EXPRESS: Facilitation effect of incidental environmental context on the computer screen for paired-associate learning

Three experiments, in which a total of 198 undergraduates engaged, investigate whether the incidental environmental context on the computer screen influences paired-associate learning. Experiment 1 compared the learning of foreign and native language words between a constant context condition, where the stimulus and response pairs were presented twice on the same 5-s video background context, and a varied context condition, where the pairs were presented twice on different video contexts. Repetition in the same context resulted in better learning than in different contexts, evaluated with a paper-and-pencil test. Experiment 2 investigated learning of paired-associate foreign and native words in the same video-contexts, or photograph-contexts, or on a neutral gray background. Both the video and the photograph contexts equally facilitated the paired-associate learning compared to the gray background. Experiment 3 investigated whether the incidental environmental context similarly facilitated face-name paired-associate learning. We added a new condition of spot illustrations, and a second testing one day later. The repetition of face-name pairs within the same complex incidental environmental context on the computer screen (either video or photograph background) facilitated the paired-associate learning. There was no significant difference in learning performance between video and photograph background contexts, which were significantly better than gray or spot illustration backgrounds which did not differ from each other. The retention interval did not interact with the effect of the background. The present results show that repetition within the same video or photograph context, covering the entire background of the video screen on which each item pair was superimposed, facilitates paired-associate learning.

Heaviness-brightness correspondence and stimulus-response compatibility

Cross-sensory correspondences can reflect crosstalk between aligned conceptual feature dimensions, though uncertainty remains regarding the identities of all the dimensions involved. It is unclear, for example, if heaviness contributes to correspondences separately from size. Taking steps to dissociate variations in heaviness from variations in size, the question was asked if a heaviness-brightness correspondence will induce a congruity effect during the speeded brightness classification of simple visual stimuli. Participants classified the stimuli according to whether they were brighter or darker than the mid-gray background against which they appeared. They registered their speeded decisions by manipulating (e.g., tapping) the object they were holding in either their left or right hand (e.g., left for bright, right for dark). With these two otherwise identical objects contrasting in their weight, stimuli were classified more quickly when the relative heaviness of the object needing to be manipulated corresponded with the brightness of the stimulus being classified (e.g., the heavier object for a darker stimulus). This novel congruity effect, in the guise of a stimulus-response (S-R) compatibility effect, was induced when heaviness was isolated as an enduring feature of the object needing to be manipulated. It was also undiminished when participants completed a concurrent verbal memory load task, countering claims that the heaviness-brightness correspondence is verbally mediated. Heaviness, alongside size, appears to contribute to cross-sensory correspondences in its own right and in a manner confirming the far-reaching influence of correspondences, extending here to the fluency with which people communicate simple ideas by manipulating a hand-held object.

The Contrast Contrast Illusion

To most observers, a patch of medium-contrast texture viewed against a background of high-contrast texture appears lower in contrast than an identical patch viewed against a homogeneous, mean gray background. This is the contrast contrast illusion. This chapter reviews basic findings concerning this illusion; for example, the contrast contrast illusion is selective for texture spatial frequency as well as for texture contrast polarity. Several theories to account for the illusion are discussed. Related concepts such as texture contrast, textual granularity, individual differences, contrast polarity, color and the contrast contrast illusion, and ecological accounts of the contrast contrast illusion are explored.

Retrieval Goal Modulates Memory for Context

fMRI was employed to assess whether the contents of recollection vary according to retrieval goal. At study, visually presented words were superimposed on urban or rural scenes or a gray background. The word–background pairs were presented in one of three spatial locations. During a scanned test phase, studied and unstudied words were presented. Two different source memory tasks were randomly interleaved. In the “background” task, the requirement was to judge whether the word had been presented against one of the two classes of scene, as opposed to the alternate class or the gray background. In the “location” task, discrimination was between words presented in one of the two lateral locations and words presented in either of the alternate locations. In both tasks, unstudied words required a separate response. In the background task, words studied against scenes elicited greater activity in parahippocampal and retrosplenial cortex than did words studied against the gray background, consistent with prior reports of scene reinstatement effects. Reinstatement effects were also evident in the location task. Relative to the background task, however, the effects were attenuated in parahippocampal cortex. In other regions, including medial prefrontal and posterior cingulate cortex, activity elicited in the location task by items associated with scenes was lower than that elicited by items presented on the gray background. The findings are interpreted as evidence that contextual retrieval is partially modulated by retrieval goal.

Performance of CIE LAB-Based Color Difference Formulae under Different Viewing Conditions

In order to investigate the performance of color difference formulae under different viewing conditions 144 pairs of sample around 17 color centers were designed and printed, and then assessed visually under four different viewing condition. STRESS values between the visual color difference and calculated color difference by five CIELAB-based color difference formulae CIELAB, BFD, CMC, CIE94, CIEDE200 were calculated. The result shows that the formulae have the similar performance but CIE94 is the best in all viewing conditions and CIELAB and BFD are the worst. All the color difference formulae have the best performance under illuminant D65 with illuminance of 1000 lx and gray background

How Are Lateral Chromatic Interactions Computed from Cone Signals?

