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.     

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.     

An investigation of the perceptual basis of redundancy gain and orthogonal interference for integral dimensions

Redundancy gain and orthogonal interference for height and width were demonstrated in two experiments using a relative coding task with number of intertrial repetitions controlled. Orthogonal interference was shown to be perceptually based rather than simply an intertrial repetitions effect as suggested by Felfoldy (1974). These results from a relative coding task were discussed in terms of the previous multidimensional processing literature. It was concluded that Lockhead’s (1972t model has been applied too generally. An alternative model (a parallel, dimensional analysis stage followed by a stage in which dimensional information is integrated) was suggested.     

Attribute models and the effect of frequency and imagery values on word recognition

Recent explanations of the word frequency effect in recognition studies (Gregg 1976; Glanzer and Bowles 1976) state that this effect occurs because words of high and low frequency differ in encoding variability and number of associative relations. These models suggest that the different recognition scores of high and low frequency words are the result of both more hits and less false positives on words that have a low frequency of occurence. As Morris (1978) showed, these models can also be applied on the effect of word imagery values on recognition performance.In the first experiment to be reported here the differential effects of words of high and low frequency and imagery values on hit and false positive rates were examined. The predicted results concerning high and low imagery values were indeed found, but the predictions with respect to high and low frequency words were not completely substantiated. However, it was shown that this deviation can be explained by a response bias effect.In a second experiment an assumption concerning the underlying distributions of high and low imagery ‘old’ and ‘new’ items was tested. In accord with the expectation it was found that the distributions of ‘old’ high and low imagery words did not differ, but that there was a clear difference in the distributions of ‘new’ high and low imagery words.     

Memory for movement: Interaction of location and distance cues and imagery ability

The present experiments examined the role of imagery ability in recall of either the terminal location or the distance of a preselected horizontal linear movement following changes in the recall starting position. Subjects were selected on the basis of their scores on a shortened version of the Betts Questionnaire upon Mental Imagery (Betts Q.M.I., Sheehan 1967). Both high and low imagers were assigned to one of four groups, HIL, LIL, HID, LID, the last letter indicating the movement cue (terminal location or distance moved) to be recalled. Recall of the appropriate movement cue from one of four new recall starting positions occurred after either a 5-sec or 30-sec unfilled retention interval. Analysis of constant error indicated all groups were unable to recall the specified movement cue independent of the other source of information, even when subjects were given explicit instructions to utilise an imagery strategy. The data corroborate our earlier findings that memory for self paced movements is based on an interaction of location and distance cues derived from the criterion movement.