Coloured filters and reading accuracy, comprehension and rate: a placebo-controlled study

Literature suggests that visuoperceptual deficits not normally assessed by eye examinations may be responsible for certain reading disabilities. Previous studies indicate that the use of nonoptical coloured filters may reduce these deficits and improve reading performance. Present research involved 49 participants with visuo-perceptual reading disabilities. Participants were divided into a control group who received no intervention, a placebo group who received filters in a colour complementary to the individual's optimal colour, and an experimental group who received specifically matched coloured filters. At posttest the experimental group reported statistically significantly fewer visual discomfort symptoms. The remainder of the results were, however, inconsistent. Some potential explanations are explored.     

A study of reading time and viewers' preferences for a variety of combinations of character-background chromaticity for small traditional Chinese characters

The purpose of the experiment was to investigate the effects of chromaticity combination on reading speeds and subjective preference ratings for small Chinese characters. The experiment was 7 (text chromaticity) x 7 (background chromaticity) split-plot design. Analysis of variance showed that the text chromaticity was not significant, but background chromaticity was. The findings suggested that achromatic color was the most effective background chromaticity with lower reading time and had a higher preference rating; however, the highly saturated short-wavelength blue was least effective.     

The AMBEGUJAS phenomenon and colour constancy

The AMBEGUJAS phenomenon is a reversible flat figure that is spontaneously shifting between two apparent 3-D shapes-'tile' and 'roof'. 2-D perceptions have very rarely been reported. Tied to the shifts between the tile and roof shapes are remarkable changes of perceived colour. In our example, the tile appears to have orange (top half) and blue-green (bottom half) surface colours in white light. The roof appears grey but in an orange illumination and with a blue-green shadow. This phenomenon appears whether a grey display is presented in two coloured illuminations, or a chromatic display with two surface colours (orange and blue-green) is presented in white light. In the coloured illuminations the tile is an example of non-constancy, since its colours are non-veridical colour perceptions. The centre stripe of the display appears to have the same orange and blue-green colours as the lateral stripes but in a shadow. This seems like a colour constancy in a non-constancy situation. An alternative to the classical definition of colour constancy is discussed.     

Representation or context as a cognitive strategy in colour constancy?

If an identification task with colour constancy as its objective is carried out under drastically changing illumination, do people rely mainly on colour information or do they rely on other sources of information? This question suggested two hypotheses for testing: (i) context hypothesis: people rely mainly on colour information (spectral reflectance or illumination chromaticity) to achieve colour constancy; (ii) representation hypothesis: people rely mainly on all other clues associated with colour to achieve colour constancy, including form information (any shape elements) and space information (spatial coordinates or spatial correlation). Experiment 1 showed that form information was readily associated with colour information to produce implicit representation. This gave the best colour-constancy performance (95.72%) and the fastest processing speed, so it probably used a top-down process. However, it was also prone to error owing to assumptions. Space information was not readily associated with colour information so colour-constancy performance was halved (48.73%) and processing time doubled. When the subject was deprived of both information sources and only given colour information, this resulted in the longest reaction times and the worst colour-constancy performance (41.38%). These results clearly support the representation hypothesis rather than the context hypothesis. When all three clues were available at the same time, the order of preference was: symbol, location, then colour. Experiment 2 showed that when form information was the main clue, colour-constancy performance was conceptually driven and processed more quickly; this supports the representation hypothesis. However, when form information was not used, colour constancy was data-driven, processed more slowly, and achieved an inferior identification rate overall; this supports the context hypothesis.     

Concave and convex phases in ambiguous figures showing colour shifts. Mach's figure and the AMBEGUJAS phenomenon

Two ambiguous figures (Mach's book-figure and the AMBEGUJAS phenomenon) have been studied. They show colour shifts synchronised with the shifts of their alternative phases. The perceived concave phase appeared to have chromatic surface colour, but the perceived convex phase can appear to be in coloured illumination and shadow (film colour). The two perceived reversible shapes of the Mach figure (the book and the tent) and the three perceived alternative shapes of the Mondrians used in the AMBEGUJAS phenomenon (a roof, a ceiling, and a tile) all can appear to have chromatic surface colours in their concave phases but appear to have coloured illumination and shadow in their convex phases.     

