A device to enable the automatic recording of rodent ultrasonic vocalizations

The difficulty of recording rodent ultrasonic vocalizations simultaneously with other behavior patterns has been overcome by the use of the apparatus described. The electronic circuitry automatically digitally codes specified frequencies of rodent ultrasounds on a behavioral recording device. A reliability study of its performance in recording vocalizations of copulating Mongolian gerbils, during experimental tests, is also described.     

An inexpensive digital millisecond timer and event counter

A simple circuit for a digital millisecond timer and event counter is described. The total cost of the unit including all components, a power supply, and an enclosure is less than $30. Daily use in simple reaction time experiments has demonstrated the reliability of the design.     

On the time constants of tachistoscopes

The time constants of commercially available, electronic tachistoscopes are shown to be much poorer than is widely assumed. When a band near the centre of the visible spectrum is isolated, the output of a typical tachistoscope lamp takes approximately 18 ms to reach 90% of its asymptotic value; the time to decay to 10% is also typically 18 ms and we demonstrate conditions under which the decaying trace remains visually effective against a dark field for more than 40 ms after the nominal offset of the lamps.

Many reports of tachistoscopic experiments published in the last two decades must be quantitatively in error; and we provide examples of experiments where qualitative conclusions may have been drawn invalidly.     

Personality and conditioning: Factors of classical CR acquisition and extinction and their relationship to personality types

Anumber of psychophysiological, cognitive and personality measures, and classical appetitive and aversive SR acquisition and extinction rates were taken from a sample of 25 male undergraduate volunteers. Principal Components Analysis of the data revealed general acquisition and extinction factors which were indexed by the psychophysiological variables. Regression analyses showed additionally that Eysenck’s E-I dimension predicts both acquisition and extinction rates, and that imagery may be an important mediational variable in CR acquisition.     

Learning capacities during sleep: A preliminary study in a group of schizophrenic inpatients

The relationship between sleep and learning processes is analysed in a sample of schizophrenic patients, starting from more recent hypotheses about the function of REM sleep in learning and memory processes. This is done by means of two experiments: in the first AA. evaluate the possibility to elicit a simple motor conditional reflex acquired during daytime in different sleep stages. With the second experiment daytime learning performances are evaluated with and without a reinforcement administered during REM sleep. Results for the first experiment underline a qualitative difference between REM and nREM sleep in a reflexological perspective. In nREM sleep the conditional response is better maintained than in REM sleep. The second experiment confirms the possibility to improve daytime learning performances after an additional presentation of learning material in REM. The joint study of sleep abnormalities and learning and cognitive impairment in schizophrenic patients is finally suggested.     

YEPS: Running real-time experiments on a timesharing system

The Yale experimental programming system is described. This system consists of user-callable subroutines and a set of modifications to the UNIX operating system which support the development and execution of real-time psychology experiments. The interactions between a timesharing operating system and the provision of real-time facilities for experiments are discussed.     

A fish activity-monitoring device using a low-power infrared photobeam

An activity-monitor system for fish or other aquatic animals has been developed that uses a single low-level infrared (IRED) photobeam. The IRED source emits with a peak wavelength of 960 nm and requires only 70-mW average power input for an operating range of greater than 50 cm in sea water. This represents an order of magnitude reduction in power and more than a doubling of range over other reported designs. The cost for a single-beam channel is approximately $30.     

Microprocessors: Their impact on real-time computing in psychology

This paper attempts to evaluate the impact of microprocessors and other products using large-scale integrated circuit technologies with a set of examples of past, current, and proposed computer applications in psychological research. I first discuss a number of developments in real-time computing that have taken place during the last 10 years. The major part of this paper describes future developments in the Computer Laboratory for Instruction in Psychological Research. We are developing an intelligent high-speed communication network that will enable computers and terminals to communicate with each other. In addition, we are developing a microprocessor-based real-time computer system. The network, the real-time system, and the general assumption underlying the development of the next generation of CLIPR facilities are described.     

The quantitative measure of pattern representation in images using orientation-specific color aftereffects

A quantitative method is developed for assessing the quality of pattern information in imagery, using the magnitude of color aftereffects as an objective index. Subjects were given instructions to project imagined bar patterns of particular width and orientation onto adapting color fields, in such a manner as to simulate standard conditions for establishing the McCollough effect. Our control procedures indicate that the resulting orientation-specific complementary color aftereffects cannot be attributed to the conditioning of particular directions of eye scanning movements to color processing during adaptation, or to other possible sources of experimental bias. Furthermore, subjects who rated themselves prior to the adaptation procedure as having relatively vivid imagery showed significantly larger aftereffects than those who reported having relatively low imagery. These results not only provide an important confirmation of our earlier finding that imagination can replace physical pattern information in the formation of basic color-feature associations in the human visual system, but also demonstrate that these aftereffects can provide a practical measure of the fidelity of pattern representation in visual images.     

Perceptual invariance for stop consonants in different positions

The basis for the invariant perception of place of articulation in pre- and postvocalic stops was investigated using the selective adaptation paradigm. Experiments 1 and 2 considered the role of identical bursts, mirror-image formant transitions, and similar onset and offset spectra in the invariant perception of place of articulation in CV and VC stimuli, and Experiment 3 considered the importance of the second two cues in a VCV context. The results of these experiments suggest that, at the level of processing tapped by selective adaptation, neither identical bursts, mirror-image formant transitions, nor similar onset and offset spectra are the basis for the invariant perception of place of articulation in initial and final position. The vowel portion of an adapter was found to affect perception of the consonant portion of a stimulus, and the direction of this effect was predictable from the acoustic characteristics of the consonant and vowel. The implications of these findings for the nature of selective adaptation are discussed.