Two forms of persistence in visual information processing

Iconic memory, which was initially regarded as a unitary phenomenon, has since been subdivided into several components. In the present work we examined the joint effects of two such components (visible persistence and the visual analog representation) on performance in a partial report task. The display consisted of 15 alphabetic characters arranged around the perimeter of an imaginary circle on the face of an oscilloscope. The observer named the character singled out by a bar-probe. Two factors were varied: exposure duration of the array (10, 50, 100, 150, 200, 300, 400 or 500 ms) and duration of blank period (interstimulus interval, ISI) between the termination of the array and the onset of the probe (0, 50, 100, 150, or 200 ms). Performance was progressively impaired as both exposure duration and ISI were increased. The results were explained in terms of a probabilistic combinatorial model in which the timecourses of visible persistence and of the visual analog representation are regarded as time-locked to the onset and to the end of stimulation, respectively. The impairing effect of exposure duration was attributed to the relatively high spatial demands of the task that could be met optimally by information in visible persistence (which declines as a function of exposure duration), but less adequately by information in the visual analog representation. A second experiment, employing a task with lesser spatial demands, confirmed this interpretation.     

Psychological compensation: a theoretical framework.

The 2 main objectives of this article are to review a variety of literatures in which the concept of compensation is used and to integrate the results of this review into a general framework of compensation. The review focuses on 4 domains of psychological inquiry: compensation for sensory handicaps, cognitive deficits, interpersonal losses, and brain injury. In the proposed framework, underlying dimensions and 4 basic steps in the progression of compensatory behavior are distinguished. The latter include origins, mechanisms, forms, and consequences. Finally, we describe ways in which researchers in particular domains can benefit from the global, process-oriented framework we propose. For most of the areas of compensation research reviewed, investigators can profit from a consideration of a broader selection of dimensions, additional steps in the process, alternative outcomes, and both objective and subjective assessment procedures.     

Single and combined effects of methylphenidate and behavior therapy on the classroom performance of children with attention-deficit hyperactivity disorder

Twenty-four boys with attention deficit-hyperactivity disorder (ADHD) participating in an intensive summer treatment program each received b.i.d. placebo and two doses of methylphenidate (MPH, 0.3 mg/kg and 0.6 mg/kg) crossed with two classroom settings: a behavior modification classroom including a token economy system, time out and daily home report card, and a regular classroom setting not using these procedures. Dependent variables included classroom observations of on-task and disruptive behavior, academic work completion and accuracy, and daily self-ratings of performance. Both MPH and behavior modification alone significantly improved children's classroom behavior, but only MPH improved children's academic productivity and accuracy. Singly, behavior therapy and 0.3 mg/kg PMH produced roughly equivalent improvements in classroom behavior. Further, the combination of behavior therapy and 0.3 mg/kg MPH resulted in maximal behavioral improvements, which were nearly identical to those obtained with 0.6 mg/kg MPH alone.The authors gratefully acknowledge the assistance of Patricia Donovan, Michelle Berry, Mary Ingram, Patricia Wells, Beth Gnagy, Karen Greenslade, Mary Hamilton, and the entire staff of the Western Psychiatric Institute and Clinic ADHD Summer Treatment Program.     

A new technique for measuring word processing time in reading

This paper reports some preliminary data on a “window-pointer” technique for measuring word processing time in reading. In this technique, almost all of the letters are masked on a page of text shown on a video monitor. The letters can be seen only through a “window” showing one word on one line. Subjects control the horizontal location of the window by moving a pointer left and right. When subjects want to move the window to the next line, the window is moved off the right end of the current line, and the pointer is moved back to the left. The window then reappears at the beginning of the next line. After some practice, subjects can move the window in approximate synchrony with their eyes, and can read the passage without any difficulty. The length of time the window spends on each word can then be used as a measure of word processing time. An analysis of these window durations indicates that they are similar in many respects to the gaze durations obtained with eye-movement monitoring techniques.     

The recording of continuous variation along four dimensions

A system is described for signalling, recording and analysing continuous changes in up to four dimensions applicable to the visual after-image and other phenomena. Some advantages of the method are discussed.     

Research in Consultation: Toward Better Analogues and Outcome Measures

Recommendations for improving consultation research include (a) strengthening consultation analogue research by incorporating “boundary” conditions into research designs and (b) extending the outcome measures used.     

Adult age differences in elaborations produced during prose recall

This study focused on adult age differences in the characteristics and quantity of elaborations produced during a prose recall task. Young (M = 24.3 years) and older (M = 67.9 years) adults were tested in 3 same-age, same-gender group size conditions: individual, dyad, and tetrad. Elaborations, which are statements not contained in the text but not inconsistent with it, were divided into 2 major categories. Denotative elaborations included statements that were closely related to the text and filled in gaps in the stories. These elaborations were equally produced by young and older adults and were significantly correlated with gist recall performance. Annotative elaborations were evaluative and interpretive comments. These statements were more frequently produced by older adults but were not correlated with recall performance. Young and older adults had different patterns of annotative elaboration production across group size conditions.     

Tachistoscopic display using color-lookup-table display devices

In this article, I describe a method for presenting multiple bit-mapped images on video displays under precise temporal control. The method makes use of the color-table animation technique that can be used with color-lookup-table display devices. The principal challenge in applying this technique to the display of multiple stimuli lies in dealing efficiently with the problem of overlapping displays. The solution described here is to allocate separate bit slices of screen memory to stimuli that overlap and to allocate sequential color-table indices to stimuli that are disjoint. Software is described that automatically computes the location of a stimulus on the screen, allocates color indices appropriately, transfers bit images to screen memory efficiently, and manipulates the color lookup table to present a given stimulus to the viewer. These operations are handled transparently; the user simply draws the stimuli and then turns them on or off under program control.     

Response preference within the Rotter I-E Scale: perceived locus of control of self, average, and ideal others

The Rotter I-E scale was administered to college juniors in education under five different instructional sets. Subjects were asked to complete it (a) as they would ordinarily (self-perception), (b) as they believed an average person of the same sex would, (c) as an average person of the opposite sex would, (d) as an ideal person of the same sex would, and (e) as an ideal person of the opposite sex would. As hypothesized, subjects saw the ideal person of both sexes as significantly more internal than themselves, while they saw the average person of both sexes as more external than themselves. These results suggest the general desirability of being perceived as internally oriented.