Global Facilitation of Attended Features Is Obligatory and Restricts Divided Attention

Peer reviewedPublisher PD

Electrophysiological Studies of Visual Attention and of Emotion Regulation

Electrophysiological methods, such as electroencephalography (EEG) and electrocardiography (ECG), measure biological activity that allow us to infer underlying cognitive processes. In the first study, we use EEG to track feature-based attention (FBA), a form of visual attention that helps one detect objects with a particular color, motion, or orientation. We explore the use of SSVEPs, generated by flicker presented peripherally, to track attention in a visual search task presented centrally. Classification results show that one can track an observer’s attended color, which suggests that these methods may provide a viable means for tracking FBA in a real-time task. In the second study, we use cardiovascular measures to examine influences of the emotion regulation strategy of reappraisal. We examine cooperation and cardiovascular responses in individuals that were defected on by their opponent in the first round of an iterated Prisoner’s Dilemma. We find significant differences between the emotion regulation conditions using the biopsychosocial (BPS) model of challenge and threat, where participants primed with the reappraisal strategy were weakly comparable with a threat state of the BPS model and participants without an emotion regulation were weakly comparable with a challenge state of the BPS model. In the third study, we use EEG to study the chromatic sensitivity of FBA for color during a visual search task. We use SSVEP responses evoked through peripheral flicker to measure the spectral tuning of color detection mechanisms and how attentional selection is affected by distractor color. Our results find smaller responses for the distractor colors and suggest that feature-based attention to a particular color involves chromatic mechanisms that both enhance the response to a target and minimize responses to distractors

Combining computer game-based behavioural experiments with high-density EEG and infrared gaze tracking

Rigorous, quantitative examination of therapeutic techniques anecdotally reported to have been successful in people with autism who lack communicative speech will help guide basic science toward a more complete characterisation of the cognitive profile in this underserved subpopulation, and show the extent to which theories and results developed with the high-functioning subpopulation may apply. This study examines a novel therapy, the "Rapid Prompting Method" (RPM). RPM is a parent-developed communicative and educational therapy for persons with autism who do not speak or who have difficulty using speech communicatively.The technique aims to develop a means of interactive learning by pointing amongst multiple-choice options presented at different locations in space, with the aid of sensory "prompts" which evoke a response without cueing any specific response option. The prompts are meant to draw and to maintain attention to the communicative task–making the communicative and educational content coincident with the most physically salient, attention-capturing stimulus – and to extinguish the sensory–motor preoccupations with which the prompts compete.ideo-recorded RPM sessions with nine autistic children ages 8–14years who lacked functional communicative speech were coded for behaviours of interest

Study, definition and analysis of pilot/system performance measurements for planetary entry experiments

Definition analysis for experimental prediction of pilot performance during planetary entr

Noncontact brain-computer interface based on steady-state pupil light reflex using independent bilateral eyes stimulation

Steady-state visual evoked potential (SSVEP), which uses blinking light stimulation to estimate the attending target, has been known as a communication technique with severe motor disabilities such as ALS and Locked-in-syndrome. Recently, it was reported that pupil diameter vibration based on pupillary light reflex has been observed in the attending target with a constant blinking frequency. This fact suggests the possibility of a noncontact BCI using pupillometers as alternatives to contacting scalp electrodes. In this study, we show an increment in the number of communication channels by stimulating both eyes alone or in combination with different frequencies. The number of selective targets becomes twice the number of frequencies using this method. Experiments are conducted by recruiting three healthy participants. We prepare six target patterns comprising three frequencies and detect the target using a coefficient of correlation of power spectrum between the pupil diameter and stimulus signal. Consequently, the average classification accuracy of the three participants of approximately 83.4% is achieved. The findings of this study demonstrate the feasibility of noncontact BCI systems

