveaux T, Collet C, Gemignani A, Massarelli R, Doyon J, Guillot A

A wide range of experimental studies have provided evidence that a night of sleep may enhance motor performance following physical practice (PP), but little is known, however, about its effect after motor imagery (MI). Using an explicitly learned pointing task paradigm, thirty participants were assigned to one of three groups that differed in the training method (PP, MI, and control groups). The physical performance was measured before training (pre-test), as well as before (post-test 1) and after a night of sleep (post-test 2). The time taken to complete the pointing tasks, the number of errors and the kinematic trajectories were the dependent variables. As expected, both the PP and the MI groups improved their performance during the post-test 1. The MI group was further found to enhance motor performance after sleep, hence suggesting that sleep-related effects are effective following mental practice. Such findings highlight the reliability of MI in learning process, which is thought consolidated when associated with sleep.

I and my colleague Giuseppe Riva have just published a letter in Science, where we propose crowd-funding - a form of crowdsourcing applied to finance - as a possible strategy to cope with the lack of investments in research.

The full text of the article is available here: gaggioli_riva_science08.pdf

Video (Italian only)

Modulating presence and impulsiveness by external stimulation of the brain

Behav Brain Funct. 2008 Aug 4;4(1):33

Authors: Beeli G, Casutt G, Baumgartner T, Jancke L

ABSTRACT: BACKGROUND: "The feeling of being there" is one possible way to describe the phenomenon of feeling present in a virtual environment and to act as if this environment is real. One brain area, which is hypothesized to be critically involved in modulating this feeling (also called presence) is the dorso-lateral prefrontal cortex (dlPFC), an area also associated with the control of impulsive behavior. METHODS: In our experiment we applied transcranial direct current stimulation (tDCS) to the right dlPFC in order to modulate the experience of presence while watching a virtual roller coaster ride. During the ride we also registered electro-dermal activity. Subjects also performed a test measuring impulsiveness and answered a questionnaire about their presence feeling while they were exposed to the virtual roller coaster scenario. RESULTS: Application of cathodal tDCS to the right dlPFC while subjects were exposed to a virtual roller coaster scenario modulates the electrodermal response to the virtual reality stimulus. In addition, measures reflecting impulsiveness were also modulated by application of cathodal tDCS to the right dlPFC. CONCLUSIONS: Modulating the activation with the right dlPFC results in substantial changes in responses of the vegetative nervous system and changed impulsiveness. The effects can be explained by theories discussing the top-down influence of the right dlPFC on the "impulsive system".

Assessing craving in young adult smokers using virtual reality.

Am J Addict. 2008 Sep-Oct;17(5):436-40

Authors: Traylor AC, Bordnick PS, Carter BL

Cigarette smokers, when confronted with cues associated with smoking, evidence strong reactions, including increased craving. These reactions have not been extensively studied in young adult smokers, a group that research suggests may respond differently than adults or adolescent smokers. We used virtual reality, which presents a complex array of smoking cues that may be particularly salient to young adult smokers, and measured self-report of craving. Young adult smokers responded strongly to these cues and, unlike adults, did not return to a baseline of craving following cue exposure, suggesting young adult smokers differ from other smokers in terms of cue responses.

Effects of mindful and non-mindful exercises on people with depression: a systematic review.

