James P. Thomas

Bio: James P. Thomas is an academic researcher from University of California, Los Angeles. The author has contributed to research in topics: Spatial frequency & Brightness. The author has an hindex of 27, co-authored 72 publications receiving 5628 citations.

Handbook of perception and human performance

Abstract: Written by well-known specialists, here is a comprehensive handbook on human perception and performance. Volume one covers theory and methods; basic visual processes; auditory, kinesthetic, cutaneous, and vestibular senses; and space and motion perception. Volume two treats information processing, perceptual organization and cognition, and human performance. Organized to facilitate reference usefulness, these volumes provide substantial cross-referencing and extensive use of illustrations. In addition, a substantial amount of tutorial material is provided, with several hundred pages devoted to the elucidation of the conceptual and methodological underpinnings of the more substantive chapters. Figure legends are extremely detailed to enhance their reference usefulness without having to search accompanying text for relevant coverage.

Handbook of Perception and Human Performance. Volume 2. Cognitive Processes and Performance

Abstract: : This chapter has attempted to bring together the laboratory and field-based techniques currently in use to assess workload. No doubt, many specific procedures of interest to particular applications have been left out of this survey. In no sense is this meant to summarily exclude these from any list of valid workload assessment techniques. In fact, several of these are acknowledged to show considerable promise (e.g., occlusion techniques and respiratory rhythms). They are not discussed here partly because of space limitations and partly because a judgment had to be made concerning the practicality and general applicability of each measure. It is hoped that the inclusion of general references will serve to point the interested reader to the individual techniques not included here. Similarly, a class of techniques frequently used to assess workload was deliberately excluded from this chapter. Task analytic methods, particularly as they are used with computer models of whole missions or operations (see e.g., Lane, Strieb, Glenn, & Wherry, 1981) constitute an important tool for work- load investigations during design and other stages of aircraft and systems development. These techniques, however, are primarily off-line analyses that utilize the kind of laboratory and field data gathered with the techniques such as those described in this chapter. They provide an overall systems answer to the workload question and as such deserve separate treatment from highly specific workload measures. The interested reader is referred to Chubb (1981), Geer (1981), Lane et al. (1981), Parks (1979), and Wherry (1984) for reviews and introductions to some of the modeling techniques used in these areas. swr

A signal detection model predicts the effects of set size on visual search accuracy for feature, conjunction, triple conjunction, and disjunction displays.

Abstract: Recently, quantitative models based on signal detection theory have been successfully applied to the prediction of human accuracy in visual search for a target that differs from distractors along a single attribute (feature search). The present paper extends these models for visual search accuracy to multidimensional search displays in which the target differs from the distractors along more than one feature dimension (conjunction, disjunction, and triple conjunction displays). The model assumes that each element in the display elicits a noisy representation for each of the relevant feature dimensions. The observer combines the representations across feature dimensions to obtain a single decision variable, and the stimulus with the maximum value determines the response. The model accurately predicts human experimental data on visual search accuracy in conjunctions and disjunctions of contrast and orientation. The model accounts for performance degradation without resorting to a limited-capacity spatially localized and temporally serial mechanism by which to bind information across feature dimensions.

Cognitive processes and performance

Abstract: Written by well-known specialists, here is a comprehensive handbook on human perception and performance. Volume one covers theory and methods; basic visual processes; auditory, kinesthetic, cutaneous, and vestibular senses; and space and motion perception. This volume treats information processing, perceptual organization and cognition, and human performance. Organized to facilitate reference usefulness, these volumes provide substantial cross-referencing and extensive use of illustrations. In addition, a substantial amount of tutorial material is provided, with several hundred pages devoted to the elucidation of the conceptual and methodological underpinnings of the more substantive chapters. Figure legends are extremely detailed to enhance their reference usefulness without having to search accompanying text for relevant coverage.

Sensory processes and perception

Abstract: THEORY AND METHODS Psychophysical Measurement and Theory (J. Falmagne) Strategy and Optimization in Human Information Processing (G. Sperling & B. Dosher) Computer Graphics (H. Greeman) BASIC SENSORY PROCESSES I (D. I. A MacLeod & J. P Thomas) The Eye as an Optical Instrument (J. P. Thomas) Sensitivity to Light (D. Hood & M. Finkelstein) Temporal Sensitivity (A. B. Watson) Seeing Spatial Patterns (L. Olzak & J. P Thomas) Colorimetry and Color Discrimination (J. Pokorny & V. Smith) Color Appearance (G. Wyszencki) Human Eye Movements (P. Hallett) BASIC SENSORY PROCESSES II (C. Sherrick & R. W Cholewiak) The Vestibular System (I. P. Howard) Cutaneous Sensitivity (C. Sherrick & R. W Cholewiak) Kinesthesia (F. J. Clark & K. W Horch) Audition I: Stimulus, Physiology, Thresholds B. Scharf & S. Buus) Audition II: Loudness, Pitch, Localization, Aural Distortion, Pathology (B. Scharf & A. Houtsma) SPACE AND MOTION PERCEPTION (H. A. Sedgwick) Motion Perception in the Frontal Plane: Sensory Aspects (S. Anstis) Perceptual Aspects of Motion in the Frontal Plane (A. Mack) The Perception of Posture, Self Motion, and the Visual Vertical (I. P. Howard) Motion in Depth and Visual Acceleration (D. M. Regan, et al.) Visual Localization and Eye Movements (L. Matin) Space Perception (H. A. Sedgwick) Representation of Motion and Space in Video and Cinematic Displays (J. Hochberg) Binocular Vision (A. Arditi) Adaptation of Space Perception (R. Welch) Intesensory Interactions (R. Welch & D. H Warren) Index.

