Measuring keyboard response delays by comparing keyboard and joystick inputs

The response characteristics of PC keyboards have to be identified when they are used as response devices in psychological experiments. In the past, the proposed method has been to check the characteristics independently by means of external measurement equipment. However, with the availability of different PC models and the rapid pace of model change, there is an urgent need for the development of convenient and accurate methods of checking. The method proposed here consists of raising the precision of the PC’s clock to the microsecond level and using a joystick connected to the MIDI terminal of a sound board to give the PC an independent timing function. Statistical processing of the data provided by this method makes it possible to estimate accurately the keyboard scanning interval time and the average keyboard delay time. The results showed that measured keyboard delay times varied from 11 to 73 msec, depending on the keyboard model, with most values being less than 30 msec.     

Performed or observed keyboard actions affect pianists' judgements of relative pitch

Action can affect visual perception if the action's expected sensory effects resemble a concurrent unstable or deviant event. To determine whether action can also change auditory perception, participants were required to play pairs of octave-ambiguous tones by pressing successive keys on a piano or computer keyboard and to judge whether each pitch interval was rising or falling. Both pianists and nonpianist musicians gave significantly more “rising” responses when the order of key presses was left-to-right than when it was right-to-left, in accord with the pitch mapping of the piano. However, the effect was much larger in pianists. Pianists showed a similarly large effect when they passively observed the experimenter pressing keys on a piano keyboard, as long as the keyboard faced the participant. The results suggest that acquired action–effect associations can affect auditory perceptual judgement.     

Social control by adult preference in operant conditioning with children

During daily sessions four institutionalized retardates and four normal, first-grade children each played a two-choice marble dropping game while an adult experimenter sat beside and watched. When one of two colored lights was presented, two tokens were dispensed as soon as the subject dropped a marble, and when the other light was on, one token was dispensed. During choice trials that were interspersed among single-colored trials the subject was required to choose one of the two different colored holes. After the subject developed a preference for the color that earned two tokens, the experimenter stated a preference for the response that earned only one token (i.e., “I like it better when you put it into the —colored hole.”) Six of the eight subjects immediately switched to the response that earned low magnitude reinforcement when the experimenter stated his preference. Only two subjects switched back to the response that earned high magnitude reinforcement when the experimenter left the room. Subjects complied with the experimenter's preference statement regardless of whether or not it also included a negative component (i.e., what the experimenter did not like). There were no systematic differences between mentally retarded and normal subjects.     

A simple and sensitive method to measure timing accuracy

Timing accuracy in presenting experimental stimuli (visual information on a PC or on a TV) and responding (keyboard presses and mouse signals) is of importance in several experimental paradigms. In this article, a simple system for measuring timing accuracy is described. The system uses two PCs (at least Pentium II, 200 MHz), a photocell, and an amplifier. No additional boards and timing hardware are needed. The first PC, a SlavePC, monitors the keyboard presses or mouse signals from the PC under test and uses a photocell that is placed in front of the screen to detect the appearance of visual stimuli on the display. The software consists of a small program running on the SlavePC. The SlavePC is connected through a serial line with a second PC. This MasterPC controls the SlavePC through an ActiveX control, which is used in a Visual Basic program. The accuracy of our system was investigated by using a similar setup of a SlavePC and a MasterPC to generate pulses and by using a pulse generator card. These tests revealed that our system has a 0.01-msec accuracy. As an illustration, the reaction time accuracy of INQUISIT for a few applications was tested using our system. It was found that in those applications that we investigated, INQUISIT measures reaction times from keyboard presses with millisecond accuracy.     