Colour constancy in goldfish and man: influence of surround size and lightness

Colour constancy was investigated by using a series of 10 simultaneously presented surface colours ranging in small steps from green through gray to red-purple. Goldfish were trained to select one medium test field when the entire setup was illuminated with white light. In the tests, either red or green illumination was used. Colour constancy, as inferred from the choice behaviour, was perfect under green illumination when the test fields were presented on a gray or a white background, but imperfect on a black background. Under red illumination and a white background, however, colour constancy was overcompensated. Here, a colour contrast effect was observed. The influence of background lightness was also found when the surround was restricted to a narrow annulus of 4-11 mm width (test field diameter: 14 mm). By applying colour metrics it could be shown that the von Kries coefficient law can describe the overall effect of colour constancy. For an explanation of the effect of surround size and lightness, lateral inhibitory interactions have to be assumed in addition, which are also responsible for simultaneous colour contrast. Very similar results were obtained in experiments with the same colours in human subjects. They had to name the test field appearing 'neutral' under the different illumination and surround conditions, as tested in the goldfish experiment.     

Optimal landing position in reading isolated words and continuous text

During isolated-word reading, within-word eye-movement tactics (i.e., whether the eye makes one or more fixations on the word) depend strongly on the eye's first fixation position in the word; there exists an optimal landing position where the probability of having to refixate the word is much smaller than when the eye first fixates other parts of the word. The present experiment was designed to test whether the optimal landing position effect still exists during text reading, and to compare the nature and strength of the effect with the effect found for isolated words. The results confirmed the existence of an optimal landing position in both reading conditions, but the effect for words in texts was weaker than it was for isolated words, probably because of the presence of factors such as reading rhythm and linguistic context. However, the effect still existed in text reading; within-word tactics during text reading are dependent on the eye's initial landing position in words. Moreover, individual fixation durations were dependent on within-word tactics. Thus, the initial landing position in words must be taken into account if one wishes to understand eye-movement behavior during text reading. Further results concerned the effects of word length and word frequency in both reading conditions.     

干扰材料的熟悉性和认知方式对语篇阅读的影响

采用熟悉词和不熟悉词为干扰材料,考察了干扰材料的熟悉性对语篇阅读的影响.实验第一阶段要求不同认知方式被试朗读插入熟悉度不同干扰材料的短文,考查被试的阅读效率;第二阶段采用学习—自由回忆任务考查不同提示条件下在短文中使用过的干扰词和新词的学习效果.结果发现:(1)对场独立者而言,熟悉词的干扰作用明显大于不熟悉词,而对场依存者而言,熟悉词和不熟悉词的干扰作用无差异;(2)在提示条件下,被试对干扰词的回忆量大于对新词的回忆量.研究结果表明,在语篇阅读过程中,与场依存者相比,熟悉的干扰材料对场独立者的影响更大;熟悉词比不熟悉词产生更大干扰的原因可能是由于其激活了读者更多的经验,而非具有加工的优势.     

Eye movements,the perceptual span,and reading speed

The perceptual span or region of effective vision during eye fixations in reading was examined as a function of reading speed (fast readers were compared with slow readers), font characteristics (fixed width vs. proportional width), and intraword spacing (normal or reduced). The main findings were that fast readers (reading at about 330 wpm) had a larger perceptual span than did slow readers (reading about 200 wpm) and that the span was not affected by whether or not the text was fixed width or proportional width. In addition, there were interesting font and intraword spacing effects that have important implications for the optimal use of space in a line of text.     

Independent effects of colour on object identification and memory

We examined the effects of colour on object identification and memory using a study-test priming procedure with a coloured-object decision task at test (i.e., deciding whether an object is correctly coloured). Objects were selected to have a single associated colour and were either correctly or incorrectly coloured. In addition, object shape and colour were either spatially integrated (i.e., colour fell on the object surface) or spatially separated (i.e., colour formed the background to the object). Transforming the colour of an object from study to test (e.g., from a yellow banana to a purple banana) reduced priming of response times, as compared to when the object was untransformed. This utilization of colour information in object memory was not contingent upon colour falling on the object surface or whether the resulting configuration was of a correctly or incorrectly coloured object. In addition, we observed independent effects of colour on response times, whereby coloured-object decisions were more efficient for correctly than for incorrectly coloured objects but only when colour fell on the object surface. These findings provide evidence for two distinct mechanisms of shape-colour binding in object processing.     

Independent effects of colour on object identification and memory

We examined the effects of colour on object identification and memory using a study–test priming procedure with a coloured-object decision task at test (i.e., deciding whether an object is correctly coloured). Objects were selected to have a single associated colour and were either correctly or incorrectly coloured. In addition, object shape and colour were either spatially integrated (i.e., colour fell on the object surface) or spatially separated (i.e., colour formed the background to the object). Transforming the colour of an object from study to test (e.g., from a yellow banana to a purple banana) reduced priming of response times, as compared to when the object was untransformed. This utilization of colour information in object memory was not contingent upon colour falling on the object surface or whether the resulting configuration was of a correctly or incorrectly coloured object. In addition, we observed independent effects of colour on response times, whereby coloured-object decisions were more efficient for correctly than for incorrectly coloured objects but only when colour fell on the object surface. These findings provide evidence for two distinct mechanisms of shape–colour binding in object processing.     

