A multicentre, UK, retrospective, observational study to assess the effectiveness of insulin glargine 300 units/ml in treating people with Type 1 diabetes mellitus in routine clinical practice (SPARTA).

AIM: To conduct an open-label study to provide UK real-world evidence regarding the use of insulin glargine 300 units/ml (U300) in people with Type 1 diabetes mellitus. METHODS: People with Type 1 diabetes who had been prescribed U300 ≥6 months before data collection and had HbA1c levels recorded within 3 months prior to U300 (baseline) were included. The primary endpoint was change in HbA1c from baseline to month 6 after U300 initiation. Other endpoints included number of documented hypoglycaemic and diabetic ketoacidosis episodes, and change in daily basal insulin dose. RESULTS: A total of 298 people with Type 1 diabetes were included [mean age 42.1 years, mean HbA1c 79 mmol/mol (9.4%)]. After U300 initiation, the mean reduction in HbA1c from baseline to month 6 was -4 mmol/mol (-0.4%; P<0.001; n=188). The total daily basal insulin dose at 6 months was 1.3 units higher than at the time of U300 initiation (P<0.001; n=275) but was not significantly different from the prior basal insulin dose. There was no clinically significant difference in weight between baseline and month 6 [mean difference +0.7 kg, 95% CI -0.1, 1.5; P=0.084; n=115). During the 6 months before and after U300 initiation, severe hypoglycaemic episodes were documented for 6/298 and 4/298 participants. Diabetic ketoacidosis episodes requiring Accident and Emergency department visits or hospitalization were documented for 4/298 and 6/298 participants, before and after U300 initiation, respectively. CONCLUSIONS: In people with Type 1 diabetes, a change in basal insulin to U300 was associated with clinically and statistically significant HbA1c improvements, without significant changes in basal insulin dose and weight. Documented severe hypoglycaemia episodes and diabetic ketoacidosis requiring Accident and Emergency department visits or hospitalization were low and similar before and after U300 initiation.

The tactile motion aftereffect suggests an intensive code for speed in neurons sensitive to both speed and direction of motion.

Neurophysiological studies in primates have found that direction-sensitive neurons in the primary somatosensory cortex (SI) generally increase their response rate with increasing speed of object motion across the skin and show little evidence of speed tuning. We employed psychophysics to determine whether human perception of motion direction could be explained by features of such neurons and whether evidence can be found for a speed-tuned process. After adaptation to motion across the skin, a subsequently presented dynamic test stimulus yields an impression of motion in the opposite direction. We measured the strength of this tactile motion aftereffect (tMAE) induced with different combinations of adapting and test speeds. Distal-to-proximal or proximal-to-distal adapting motion was applied to participants' index fingers using a tactile array, after which participants reported the perceived direction of a bidirectional test stimulus. An intensive code for speed, like that observed in SI neurons, predicts greater adaptation (and a stronger tMAE) the faster the adapting speed, regardless of the test speed. In contrast, speed tuning of direction-sensitive neurons predicts the greatest tMAE when the adapting and test stimuli have matching speeds. We found that the strength of the tMAE increased monotonically with adapting speed, regardless of the test speed, showing no evidence of speed tuning. Our data are consistent with neurophysiological findings that suggest an intensive code for speed along the motion processing pathways comprising neurons sensitive both to speed and direction of motion.

Constant time delay with discrete responses: a review of effectiveness and demographic, procedural, and methodological parameters.

Constant time delay, a variation of progressive time delay, is a response prompting strategy designed to provide and remove prompts in a systematic manner on a time dimension. Constant time delay has two defining characteristics: (a) initial trials involve presentation of the target stimulus followed immediately by delivery of a controlling prompt; and (b) on all subsequent trials, the target stimulus is presented, a response interval of a fixed duration is delivered, the controlling prompt is provided, and a second response interval is delivered as needed. Reports of 36 studies using the constant time delay procedure with discrete behaviors were identified and analyzed. The results are described in terms of demographic variables (i.e., the types of subjects, settings, behaviors, instructors, and instructional arrangements), and the procedural parameters of the strategy. The effectiveness of the strategy and the outcome measures are summarized. Finally, the methodological adequacy of the constant time delay research is examined. Implications for practice and for further research are presented.

A purely temporal transparency mechanism in the visual system.

I report evidence for a purely temporal perceptual transparency mechanism. Rapid alternation of two images in the same location can result in the simultaneous experience of both, accompanied by a sense of transparency. This is true even when the sum of the two images does not appear transparent, which suggests that the percept is not mediated by the static transparency processes. At slow rates, alternating gratings were experienced as successive. As the rate was increased, by 8 Hz observers experienced the gratings as simultaneous. The rapidly alternating gratings are apparently processed separately before being combined for awareness by a process that integrates over about 120 ms. A final experiment tested whether the common presentation time of different parts of an image in alternation with another would cause the parts to perceptually bind. Observers did not distinguish between a rapidly alternating intact grating display and one in which halves of the display were exchanged in time. In other words, temporal binding across space did not occur. The temporal transparency phenomenon, in addition to informing theories of transparency and the dynamics of visual processing, may also be useful for the creation of transparent displays for electronic devices.

The spoke brightness illusion originates at an early motion processing stage.

