Night Vision Goggle and Counterweight Use Affect Neck Muscle Activity During Reciprocal Scanning

BACKGROUND: Mass, moment of inertia, and amplitude of neck motion were altered during a reciprocal scanning task to investigate how night vision goggles (NVGs) use mechanistically is associated with neck trouble among rotary-wing aircrew.METHODS: There were 30 subjects measured while scanning between targets at 2 amplitudes (near and far) and under 4 head supported mass conditions (combinations of helmet, NVGs, and counterweights). Electromyography (EMG) was measured bilaterally from the sternocleidomastoid and upper neck extensors. Kinematics were measured from the trunk and head.RESULTS: Scanning between the far amplitude targets required higher peak angular accelerations (7% increase) and neck EMG (between 1.24.5% increase), lower muscle cocontraction ratios (6.7% decrease), and fewer gaps in EMG (up to a 59% decrease) relative to the near targets. Increasing the mass of the helmet had modest effects on neck EMG, while increasing the moment of inertia did not.DISCUSSION: Target amplitude, not head supported mass configuration, had a greater effect on exposure metrics. Use of NVGs restricts field-of-view, requiring an increased amplitude of neck movement. This may play an important role in understanding links between neck trouble and NVG use.Healey LA, Derouin AJ, Callaghan JP, Cronin DS, Fischer SL. Night vision goggle and counterweight use affect neck muscle activity during reciprocal scanning. Aerosp Med Hum Perform. 2021; 92(3):172181.

Influences of Stress on Interactions with Decision Support

People regularly interact with automation to make decisions. Research shows that reliance on recommendations can depend on user trust in the decision support system (DSS), the source of information (i.e. human or automation), and situational stress. This study explored how information source and stress affect trust and reliance on a DSS used in a baggage scanning task. A preliminary sample of sixty-one participants were given descriptions for a DSS and reported trust before and after interaction. The DSS gave explicit recommendations when activated and participants could choose to rely or reject the choice. Results revealed a bias towards self-reliance and a negative influence of stress on trust, particularly for participants receiving help from automation. Controlling for perceived reliability may have eliminated trust biases prior to interaction, while stress may have influenced trust during the task. Future research should address potential differences in task motivation and include physiological measures of stress.

An Investigation of the Slope Parameters of Reaction Times and P3 Latencies in the Sternberg Memory Scanning Task – A Fixed-Links Model Approach

The speed of retrieving information from short-term memory is thought to be captured in the slope of the linear function of reaction times (RTs) regressed on set size in the Sternberg memory scanning task (SMST). Individual differences in the slope parameter have been hypothesized to correlate with general intelligence (g). However, this correlation can usually not be found. This present study chose a fixed-links model (FLM) approach to re-evaluate the RT slope parameter on a latent level in a sample of 98 participants aged 18 to 61 years. The same was tried for P3 latencies to investigate whether or not both parameters measure the same cognitive processes in the SMST, and to assess the usability of both slopes to predict g. For RTs, a linear increase with set size was found. The RT slope correlated with g on a manifest level already. The FLM approach could significantly increase the relationship between the slope and g. For P3 latencies, no evidence for a linear increase was found. This indicates that RTs and P3 latencies do not measure the same cognitive processes in the SMST. The FLM proved suitable to investigate the association between the speed of short-term memory scanning and intelligence.

A-08 VOMS Scores Relationship to King-Devick Scores in Males

Objective Burkhart and colleagues (2020) showed that positive screening on the Vestibular Ocular Motor Screening (VOMS) and slower King Devick scores were predictive of protracted recovery in male adolescents. The purpose of this study was to examine the relationship between positive VOMS screening and King-Devick Trial 1 scores in a similar population. Method 300 male participants age 10–18 were administered VOMS and King-Devick Trial 1 within 7-days of their injury at a specialty concussion clinic between 2017–2019. We hypothesized that slower speeds on King-Devick Trial 1 would be related to a positive screening on the VOMS (i.e. symptom provocation of +2, convergence of > 6 mm). Odds ratios were calculated to estimate the likelihood of screening positive on the VOMS among those with a King-Devick Trial 1 score above the median compared to those with a score below the median. Results Those scoring above the median on King-Devick Trial 1 (i.e. slower times) were 74% more likely to have a positive screening on the VOMS, OR = 1.74, 95% CI [1.10–2.78], p = 0.02, relative to those with a King-Devick Trial 1 above the median. Conclusions The VOMS was created to be a symptom provocation tool sensitive to concussion. However, this study demonstrated that the VOMS is also related to performance on objective visual scanning task. Specifically, adolescent males with slower scores on the King-Devick Trial 1 were more likely to have a positive screening on the VOMS.

The diffusion model of reaction time for recent negative probes

The study investigates the problem of information displacement from short-term memory. In two experiments, reaction times for recent negative probes were analyzed in the Sternberg’s memory scanning task. The diffusion model of reaction times was used with parameters estimated with the fast-dm software. It was found (experiment 1) that recent negative probes are characterized by a reduction in the speed of information accumulation (drift rate). This suggests residual activation of irrelevant cognitive representation in memory after they have been displaced from short-term memory. It was also found (experiment 2) that negative probes semantically related to items in a preceding target set (semantic recent negative probes) are characterized by a similar decrease in the drift rate. This suggests activation spreading from irrelevant cognitive representations displaced from short-term memory along semantic connections and identifies activated long-term memory as the target of information displacement from short-term memory. Additional mechanisms of short-term memory scanning (negative priming and dynamic decision thresholds) are discussed.

Is poor coordination of saccades in dyslexics a consequence of reading difficulties? A study case

We hypothesize that the high quality of binocular coordination of saccades in reading is progressively learned during childhood, and this oculomotor learning is based on a synergy between saccades and vergence. In present work deficits in the binocular control of saccades in six dyslexic children (mean age was 11±2.48 years) are studied for two tasks (text reading and Xs-C scanning), and at two viewing distances (40 cm and 100 cm). Fixation durations resulting are longer in Xs-C scanning task than in text reading task. We postulate that while reading motor preparation processes are executed with less demand for attentional resources. Importantly all physiological parameters of the saccades were the same for the two conditions and in either distance. Namely disconjugacy of saccades and disconjugate post-saccadic drifts were high but similar for the two conditions. Time analysis applied on saccade amplitude disconjugacy, on disconjugate post-saccadic drift and on fixation duration showed no significant effect of repetition or time. we believe that the binocular coordination deficits in dyslexic children reflect some type of microdyspraxia due to reduced oculomotor learning, perhaps related to inefficiency of the magnocellular visual system and the cerebellar functions.