2～3岁儿童对视频信息的理解

选取2岁、2．5岁和3岁儿童72名,比较儿童通过窗口、视频和模型三种条件观看藏玩具过程,然后正确找到玩具的表现,考察了2～3岁儿童对视频信息的理解特点。结果表明：（1）与通过直接经验获得信息相比,2岁与2.5岁儿童从视频获得表征信息存有一定困难;3岁儿童能够顺利地从视频获得并运用表征信息。（2）2～3岁儿童在视频条件下获取表征信息的能力要强于模型条件。研究认为3岁前儿童完成将视频图像视为真实物向视为表征信息的转换,双重表征并非儿童将视频图像作为表征信息加以理解的先决条件。     

A low-cost method for digitizing videotaped continuous movements on the Macintosh

We describe an inexpensive means of digitizing videotaped positions of moving points, such as the positions of the joints of a person who is performing an action. Single-frame video images and a Macintosh computer monitor are optically superimposed, using a half-silvered mirror, and the positions of reference points in the video image are manually clicked in by the operator, so that the screen coordinates of the reference points on each frame can be stored in a text file for later analysis. The digitizing program records comments and identifying information along with the position data.     

Automated 3-D tracking of video-captured movement using the example of an aquatic mollusk

We describe a computer program that tracks the three-dimensional coordinates of a snail (moving within a tank) from images captured by a single video camera. The tank and a mirror placed at 45° to one side are viewed to provide direct and reflected images of a pond snail,Lymnaea stagnalis, moving around the tank. The output of the camera is captured with an IBM-compatible PC using a frame-grabbing VideoBlaster board. The main features of our Windows program is the frame-by-frame analysis of the captured video, enhancement of contrast, location of dark “snails,” discrimination by size, trigonometric determination of thex, y, z coordinates, and the final export of data in a spreadsheet-ready format. After the user has outlined the position of the tank on the screen and set the discrimination thresholds, no further user activity is required. This makes the analysis of slowly moving mollusks much less operator intensive and less tedious. The method is applicable to other faster moving organisms (e.g., fish) because the analysis is performed on captured video sequences.     

The Heuristic and Motivational Value of Video Reinforcement

Four rhesus monkeys (Macaca mulatta) were tested on joystick-based computer tasks in which they could choose to be reinforced either with pellets-only or with pellets + video. A variety of videotapes were used to reinforce task performance. The monkeys significantly preferred to be rewarded with a pellet and 10 s of a blank screen than a pellet plus 10 s of videotape. When they did choose to see videotaped images, however, they were significantly more likely to view video of themselves than video of their roommate or of unfamiliar conspecifics. These data support earlier findings of individual differences in preference for video reinforcement, and have clear implications for the study of face-recognition and self-recognition by nonhuman primates.     

The Observer Video-Pro: New software for the collection, management, and presentation of time-structured data from videotapes and digital media files

The Observer Video-Pro is a system for collecting, managing, analyzing, and presenting observational data. It integrates The Observer software with time code and multimedia hardware components. It extends the functionality of a conventional real-time event recording program in various ways. Observational data can be collected, reviewed, and edited with synchronized display of the corresponding video images. For optimal visual feedback during coding, one can display the video image in a window on the computer screen. Video playback from either a VCR or a digital media file can be controlled by the computer, allowing software-controlled jog, shuttle, and search functions. Besides a wide range of VCRs, The Observer Video-Pro supports all major digital video file formats. The software allows the user to summarize research findings in numerical, graphical, or multimedia format. One can create a time-event plot for a quick glance at the temporal structure of the observed process, or run specific analysis procedures and generate reports with statistics. An Event Summary function is available for exploratory and qualitative analysis. Video material can be summarized in a Video Play List, which allows on-screen summary presentations or the creation of highlight compilations on tape, CD, or other media. Video images can be captured and saved as disk files, for use as illustrations in documents, slides for presentations, and so forth. In this paper we describe the design and operation of the system, illustrated with a case study from research on Repetitive Strain Injury (RSI).     

A context-specific latent inhibition effect in a human conditioned suppression task

Three studies used a computer video game preparation to demonstrate latent inhibition in adult humans. In all studies participants fired torpedoes at a target spaceship by clicking the mouse. Conditioned stimuli (CSs) were presented in the form of coloured “sensors” at the bottom of the screen. Conditioning was conducted by pairing a sensor with an attack from the target spaceship. Participants learned to suppress their rate of mouse clicking in preparation for an attack. In Experiment 1 a total of 10 preexposures to the sensor CS, prior to conditioning, retarded acquisition of suppression. In Experiment 2 the effect of preexposure was shown to be context specific. Experiment 3 showed little generalization of the preexposure effect from one sensor CS to another. Experiment 3 also showed that preexposure did not make the sensor CS inhibitory. Comparisons with conditioned suppression procedures with animals and negative-priming procedures are briefly discussed.     