Some experiments on the organization of a class of imitative behaviors

A retarded child was taught to imitate diverse demonstrations made by an experimenter, until new demonstrations were imitated correctly upon first presentation without direct training. These imitations could be maintained without reinforcement, when they were distributed among other reinforced imitations. Factors responsible for the continued performance of these unreinforced imitations were examined. When subjected to massed extinction trials, unreinforced imitations eventually disappeared; they reappeared when again interspersed among reinforced imitations. In addition, the stimulus function of "similarity of response between subject and experimenter" was examined. The subject was taught a set of non-imitative responses, through discriminative stimuli controlled by the experimenter, and a comparable imitative set. Unreinforced non-imitations, like reinforced imitations, were maintained only when interspersed among reinforced imitations. When all reinforcement was discontinued, all responses extinguished similarly, indicating that reinforcement was necessary to maintain the response-class organization, but not confirming an essential role for "similarity" as such.     

A vigilance task sensitive to the effects of stimulants, hypnotics, and environmental stress: The Scanning Visual Vigilance Test

The Scanning Visual Vigilance Test is a variable-length detection test designed to assess the ability of individuals to maintain visual alertness for sustained periods of time. The test was designed to be sensitive to changes in vigilance produced by subtle variations in performance, such as those produced by low doses of centrally acting food constituents, drugs, or environmental stress. The test has been shown to be sensitive to the effects of stimulants and sedatives, as well as cold stress and sleep loss. It requires the subject to continuously scan a video monitor to detect the occurrence of infrequent stimuli that are difficult to detect. The number of stimuli correctly detected, false alarms, and reaction times are recorded. The stimulus is a small rectangle displayed for 2 sec at random locations on a darker region of a video monitor at random or pseudo-random times. The brightness of the stimulus can be adjusted for each subject individually on an automated threshold detection test. Training and test session length are defined by the experimenter. Hardware requirements are an IBM-compatible personal computer (286 or higher) with a color or grayscale VGA monitor.     

THE TRAINING AND GENERALIZATION OF A CONVERSATIONAL SPEECH FORM IN NONVERBAL RETARDATES1

Differential reinforcement and imitation were used with two retarded children to train three sequential verbal responses associated with the display of a picture and questions related to that picture. Each response consisted of a three-word chain in sentence form; combined with verbal responses from the experimenter, this trained sequence formed a short conversational unit. Three experimenters measured the use of each sentence in settings different than the one in which training took place, and with pictures different than those used during training. Two types of generalization sessions were used: (1) General sessions, during which 10 pictures never used during training were displayed to the subject with reinforcement delivered on a noncontingent basis, and (2) Intermixed sessions, during which 10 pictures never used during training were displayed to the subject, but a picture having received training was also displayed, and correct responses to this picture were reinforced on a variable schedule. Both subjects learned the sentences being trained. However, little generalization was evident from this training when all experimenters conducted General probe sessions. Generalization occurred with one experimenter only after that experimenter conducted Intermixed probe sessions. Generalization to a third experimenter was then observed (i.e., after the first two experimenters had conducted Intermixed probe sessions) without the use of Intermixed probe sessions by this third experimenter.     

Programming without programming: The system Butterfly for professional psychologists

This paper describes a system for creating and running adaptive psychological experiments on IBM PC compatible computers. The system is a collection of programming routines for IBM PC machines (text mode) that allows psychologists to create and edit experiments, collect and handle data, and transfer data into other systems without any programming. Stimulus variables include location, character, time, color, and sound. A special set of criteria is designed to conduct adaptive studies, such as operant conditioning experiments, in which experimental trials must be modified on the basis of a subject’s performance. The system supports multidimensional structural responses with feedback. Reaction and response time and the response contents can be collected from the keyboard, mouse, and game port.     

