On-line eye movement recorders: The good,the bad,and the ugly

The first section of this paper describes three types of problems inherent in the use of on-line eye movement recorders (EMRs), These types of problems are (1) that software is difficult to develop, (2) that an on-line EMR is subject to all difficulties that are normally inherent in computer use and, (3) that with an on-line EMR. it is difficult to detect when the gaze is falling on an object that has an irregularly shaped boundary. It is argued that a large class of eye movement experimentation could be done as easily or more easily with an off-line EMR. The second section of the paper describes an off-line EMR laboratory currently in use by the author.     

An automated eye movement laboratory for on-line electrooculography

This paper describes an automated eye movement laboratory that uses electrooculography (EOG) to study people’s eye movements while they read. An on-line minicomputer processes bioelectric potentials that correspond to saccadic eye movements. Horizontal saccades larger than 1.5 deg of visual angle are detected and analyzed in real-time as they occur. The laboratory is designed for prolonged yet unobtrusive observation of human eye movements during sustained reading periods of minutes or hours. All important functions regarding data collection and data reduction are performed automatically, according to simple procedures that can be applied uniformly and without bias to nearly all subjects that we study. Results from three experiments are cited in order to quantify the performance of the laboratory with respect to four criteria: saccade detection accuracy, measurement accuracy, sensitivity, and the uniformity of these measures over different subjects.     

Reliability of a portable head-mounted eye tracking instrument for schizophrenia research

Smooth pursuit eye movement (SPEM) abnormalities are some of the most consistently observed neurophysiological deficits associated with genetic risk for schizophrenia. SPEM has been traditionally assessed by infrared or video oculography using laboratory-based fixed-display systems. With growing interest in using SPEM measures to define phenotypes in large-scale genetic studies, there is a need for measurement instruments that can be used in the field. Here we test the reliability of a portable, head-mounted display (HMD) eye movement recording system and compare it with a fixed-display system. We observed comparable, modest calibration changes across trials between the two systems. The between-methods reliability for the most often used measure of pursuit performance, maintenance pursuit gain, was high (ICC = 0.96). This result suggests that the portable device is comparable with a lab-based system, which makes possible the collection of eye movement data in community-based and multicenter familial studies of schizophrenia.     

Eye movements in active visual search: A computable phenomenological model

We present a computational model and corresponding computer simulations that mimic phenomenologically the eye movement trajectories observed in a conjunctive visual search task. The element of randomness is captured in the model through a Monte Carlo selection of a particular eye movement based on its probability, which depends on three factors, adjusted to match to the observed saccade amplitude distribution, forward bias in consecutive saccades, and return rates. Memory is assumed to operate through tagging of objects already recognized as nontargets, which, in turn, requires their processing within the attentional area of conspicuity (AC). That AC is adjusted so that computer simulations optimally reproduce the distribution of the number of saccades, the failure rate for capturing the target, and the return rate to previously inspected locations. For their viability, computer simulations critically depend on memory’s being long-ranged. In turn, the simulations confirm the formation of circulating or spiraling patterns in the observed eye trajectories. We also relate consistently the average number of saccades per trial to the saccade amplitude distribution by modeling analytically the combined roles of the AC in attention and memory. The full Supplemental Appendix A for this article may be downloaded from http:// app.psychonomic-journals.org/content/supplemental.     

Remembering a location makes the eyes curve away

Working memory is a system that keeps limited information on-line for immediate access by cognitive processes. This type of active maintenance is important for everyday life activities. The present study shows that maintaining a location in spatial working memory affects the trajectories of saccadic eye movements toward visual targets, as the eyes deviate away from the remembered location. This finding provides direct evidence for a strong overlap between spatial working memory and the eye movement system. We argue that curvature is the result of the need to inhibit memory-based eye movement activity in the superior colliculus, in order to allow an accurate saccade to the visual target. Whereas previous research has shown that the eyes may deviate away from visually presented stimuli that need to be ignored, we show that the eyes also curve away from remembered stimuli.     