Eyetracking for two-person tasks with manipulation of a virtual world

Eyetracking facilities are typically restricted to monitoring a single person viewing static images or prerecorded video. In the present article, we describe a system that makes it possible to study visual attention in coordination with other activity during joint action. The software links two eyetracking systems in parallel and provides an on-screen task. By locating eye movements against dynamic screen regions, it permits automatic tracking of moving on-screen objects. Using existing SR technology, the system can also cross-project each participant’s eyetrack and mouse location onto the other’s on-screen work space. Keeping a complete record of eyetrack and on-screen events in the same format as subsequent human coding, the system permits the analysis of multiple modalities. The software offers new approaches to spontaneous multimodal communication: joint action and joint attention. These capacities are demonstrated using an experimental paradigm for cooperative on-screen assembly of a two-dimensional model. The software is available under an open source license.     

An inexpensive videoprojection/digitization system for behavioral research

We present an inexpensive approach to image analysis of spatial coordinates for behavioral research. Image analysis of still video images (freeze frames) with current technology can be prohibitively expensive, as well as time consuming. The system outlined here provides an accurate, inexpensive, and fast approach to acquiring information from videotape. It consists simply of a video monitor, bellows, large diameter lens, and a digitizing tablet. The images are projected onto a digitizing tablet, and data acquisition is controlled with a series of three functions written in APL. We used this system to acquire positional information on fish responding to the threat of aerial predation. We discuss several approaches to design and construction of this system, as well as provide computer listings for initiation of communication with digitization boards.     

A context-specific latent inhibition effect in a human conditioned suppression task

Three studies used a computer video game preparation to demonstrate latent inhibition in adult humans. In all studies participants fired torpedoes at a target spaceship by clicking the mouse. Conditioned stimuli (CSs) were presented in the form of coloured “sensors” at the bottom of the screen. Conditioning was conducted by pairing a sensor with an attack from the target spaceship. Participants learned to suppress their rate of mouse clicking in preparation for an attack. In Experiment 1 a total of 10 preexposures to the sensor CS, prior to conditioning, retarded acquisition of suppression. In Experiment 2 the effect of preexposure was shown to be context specific. Experiment 3 showed little generalization of the preexposure effect from one sensor CS to another. Experiment 3 also showed that preexposure did not make the sensor CS inhibitory. Comparisons with conditioned suppression procedures with animals and negative-priming procedures are briefly discussed.     

Surreptitiously projecting different movies to two subsets of viewers

A new technique (manipulation of overlapping rivalrous images by polarizing filters, or MORI) has been invented for presenting on the same screen two different images that can be seen separately by two groups of viewers without their noticing the overlap. It can easily create desired artificial conflicts among viewers. Two perpendicular polarizing filters provide separate invisible channels from dual video projectors to two groups of viewers on a single screen. The basic principle of the presentation technique, details of the apparatus, and limitations are introduced. As an example of the application of this technique, an eyewitness experiment is briefly reported. The results of experiments conducted by the author and colleagues provide evidence of the effectiveness of this technique with various projectors, video materials, group sizes, and ages of participants.     

The PC tachistoscope has 240 pages

Myors (1998) showed how to combine familiar video page switching with bit-plane layering in video mode 0dh to increase the capacity of the PC tachistoscope from 8 to 32 pages. The present article shows how to combine video page switching with color page switching to implement a 240-page tachistoscope, thus producing an almost eightfold increase in the capacity of the PC tachistoscope. The main limitation of this technique is that the images cannot all be located in the same position on the screen. Complete source code in C is included.     