Toward a Theory of Situation Awareness in Dynamic Systems

Abstract: This paper presents a theoretical model of situation awareness based on its role in dynamic human decision making in a variety of domains. Situation awareness is presented as a predominant concern in system operation, based on a descriptive view of decision making. The relationship between situation awareness and numerous individual and environmental factors is explored. Among these factors, attention and working memory are presented as critical factors limiting operators from acquiring and interpreting information from the environment to form situation awareness, and mental models and goal-directed behavior are hypothesized as important mechanisms for overcoming these limits. The impact of design features, workload, stress, system complexity, and automation on operator situation awareness is addressed, and a taxonomy of errors in situation awareness is introduced, based on the model presented. The model is used to generate design implications for enhancing operator situation awareness and future directio...

Is the P300 component a manifestation of context updating

Abstract: To understand the endogenous components of the event-related brain potential (ERP), we must use data about the components' antecedent conditions to form hypotheses about the information-processing function of the underlying brain activity These hypotheses, in turn, generate testable predictions about the consequences of the component We review the application of this approach to the analysis of the P300 component The amplitude of the P300 is controlled multiplicatively by the subjective probability and the task relevance of the eliciting events, whereas its latency depends on the duration of stimulus evaluation These and other factors suggest that the P300 is a manifestation of activity occurring whenever one's model of the environment must be revised Tests of three predictions based on this “context updating” model are reviewed Verleger's critique is based on a misconstrual of the model as well as a partial and misleading reading of the relevant literature

Guided Search 2.0 A revised model of visual search

Abstract: An important component of routine visual behavior is the ability to find one item in a visual world filled with other, distracting items. This ability to performvisual search has been the subject of a large body of research in the past 15 years. This paper reviews the visual search literature and presents a model of human search behavior. Built upon the work of Neisser, Treisman, Julesz, and others, the model distinguishes between a preattentive, massively parallel stage that processes information about basic visual features (color, motion, various depth cues, etc.) across large portions of the visual field and a subsequent limited-capacity stage that performs other, more complex operations (e.g., face recognition, reading, object identification) over a limited portion of the visual field. The spatial deployment of the limited-capacity process is under attentional control. The heart of the guided search model is the idea that attentional deployment of limited resources isguided by the output of the earlier parallel processes. Guided Search 2.0 (GS2) is a revision of the model in which virtually all aspects of the model have been made more explicit and/or revised in light of new data. The paper is organized into four parts: Part 1 presents the model and the details of its computer simulation. Part 2 reviews the visual search literature on preattentive processing of basic features and shows how the GS2 simulation reproduces those results. Part 3 reviews the literature on the attentional deployment of limited-capacity processes in conjunction and serial searches and shows how the simulation handles those conditions. Finally, Part 4 deals with shortcomings of the model and unresolved issues.

The Theory of Event Coding (TEC): a framework for perception and action planning.

Abstract: Traditional approaches to human information processing tend to deal with perception and action planning in isolation, so that an adequate account of the perception-action interface is still missing On the perceptual side, the dominant cognitive view largely underestimates, and thus fails to account for, the impact of action-related processes on both the processing of perceptual information and on perceptual learning On the action side, most approaches conceive of action planning as a mere continuation of stimulus processing, thus failing to account for the goal-directedness of even the simplest reaction in an experimental task We propose a new framework for a more adequate theoretical treatment of perception and action planning, in which perceptual contents and action plans are coded in a common representational medium by feature codes with distal reference Perceived events (perceptions) and to-be-produced events (actions) are equally represented by integrated, task-tuned networks of feature codes – cognitive structures we call event codes We give an overview of evidence from a wide variety of empirical domains, such as spatial stimulus-response compatibility, sensorimotor synchronization, and ideomotor action, showing that our main assumptions are well supported by the data

A sensorimotor account of vision and visual consciousness-Authors' Response-Acting out our sensory experience

Abstract: Many current neurophysiological, psychophysical, and psychological approaches to vision rest on the idea that when we see, the brain produces an internal representation of the world. The activation of this internal representation is assumed to give rise to the experience of seeing. The problem with this kind of approach is that it leaves unexplained how the existence of such a detailed internal representation might produce visual consciousness. An alternative proposal is made here. We propose that seeing is a way of acting. It is a particular way of exploring the environment. Activity in internal representations does not generate the experience of seeing. The outside world serves as its own, external, representation. The experience of seeing occurs when the organism masters what we call the governing laws of sensorimotor contingency. The advantage of this approach is that it provides a natural and principled way of accounting for visual consciousness, and for the differences in the perceived quality of sensory experience in the different sensory modalities. Several lines of empirical evidence are brought forward in support of the theory, in particular: evidence from experiments in sensorimotor adaptation, visual \"filling in,\" visual stability despite eye movements, change blindness, sensory substitution, and color perception.