Tachistoscopic presentation and millisecond timing on the IBM PC/XT/AT and PS/2: A Turbo Pascal unit to provide general-purpose routines for CGA,Hercules, EGA,and VGA monitors

A review of the literature on adopting microcomputers for use in tachistoscopic research paradigms illustrates the need for a comprehensive package to effectively deal with the wide variety of video displays and microcomputers used in experimental settings. In addition, because of the large number of possible configurations created when video displays and computer systems are combined, there is a need to be able to efficiently drive any such combination without rewriting program code. A Turbo Pascal unit is presented to provide standard tachistoseopic routines compatible with monochrome, CGA, Hercules, EGA, and VGA video technology. Procedures that synchronize both text and graphics mode stimuli with the vertical retrace pulse are given, as are routines to provide access to a timer with better than millisecond precision. Pascal code is described that will run on the IBM PC, XT, AT, or PS/2, as well as on any compatible machine. The versatility of the unit allows the experimenter to use generic video and timer commands that will automatically adapt at run time to the system that is being used, without further experimenter intervention.     

Unprompted recall and reporting of hidden objects by a chimpanzee (Pan troglodytes) after extended delays

The ability to recall features of environments not present to the senses is important in human thinking, planning, and communication, but to date there are almost no data on recall capabilities in nonverbal animals. In this study, the author used symbol knowledge as a tool to study chimpanzee memory. An 11-year-old female chimpanzee (Pan troglodytes) that had already learned a large number of arbitrarily designated geometric forms (lexigrams) watched as an experimenter hid an object in the woods outside her outdoor enclosure. The type and location of the object varied across trials. After an imposed delay of up to 16 h, the chimpanzee could interact indoors with a person who did not know that an object had been hidden, let alone the type or location of the object. A keyboard in the indoor cage displayed 256 lexigrams. From Trial 1, the chimpanzee seemed to do whatever it took to catch the person's attention and then touched the lexigram corresponding to the type of object hidden, pointed outdoors, went outdoors (if followed), and continued to point manually toward the object and vocalize until the person found the object. The subject indicated nonfood objects as well as more than 20 food types.     

Determinants of confirming and disconfirming responses to negative social labels

Two experiments explored the question of when people will respond to negative labels by confirming them and when they will respond by disconfirming them. In a field experiment subjects were accused of not taking advantage of the opportunities available in a nearby city, and in a laboratory experiment they were accused of having low self-confidence. After these accusations, subjects were given an opportunity to behave in ways that varied in the degree to which they were consistent with the experimenter's labels. For some subjects the experimenter's accusations included mention of the fact that the negative label also applied to many other members of their group, while for other subjects this group factor was not mentioned. The reference to the group either increased or decreased subjects' label-confirming behavior, depeding on whether the subject had provided the experimenter with evidence consistent with the label before the accusations were made. When the experimenter had this evidence, subjects subsequently confirmed the label more if the fact that the negative label applied to many group members was mentioned than if it was not mentioned. When the experimenter accused the subject without having any evidence, subjects disconfirmed the label more if the group was mentioned than if it was not.     

The surreptitious observation design: an experimental paradigm for distinguishing artifact from essence in hypnosis

Administered a hypnotic induction and 5 standard hypnotic suggestions twice via audiotape to a group of high-hypnotizable subjects and a group of low-hypnotizable simulators. During the first administration, subjects were led to believe that they were alone. However, their behavior was surreptitiously recorded on videotape and observed on a video monitor. The second administration occurred in the presence of an experimenter who had not been informed of group assignment. When unaware that they were being observed, simulators were significantly less responsive to suggestions than they were when openly observed. In contrast, the behavior of nonsimulating subjects was not affected by the presence of an experimenter. These data indicate that the responses of highly hypnotizable subjects to standard hypnotic suggestions cannot be accounted for in terms of simple compliance with experimental demand.     

Effect of VDT keyboard height and inclination on musculoskeletal discomfort for wheelchair users

This study investigated the effect of keyboard height and inclination on musculoskeletal discomfort for wheelchair users. Eight Taiwanese male wheelchair users (28.75 +/- 8.75 years) were recruited as participants to perform nine experimental combinations of data entry tasks. Three keyboard heights and three inclinations were evaluated. Musculoskeletal discomfort was estimated by Rating of Perceived Exertion and Subjective Preference Ranking. Each subject performed a data entry task for all nine experimental combinations in a random order. The seated posture of all participants during the data entry operation was the upright posture. The height of the screen's center was adjusted according to the eye level of each subject. Analysis showed the keyboard height and keyboard inclination significantly affected rating of musculoskeletal discomfort. It is suggested that the optimum keyboard height choice is elbow-level height or 5 cm below elbow level with the keyboard inclination horizontal to the seat of the wheelchair.     

