The Future of Union Identities and Niche Unionism

This chapter first explores the implications of the work for the understanding of trade union identities and niche unionism. It argues for the multidimensional framework as being superior to a one-dimensional continuum and other theorisations which are variously considered outdated, inappropriate or requiring rigid categorisation. Secondly it discusses critical questions with implications for the future of trade union organisation and the challenge of organising the unorganised. These concern the primacy of general unions, the persistence of niche unions, whether general or niche unions are better placed to organise the unorganised and whether niche identity is a barrier to expanding membership territories. It argues that despite an apparent ‘direction of travel’ from niche in general unions, new niche unions continue to be formed. Whilst general unions could absorb further niche unions and bring greater resources, niche unions might be better placed to organise the unorganised. It recognises that ‘new generation unions’, although not projecting a new form of identity, may prove a significant development in union renewal and revitalisation. Finally, it makes clear that the work is not presented as the last word on trade union identities and niche unionism, but rather a starting point for further debate and discussion.

Luminance-Induced Shift in the Apparent Direction of Gaze

Changing the luminance of one side of the sclera induces an apparent shift of the perceived direction of gaze toward the darker side of the sclera. This luminance-induced gaze shift was measured in photographic and schematic images of eyes. The effect was substantial: a moderate darkening of one side of the sclera induced an apparent shift of 8 to 10 deg of gaze; the maximum darkening induced a shift of 15 deg of gaze or more. The effect of scleral darkening was also compared to the gaze shift induced by an actual shift of the iris. The effects of the two cues were measured independently and in combination. When pitted against each other, their effects could be nulled, demonstrating that they act on a common level. Predictions of the relative strengths of the luminance and iris shift cues were developed for two simple luminance-based mechanisms: flux ratio and luminance centroid. The data showed the luminance cue was less effective than the models predicted in determining gaze direction. As an alternative source for the gaze shift, irradiation effects on apparent size could create a perceived shift in the iris position but a direct measure of the irradiation shift showed that this was far too small. The results suggest that at least one important mechanism for gaze judgment is based on low-level analysis of the luminance configuration within the eye.

Biological Motion Shown Backwards: The Apparent-Facing Effect

We examined how showing a film backwards (reverse transformation) affects the visual perception of biological motion. Adults and 6-year-old children saw first a point-light quadruped moving normally as if on a treadmill, and then saw the same display in reverse transformation. For other groups the order of presentation was the opposite. Irrespective of the presentation mode (normal or reverse) and of the facing of the point-light figure (rightward or leftward), a pronounced apparent-facing effect was observed: the perceptual identification of a display was mainly determined by the apparent direction of locomotion. The findings suggest that in interpreting impoverished point-light biological-motion stimuli the visual system may neglect distortions caused by showing a film backwards. This property appears to be robust across perceptual development. Possible explanations of the apparent-facing effect are discussed.

Footsteps and Inchworms: Illusions Show That Contrast Affects Apparent Speed

A horizontal grey bar that drifts horizontally across a surround of black and white vertical stripes appears to stop and start as it crosses each stripe. A dark bar appears to slow down on a black stripe, where its edges have low contrast, and to accelerate on a white stripe, where its edges have high contrast. A light-grey bar appears to slow down on a white stripe and to accelerate on a black stripe. If the background luminances at the leading and trailing edges of the moving bar are the same, the bar appears to change speed, and if they are different the bar appears to change in length. A plaid surround can induce 2-D illusions that modulate the apparent direction, not just the speed, of moving squares. Thus, the motion salience of a moving edge depends critically on its instantaneous contrast against the background.

Motion Aftereffects of Wagon Wheels: Motion Aftereffects Follow Apparent Rather Than Real Movement

Power and Moulden have proposed a model which accounts for the movement of gratings in apertures including the barber pole illusion. It predicts the direction of motion aftereffects which follow from perceived veridical motion and the direction of these aftereffects which follow from the illusory movement experienced during the barber pole illusion. At a perceptual level, the model predicts motion aftereffects will follow direction of apparent movement rather than veridical direction. Four experiments tested this prediction. In Exp. 1 a spiral was viewed under flickering light so it appeared to be moving in the direction opposite to true motion, and the aftereffect was opposite to the apparent direction. In Exp. 2 the spiral was viewed through a narrow aperture so that it was effectively a grating appearing to move in the opposite direction to veridical motion. Again, the motion aftereffect was opposite to the apparent rather than true direction of rotation. In Exp. 3 a sectored disc was used, and similar results were obtained. In Exp. 4 the sectored disc was videotaped so that it appeared to be rotating in the direction opposite to true motion. The after motion to this “wagon wheel” effect was opposite to its apparent direction of rotation on the screen. In all experiments the predictions were confirmed, thereby confirming the general principle that motion aftereffecrs follow apparent rather than real direction of movemenr.

The Kongsi

In the early evening in Jakarta, a group of Chinese businessmen meet in one of the city's better Chinese restaurants. Over succulent Peking duck, tasty pigeon, spicy sweet and sour pork, rich shrimp fried in butter and steaming fried rice, the group gossips with no apparent direction. Conversation touches on the latest political rumors, problems with government officials, the rate of inflation, the high cost of money, and the scarcity of opportunities these days.

Some Tests of the Marr-Ullman Model of Movement Detection

Several psychophysical experiments are described which test and uphold predictions derived from the Marr–Ullman model of movement detection. First, we demonstrate the existence of adaptation which is specific not merely to the direction of movement of an edge, but also to its contrast polarity. Second, it is shown that adaptation to a spatially homogeneous field whose luminance is modulated according to a temporal sawtooth waveform produces predictable changes in sensitivity to the movement of an edge; these changes, too, are specific to particular conjunctions of direction and edge polarity. Third, similar changes in sensitivity are demonstrated to occur when the luminance of an edge is physically perturbed at the moment of its displacement. Finally, it is shown that, as predicted, the sudden onset of an edge can itself give rise to a momentary impression of movement, the apparent direction of which depends upon the change in luminance that accompanies the onset of the edge.