The influence of stimulus and behavioral histories on predictive control of smooth pursuit eye movements

The smooth pursuit system has the ability to perform predictive feedforward control of eye movements. This study attempted to examine how stimulus and behavioral histories of past trials affect the control of predictive pursuit of target motion with randomized velocities. We used sequential ramp stimuli where the rightward velocity was fixed at 16 deg/s while the leftward velocity was either fixed (predictable) at one of seven velocities (4, 8, 12, 16, 20, 24, or 28 deg/s) or randomized (unpredictable). As a result, predictive pursuit responses were observed not only in the predictable condition but also in the unpredictable condition. Linear mixed-effects (LME) models showed that both stimulus and behavioral histories of the previous two or three trials influenced the predictive pursuit responses in the unpredictable condition. Intriguingly, the goodness of fit of the LME model was improved when both historical effects were fitted simultaneously rather than when each type of historical data was fitted alone. Our results suggest that predictive pursuit systems allow us to track randomized target motion using weighted averaging of the information of target velocity (stimulus) and motor output (behavior) in past time sequences.

Update on the role of Angiogenesis in Diabetes associated Nephropathy

Diabetic mellitus is common worldwide health problem which brings about different rigorous complications like retinopathy, nephropathy and numerous other lethal complications. Diabetic nephropathy is the major cause for blindness and renal failure in many of the developing countries. Hyperglycemia induced diabetic nephropathy gets elicited through improved development of reactive oxygen species in multiple cell types. The starting of organ damage or kidney failure shows some symptomatic effect or morphological changes as in one or both the kidneys like expansion or enlargement of kidneys from their original size and this enlargement process is known as nephromegaly. Microalbuminuria is the best possible predictable condition proceeding towards renal failure. This review briefly discussed about the diabetic nephropathy with regard to progression, angiogenic and non-angiogenic factors involved in pathogenesis and treatment of angiogenesis in diabetic nephropathy.

Knowing What’s Coming: Unpredictable Motion Causes More Motion Sickness

Objective This study explores the role of anticipation in motion sickness. We compared three conditions varying in motion predictability and assessed the effect of anticipation on subsequent illness ratings using a within-subjects design. Background Anticipation is thought to play a role in motion sickness by reducing the discrepancy between sensed and expected sensory information. However, both the exact role and potential magnitude of anticipation on motion sickness are unknown. Method Participants ( N = 17) were exposed to three 15-min conditions consisting of repeated fore-aft motion on a sled on a 40-m rail (1) at constant intervals and consistent motion direction, (2) at constant intervals but varied motion direction, and (3) at varied intervals but consistent motion direction. Conditions were otherwise identical in motion intensity and displacement, as they were composed of the same repetitions of identical blocks of motion. Illness ratings were recorded at 1-min intervals using an 11-point motion sickness scale. Results Average illness ratings after exposure were significantly lower for the predictable condition, compared with both the directionally unpredictable condition and the temporally unpredictable condition. Conclusion Unpredictable motion is significantly more provocative compared with predictable motion. Findings suggest motion sickness results from a discrepancy between sensed and expected motion, rather than from unpreparedness to motion. Application This study underlines the importance of an individual’s anticipation to motion in motion sickness. Furthermore, this knowledge could be used in domains such as that of autonomous vehicles to reduce carsickness.

Non-Chemical Solder Bump Removal Technique for Repackaging Flip Chip ICs

In this paper we will discuss an empirically discovered technique to remove residual solder bumps or remnants using reflow and wicking to a gold plated surface rather than mechanical or chemical means. Extraction of flip chip ICs, for the purpose of repackaging, can leave bond pads in inconsistent and undesirable conditions such as 1) retaining remnants of the solder bumps or 2) damaged or eliminated pad metal caused by acid or mechanical means used to separate the IC from the board. These conditions hinder subsequent wire bonding and probe card use. Though other techniques have been found to be suitable at times, the technique described in this paper consistently leaves the bonding area in an acceptable, more predictable condition, as the bulk of the solder bump material is removed. This lends to a higher wire bonding success rate.

Maintaining Grip: Anticipatory and Reactive EEG Responses to Load Perturbations

Previous behavioral work has shown the existence of both anticipatory and reactive grip force responses to predictable load perturbations, but how the brain implements anticipatory control remains unclear. Here we recorded electroencephalographs while participants were subjected to predictable and unpredictable external load perturbations. Participants used precision grip to maintain the position of an object perturbed by load force pulses. The load perturbations were either distributed randomly over an interval 700- to 4,300-ms (unpredictable condition) or they were periodic with interval 2,000 ms (predictable condition). Preparation for the predictable load perturbation was manifested in slow preparatory brain potentials and in electromyographic and force signals recorded concurrently. Preparation modulated the long-latency reflex elicited by load perturbations with a higher amplitude reflex response for unpredictable compared with predictable perturbations. Importantly, this modulation was also reflected in the amplitude of sensorimotor cortex potentials just preceding the long-latency reflex. Together, these results support a transcortical pathway for the long-latency reflex and a central modulation of the reflex grip force response.