A review of the DTS: Diathermic Syncope® system with a discussion regarding its use for kosher slaughter (shechita).

Over the last several decades an alternative to current methods of stunning cattle has been developed. This system, DTS: Diathermic Syncope®, has been suggested to the Jewish and Muslim communities as a means to achieve pre-cut stunning in conformity with both religious and EU regulations without a need to resort to a derogation that permits an exemption from the EU requirement to pre-stun all animals undergoing slaughter. The developer's contention is that the system induces fainting, and thus should be acceptable to all groups, including the kosher (Jewish) and Halal (Muslim) consumer. A review of the system based on publications and reports from the developer itself suggests that in reality the system selectively heats the brain, leading to an epileptic-type seizure with tonic-clonic phases and unconsciousness lasting several minutes. It does not induce a (benign) faint, and use of the system might cause structural brain damage. Thus, this system is unlikely to be acceptable under Jewish religious law and its animal welfare value can be questioned.

A novel variation of the Stroop task reveals reflexive supremacy of peripheral over gaze stimuli in pro and anti saccades.

A long-standing controversy in social attention debates whether gaze-of-another induces reflexive shifts of one's own attention. In attempting to resolve this controversy, we utilized a novel Stroop task, the PAT Stroop, in which pro- and anti-saccade (PAT) responses are made to competing gaze and peripheral stimuli. The first experiment demonstrated a "Stroop effect" for peripheral stimuli, i.e. peripheral distractors interfered with gaze triggers, but gaze distractors did not interfere with peripheral triggers. These results were replicated in the second experiment, which also negated the possibility that the mere display and practice of the "clean PAT" influenced the results. Thus, the use a new PAT Stroop task demonstrated reflexive supremacy of peripheral stimuli over gaze stimuli. This novel variant of the Stroop task demonstrated similar characteristics to the classic color naming Stroop - i.e. an asymmetrical pattern, and again showed the utility and versatility of stoop-like tasks in probing mental tasks.

Preliminary evidence linking complex-PTSD to insomnia in a sample of Yazidi genocide survivors.

Complex post-traumatic stress disorder (CPTSD) is a psychiatric diagnosis that includes three additional symptom clusters beyond those necessary for post-traumatic stress disorder (PTSD) diagnosis. CPTSD is typically associated with a prolonged trauma exposure in which a person's destiny is under the control of other people and escape is not an option. Insomnia prevalence in women suffering from CPTSD was compared to the prevalence of insomnia in those with no-PTSD and those with only PTSD. Yazidi women (N = 108, age = 24.41 ±â€¯5.71) former captives of the Islamic State terrorist group were queried about captivity variables, psychological distress, resilience, PTSD, CPTSD, and insomnia. CPTSD prevalence was high (>50%) and was highly correlated with insomnia (95% of those with CPTSD had insomnia). A dichotomous insomnia variable was regressed on age and marital-status (Step 1), captivity-duration and number of fellow captives (Step 2), resilience and psychological distress (Step 3), and group (no-PTSD/PTSD/CPTSD) (Step 4). Insomnia was 18 times more likely in the CPTSD group than in the no-PTSD group. There were no differences in insomnia prevalence between the no-PTSD and PTSD groups. Insomnia levels among Yazidi women released from captivity support an understanding of CPTSD as a separate entity than PTSD. Potential factors linking CPTSD to insomnia, beyond those associated with PTSD are discussed.

The effects of dual tasking on gait synchronization during over-ground side-by-side walking.

Recent studies have shown that gait synchronization during natural walking is not merely anecdotal, but it is a repeatable phenomenon that is quantifiable and is apparently related to available sensory feedback modalities. However, the mechanisms underlying this phase-locking of gait have only recently begun to be investigated. For example, it is not known what role, if any, attention plays. We employed a dual tasking paradigm in order to investigate the role attention plays in gait synchronization. Sixteen pairs of subjects walked under six conditions that manipulated the available sensory feedback and the degree of difficulty of the dual task, i.e., the attention. Movement was quantified using a trunk-mounted tri-axial accelerometer. A gait synchronization index (GSI) was calculated in order to quantify the degree of synchronization of the gait pattern. A simple dual task resulted in an increased level of synchronization, whereas a more complex dual task lead to a reduction in synchronization. Handholding increased synchronization, compared to the same attention condition without handholding. These results indicate that in order for two walkers to synchronize, some level of attention is apparently required, such that a relatively complex dual task utilizes enough attentional resources to reduce the occurrence of synchronization.