Menetelmiä lasten näkötiedon käsittelyn arvioimiseksi katseenseurannan avulla

Cortical visual processing and mechanism under eye movements and visiospatial attention undergo prominent developmental changes during the first 12 months of infancy. At that time, these key functions of vision are tightly connected to the early brain development in general. Thus, they are favourable targets for new research methods that can be used in treatment, prediction, or detection of various adverse visual of neurocognitive conditions. This thesis presents two eye tracker assisted test paradigms that may be used to evaluate and quantify different functions of infants’ visual processing. The first study concentrates on the analysis of the gaze patterns in classic face-distractor competition paradigm known to tap mechanisms under infant’s attention disengagement and visuospatial orienting. A novel stimuli over a given period of time. In further evaluation, the metric is shown to be sensitive to developmental changes in infants’ face processing between 5 and 7 months of age. The second study focuses on the visual evoked potentials (VEPs) elicited by orientation reversal, global form, and clobal motion stimulation known to measure distinct aspects of visual processing at the cortical level. To improve the reality of such methods, an eye tracker is integrated to the recording setup, which can be used to control stimulus presentation to capture the attention of the infant, and in the analysis to exclude the electroencephalography (EEG) segments with disorientated gaze. With this setup, VEPs can be detected from the vast majority of the tested 3-month-old infants (N=39) using circular variant of Hotelling’s T2 test statistic and two developed power spectrum based metrics. After further development already in progress, the presented methods are ready to be used clinically in assessments of neurocognitive development, preferably alongside other similar biomarker tests of infancy.Näkötiedon käsittely aivokuorella sekä silmänliikkeiden ja visuospatiaalisen tarkkaavaisuuden mekanismit kehittyvät valtavasti lapsen ensimmäisen 12 elinkuukauden kuluessa. Nämä näön avaintoiminnot ovat tiukasti sidoksissa aivojen yleiseen varhaiskehitykseen, jonka vuoksi ne ovat suotuisia kohteita uusille tutkimusmenetelmille käytettäväksi visuaalisen tai neurologisten ongelmien hoidossa, ennustuksessa ja löytämisessä. Tämä työ esittelee kaksi katseenseurantaa hyödyntävää koeasetelmaa, joita voidaan käyttää lasten kortikaalisen näkötiedon käsittelyn arvioinnissa ja kvantifionnissa. Ensimmäisessä tutkimuksessa kehitettiin mitattujen katsekuvioiden analyysiä klassisessa kasvokuva-distraktori-koeasetelmassa, jonka tiedetään koskettavan lasten tarkkavaisuuden vapauttamiseen ja katseen siirtoon liittyviä mekanismeja. Työssä kehitetyllä laskennallisella mittarilla pystytään määrittämään tarkkavaisuuden jakautuminen ruudun keskellä ja raunalla esitettyjen ärsykkeiden välillä haluttuna aikana. Jatkotarkastelu osoittaa mittarin olevan herkkä kasvokuvien käsittelyn kehityksen muutoksille 5 ja 7 kuukauden ikäisten lasten välillä. Toinen osatyö keskittyy näkötiedon kortikaalista käsittelyä heijastavien, suunnan kääntämisen, globaalin muodon tai liikkeen tuottamien näköherätepotentiaalien mittaamiseen ja analyysiin. Parantaakseen menetelmien luotettavuutta laitteistoon liitetään silmänliikekamera, joka mahdollistaa sekä ärsyketoiston ohjaamisen lapsen tarkkaavaisuuden mukaisesti että kerätyn aivosähkökäyrän karsimisen niiltä osin, jolloin lapsen katse oli harhautunut esityksestä. Käyttäen muunnelmaa Hotellingin T2 statistiikasta ja kahta työssä kehitettyä, tehospektriin pohjautuvaa analyysimenetelmää herätevasteet pystytään löytämään valtaosalta 3 kuukauden ikäisistä lapsista (N=39). Meneillään olevan jatkokehityksen jälkeen esitetyt menetelmät ovat valmiita kliiniseen käyttöön neurokognitiivisen kehityksen arvioinnissa muiden vastaavien biomarkkeritutkimuksen rinnalla

Seuratun kappaleen poikkeuttaminen silmänräpäysten aikana: käyttäytymis- ja neuromagneettisia havaintoja

