The effect of texture oil the magnitude of

The magnitude of simultaneous brightness contrast was measured while the coarseness of the textural overlay was varied. Remits from 10 Ss indicate that as the size of elements in the texture increases, the amount of obtained contrast decreases. An interpretation of these results in terms of the spread of lateral inhibitory effects is offered.     

The influence of optical aberrations on the magnitude of the Poggendorff illusion

The amount of blurring of the retinal image can be reduced by proper selection of an artificial pupil and a chromatic filter. Reduction of the amount of blurring due to optical aberrations by viewing through a 1-mm artificial pupil and an interference filter in the eye, results in a concomitant reduction in the magnitude of the Poggendorff illusion. The magnitude of the reduction is smaller, however, than would be expected if the illusion was predominantly determined by blur due to optical aberration.     

The effects of load variability in short-term memory task

Six groups of Ss viewed briefly exposed arrays of letters, half designated high-valued and half low-valued. Immediately after each exposure Ss wrote down as many of the stimuli as they could remember. For three groups, the number of letters in each exposure was constant from trial to trial; for the remaining three groups, the number of letters in each exposure varied from trial to trial. This tested the hypothesis that load variability influences the development of an efficient response strategy which, in turn, affects the processing of information stored in short-term memory. The data supported this hypothesis. Performance was superior under the constant load condition due to the ability of these Ss to correctly report both high- and low-valued letters. Poor performance was observed under the variable load condition because of a decrease in the number of low valued letters correctly reported.     

Differentiation and decrement in the Mueller-Lyer illusion

Two experiments were conducted to test the hypothesis that decrement of the Mueller-Lyer illusion with inspection is due to learning to differentiate the test element from the accessory lines. In one experiment, the test element is predifferentiated for the observer by means of configurational variations and in the other by restriction of attention. Although the initial magnitude of the illusion is found to be inversely proportional to the amount of predifferentiation, the slopes of the decrement curves are not affected.     

Static visual noise and the ansbacher effect

In Experiment I subjects made estimates of the apparent length of a 12 cm. long light arc-line rotating around a central fixation point at arc speeds of 66, 99, 132 and 165 cm./sec. Apparent contraction of the arc occurred as a function of speed, there being greater contraction in the presence of a superimposed random pattern of I cm. light squares (visual noise) than in its absence. The results of Experiment II indicated that there was no significant difference in length due to visual noise when the arcs were stationary. In Experiment III subjects made estimates of the speed of rotation of the arc and it was found that visual noise did not significantly affect the apparent arc-speed.     

Retinal painting and visual information storage

As a measure of visual information storage (VIS), Haber and Nathanson (1968) have used a retinal painting task involving passing a narrow slit across a drawing which the S has to see as a single percept. Two experiments were conducted to evaluate this task as a measure of VIS. In experiment 1 it was shown that contrary to other measures of VIS, adults have longer values than children. In experiment 2 dyslexic and control children performed at equivalent levels on this task. It is suggested that retinal painting involves a different persistence effect to that normally used as a measure of VIS.     

Child abuse: Prognostic factors in therapy effectiveness

We have attempted to define the problem of child abuse by separating the abusers into two categories. Pattern abusers seem to be primarily a social issue in that the abuse is an outgrowth of the parental charge to control her/his child. However, another abuser is seen as a borderline or psychotic individual when the abuse is an outgrowth of a transferential distortion on the part of the parent. It was suggested that family therapy for the latter may be the preferential mode of intervention.     

Effects of inadmissible Evidence on the Decisions of Simulated Jurors: A Moral Dilemma

In a 2 × 3 design, simulated jurors received either weak or strong evidence against a defendant in a murder case. Within each evidence condition, subjects were given either additional evidence ruled admissible, additional evidence ruled inadmissible, or no additional evidence. Results indicated that ( a ) jurors were biased by inadmissible evidcnce in the weak-evidence but not in the strong-evidence condition, ( b ) strong evidence resulted in more guilty verdicts than did weak evidence, ( c ) confidence in verdict was influenced by strength of evidence, and ( d ) confidence of guilt was positively correlated with severity of punishment. Implications of the results are discussed within the context of the judicial process.     

The influence of the interaction of weight and volume on subjective heaviness

A model previously proposed for the size-weight illusion (Cross & Rotkin, 1975) was found unsatisfactory because the postulated volume parameter was not independent of the unit of measurement of weight and the model yielded a paradoxical prediction that the perceived heaviness of small objects should decrease as their weight increased. A new model was proposed based on Stevens and Rubin’s (1970) finding that heaviness functions are a family of con-verging power functions and some of Cross and Rotkin’s developments. The model was ex-amined by estimating its parameters from data previously reported by Cross and Rotkin, Stevens and Rubin, and Kolehmainen and Mikkonen (1970). The equations was found to fit each set of data well. Four independent estimates of a volume parameter of the model were in close agreement, .18, .21, .21, and .24, which is consistent with the model. nt]mis|This research was supported by Grants A0151 and A9582 from the National Research Council of Canada.