The role of colour in implicit and explicit memory performance

We present two experiments that examine the effects of colour transformation between study and test (from black and white to colour and vice versa, or from incorrectly coloured to correctly coloured and vice versa) on implicit and explicit measures of memory for diagnostically coloured natural objects (e.g., yellow banana). For naming and coloured-object decision (i.e., deciding whether an object is correctly coloured), there were shorter response times to correctly coloured-objects than to black-and-white and incorrectly coloured-objects. Repetition priming was equivalent for the different stimulus types. Colour transformation did not influence priming of picture naming, but for coloured-object decision priming was evident only for objects remaining the same from study to test. This was the case for both naming and coloured-object decision as study tasks. When participants were asked to consciously recognize objects that they had named or made coloured-object decisions to previously, whilst ignoring their colour, colour transformation reduced recognition efficiency. We discuss these results in terms of the flexibility of object representations that mediate priming and recognition.     

Diagnostic colours contribute to the early stages of scene categorization: Behavioural and neurophysiological evidence

We examined the effects of colour cues on the express categorization of natural scenes. Using a go/no-go paradigm sensitive to fast recognition processes, we measured early event-related potential (ERP) correlates of scene categorization to elucidate the processing stage at which colour contributes to scene recognition. Observers were presented with scenes belonging to four colour-diagnostic categories (desert, forest, canyon and coastline). Scenes were presented in one of three forms: Diagnostically coloured, nondiagnostically coloured, or greyscale images. In a verification task, observers were instructed to respond whenever the presented stimulus matched a previously presented category name. Reaction times and accuracy were optimal when the stimuli were presented as their original diagnostically coloured version, followed by their greyscale version, and lastly by their nondiagostically coloured version. These effects were mirrored in the early (i.e., 150 ms following stimulus onset) ERP frontal correlates. Their onset was delayed for greyscale scenes compared to diagnostically coloured scenes, and for nondiagnostically coloured scenes compared to the other two conditions. Frontal ERP amplitudes also decreased for greyscale and nondiagnostically coloured scenes. Together, the results suggest that diagnostic colours are part of the scene gist responsible for express scene categorization.     

IN DEFENCE OF NATURAL DAYLIGHT

Objects appear different as the illumination under which they are perceived varies. This fact is sometimes thought to pose a problem for the view that colours are mind‐independent properties: if a coloured object appears different under different illuminations, then under which illumination does the object appear the colour it really is? I argue that given the nature of natural daylight, and certain plausible assumptions about the nature of the colours it illuminates, there is a non‐arbitrary reason to suppose that it is under natural daylight that we are able to perceive the real colours of objects.     

Does repeated reading predict reading development over time? A study of children from Grade 3 to 4

The purpose of this study was to investigate whether immediate gains in reading fluency achieved during repeated reading of text can predict long‐term reading development over and above traditional predictors of reading development. Eighty‐one Grade 3 children read texts three times consecutively and were instructed either to read as quickly as possible (speed‐focused repeated reading), or to retell the text afterwards (meaning‐focused repeated reading). Measures of text reading fluency, sentence reading fluency, and text comprehension were administered to the children in Grades 3 and 4 to assess their reading development over time. The results indicate that children's immediate response to repeated reading can contribute to the prediction of their development of reading fluency over time. Even after controlling for individual differences in general cognitive ability, word reading fluency, rapid automatized naming, and vocabulary, the experimental measure with meaning‐focused repeated reading remained a significant predictor.     

Perception of illumination

Abstract.— Previous research on the perception of illumination has primarily been occupied with the apparent paradox that "we must know the object colour in order to utilize the reflected light as an index of illumination, while we must know the illumination in order to use the reflected light as an index of object colour". The present study shows this paradox to exist only as a long as the traditional one-dimensional conception of achromatic colours is maintained. Two experiments are reported. In Exp. 1 it is shown that by mere variation of the luminance difference of two adjacent areas, a consistent shift in colourlshadow discrimination is obtained; i.e. within a certain range of luminance differences the observer may find it difficult to decide whether the difference is one of colour (two fields of different greyness in common illumination) or one of illumination (two fields of equal greyness under different illumination), above this range the observer perceives the differences as one of illumination. Taking the bidimensionality of achromatic colours into account in Exp. 2, results are obtained which show the brightness (alternatively termed luminosity) relations of adjacent areas to be the critical factor for the perceptual shift.     