The selective disruption of spatial working memory by eye movements

In the late 1970s/early 1980s, Baddeley and colleagues conducted a series of experiments investigating the role of eye movements in visual working memory. Although only described briefly in a book (Baddeley, 1986), these studies have influenced a remarkable number of empirical and theoretical developments in fields ranging from experimental psychology to human neuropsychology to nonhuman primate electrophysiology. This paper presents, in full detail, three critical studies from this series, together with a recently performed study that includes a level of eye movement measurement and control that was not available for the older studies. Together, the results demonstrate several facts about the sensitivity of visuospatial working memory to eye movements. First, it is eye movement control, not movement per se, that produces the disruptive effects. Second, these effects are limited to working memory for locations and do not generalize to visual working memory for shapes. Third, they can be isolated to the storage/maintenance components of working memory (e.g., to the delay period of the delayed-recognition task). These facts have important implications for models of visual working memory.     

A microprocessor control and recording system for instrumental behavior research

This paper describes a miroprocessor system developed for experimental control and data collection in real time. By connecting the experimental equipment to the microprocessor via a serial communication interface, transmission of various animal test-chamber functions over greater distances with only a few cables is facilitated. The microprocessor is programmed on a host computer (PDP/8). A combined terminal station with a cassette deck is used for data and program storage.     

Instrumentation designed to simulate the effects of prisms used in studies of visual rearrangement

A system is described which simulates some of the visual rearrangements and changes in sensorimotor relations that occur when experimental subjects move their eyes while looking through a contact lens with a prism attached. The simulated system is more convenient than a system based on the use of a contact lens, and it is based on measures of eye movement that are important in research on the perceptual effects of visual rearrangement. The effects that occur are reviewed in this paper. We also show in detail how the artificial system, which has an eye movement monitor interfaced with a computer and display, simulates the former effects. The data show that experimental subjects who experience visual rearrangement by simulated means manifest the same kind of perceptual adaptation produced in studies in which visual rearrangement is generated by means of a prism mounted on a contact lens.     

An artificial eye for evaluating videobased eye recording systems

Videobased corneal-reflection-to-pupil-center systems are widely used in eye movement research. In this paper, an artificial eye drawn on a computer screen is presented. The artificial eye provides a way to simulate measurements of eye position in human subjects. The method allows testing videobased systems on the level of the signal and on the level of the calibration algorithm used to map the eye position parameters to stimulus space. In addition, the artificial eye can be used to evaluate specific hypotheses concerning the functioning or malfunctioning of the eye recorder and as a help in developing data analysis programs.     

A simple method to record arm positioning movements in man with an Apple computer

This paper describes a simple method to record arm positioning movements in humans, via the game paddle entry of an Apple computer. A machine language subroutine reads the successive positions of a rotating potentiometer, with an angular accuracy of .5 deg and a time interval between two measures of 2.5 msec, and stores them sequentially in RAM memory. These measures can be retrieved for further computations of movement parameters.     

Moving window generator for reading experiments

An inexpensive PC-based moving window generator with an eye movement recording system is described. The moving window technique, activated by current eye movements, has an advantage over the fixed window technique in measuring the effective visual field size during reading. A variable rectangular window, through which the subject observes the text, is generated on a PC-controlled CRT screen. The system includes a frame buffer memory, an analog-to-digital conversion unit, and an eye movement recording system. The system works well for measuring approximate field size during reading.     