A small gray test field superimposed on a large colored background appears tinted in a color complementary to that of the surround. We tested the hypothesis whether photoreceptor sensitivity in the test field is altered in the presence of a colored surround. We investigated this effect using dichoptic viewing conditions. With the left eye, subjects viewed a small gray target superimposed on a large colored background. The right eye saw a gray target superimposed on a large gray background. When the two images were fused, observers perceived one homogeneous background and two targets. Observers matched the color of the target seen by the right eye to that seen by the left eye. A modified two-stage model for chromatic induction assuming that both receptor and postreceptor mechanisms contribute to the shift in color was fitted to the matched settings. We find that the dichoptic viewing effects presented here are well explained by an approximately equal contribution of receptor and postreceptor processes to the perceived shift in color.

Preferred Hemifields Learn Less

Subjects were tested on orientation and colour pop-out tasks. Orientation pop-out stimuli were 3 × 3, 5 × 5, or 7 × 7 arrays of vertical light (white) bars (on a black background) with a target element of diagonal (45°) orientation (present on half of the trials). Colour pop-out stimuli consisted of 60° oriented bars with blue distractor and yellow target elements (on a gray background). Inter-element distance was 40 min arc. The arrays were presented eccentrically, in the right or left hemifield, so that the distance of their centres from the fixation cross was 2.5 – 6.5 deg. First we tested performance in the right and left hemifields, with interleaved trials. Most subjects (7/9) had a right-hemifield preference for the orientation and/or colour task. The remaining 2 had a left-hemifield preference. For the six subjects tested on both tasks, all but one had more laterality for colour than for orientation. Thus, for the 15 conditions tested (9 orientation + 6 colour), most (8/15) showed better performance in the right hemifield; the minority (2/15) were better on the left; and a third were about equal in both hemifields. Subjects were recalled for a second session with the same tasks, to test improvement due to first session training. Almost all showed significantly greater improvement for the non-preferred hemifield. This effect was so strong that often preference was switched. Surprisingly, preferred-hemifield performance actually declined for many subjects. Thus, the effect seems related to competition, and perhaps an automatic attention-directing mechanism.

Asymmetries in Brightness and Darkness for Assimilation and Simultaneous Contrast?

Recently, de Weert and Spillmann (1995 Vision Research35 1413 – 1419) reported a striking example of assimilation. Their stimulus was a pincushion formed by four arcs, each consisting of a number of black and white rings on a gray background (the area surrounded by the rings, see their figure 1). When the gray background is immediately surrounded by white rings, the background appears lighter and vice versa. When a subject is asked to match the luminance of a circle in a different spatial location for both the ‘lighter’ and the ‘darker’ pincushion, the matching luminance of the test is lower than the actual background luminance. This result is surprising but also counterintuitive. For example if a ‘light’ pincushion is matched with a ‘dark’ pincushion, it is expected that the luminance of a ‘light’ pincushion needs to be decreased in order to match the ‘dark’ pincushion. Conversely, the luminance of the ‘dark’ pincushion needs to be increased to match the ‘light’ pincushion. Therefore luminance values on both sides of the default background luminance are expected. We replicated their basic experiment and found the same results. In additional conditions, we had subjects adjust the background luminance of a ‘light’ pincushion compared to a ‘dark’ and vice versa. In that case the luminance values were symmetrical on either side of the default background luminance. It would seem that the method of testing is crucial here. Therefore we also tested simultaneous contrast stimuli (all rings were made black or white) using the circle-match-task as in their original experiment. We found that both values were nicely distributed on both sides of the background luminance value, indicating that de Weert and Spillmann's finding is not attributable to the test condition as such.

Memory Representation of Object Colours

Memory colours, ie colours recalled in association with familiar objects, impose a powerful constraint on colour appraisal of images of natural scenes. The purpose of this study is to specify the memory representation of one particular object colour. To this end, the colour of a banana was manipulated by varying hue-angle and saturation in the CIELUV colour space. Subjects' task was to rate the similarity in colour of the resulting banana samples displayed on the screen to the typical ripe banana stored in their mind. In order to examine the dependence of memory colour on texture information and context, three ways of presentation were used: original (banana among other fruit), isolated (the same banana against a homogenous gray background), and contour (silhouette of the banana with its average colour against the gray background). The relationships between the similarity judgments and chromaticity coordinates of the manipulated banana-represented points in the CIELUV colour space is described by a bivariate normal distribution with four parameters: two means and two variances of the Gaussians on the hue and saturation dimensions. For all three types of presentation, the variance of hue is significantly smaller than the variance of saturation; this suggests that memory description of hue is more precise than that of saturation. The data show systematic differences in the hue of memory colour between the original, isolated, and contour presentations of the banana. A model describing the hue shift in terms of illuminant and surface information content in the images is discussed.