Color-word interference in relation to comparative compatibility: evidence for two sources of interference]

In previous studies on colour-word interference ('Stroop-phenomenon') stimulus-response-compatibility (word-speech, colour-speech) and task mode (word reading, colour determining) have usually been confounded or not been crossed completely. An experiment is reported where these two factors were varied orthogonally (besides type of stimulus: incongruent, congruent and control). Compatibility was varied by using response keys with varying labelling of the keys (colours or words). The results show--contrary to traditional expectations--the usual pattern of interference in spite of the response key conditions. The existence of response delays of different magnitude indicates separate sources of interference. Encoding interference is found under conditions of high-compatible colour determining by coloured response keys (colour-colour key), recoding interference under conditions of low-compatible reading (word-colour key), both presented here in an isolated form. Both modes of interference should therefore contribute to the interference under conditions of low-compatible colour determining which is the traditional Stroop condition. In an attempt to predict this complete interference encoding interference was shown to be the more stable predictor. The same was true of interference as measured here in a list version.     

照明环境与LCD显示界面背景饱和度的交互效应对视觉绩效的影响

摘 要 采用E-prime编排认知实验研究照明环境与TFT-LCD视觉显示终端界面背景饱和度的交互效应对视觉绩效的影响。依据字母视力表设计原理制作认知材料,以认知速度与准确率为视觉绩效评价指标。结果发现,照度与饱和度的交互效应对视觉绩效存在显著影响,色温与饱和度的交互效应仅对准确率存在显著影响,三因素交互作用对准确率存在显著影响。结果表明,不同照度、色温下,通过调节显示终端界面背景饱和度可改善视觉绩效。     

Sentential structure and the perceptual spans of two samples of disabled readers

The constructs of accuracy and speed were adopted as performance criteria against which to define two clinical samples of disabled readers. Accuracy-disabled subjects had failed to achieve reliable age-appropriate word recognition skills. Rate-disabled readers were age-appropriate in word recognition accuracy but deficient on measures of contextual accuracy and reading speed. When their eye-voice spans were measured under different text manipulations, accuracy-disabled and rate-disabled children differed in the magnitude of their perceptual spans during the act of reading. The two samples did not differ in the extent to which they availed themselves of contextual constraints to extend their spans in the reading of connected text. Both samples of disabled readers appeared able to use syntactic information as an independent source of sentential information in reading, even the sample whose reading disability was associated with oral syntax deficits. Comparisons with a previous sample of normal beginning readers suggested both types of disabled readers to be reading with perceptual spans of reduced dimensions.This research was supported by operating funds from the Medical Research Council of Canada, the Ontario Mental Health Foundation/COMSOC Provincial Lottery Grants Program, and The Hospital for Sick Children Foundation. The author gratefully acknowledges the generous contributions of Terry Smialy and Judy Millington in assisting with all phases of data collection and data analysis. Special thanks are due Judy Millington for her skill in computing and analyzing the phrase boundary and pseudoboundary counts. Identification of the present rate-disabled subjects was made possible through the assistance of Andrew Biemiller, Donald G. Doehring, and Roger T. Lennon, who made previously unpublished normative data on reading speed available for use in this research project. The generosity of these individuals is very gratefully acknowledged. This paper was presented in part to the annual meeting of the American Psychological Association, Anaheim, California, August 1983.     

The effect of orthographic and emotional neighbourhood in a colour categorization task

This study investigated whether and how the strength of reading interference in a colour categorization task can be influenced by lexical competition and the emotional characteristics of words not directly presented. Previous findings showed inhibitory effects of high-frequency orthographic and emotional neighbourhood in the lexical decision task. Here, we examined the effect of orthographic neighbour frequency according to the emotional valence of the higher-frequency neighbour in an emotional orthographic Stroop paradigm. Stimuli were coloured neutral words that had either (1) no orthographic neighbour (e.g. PISTIL [pistil]), (2) one neutral higher-frequency neighbour (e.g. tirade [tirade]/TIRAGE [draw]) or (3) one negative higher-frequency neighbour (e.g. idiome [idiom]/IDIOTE [idiotic]). The results showed that colour categorization times were longer for words with no orthographic neighbour than for words with one neutral neighbour of higher frequency and even longer when the higher-frequency neighbour was neutral rather than negative. Thus, it appears not only that the orthographic neighbourhood of the coloured stimulus words intervenes in a colour categorization task, but also that the emotional content of the neighbour contributes to response times. These findings are discussed in terms of lexical competition between the stimulus word and non-presented orthographic neighbours, which in turn would modify the strength of reading interference on colour categorization times.