Björn Breidegard

A communication structure for a multiprocessor computer with distributed global memory

An experimental multiprocessor computer was designed and built in order to explore the feasibility of certain internal communication mechanisms. The system consisted of seven processing elements, each containing a part of the global memory connected to a local bus. For each processor the global memory is seen as one single, linearly addressable structure. The processing elements were all connected to a common, global bus, consisting of three separate busses in order to increase the capacity. A bus selection unit was designed, capable of making a unique bus selection for each request, within a fraction of a memory cycle. The experiments have shown that communication structures based on distributed global memory and global bus systems can be used efficiently for medium scale systems.

Speakers’ Acceptance of Real-Time Speech Exchange Indicates That We Use Auditory Feedback to Specify the Meaning of What We Say

Speech is usually assumed to start with a clearly defined preverbal message, which provides a benchmark for self-monitoring and a robust sense of agency for one’s utterances. However, an alternative hypothesis states that speakers often have no detailed preview of what they are about to say, and that they instead use auditory feedback to infer the meaning of their words. In the experiment reported here, participants performed a Stroop color-naming task while we covertly manipulated their auditory feedback in real time so that they said one thing but heard themselves saying something else. Under ideal timing conditions, two thirds of these semantic exchanges went undetected by the participants, and in 85% of all nondetected exchanges, the inserted words were experienced as self-produced. These findings indicate that the sense of agency for speech has a strong inferential component, and that auditory feedback of one’s own voice acts as a pathway for semantic monitoring, potentially overriding other feedback loops.

TongueWise: Tongue-computer interface software for people with tetraplegia

Many computer interfaces and assistive devices for people with motor disabilities limit the input dimensionality from user to system, in many cases leading to single switch interfaces where the user can only press one button. This can, either limit the level of direct access to the functionalities of the operating system, or slow down speed of interaction. In this paper we present TongueWise: a software developed for a tongue computer interface that can be activated with the tip of the tongue and that provides direct input that covers most of the standard keyboard and mouse commands.

On the tip of the tongue: learning typing and pointing with an intra-oral computer interface

Abstract Purpose: To evaluate typing and pointing performance and improvement over time of four able-bodied participants using an intra-oral tongue-computer interface for computer control. Background: A physically disabled individual may lack the ability to efficiently control standard computer input devices. There have been several efforts to produce and evaluate interfaces that provide individuals with physical disabilities the possibility to control personal computers. Method: Training with the intra-oral tongue-computer interface was performed by playing games over 18 sessions. Skill improvement was measured through typing and pointing exercises at the end of each training session. Results: Typing throughput improved from averages of 2.36 to 5.43 correct words per minute. Pointing throughput improved from averages of 0.47 to 0.85 bits/s. Target tracking performance, measured as relative time on target, improved from averages of 36% to 47%. Path following throughput improved from averages of 0.31 to 0.83 bits/s and decreased to 0.53 bits/s with more difficult tasks. Conclusions: Learning curves support the notion that the tongue can rapidly learn novel motor tasks. Typing and pointing performance of the tongue-computer interface is comparable to performances of other proficient assistive devices, which makes the tongue a feasible input organ for computer control. Implications for Rehabilitation Intra-oral computer interfaces could provide individuals with severe upper-limb mobility impairments the opportunity to control computers and automatic equipment. Typing and pointing performance of the tongue-computer interface is comparable to performances of other proficient assistive devices, but does not cause fatigue easily and might be invisible to other people, which is highly prioritized by assistive device users. Combination of visual and auditory feedback is vital for a good performance of an intra-oral computer interface and helps to reduce involuntary or erroneous activations.

Disclosing the Secrets of Braille Reading—Computer-Aided Registration and Interactive Analysis

The pilot project reported here utilized the first technology ever developed for the computerized on-line registration and analysis of finger movements during Braille reading. Five congenitally blind subjects performed tactile reading of pedagogically carefully selected texts. Two specialists in visual impairments analyzed the computer-registered reading activities using specially designed interaction software. The subjects themselves were interviewed and contributed to discussions about their own individual reading styles. The analyses of this first handful of subjects reveal a number of important strategies and preferences with regard to on-line tactile reading. Further, the results challenge several assumptions and practices in Braille teaching. This pilot project lays the foundation for more comprehensive large-scale studies—both cross-sectional and longitudinal ones—studies long wanted in the domain of tactile reading.

BBDS-a design tool for architectural evaluation and rapid prototyping of performance critical digital systems

BBDS, an interactive graphical design tool for developing clock cycle true system models, is described. A design idea is entered through graphical interaction based on the Werner diagram. All important decisions about scheduling and allocation of operations are visually explicit. The design can rapidly be verified through simulation, timing analysis, area estimation and prototyping in programmable gate arrays. This allows very fast evaluation of an architectural idea, and allows for a series of fast iterative design improvements, BBDS also enforces a set of formally defined rules based on attributes of signals and component connectors to guarantee consistency of the clocking scheme. Both standard components and software can be accommodated. BBDS can be used to investigate the partitioning of a computer system into software and hardware, and is based on automatic synthesis with a user selectable target library.<<ETX>>

Auditory Feedback Is Used for Self-Comprehension: When We Hear Ourselves Saying Something Other Than What We Said, We Believe We Said What We Hear

Auditory Feedback Is Used for Self-Comprehension : When We Hear Ourselves Saying Something Other Than What We Said, We Believe We Said What We Hear

Computer-based automatic finger- and speech-tracking system

This article presents the first technology ever for online registration and interactive and automatic analysis of finger movements during tactile reading (Braille and tactile pictures). Interactive software has been developed for registration (with two cameras and a microphone), MPEG-2 video compression and storage on disk or DVD as well as an interactive analysis program to aid human analysis. An automatic finger-tracking system has been implemented which also semiautomatically tracks the reading aloud speech on the syllable level. This set of tools opens the way for large scale studies of blind people reading Braille or tactile images. It has been tested in a pilot project involving congenitally blind subjects reading texts and pictures.

Design for Me

In this paper, as a generative contrast to the notion of design “for all”, we present and discuss the potential benefits of a design “for me” approach, where the design process from the starts from, and initially is targeted at, just one person. Given many things developed for a user group or a constructed average user, in this text we describe starting from design for a single user as an alternative approach for achieving useful and useworthy designs. We provide an example from the development of an assistive device as the starting point and discuss how and why this alternative approach should be of interest for everyone interested in usability.

The Minimeter – Enabling communication technology for people with severe brain injuries

BACKGROUND: The Minimeter is a communication tool developed for people with severe brain injuries (almost no mobility, limited gaze control and eye blink ability, without speech, and with varying degrees of cognitive difficulties). Previously, they have not been able to communicate reliably even on a yes- or no-level. OBJECTIVE: To capture even minor movements intended for interaction and communication (starting at a yes-no level) with the environment or people around and to yield immediate and intuitive feedback to the users to help them develop both their abilities and ambitions. METHODS:Longitudinal iterative design of the appropriate communication technology in close collaboration with the intended users in their situated everyday life. RESULTS: During more than 13 years about 30 people with severe brain injuries have achieved new communication abilities through The Minimeter. The tool and its manual, utilizing the parallel advancements in overall computer and game technology, are now freely available as specially designed software for a standard PC with a web camera or accelerometer. CONCLUSIONS: The Minimeter opens up for learning and hope and provides earlier inaccessible possibilities for users with severe cognitive and mobile limitations to express and realize their needs, wishes and sometimes even dreams.