Face stimulus eliminates antisaccade-cost: gaze following is a different kind of arrow.

When a person suddenly looks in a certain direction, others seem to shift their attention to the same, looked-at, location. This common observation, that gaze-of-another seems to trigger reflexive shifts of attention within an observer, has been demonstrated in various studies. Yet just how reflexive it truly is, is an on-going controversy. Unlike most studies in which gaze cues were distractors in a cueing paradigm, the current study used gaze cues as triggers in a mixed pro- and anti-saccade task and a Posner-like discrimination task. In a set of two experiments, we investigated whether attention triggered by gaze-of-another differs from attention triggered by peripheral (exogenous) and arrow stimuli. In the first experiment, gaze cues resulted in slowed saccadic responses and in the elimination of the anti-saccade-cost associated with reflexive orienting. Pro-saccades triggered by peripheral cues had significantly fewer errors and shorter reaction times than anti-saccades. However, there was no significant difference between pro and anti-saccades triggered by gaze cues. Thus, counter to expectations, gaze did not produce reflexive shifts of overt attention. The second experiment showed that attention triggered by gaze cues is no different from attention triggered by biologically irrelevant arrow cues. They both eliminated the anti-saccade-cost and displayed prolonged reaction times. However, manual discrimination RTs showed no significant differences between gaze and peripheral cues. Together, these results suggest that neither gaze nor arrow cues trigger reflexive shifts of overt attention.

Back to basics: The effects of block vs. interleaved trial administration on pro- and anti-saccade performance.

The pro and anti-saccade task (PAT) is a widely used tool in the study of overt and covert attention with promising potential role in neurocognitive and psychiatric assessment. However, specific PAT protocols can vary significantly between labs, potentially resulting in large variations in findings across studies. In light of recent calls towards a standardization of PAT the current study's objective was to systematically and purposely evaluate the effects of block vs. interleaved administration-a fundamental consideration-on PAT measures in a within subject design. Additionally, this study evaluated whether measures of a Posner-type cueing paradigm parallels measures of the PAT paradigm. As hypothesized, results indicate that PAT performance is highly susceptible to administration mode. Interleaved mode resulted in larger error rates not only for anti (blocks: M = 22%; interleaved: M = 42%) but also for pro-saccades (blocks: M = 5%; interleaved: M = 12%). This difference between block and interleaved administration was significantly larger in anti-saccades compared to pro-saccades and cannot be attributed to a 'speed/accuracy tradeoff'. Interleaved mode produced larger pro and anti-saccade differences in error rates while block administration produced larger latency differences. Results question the reflexive nature of pro-saccades, suggesting they are not purely reflexive. These results were further discussed and compared to previous studies that included within subject data of blocks and interleaved trials.

Beating their chests: University students with ADHD demonstrate greater attentional abilities on an inattentional blindness paradigm.

OBJECTIVE: Adults diagnosed with attentional deficit disorder (ADHD) are easily distracted in many tasks. Yet ADHD performance on inattentional blindness (IB) tasks has not been examined. Such investigation may aid in discriminating between 3 ADHD models: the neurological model, the perceptual load theory, and the "hunter versus farmer" hypothesis. METHOD: Distractibility was assessed in ADHD and non-ADHD college students using the MOXO task that involves detection of a single attended stimulus that repeatedly appears in the same place and in the well-known IB "gorilla" video which involves tracking of a stimulus moving at a fast pace in a dynamic, complex manner. RESULTS: ADHD college students showed increased distractibility in the MOXO task. By contrast, they performed better than controls in the attended channel of the IB task, while they were also better at noticing the unattended stimuli and thus exhibiting little-to-no inattentional blindness. CONCLUSIONS: As no attentional tradeoffs were evident in the IB task, it appears that the results are most consistent with the "hunter versus farmer" hypothesis, which postulates that ADHD individuals have an alternative cognitive style which is less equipped to deal with detection of repeated stimuli while comprising advantages in the tracking of stimuli moving in a fast dynamic manner.