Br J Clin Psychol. 2008 Sep;47(Pt 3):303-22

Authors: Tsang HW, Chan EP, Cheung WM

PURPOSE: An emerging body of evidence has shown the therapeutic effect of both mindful and non-mindful physical exercises on the treatment of depression. The purpose of this study is to examine the effectiveness of mindful and non-mindful physical exercises as an intervention in managing depression or depressive symptoms based on a systematic literature review. METHODS: Our review was conducted among five electronic databases to identify randomized controlled trials (RCTs), which tested the effects of mindful or/and non-mindful physical exercises on depression. Studies were classified according to the baseline depression status of participants and its relation to allocation concealment, blinding at outcome assessment, follow-up, and whether intention to treat analysis was employed. RESULTS: The results based on 12 RCTs indicated that both the mindful and non-mindful physical exercises were effective in their short-term effect in reducing depression levels or depressive symptoms. However, most of studies had methodological problems that only small sample size was used, and the maintenance effects of physical exercise were not reported. Specific comparisons between RCTs on mindful and non-mindful exercises were not performed because of the limitations on the designs. CONCLUSIONS: We recommend that more well-controlled studies have to be conducted in the future to address the short- and long-term effects of physical exercise on alleviating depression. Efforts should be focused on unveiling the differential effects of mindful and non-mindful exercises on depression and the underlying mechanisms of their therapeutic action.

"Thinking about Not-Thinking": Neural Correlates of Conceptual Processing during Zen Meditation.

PLoS ONE. 2008;3(9):e3083

Authors: Pagnoni G, Cekic M, Guo Y

"Thinking about Not-Thinking": Neural Correlates of Conceptual Processing during Zen Meditation.

PLoS ONE. 2008;3(9):e3083

Authors: Pagnoni G, Cekic M, Guo Y

Home-based motor imagery training for gait rehabilitation of people with chronic poststroke hemiparesis.

Arch Phys Med Rehabil. 2008 Aug;89(8):1580-8

Authors: Dunsky A, Dickstein R, Marcovitz E, Levy S, Deutsch J

Virtual Rehabilitation in an Activity Centre for Community-Dwelling Persons with Stroke. The Possibilities of 3-Dimensional Computer Games.

Cerebrovasc Dis. 2008 Jul 31;26(3):289-296

Authors: Broeren J, Claesson L, Goude D, Rydmark M, Sunnerhagen KS

Background: The main purpose of this study was to place a virtual reality (VR) system, designed to assess and to promote motor performance in the affected upper extremity in subjects after stroke, in a nonhospital environment. We also wanted to investigate if playing computer games resulted in improved motor function in persons with prior stroke. Methods: The intervention involved 11 patients after stroke who received extra rehabilitation by training on a computer 3 times a week during a 4-week period. The control group involved 11 patients after stroke who continued their previous rehabilitation (no extra computer training) during this period. The mean age of all was 68 years (range = 47-85) and the average time after stroke 66 months (range = 15-140). The VR training consisted of challenging games, which provided a range of difficulty levels that allow practice to be fun and motivating. An additional group of 11 right-handed aged matched individuals without history of neurological or psychiatric illnesses served as reference subjects. Results: All the participants reported that they were novel computer game players. After an initial introduction they learned to use the VR system quickly. The treatment group demonstrated improvements in motor outcome for the trained upper extremity, but this was not detected in real-life activities. Conclusions: The results of this research suggest the usefulness of computer games in training motor performance. VR can be used beneficially not only by younger participants but also by older persons to enhance their motor performance after stroke.

Auditory and Spatial Navigation Imagery in Brain-Computer Interface using Optimized Wavelets.

J Neurosci Methods. 2008 Jul 6;

Authors: Cabrera AF, Dremstrup K

Features extracted with optimized wavelets were compared with standard methods for a Brain-Computer Interface driven by non-motor imagery tasks. Two non-motor imagery tasks were used, Auditory Imagery of a familiar tune and Spatial Navigation Imagery through a familiar environment. The aims of this study were to evaluate which method extracts features that could be best differentiated and determine which channels are best suited for classification. EEG activity from 18 electrodes over the temporal and parietal lobes of nineteen healthy subjects was recorded. The features used were autoregressive and reflection coefficients extracted using autoregressive modeling with several model orders and marginals of the wavelet spaces generated by the Discrete Wavelet Transform (DWT). An optimization algorithm with 4 and 6 taps filters and mother wavelets from the Daubechies family were used. The classification was performed for each single channel and for all possible combination of two channels using a Bayesian Classifier. The best classification results were found using the marginals of the Optimized DWT spaces for filters with 6 taps in a 2 channels classification basis. Classification using 2 channels was found to be significantly better than using 1 channel (p<<0.01). The marginals of the optimized DWT using 6 taps filters showed to be significantly better than the marginals of the Daubechies family and autoregressive coefficients. The influence of the combination of number of channels and feature extraction method over the classification results was not significant (p=0.97).