THE ROLE OF SUBJECT VERBALIZATION IN GENERALIZED CORRESPONDENCE

We examined the role of subject verbalization in the generalization of verbal-nonverbal correspondence. Twelve kindergarten children underwent correspondence training (subject verbalization) or received reinforcement for performing an experimenter-selected behavior (experimenter verbalization). A reversal design, along with the introduction of a multiple baseline design across behaviors, was used to assess functional relations. Pupils who received correspondence training demonstrated greater generalization. Our findings suggest that subject verbalization may be necessary to accomplish generalized correspondence.     

An inexpensive CRT terminal controller/computer

An inexpensive CRT terminal controller/computer is described. The board integrates virtually any keyboard and CRT monitor into a work station with firmware-governed intelligence. The system is designed to fill the cost/functionality niche below the Apple microcomputer. It can be configured as a dumb or smart terminal (approximately $100 plus keyboard and CRT monitor), as a self-contained computer that runs ROM-based software such as a small BASIC or an assembler/disassembler fan additional $100 in chips), or as a word processor if aa audio cassette ($50) or dual digital cassettes with controller ($125) are added.     

Measuring the stop point of rapid smoking

A method and an apparatus are described for measuring the point at which subjects elect to stop smoking when cigarette smoke is delivered more rapidly than in typical smoking. The device allows either the subject or the experimenter to control the volume of smoke and the interval between puffs. The device delivers reliable quantities of particulate matter from cigarette smoke. Subjects retested a week apart exhibited consistent stopping points.     

An analysis of generalized imitation

An experimenter presented English words to three intermediate-level children and reinforced accurate imitation of these words. The experimenter also presented novel Spanish words, but the imitation of these words was never experimentally reinforced. One subject quickly ceased performing non-reinforced imitative responses. The other two subjects were exposed to a series of conditions designed to facilitate discrimination. Upon observing the first subject for one session they immediately ceased imitating Spanish demonstrations. For all three subjects, when reinforcement was delivered for responses other than imitation, all imitative responses eventually ceased. When reinforcement was reintroduced for English imitations there was an immediate resumption of such responses to their previous 100% level. The occurrence of non-reinforced imitations in this and previous studies was discussed as being a function of one or combination of four variables: (1) similarity acquiring conditioned reinforcing properties, or (2) instructional, (3) coincidental, or (4) conditional stimulus generalization.     

Imitation of Self-Stimulation:

Three autistic children participated in single subject, reversal designs to compare the impact of over correction and adult imitation on self-stimulation. In addition to continuous 10-second observations of frequency of self-stimulation during 10 minute sessions, experimenter and observer also rated the child's mood, attention to the experimenter and quality of attention paid. The order of interventions was randomized fro each subject with baseline preceding each intervention. Although each child's response pattern was unique, the data showed systematic changes in rates of self-stimulation across conditions for two of the children with mean levels of self-stimulation declining during the over correction procedure and increasing during imitation. There were parallel changes in mood and attention with all three children appearing “happiest” and most attentive when their self-stimulatory behavior was imitated by the adult. These results raise interesting possibilities for using adult imitation as a vehicle for establishing a reinforcing relationship with the autistic child.     

A portable device for group modification of classroom attending behavior

There is a need for a portable means of signalling appropriate classroom behavior that the teacher can carry with her as she moves about the room. An inexpensive wireless switch, adapted for classroom use, was used to turn on a clock when all children were attending to their work. When a movie was made contingent on accumulating a specific number of minutes on the clock, class-attending increased. Throughout these conditions, the records of class attending made by an independent observer with a stopwatch correlated highly with the remote controlled clock.