Color aftereffect contingent on text

During adaptation, two different letter strings (each five or six letters) were presented to subjects alternately, one in green and the other in magenta. The extent to which these letter strings subsequently elicited a color aftereffect was assessed. In different experiments, the chromatic letter strings consisted of words and nonwords. The results indicated that letter strings that form English words can contingently elicit a color aftereffect. This was the case even when the words were anagrams. There was no evidence that nonword letter strings could contingently elicit such an aftereffect, even when the nonwords conformed to English orthography. The results are relevant to understanding other contingent color aftereffects (McCollough effects), illusory color noted by computer operators who work at monochrome (green or amber) displays, and the processing of text.     

Color aftereffects contingent on perceptual organization

The present experiment demonstrated that (a) cognitive organizational factors influence an orientation-contingent color (McCollugh) aftereffect, and (b) adaptation to colored gratings affected the perceptual organization of a reversible figure. Following adaptation to colored gratings, color aftereffects were reported in only one of two organizations of a reversible figure, and the colors conformed to the subjective contours of the test pattern rather than exclusively to the regions defined by horizontal and vertical pattern elements. In addition, an organization of the reversible figure that segregated vertical and horizontal pattern elements was dominant subsequent to adaptation.     

Explaining contingent facts

Philosophical Studies - I argue against a principle that is widely taken to govern metaphysical explanation. This is the principle that no necessary facts can, on their own, explain a contingent...     

Logic and contingent existence

It is argued here that Prior's non-standard modal system Q, and the Parry–Dunn system of analytic implication, though entirely independent and independently motivated systems, together provide a rationale for explicating the concept of validity in a non-standard way; their implications are explored for the theory of natural deduction as well as for modal logic and the concept of entailment. I give an account of formal logic from this non-standard viewpoint, together with an informal presentation of the system that unites the insights of Prior (drawing on Russell) and, Parry (drawing on Kant), and the motivations for both in the concept of the contingent existence – as opposed to the contingent truth or falsehood – of a proposition.     

A color aftereffect contingent on complex pattern features

It was shown that a McCollough-type color aftereffect could be induced using a pair of patterns each of which contained lines of many orientations (radial lines and concentric circles). That is, the two patterns appear to be color adapted independently. The effect could simply be a new version of the McCollough effect facilitated by a tendency to fixate the centers of the patterns. Also, the size features of the displays could be used as the basis of a spatial frequency analyzer explanation. Experimental data were used to test both of these suggestions, but very little support was found for either. It was therefore suggested that the major basis of the effect was the color adaptation of “curvature analyzers.”     

Negative identity priming is contingent on stimulus repetition

Five experiments demonstrate that negative identity priming is contingent on stimulus repetition. In ignored repetition conditions, priming was initially positive and became negative as the number of repetitions increased. Moreover, it was repetition as a target, not as a distractor, that was critical for negative priming. The effects of repetition were general: They were found with both naming and same-different paradigms, verbal and pictorial material, familiar and unfamiliar stimuli, and vocal and manual responses. Findings support an activation-based model of negative priming (G. B. Malley & D. L. Strayer, 1995) and are problematic for the episodic retrieval model of negative priming (W. T. Neill & L. A. Valdes, 1992). Finally, the experiments did not replicate B. DeSchepper and A. Treisman's (1996) reported negative priming with nonrepeated novel shapes.     

Compounding is not contingent on level-ordering in acquisition

A popular explanation of children’s avoidance of regular plurals in non-head position of compounds has been that level-ordering is in place at the beginning of children’s acquisition of compounding [Cognition 21 (1985) 73]. If this is true, then bilingualism should not make a difference. This study tested this possibility by comparing production of novel compound nouns in 25 monolingual English and 25 French-English bilingual children between the ages of 3 and 4 years. Bilingual children allowed regular plurals in non-head position significantly more often than monolinguals. This finding suggests that children can acquire compounding before learning to avoid plurals inside compounds. In discussing this finding, some reasons to doubt the existence of level-ordering are raised and possible alternatives are discussed.     

Disruptive effects of contingent food on high-probability behavior

The delivery of food contingent on 10 s of consecutive toy engagement resulted in a decrease in engagement and a corresponding increase in other responses that had been previously reinforced with food. Similar effects were not observed when tokens exchangeable for the same food were delivered, suggesting that engagement was disrupted by the contingent provision of the food, which may have functioned as a discriminative stimulus that occasioned competing responses.     

Isoluminance and contingent color aftereffects

In the typical induction of the orientation-contingent color aftereffect (CCAE), the stimuli are composed of elements that differ in both color and luminance. Three experiments are reported that show that chromatic contrast between stimulus elements is insufficient for the induction of the orientation-CCAE and that luminance contrast is necessary. These experiments expand on previous research concerned with the role of luminance contrast in the induction of orientation-CCAEs by eliminating alternative explanations.     

Dichoptic induction of movement aftereffects contingent on color and on orientation

Some comparative experiments on the dichoptic induction of the movement aftereffect (MAE) contingent on color and the MAE contingent on orientation are reported. Colorcontingent movement aftereffects could be evoked only when the eye which had viewed color during adaptation also viewed color during test sessions. When the apparent color of the test field was changed by binocular color rivalry, contingent movement aftereffects (CMAEs) appropriate to the suppressed color were reported. After dichoptic induction of the orientation-contingent MAE, aftereffects could be obtained whether the eliciting gratings and stationary test fields were presented together to either eye alone or were dichoptically viewed.     

Visual aftereffect of texture density contingent on color of frame

An aftereffect of perceived texture density contingent on the color of a surrounding region is reported. In a series of experiments, participants were adapted, with fixation, to stimuli in which the relative density of two achromatic texture regions was perfectly correlated with the color presented in a surrounding region. Following adaptation, the perceived relative density of the two regions was contingent on the color of the surrounding region or of the texture elements themselves. For example, if high density on the left was correlated with a blue surround during adaptation (and high density on the right with a yellow surround), then in order for the left and right textures to appear equal in the assessment phase, denser texture was required on the left in the presence of a blue surround (and denser texture on the right in the context of a yellow surround). Contingent aftereffects were found (1) with black-and-white scatter-dot textures, (2) with luminance-balanced textures, and (3) when the texture elements, rather than the surrounds, were colored during assessment. Effect size was decreased when the elements themselves were colored, but also when spatial subportions of the surround were used for the presentation of color. The effect may be mediated by retinal color spreading (Pöppel, 1986) and appears consistent with a local associative account of contingent aftereffects, such as Barlow’s (1990) model of modifiable inhibition.