Computer workstations: Explorations in human and machine cognition

Professional and scientific work will increasingly be conducted at computer workstations. An expert-system adaptive interface is one method for supporting learning and raising productivity of workstation activities. A prototype application for an adaptive interface is described in terms of machine intelligence, needs, design philosophy, and cognitive research. The intelligent interface prototype includes the operator’s psychometric profile, prior performance history, and a current keystroke performance stack within a conventional expert system. Productions in the form of conditionals between the operator’s keystrokes and three types of commands to the underlying software are described and illustrated. Commands entered, syntax errors, excessive repetition of keystrokes, and skill level are used to detect the user’s intentions and accordingly modify the display and command structure of the underlying software. Determining human intentions to produce machine adaptation to individual users is not a trivial task. Efforts to develop a powerful and general adaptive interface pose significant problems, and success cannot be assured without intensive cognitive research.     

Taming the Heathkit-Votrax speech synthesizer

Three inexpensive text-to-speech synthesizers are described, intelligibility data from a pilot experiment are reported, and software is offered that has been written to facilitate the phonemic programming of the Heathkit-Votrax synthesizer.     

A Commodore 64-based interface system for the operant laboratory

A system of interfaces for the Commodore 64 (C-64) microcomputer for use in the operant laboratory is described. This system frees the experimenter from limitations on the number of I/O lines available on the user port of the C-64 and offers the control of operant chambers for a low cost. Subroutines in machine code to control the interfaces, offering millisecond timing of external events, are presented. A sample BASIC program demonstrates how the subroutines are called from BASIC to run a simple discrimination experiment.     

Monocular without stereopsis with and head movement

Random dots moving with various velocity gradients were presented to observers; the motion was yoked to head movement in one condition and to no head movement in another. In Experiment 1, 12 observers were shown motion gradients with sine, triangle, sawtooth, and square waveforms with amplitudes (equivalent disparities) of 12′ and 1° 53′. In Experiment 2, 48 observers were shown only the sinewave or square-wave gradient of 1° 53′ disparity either with or without head movement so that the observers’ expectation to see depth in one condition did not transfer to another. The main findings were: (1) with 12′ disparity, the head-movement condition produced perceived depth but almost no perceived motion, whereas the no-head-movement condition produced both perceived depth and perceived motion; (2) with 1° 53′ disparity, both conditions produced perceived depth and perceived motion; and (3) when the expectation to see depth was removed, the no-head-movement condition with the square-wave gradient produced no perceived depth, only motion. We suggest that monocular stereopsis with head movement can be achieved without perception of motion but monocular stereopsis without head movement requires perception of motion.     

The orienting response,and future directions of its development

The orienting response (OR) is a specific behavioral act directed towards extraction of information from the environment. Head and eye movements represent only the tip of the iceberg of internal responses, which includes vascular modifications, EEG changes, and event-related potentials. Two mechanisms of the OR have to be differentiated: voluntary and involuntary. In the event-related potential, such a differentiation is expressed in mismatch negativity (involuntary effect) and processing negativity (voluntary effect). Single unit studies have shown that hippocampal neurones are simulating specific features of the OR as a response to novelty. Repeated presentation of stimuli results in a selective habituation of novelty detectors in hippocampus and of the OR. The trace of a standard stimulus formed at the level of hippocampal neurones matches the features of the standard stimulus and can be called a “neuronal model of the stimulus.” The OR is triggered by mismatch between the test stimulus and the elaborated neuronal model, and is activated by verbal instruction, by reinforcement during the initial stage of conditioned reflex elaboration, and by differentiation of signal and non-signal stimuli. A promising new area of practical application of the OR lies in the evaluation of a corridor of optimal functional state for efficient computer-based learning. Registration of the OR and defensive responses can be used for an objective evaluation of the functional state of the student, or, in a wider sense, of the industrial operator. New avenues of OR research are opened by recent techniques that isolate single-trial event related potentials, and their correlation with autonomic and behavioral manifestations of the OR. The combination of single unit recording with such isolated event related potentials can elucidate the neuronal basis of OR generation. Intracellular recording combined with dye injection can be used for analysis of the synaptic contacts involved in generation of the OR. Integration of macro and micro levels of OR organization can be achieved in a computerized model that can be used for simulation and planning of experiments. A step-by-step improvement of the model will accumulate knowledge about the OR as an important mechanism of information processing.     

Development of Standard Anchors for Scoring Generic Past-Behaviour Questions in Structured Interviews

A structured interviewing system was developed which included an item bank of pre-written past-behaviour questions. Scoring anchors for each of 168 questions in the item bank were created from analysis of protocols from individual assessments. A concurrent validation study was conducted, focusing on the job of highway patrol sergeant. Job knowledge experts used a job analysis tool to select a subset of twelve questions from the item bank. Panel interviews were conducted with 32 highway patrol sergeants as subjects. Average inter-rater reliability was 0.65 and interview validity was 0.42 for group consensus scores and 0.44 for panel average scores. Discussion focused on practical issues affecting the interviewing system.