Crowding expands and is less sensitive to target-flanker differences during a shift of visual attention.

Target-flanker similarity and critical spacing control visual crowding when attention is pre-allocated, but these have not been studied when attention shifts. Flanked target Gabors appeared 8° left and right of central fixation throughout each 1.5 s trial. Subjects reported target Gabor tilt. In Expt. 1, target blinks increased accuracy, and flanker blinks decreased it, but only when attention shifted left or right from a central RSVP cue, hardly before it, indicating an exogenous/endogenous synergy. Whether parallel or orthogonal, flankers of the same wavelength as the target crowded substantially. Parallel half-wavelength flankers also crowded, but orthogonal half-wavelength ones did not. In Expt. 2, crowding when attention shifts was the same for targets and flankers within Bouma's bound (2.5° apart) as outside it (5.0° apart.) In Expt. 3, Bouma's bound was restored when attention was focused continuously on the target. We conclude that crowding temporarily expands and becomes less discriminative when attention shifts.

Investigating Neural Sensorimotor Mechanisms Underlying Flight Expertise in Pilots: Preliminary Data From an EEG Study.

Over the last decade, the efforts toward unraveling the complex interplay between the brain, body, and environment have set a promising line of research that utilizes neuroscience to study human performance in natural work contexts such as aviation. Thus, a relatively new discipline called neuroergonomics is holding the promise of studying the neural mechanisms underlying human performance in pursuit of both theoretical and practical insights. In this work, we utilized a neuroergonomic approach by combining insights from ecological psychology and embodied cognition to study flight expertise. Specifically, we focused on the Mirror Neuron system as a key correlate for understanding the interaction between an individual and the environment, suggesting that it can be used to index changes in the coupling of perception-action associated with skill development. In this study, we measured the EEG mu suppression as a proxy of the Mirror Neuron system in experts (pilots) and novices while performing a distance estimation task in a landing scenario. To survey the specificity of this measure, we considered central, parietal and occipital electrode pools and analyzed alpha (8-13 Hz) and beta (18-25 Hz) rhythm bands. We hypothesized that in experts vs. novices, specific neural sensorimotor brain activity would underpin the connection between perception and action in an in-flight context. Preliminary results indicate that alpha and beta rhythm suppression was area-specific irrespective of groups, present in the central electrodes placed over the motor areas. Group analysis revealed that specifically alpha mu rhythm, but not beta, was significantly more suppressed in pilots vs. novices. Complementing these findings we found a trend in which the strength of mu suppression increased with the sense of presence experienced by the pilots. Such sensorimotor activation is in line with the idea that for a pilot, a distance judgment is intimately associated with the function of landing. This reflects the ability to use optical invariants to see the world in terms of the capabilities of the aircraft (e.g., reachability and glide angle). These preliminary findings support the role of embodied simulation mechanisms in visual perception and add important insights into a practical understanding of flight expertise, suggesting sensorimotor mechanisms as potential neuro-markers.