Oculomotor control and the maintenance of spatially and temporally distributed events in visuo-spatial working memory

Previous studies have demonstrated that working memory for spatial location can be significantly disrupted by concurrent eye or limb movement (Baddeley, 1986; Smyth, Pearson, & Pendleton, 1988). Shifts in attention alone can also interfere with spatial span (Smyth & Scholey, 1994), even with no corresponding movement of the eyes or limbs (Smyth, 1996). What is not clear from these studies is how comparable is the magnitude of effect caused by different forms of spatial disrupter. Recently, it has been demonstrated that limb movements produce as much interference with spatial span as do reflexive saccades (Lawrence, Myerson, Oonk, & Abrams, 2001). In turn this has led to the hypothesis that all spatially directed movement can produce similar effects in visuo-spatial working memory. This paper reports the results of five experiments that have contrasted the effect of concurrent eye movement, limb movement, and covert attention shifts on participants' working memory for sequences of locations. All conditions involving concurrent eye movement produced significantly greater reduction in span than equivalent limb movement or covert attention shifts with eyes fixated. It is argued that these results demonstrate a crucial role for oculomotor control processes during the rehearsal of location-specific representations in working memory.     

Rehearsal in serial memory for visual-spatial information: Evidence from eye movements

It is well established that rote rehearsal plays a key role in serial memory for lists of verbal items. Although a great deal of research has informed us about the nature of verbal rehearsal, much less attention has been devoted to rehearsal in serial memory for visual-spatial information. By using the dot task—a visual-spatial analogue of the classical verbal serial recall task—with delayed recall, performance and eyetracking data were recorded in order to establish whether visual-spatial rehearsal could be evidenced by eye movement. The use of eye movement as a form of rehearsal is detectable (Experiment 1), and it seems to contribute to serial memory performance over and above rehearsal based on shifts of spatial attention (Experiments 1 and 2).     

Performance of a computer system for recording eye fixations using limbus reflection

A computer system was developed to measure and record locus and duration of the eye axis of gaze using a limbus reflection technique. System hardware and operating procedures for on-line data collection and correction are described. Algorithms are presented that separate fixations from movements. Based on these algorithms, system performance was measured in terms of spatial accuracy of eye fixations and temporal accuracy of saccadic movements.     

A software system for real-time control of psychological experiments

This paper describes an all-purpose experimental system, “APES,” for use in a microprocessor-controlled behavioral pharmacology laboratory. APES is an assembly language program that can run on any of the DEC PDP-11 family processors under an RT-11 single-job operating system. Its main purpose is the real-time control of psychological experimentation. The capabilities of the system are: (1) system generation of all operant or Pavlovian conditioning paradigms, (2) collection and storage of both behavioral and physiological data in a machine-readable format for later statistical analysis, and (3) operation that can be accomplished by individuals who have no computer programming experience.     

眼跳的研究范式及其主要认知功能

眼跳运动系统为研究者探索行为的认知控制机制提供了有力工具。已有研究发现,很多认知过程会影响不同类型眼跳任务中的眼跳参数。在系统梳理已有研究的基础上,从以下4个方面系统阐述和评价了眼跳运动的研究范式和主要认知功能：（1）视觉导向眼跳的研究范式和变式及其认知功能,包括空白/重叠效应、分心物效应、提示效应、学习效应等;（2）预测性眼跳的研究范式和认知控制,涉及神经生物钟理论、视空间工作记忆、指导语等;（3）记忆导向眼跳的研究范式和变式及其认知控制,包括分心物效应、年龄效应、视空间工作记忆的抑制效应、注意等;（4）反向眼跳的研究范式和变式及其认知控制,包括反向眼跳抑制、眼跳决策信号竞争整合模型、工作记忆容量、注意、错误监控、学习、奖励和年龄效应等。最后,结合已有研究范式对未来眼跳研究的趋势和需解决的问题进行了展望。     

视觉短时记忆与视知觉的信息整合

与知觉整合和跨眼跳的信息整合一样,视觉短时记忆与视知觉的信息整合也是人们加工并保持整体性场景知觉的重要前提条件。近年来研究者们使用空白单元格定位任务进行了一些研究,试图寻求视觉短时记忆与视知觉信息整合的实验证据并探讨其整合机制。该文对已有的相关实验范式、实验证据和整合机制进行了介绍并加以分析,并指出未来研究可以在行为数据的基础上结合眼动和脑成像的数据寻求汇聚性证据