The visual world is perceived as continuous despite frequent interruptions of sensory data due to eyeblinks and rapid eye movements. To create the perception of constancy, the brain makes use of fill-in mechanisms. This study presents an experiment in which the location of an object during smooth pursuit tracking is altered during eyeblinks. The experiment investigates the effects of blink suppression and fill-in mechanisms to cloud the discrimination of these changes. We employed a motion-tracking task, which promotes the accurate evaluation of the object’s trajectory and thus can counteract the fill-in mechanisms. Six subjects took part in the experiment, during which they were asked to report any perceived anomalies in the trajectory. Eye movements were monitored with a video-based tracking and brain responses with simultaneous MEG recordings. Discrimination success was found to depend on the direction of the displacement, and was significantly modulated by prior knowledge of the triggered effect. Eye-movement data were congruent with previous findings and revealed a smooth transition from blink recovery to object locating. MEG recordings were analysed for condition-dependent evoked and induced responses; however, intersubject variability was too large for drawing clear conclusions regarding the brain basis of the fill-in mechanisms.Visuaalinen maailma koetaan jatkuvana, vaikka silmänräpäykset ja nopeat silmänliikkeet aiheuttavat keskeytyksiä sensoriseen tiedonkeruuseen. Luodakseen käsityksen pysyvyydestä, aivot käyttävät täyttömekanismeja. Tämä tutkimus esittelee kokeen, jossa kappaleen seurantaa hitailla seurantaliikkeillä häiritään muuttamalla sen sijaintia silmänräpäysten aikana. Tämä koe tutkii, kuinka silmänräpäysten aiheuttama suppressio ja täyttömekanismit sumentavat kykyä erotella näitä muutoksia. Käytimme liikeseurantatehtävää, joka vastaavasti edistää kappaleen liikeradan tarkkaa arviointia. Kuusi koehenkilöä osallistui kokeeseen, jonka aikana heitä pyydettiin ilmoittamaan kaikki havaitut poikkeamat kappaleen liikeradassa. Silmänliikkeitä tallennettiin videopohjaisella seurannalla, ja aivovasteita yhtäaikaisella MEG:llä. Erottelykyvyn todettiin riippuvan poikkeutuksen suunnasta, sekä merkittävästi a priori tiedosta poikkeutusten esiintymistavasta. Silmänliikedata oli yhtenevää aiempien tutkimusten kanssa, ja paljasti sujuvan siirtymisen silmänräpäyksistä palautumisesta kappaleen paikallistamiseen. MEG-tallenteet analysoitiin ehdollisten heräte- ja indusoitujen vasteiden löytämiseksi, mutta yksilölliset vaste-erot koehenkilöiden välillä olivat liian suuria selkeiden johtopäätösten tekemiseksi täyttömekanismien aivoperustasta

Psychophysiology-based QoE assessment : a survey

We present a survey of psychophysiology-based assessment for quality of experience (QoE) in advanced multimedia technologies. We provide a classification of methods relevant to QoE and describe related psychological processes, experimental design considerations, and signal analysis techniques. We summarize multimodal techniques and discuss several important aspects of psychophysiology-based QoE assessment, including the synergies with psychophysical assessment and the need for standardized experimental design. This survey is not considered to be exhaustive but serves as a guideline for those interested to further explore this emerging field of research

Dose-dependent sensorimotor impairment in human ocular tracking after acute low-dose alcohol administration

Key points: Oculomotor behaviours are commonly used to evaluate sensorimotor disruption due to ethanol (EtOH). The current study demonstrates the dose-dependent impairment in oculomotor and ocular behaviours across a range of ultra-low BACs (\u3c0.035%). Processing of target speed and direction, as well as pursuit eye movements, are significantly impaired at 0.015% BAC, suggesting impaired neural activity within brain regions associated with the visual processing of motion. Catch-up saccades during steady visual tracking of the moving target compensate for the reduced vigour of smooth eye movements that occurs with the ingestion of low-dose alcohol. Saccade dynamics start to become ‘sluggish’ at as low as 0.035% BAC. Pupillary light responses appear unaffected at BAC levels up to 0.065%. Abstract: Changes in oculomotor behaviours are often used as metrics of sensorimotor disruption due to ethanol (EtOH); however, previous studies have focused on deficits at blood-alcohol concentrations (BACs) above about 0.04%. We investigated the dose dependence of the impairment in oculomotor and ocular behaviours caused by EtOH administration across a range of ultra-low BACs (≤0.035%). We took repeated measures of oculomotor and ocular performance from sixteen participants, both pre- and post-EtOH administration. To assess the neurological impacts across a wide range of brain areas and pathways, our protocol measured 21 largely independent performance metrics extracted from a range of behavioural responses ranging from ocular tracking of radial step-ramp stimuli, to eccentric gaze holding, to pupillary responses evoked by light flashes. Our results show significant impairment of pursuit and visual motion processing at 0.015% BAC, reflecting degraded neural processing within extrastriate cortical pathways. However, catch-up saccades largely compensate for the tracking displacement shortfall caused by low pursuit gain, although there still is significant residual retinal slip and thus degraded dynamic acuity. Furthermore, although saccades are more frequent, their dynamics are more sluggish (i.e. show lower peak velocities) starting at BAC levels as low as 0.035%. Small effects in eccentric gaze holding and no effect in pupillary response dynamics were observed at levels below 0.07%, showing the higher sensitivity of the pursuit response to very low levels of blood alcohol, under the conditions of our study