Does erotic stimulus presentation design affect brain activation patterns? Event-related vs. blocked fMRI designs.

Behav Brain Funct. 2008 Jul 22;4(1):30

Authors: Buehler M, Vollstaedt-Klein S, Klemen J, Smolka MN

ABSTRACT: BACKGROUND: Existing brain imaging studies, investigating sexual arousal via the presentation of erotic pictures or film excerpts, have mainly used blocked designs with long stimulus presentation times. METHODS: To clarify how experimental functional magnetic resonance imaging (fMRI) design affects stimulus-induced brain activity, we compared brief event-related presentation of erotic vs. neutral stimuli with blocked presentation in 10 male volunteers. RESULTS: Brain activation differed depending on design type in only 10% of the voxels showing task related brain activity. Differences between blocked and event-related stimulus presentation were found in occipitotemporal and temporal regions (Brodmann Area (BA) 19, 37, 48), parietal areas (BA 7, 40) and areas in the frontal lobe (BA 6, 44). CONCLUSIONS: Our results suggest that event-related designs might be a potential alternative when the core interest is the detection of networks associated with immediate processing of erotic stimuli. Additionally, blocked, compared to event-related, stimulus presentation allows the emergence and detection of non-specific secondary processes, such as sustained attention, motor imagery and inhibition of sexual arousal.

Development and preliminary evaluation of a prototype audiovisual biofeedback device incorporating a patient-specific guiding waveform.

Phys Med Biol. 2008 May 12;53(11):N197-N208

Authors: Venkat RB, Sawant A, Suh Y, George R, Keall PJ

The aim of this research was to investigate the effectiveness of a novel audio-visual biofeedback respiratory training tool to reduce respiratory irregularity. The audiovisual biofeedback system acquires sample respiratory waveforms of a particular patient and computes a patient-specific waveform to guide the patient's subsequent breathing. Two visual feedback models with different displays and cognitive loads were investigated: a bar model and a wave model. The audio instructions were ascending/descending musical tones played at inhale and exhale respectively to assist in maintaining the breathing period. Free-breathing, bar model and wave model training was performed on ten volunteers for 5 min for three repeat sessions. A total of 90 respiratory waveforms were acquired. It was found that the bar model was superior to free breathing with overall rms displacement variations of 0.10 and 0.16 cm, respectively, and rms period variations of 0.77 and 0.33 s, respectively. The wave model was superior to the bar model and free breathing for all volunteers, with an overall rms displacement of 0.08 cm and rms periods of 0.2 s. The reduction in the displacement and period variations for the bar model compared with free breathing was statistically significant (p = 0.005 and 0.002, respectively); the wave model was significantly better than the bar model (p = 0.006 and 0.005, respectively). Audiovisual biofeedback with a patient-specific guiding waveform significantly reduces variations in breathing. The wave model approach reduces cycle-to-cycle variations in displacement by greater than 50% and variations in period by over 70% compared with free breathing. The planned application of this device is anatomic and functional imaging procedures and radiation therapy delivery.

Energetic assessment of trunk postural modifications induced by a wearable audio-biofeedback system.

Med Eng Phys. 2008 Jul 2;

Authors: Giansanti D, Dozza M, Chiari L, Maccioni G, Cappello A

Web GIS in practice VI: a demo "playlist" of geo-mashups for public health neogeographers.