When a bright white disk revolves around a fixation point on a gray background, observers perceive a "spoke": a dark gray region that connects the disk with the fixation point. Our first experiment suggests that motion across the retina is both necessary and sufficient for spokes: The illusion occurs when a disk moves across the retina even though it is perceived to be stationary, but the illusion does not occur when the disk appears to move while remaining stationary on the retina. A second experiment shows that the strength of the illusion decreases with decreasing luminance contrast until subjective equiluminance, where little or no spoke is perceived. These results suggest that spokes originate at an early, predominantly luminance-based stage of motion processing, before the visual system discounts retinal motion caused by smooth pursuit.

Tracking an object through feature space.

Visual attention allows an observer to select certain visual information for specialized processing. Selection is readily apparent in 'tracking' tasks where even with the eyes fixed, observers can track a target as it moves among identical distractor items. In such a case, a target is distinguished by its spatial trajectory. Here we show that one can keep track of a stationary item solely on the basis of its changing appearance--specified by its trajectory along colour, orientation, and spatial frequency dimensions--even when a distractor shares the same spatial location. This ability to track through feature space bears directly on competing theories of attention, that is, on whether attention can select locations in space, features such as colour or shape, or particular visual objects composed of constellations of visual features. Our results affirm, consistent with a growing body of psychophysical and neurophysiological evidence, that attention can indeed select specific visual objects. Furthermore, feature-space tracking extends the definition of visual object to include not only items with well defined spatio-temporal trajectories, but also those with well defined featuro-temporal trajectories.

On the lawfulness of grouping by proximity.

The visual system groups close things together. Previous studies of grouping by proximity have failed to measure grouping strength or to assess the effect of configuration. We do both. We reanalyze data from an experiment by Kubovy and Wagemans (1995) in which they briefly presented multi-stable dot patterns that can be perceptually organized into alternative collections of parallel strips of dots, and in which they parametrically varied the distances between dots and the angles between alternative organizations. Our analysis shows that relative strength of grouping into strips of dots of a particular orientation approximates a decreasing exponential function of the relative distance between dots in that orientation. The configural or wholistic properties that were varied--such as angular separations of the alternative organizations and the symmetry properties of the dot pattern--do not matter. Additionally, this grouping function is robust under transformations of scale in space (Experiment 1) and time (Experiment 2). Grouping of units which are themselves the result of grouping (i.e., pairs of dots; Experiment 3) also follows our nonconfigural rule.

The midstream order deficit.

The relative order of an auditory sequence can be more difficult to apprehend when it is presented repeatedly without pause (i.e., cycling) than when it is presented only once (Warren, Obusek, Farmer, & Warren, 1969). We find that this phenomenon, referred to as the midstream order deficit (MOD), can also occur with visual stimuli. The stimuli need not form separate perceptual "streams," and the effect can occur with presentation rates as slow as five items per second, even though the identification of individual letters is very accurate at this rate. However, if the first item of the sequence is visually very distinct from the preceding items, relative order reports can be as accurate in the cycling condition as in the single-presentation condition. Our results suggest that the MOD is not due to masking, attentional blink, repetition blindness, Reeves and Sperling's (1986) order illusion, memory limitations, or decision criteria. The MOD may reflect an attentional cost to the initiation of order encoding, which is distinct from the allocation of attention is required in order to detect and identify individual items. To initiate order encoding successfully, one's attention must be set for, or captured by, an initial salient event.

Wakes and spokes: new motion-induced brightness illusions.

Under certain conditions, high-contrast moving figures induce adjacent illusory regions, 'wakes' and 'spokes', which have contrast polarity opposite the inducing figures. In this paper we document properties of these novel phenomena. When the illusions are induced by a moving bar, spokes appear on the side of the bar closer to fixation and connect the bar to the fixation point, regardless of the momentary position of the bar or whether it is moving to the left or to the right. Although spokes often extend up to the fixation point, they never extend beyond it. This is not due to blocking of the spoke's spread by the fixation point, because in another experiment spokes extend directly through an intervening figure. Whereas spokes emanate from the end of a horizontally moving bar closest to fixation, wakes emanate from the end farthest from fixation. In contrast to spokes, wakes do not show a towards-fixation bias. Instead, the wake's end trails the position of the bar, like a ship's wake. The higher the bar velocity, the more the end of the wake appears to trail it, suggesting that wakes are caused by a process which spreads from the edge of moving figures. Wakes and spokes, as distinct illusions, should provide significant constraints on theories of human motion and brightness perception processes.

Skin protection, Viton, and solubility parameters.

Permeation is a function of diffusion and solubility of the solvent/polymer system. A physical-chemical constant that has been used previously to predict solubility is the three-dimensional solubility parameter (3-DSP). This paper reports a method for calculating the 3-DSP for the polymer Viton, new permeation data for Viton and 14 solvents, and the application of the 3-DSP to a model for predicting permeation parameters. The 3-DSP values for Viton (J/cc)1/2 were dispersion = 17.0, polar = 10.6, and hydrogen bonding = 6.1. A correlation coefficient of 0.65 was obtained when the natural log of breakthrough time for 19 solvents was regressed against the differences of the 3-DSP's for these 19 solvents and Viton. A value of 0.69 was obtained for the natural log of the permeation rate vs 16 solvent-Viton 3-DSP differences. While the variance unaccounted for in these regression tests does not allow quantitative prediction of permeation parameters, qualitative prediction of polymer suitability is possible.