Application of virtual reality graphics in assessment of concussion.

Abnormal balance in individuals suffering from traumatic brain injury (TBI) has been documented in numerous recent studies. However, specific mechanisms causing balance deficits have not been systematically examined. This paper demonstrated the destabilizing effect of visual field motion, induced by virtual reality graphics in concussed individuals but not in normal controls. Fifty five student-athletes at risk for concussion participated in this study prior to injury and 10 of these subjects who suffered MTBI were tested again on day 3, day 10, and day 30 after the incident. Postural responses to visual field motion were recorded using a virtual reality (VR) environment in conjunction with balance (AMTI force plate) and motion tracking (Flock of Birds) technologies. Two experimental conditions were introduced where subjects passively viewed VR scenes or actively manipulated the visual field motion. Long-lasting destabilizing effects of visual field motion were revealed, although subjects were asymptomatic when standard balance tests were introduced. The findings demonstrate that advanced VR technology may detect residual symptoms of concussion at least 30 days post-injury.     

Further investigations of how rare disaster information affects risk taking: A registered replication report

Psychonomic Bulletin & Review - Across two experiments, Newell, Rakow, Yechiam, and Sambur (Nature Climate Change, 6(2), 158–161, 2016) demonstrated that providing rare disaster...     

Intraindividual Variability of Neuromotor Function Predicts Falls Risk in Older Adults and those with Type 2 Diabetes

This study was designed to examine the effect of increasing age and type 2 diabetes on the average responses and inter- and intraindividual variability of falls risk, reaction time, strength, and walking speed for healthy older adults and older persons with type 2 diabetes (T2DM). Seventy-five older individuals (controls) and 75 persons with T2DM aged between 50 and 79 years participated in the study. Assessments of falls risk, reaction time (RT), knee extension strength, and walking speed were conducted. The results revealed that advancing age for both control and T2DM groups was reflected by a progressive increase in falls risk, decreased leg strength and a decline (i.e., slowing) of reactions and gait speed. Conversely, the level of intraindividual variability for the RT, strength and gait measures increased with increasing age for both groups, with T2DM persons tending to be more variable compared to the healthy controls of similar age. In contrast to the intraindividual changes, measures of interindividual variability revealed few differences between the healthy elderly and T2DM individuals. Taken together, the findings support the proposition that intraindividual variability of neuromotor measures may be useful as a biomarker for the early detection of decline in physiological function due to age or disease.     

Getting scarred and winning lotteries: effects of exemplar cuing and statistical format on imagining low‐probability events

Three experiments tested the exemplar cuing and frequency format accounts of how the ‘imaginability’ of low‐probability events is enhanced. The experiments manipulated imaginability by varying the statistics used to describe negative (e.g. being scarred as a result of laser surgery) and positive (e.g. winning a lottery) low‐probability events. The results strongly supported the frequency format account, whereby imaginability is enhanced through the use of frequency formats for conveying statistical information (e.g. 20 out of 2000 as opposed to 0.01%). However, only limited support was found for exemplar cuing (EC) theory. Overall the results support the claim that the imaginability of outcomes plays a key role in thinking about low‐probability events, but question the mechanisms specified by EC theory for mediating such effects. Copyright © 2007 John Wiley & Sons, Ltd.     

Online feedback and the regulation of degrees of freedom in motor control

We tested the hypothesis that the degree to which online feedback is used to control movement influences the regulation of degrees of freedom in a task. Ten participants performed an isometric force production task with their two index fingers with the goal of matching the total force to a target waveform. The role of online feedback was manipulated by changing three factors - the tracking mode, the profile of the target waveform, and the visual gain. The results showed that the coupling between the finger forces was lower in conditions where participants used online feedback to correct their movements compared to conditions where more feedforward strategies were used. The availability of online feedback is dependent on the nature of the task and this contributes to task-dependent changes in the regulation of the degrees of freedom.     