Int J Health Geogr. 2008 Jul 18;7(1):38

Authors: Kamel Boulos MN, Scotch M, Cheung KH, Burden D

ABSTRACT: 'Mashup' was originally used to describe the mixing together of musical tracks to create a new piece of music. The term now refers to Web sites or services that weave data from different sources into a new data source or service. Using a musical metaphor that builds on the origin of the word 'mashup', this paper presents a demonstration "playlist" of four geo-mashup vignettes that make use of a range of Web 2.0, Semantic Web, and 3-D Internet methods, with outputs/end-user interfaces spanning the flat Web (two-dimensional -- 2-D maps), a three-dimensional -- 3-D mirror world (Google Earth) and a 3-D virtual world (Second Life (R)). The four geo-mashup "songs" in this "playlist" are: 'Web 2.0 and GIS (Geographic Information Systems) for infectious disease surveillance', 'Web 2.0 and GIS for molecular epidemiology', 'Semantic Web for GIS mashup', and 'From Yahoo! Pipes to 3-D, avatar-inhabited geo-mashups'. It is hoped that this showcase of examples and ideas, and the pointers we are providing to the many online tools that are freely available today for creating, sharing and reusing geo-mashups with minimal or no coding, will ultimately spark the imagination of many public health practitioners and stimulate them to start exploring the use of these methods and tools in their day-to-day practice. The paper also discusses how today's Web is rapidly evolving into a much more intensely immersive, mixed-reality and ubiquitous socio-experiential Metaverse that is heavily interconnected through various kinds of user-created mashups.

The effects of self-involvement on attention, arousal, and facial expression during social interaction with virtual others: A psychophysiological study.

Soc Neurosci. 2006;1(3-4):184-95

Authors: Mojzisch A, Schilbach L, Helmert JR, Pannasch S, Velichkovsky BM, Vogeley K

Social neuroscience has shed light on the underpinnings of understanding other minds. The current study investigated the effect of self-involvement during social interaction on attention, arousal, and facial expression. Specifically, we sought to disentangle the effect of being personally addressed from the effect of decoding the meaning of another person's facial expression. To this end, eye movements, pupil size, and facial electromyographic (EMG) activity were recorded while participants observed virtual characters gazing at them or looking at someone else. In dynamic animations, the virtual characters then displayed either socially relevant facial expressions (similar to those used in everyday life situations to establish interpersonal contact) or arbitrary facial movements. The results show that attention allocation, as assessed by eye-tracking measurements, was specifically related to self-involvement regardless of the social meaning being conveyed. Arousal, as measured by pupil size, was primarily related to perceiving the virtual character's gender. In contrast, facial EMG activity was determined by the perception of socially relevant facial expressions irrespective of whom these were directed towards.

Have a look at the Web Trend Map 2008, by Information Architects

The map is based on the Tokyo underground

Larger formats are available:

1. Clickable Startpage with daily updated iA surf tips
2. Big, A3 PDF (8MB, printable)
3. 1600 x 1024 Wallpaper
4. 1440 x 900 Wallpaper

Techniques and devices to restore cognition.

Behav Brain Res. 2008 Oct 10;192(2):149-65

Authors: Serruya MD, Kahana MJ

Executive planning, the ability to direct and sustain attention, language and several types of memory may be compromised by conditions such as stroke, traumatic brain injury, cancer, autism, cerebral palsy and Alzheimer's disease. No medical devices are currently available to help restore these cognitive functions. Recent findings about the neurophysiology of these conditions in humans coupled with progress in engineering devices to treat refractory neurological conditions imply that the time has arrived to consider the design and evaluation of a new class of devices. Like their neuromotor counterparts, neurocognitive prostheses might sense or modulate neural function in a non-invasive manner or by means of implanted electrodes. In order to paint a vision for future device development, it is essential to first review what can be achieved using behavioral and external modulatory techniques. While non-invasive approaches might strengthen a patient's remaining intact cognitive abilities, neurocognitive prosthetics comprised of direct brain-computer interfaces could in theory physically reconstitute and augment the substrate of cognition itself.