Richard A. Roemer

Relations between gross and unit evoked activity in pericruciate cortex of cat.

Abstract Single and multiple units, both cells of origin of pyramidal tract (PT) and unidentified units, were studied in relation to the local gross evoked potential to peripheral stimulation in pericruciate association cortex of the chloralosed cat. Both PT and non-PT cells were polymodal, with the PT cells firing later and for a longer duration. PT cells generate a near mirror image of the initial component of the evoked association potential. Spike height analysis on multiple unit data showed that small and large units had the highest probability of firing on the maximum negative slope and maximum negativity, respectively, of the evoked potential.

Habituation of the pyramidal response in unanesthetized cat

Abstract Evoked pyramidal activity characteristics in unanesthetized cats were studied in relation to the intensity and frequency of repeated somatic stimuli. An early component of the evoked pyramidal activity exhibited habituation while a later component showed sensitization. Both habituating and sensitizing components were affected by stimulus manipulations. The results are consistent with a dual-process theory of habituation.

A technique for quantifying and analyzing evoked responses

Two computer programs are discussed. One is used in the analog-to-digital conversion of and averaging of the responses; the other employs fuil-wave rectification and numerical integration as a method of comparing waveforms.

A low-cost integrated circuit comparator system

This paper describes a circuit that allows multiple-unit neural activity to be converted to standardized pulses for computer data acquisition. Positive or negative spikes can be converted at any voltage level from positive 25 V to. negative 25 V with visual identification of exactly where on the amplified spike potential conversion occurs. This circuit provides active output voltages compatible with TTL logic.

The use of on-line computers in psychobiology

This paper examines several areas in the use of laboratory computers in psychobiology, specifically how they are being used, the problems in languages and software, in interfacing computers to experimental configurations, and in the hardware involved. The paper defines the experimental tasks and data requirements which tend to distinguish computer usage in physiological research from other areas of psychology and the tasks which absolutely necessitate the use of a computer and in what mode. Finally we present our views of the dangers of computer use and misuse and make our own subjective evaluation of how well computers are living up to their end of the bargain, how well scientists are doing at their end, and where we should go from here.

A real-time control system for CAI and prothesis

An integrated hardware and software system was used for the real-time control of text display in a CAI environment. Reliability and cost considerations led to the development of a digital EOG transducer, which was used in conjunction with a KIM-1 microcomputer. This paper traces the development of that system from a complex and expensive PDP-11-based system to a microcomputer firmware approach. Such a system could, in real time, accomplish a similar display task for severely handicapped nonvocal individuals.