Colored-Speech Synaesthesia Is Triggered by Multisensory, Not Unisensory, Perception

ABSTRACT— Although it is estimated that as many as 4% of people experience some form of enhanced cross talk between (or within) the senses, known as synaesthesia, very little is understood about the level of information processing required to induce a synaesthetic experience. In work presented here, we used a well-known multisensory illusion called the McGurk effect to show that synaesthesia is driven by late, perceptual processing, rather than early, unisensory processing. Specifically, we tested 9 linguistic-color synaesthetes and found that the colors induced by spoken words are related to what is perceived (i.e., the illusory combination of audio and visual inputs) and not to the auditory component alone. Our findings indicate that color-speech synaesthesia is triggered only when a significant amount of information processing has occurred and that early sensory activation is not directly linked to the synaesthetic experience.     

Cognitive-behavioural therapy for adolescents with bulimic symptomatology: The acceptability and effectiveness of internet-based delivery

Background

The evidence base for the treatment of adolescents with bulimia nervosa (BN) is limited.

Aims

To assess the feasibility, acceptability, and clinical outcomes of a web-based cognitive-behavioural (CBT) intervention for adolescents with bulimic symptomatology.

Method

101 participants were recruited from eating disorders clinics or from beat, a UK-wide eating disorders charity. The programme consisted of online CBT sessions (‘Overcoming Bulimia Online’), peer support via message boards, and email support from a clinician. Participants' bulimic symptomatology and service utilisation were assessed by interview at baseline and at three and six months. Participants' views of the treatment package were also determined.

Results

There were significant improvements in eating disorder symptoms and service contacts from baseline to three months, which were maintained at six months. Participants' views of the intervention were positive.

Conclusions

The intervention has the potential for use as a first step in the treatment of adolescents with bulimic symptomatology.     

Brainstem auditory electrical response characteristics of stutterers and nonstutterers: A preliminary report

In the present study, eight adult male stutterers and nonstutterers showed no significant latency or amplitude differences in BSERs recorded in response to monaural and binaural clicks. However, significantly greater variance was found in the stutterers' group under the monaural stimulation condition at click rates of 12/sec and 5/sec. Left and right monaural waveforms were subtracted individually from the binaural waveform. The resultant binaural interaction difference traces were examined to determine auditory tract preference for binaural stimulation. While some subjects from both groups showed no auditory tract preference, it was found that the significant variance between groups for wave V latency was attributable to the subset of stutterers without auditory tract preference. This finding is interpreted as evidence of neurological differences in stutterers' auditory processing at the brainstem level.     

Speed and accuracy of compensatory responses to limb disturbances

This study examines the speed and accuracy of compensatory responses to flexion-extension perturbations of the wrist in the horizontal plane. In Experiments 1 and 2 the subjects were required to establish an initial flexion or extension force of approximately 15% maximum at a prescribed initial muscle length. The perturbations changed the load force by +/-5% in both simple and choice reaction protocols. The results showed that the latencies to compensate for the perturbation were longer when the direction of disturbance was unknown (i.e., choice effect) and when the perturbation unloaded the muscle (i.e., directional effect). Accuracy constraints on the compensatory response increased movement time and reduced the variability of latency without affecting mean latency. In Experiment 3, a visual stimulus generated a comparable choice effect on latency to that produced by the perturbations, but no directional effect in relation to the preload was apparent. Our behavioral analysis of compensatory responses triggered by wrist perturbations confirms that these responses are susceptible to variables that influence the initiation of voluntary movements. Our analysis also demonstrates a directional preload effect that is stimulus specific.     

Kinematic information feedback for learning a rapid arm movement

The experiments reported examine the notion that knowledge of results (KR) about the outcome of a response does not provide the necessary information for optimizing performance in many skilled activities. The effect of traditional KR was contrasted with various kinematic feedback parameters in the acquisition of a single degree of freedom response requiring the minimization of movement time. Experiment 1 showed that the presentation of discrete kinematic information feedback (peak accelaration, time to peak accelaration, and velocity at the target location) did not facilitate performance over movement-time KR. Experiment 2 revealed that presentation of a computer generated velocity-time representation of the movement as terminal information feedback improved performance over movement-time KR. This facilitation occured even without knowledge of the kinematics for optimal performance. The findings suggest that the task criterion specifies the appropriate information feedback for skill learning in that the information feedback must match the constraints imposed upon response output.