Can the red-green duochrome test be used prior to correcting the refractive cylinder component?

PURPOSE: A primary task of the eye care professional is determining the refraction, or optical correction, of a patient. The duochrome red-green test is a standard tool for verification of the final refraction. Traditionally, it is recommended for use both prior to and subsequent to determining the cylindrical or astigmatic component of the refraction. In order for it to be effective when used before correcting the cylinder it is necessary that the COLC (Circle of Least Confusion) be on the retina. This study examined whether it is necessarily true that the duochrome response in uncorrected astigmatism will be as trust-worthy as it is with corrected cylinders. METHODS: The red-green examination was performed monocularly under the following three conditions: a. fully corrected refraction for the subgroup of eyes that had spherical refractions and for the subgroup of eyes with sphero-cylindrical refractions. b. best sphere-only correction without cylinder correction in sphero-cylindrical eyes c. an induced cylinder error in spherical eyes. The interval between the last "red" response and the first "green" response for the right eyes as a group and separately for the physiological cylinder and induced cylinder correction sub-groups was calculated and compared using a paired, two-tailed t-test. RESULTS: The intervals between "red" and "green" responses were not significantly different in the population as a whole and in the uncorrected physiological cylinder and induced cylinder subgroups examined. CONCLUSION: Based on the finding that the interval of red-green equality with fully corrected cylinder and without the cylindrical correction are not significantly different, the red-green duochrome test can indeed be used both before and after cylindrical correction.

Assessing the utility of visual acuity measures in visual prostheses.

There are presently several ongoing clinical trials to provide usable sight to profoundly visually impaired patients by means of electrical stimulation of the retina. Some of the blind patients implanted with retinal prosthesis reported un-patterned perception and yet benefit from the device in many activities of daily living, seemingly because they adopt active scanning strategies. The aim of the present work is to evaluate if and under what conditions a measured visual acuity level is truly an indication that the brain perceived a patterned image from the electrical stimulation of the visual prosthesis. Sighted subjects used a pixelized simulator in which they perceived either a low resolution sub-sampling of the original image ("normal mode"--patterned vision) or an image that was solely a function of the brightness and size of the original image ("brightness mode"--no patterned vision). Results show that subjects were able to adopt a head scanning strategy that enabled acuity beyond the resolution set by a static view of the stimulus. In brightness mode, i.e. without patterned vision, most subjects achieved a measurable acuity level better than the limit set by the geometrical resolution of the entire array but worse than the limit set by the distance between neighboring simulated pixels. In normal mode all subject achieved acuity level that is better than the geometrical resolution of the simulated pixels. Thus, visual acuity levels comparable with the electrodes/pixels resolution implies that the patient perceives an image with spatial patterns.

The transplantation of solid organs from HIV-positive donors to HIV-negative recipients: ethical implications.

HIV-positive individuals have traditionally been barred from donating organs due to transmission concerns, but this barrier may soon be lifted in the USA in limited settings when recipients are also infected with HIV. Recipients of livers and kidneys with well-controlled HIV infection have been shown to have similar outcomes to those without HIV, erasing ethical concerns about poorly chosen beneficiaries of precious organs. But the question of whether HIV-negative patients should be disallowed from receiving an organ from an HIV-positive donor has not been adequately explored. In this essay, we will discuss the background to this scenario and the ethical implications of its adoption from the perspectives of autonomy, beneficence/non-maleficence and justice.

Impaired vestibulo-ocular reflex (VOR) in spinocerebellar ataxia type 3 (SCA3): bedside and search coil evaluation.

Vestibulo-Ocular Reflex (VOR) abnormalities in cerebellar ataxias are a matter of renewed interest. We have previously reported vestibular areflexia in a group of Yemenite-Jews with Spinocerebellar Ataxia Type 3 (SCA3) who had clear bilateral pathological horizontal Head Impulse Test (HIT). The objective of this study was to evaluate the VOR of ten SCA3 patients who have variable bedside HIT responses by recording their eye movements using magnetic search coils and to correlate these results with their clinical and genetic data. Eight out of the ten patients have abnormal horizontal HIT detected by both clinical bedside examination and laboratory tests. Results of bedside HIT testing were significantly correlated with the VOR gain recorded using magnetic search coils. No significant correlations were found between VOR gain and other clinical or genetic data. Our study confirms the presence of defective VOR in SCA3 patients and corroborates the useful of the HIT as a reliable bedside test for diagnosis of VOR deficits.