Capuchin monkeys (Cebus apella) respond to video images of themselves

Many studies have used mirror-image stimulation in attempts to find self-recognition in monkeys. However, very few studies have presented monkeys with video images of themselves; the present study is the first to do so with capuchin monkeys. Six tufted capuchin monkeys were individually exposed to live face-on and side-on video images of themselves (experimental Phase 1). Both video screens initially elicited considerable interest. Two adult males looked preferentially at their face-on image, whereas two adult females looked preferentially at their side-on image; the latter elicited lateral movements and head-cocking. Only males showed communicative facial expressions, which were directed towards the face-on screen. In Phase 2 monkeys discriminated between real-time, face-on images and identical images delayed by 1 s, with the adult females especially preferring real-time images. In this phase both screens elicited facial expressions, shown by all monkeys. In Phase 3 there was no evidence of discrimination between previously recorded video images of self and similar images of a familiar conspecific. Although they showed no signs of explicit self-recognition, the monkeys’ behaviour strongly suggests recognition of the correspondence between kinaesthetic information and external visual effects. In species such as humans and great apes, this type of self-awareness feeds into a system that gives rise to explicit self-recognition.     

A method for analyzing the motion of an object on a VTR screen with an Apple II computer

To detect position on a video tape recorder (VTR) monitor screen, two different types of apparatus were developed. One was a light pen, and the other was an instrument similar to an X-Y tracker. These were designed to work with the Apple II computer. Their circuit diagrams are presented.     

Reading instruction and remediation with the aid of computer speech

In this paper, we describe the application of new computer and speech synthesis technologies for reading instruction. Stories are presented on the computer screen, and readers may designate words or parts of words that they cannot read for immediate speech feedback. The important contingency between speech sounds and their corresponding letter patterns is emphasized by displaying the letter patterns in reverse video as they are spoken. Speech feedback is provided by an advanced text-to-speech synthesizer (DECtalk). Intelligibility data are presented, showing that DECtalk can be understood almost as well as natural human speech by both normal adults and reading disabled children. Preliminary data from 26 disabled readers indicate that there are significant benefits of speech feedback for reading comprehension and word recognition, and that children enjoy reading with the system.     

Independent control of dual video subsystems on the IBM PC and compatibles

Two methods for generating video output on multiple video monitors are described. The first method involves splitting the signal from a single video adaptor card-so that multiple video monitors may be attached. Although this method is simple and relatively cost-effective, it is limited to adaptors that produce only digital video signals, thus precluding the use of VGA systems and composite displays. The second method involves the installation and programming of video adaptors: Two sample programs, which control a secondary adaptor by means of either BIOS routines or direct commands via C code, are described. Although more complex, this second method allows output to each display to be controlled independently. Furthermore, output to one screen may consist of graphics information while output to the second screen consists of text. Together, both methods can be used to create an experimental system composed of multiple data-collection stations and an independent experimenter console.     

Can computer mice be used as low-cost devices for the acquisition of planar human movement velocity signals?

The main goal of this work is to determine whether a computer mouse can be used as a low-cost device for the acquisition of two-dimensional human movement velocity signals in the context of psychophysical studies and biomedical applications. A comprehensive overview of the related literature is presented, and the problem of characterizing mouse movement acquisition is analyzed and discussed. Then, the quality of velocity signals acquired with this kind of device is measured on horizontal oscillatory movements by comparing the mouse data to the signals acquired simultaneously by a video motion tracking system and a digitizing tablet. A synthesis of the information gathered in this work indicates that the computer mouse can be used for the reliable acquisition of biosignals in the context of human movement studies, particularly for many applications dealing with the velocity of the end effector of the upper limb. This paper concludes by discussing the possibilities and limitations of such use.     

A high-resolution color graphic display four-channel software tachistoscope

A software tachistoscope for IBM-PC-compatible personal computers equipped with Tseng-ET4000-based VGA boards is described. It is shown how up to four bit-mapped color images with a resolution of up to 800 X600 pixels may be stored in video display memory and alternatingly be selected for screen display in synchrony with the vertical retrace signal of the video controller.     

A computer interview language: Programming the on-line interactive computer

Seven computer interview and two disk file commands are executed by a computer program to display multiple-choice questions on a CRT video screen, to record clients’ answers, and to branch to various sets of questions. The program interpreting these commands uses little computer memory and does not require change each time the interview is altered or expanded. It can be written in almost any general-purpose programming language.     

Graphic precision: Controlling stimulus displays on IBM PC-compatible computers

Tachistoscopic presentation of stimuli on IBM PC-compatible computers is limited by a number of factors, including video retrace rates, screen scrolling, and the shape and density of picture elements. A method is presented for overcoming these difficulties through the use of enhanced graphic adapters or video graphic arrays. A C-language program demonstrates (1) synchronous scroll-free displays achieved by writing alternating images to “hidden” pages of video memory, (2) alternative techniques for erasing images, and (3) use of an empirically derived aspect ratio to produce symmetrical figures.