Multiple saccadic abnormalities in spinocerebellar ataxia type 3 can be linked to a single deficiency in velocity feedback.

PURPOSE: The purpose of the current research is to understand if the different eye movement abnormalities in patients with the same neurologic disease are related to varied disease processes or, alternately, do different patients adopt different strategies to overcome a singular brain deficiency. METHODS: Using a magnetic search coil, we measured saccade dynamics, that is position and velocity waveforms, for patients diagnosed with spinocerebellar ataxia type 3 (SCA-3), also known as Machado-Joseph disease (MJD). RESULTS: We observed that the saccadic waveform of the majority of the SCA-3 patients (7 of 10) exhibited dynamic overshoot, with the eye passing the desired endpoint and making a rapid correction before coming to rest. Patients with normal waveforms, that is with no dynamic overshoot, had saccades with relatively low peak velocity. CONCLUSIONS: Velocity feedback in a closed loop control system is essential for providing a fast response without overshoot. Lack of a velocity feedback or an imbalance between position and velocity gains yields a tradeoff between response time and overshoot. While the goal of a saccade is to get to the desired position, models based on animal research suggest that the saccadic control also incorporates a velocity feedback. Results presented here indicated that all SCA-3 patients had deviations in the saccadic waveform, albeit of two types, either slow saccades or dynamic overshooting saccades. Using saccadic models based on animal research can explain how a single deficit, that is a mismatched velocity control of the motor error due to the disease, can yield these two different abnormalities in human patients.

Misjudging their own steps: why elderly people have trouble crossing the road.

OBJECTIVE: The aim of this study was to test whether elderly individuals underestimate the time that it will take them to cross a street by comparing estimated with actual road-crossing time. BACKGROUND: In many developed countries, elderly people are overrepresented among pedestrian fatalities from motor vehicle accidents. There is surely more than one contributing factor to this phenomenon, and many have been offered. We propose that one additional factor may be that although older people are consciously aware that they no longer walk at the same pace as they once did, they do not take this fact into consideration when planning a street crossing. METHOD: We compared the ability of young and old pedestrians to estimate the time that it will take them to cross a street, using both prospective and retrospective time estimation. RESULTS: A significant interaction was found between age group and crossing time. Among elderly participants, actual crossing times were significantly longer than both their precrossing estimation and their postcrossing estimation, which did not significantly differ from each other. In contrast, the undergraduate group's crossing times did not display a significant difference across measurements. CONCLUSION: This study implies that even if older pedestrians correctly evaluate the road situation, they may nonetheless endanger themselves by underestimating the time that it will take them to cross the street.We suggest that minimizing this effect could be accomplished by educating seniors to the fact that they are not as fast as they once were and that this fact needs to be factored in to street-crossing decisions.

Modality-specific communication enabling gait synchronization during over-ground side-by-side walking.

An attentive observer will notice that unintentional synchronization of gait between two walkers on the street seems to occur frequently. Nonetheless, the rate of occurrence and motor-sensory mechanisms underlying this phase-locking of gait have only recently begun to be investigated. Previous studies have either been qualitative or carried out under non-natural conditions, e.g., treadmill walking. The present study quantitatively examined the potential sensory mechanisms that contribute to the gait synchronization that occurs when two people walk side by side along a straight, over-ground, pathway. Fourteen pairs of subjects walked 70 m under five conditions that manipulated the available sensory feedback. The modalities studied were visual, auditory, and tactile. Movement was quantified using a trunk-mounted tri-axial accelerometer. A gait synchronization index (GSI) was calculated to quantify the phase synchronization of the gait rhythms. Overall, 36% of the walks exhibited synchrony. Tactile and auditory feedback showed the greatest ability to synchronize, while visual feedback was the least effective. The results show that gait synchronization during natural walking is common, quantifiable, and has modality-specific properties.