Non-aging fore-periods and simple reaction time

This study deals with the relationship between the momentary objective probability of the delivery of a stimulus and the reaction time in a simple reaction-time task. The hypothesis was that the reaction time is closely related to the objective probability via expectancy i.e., the momentary probability of the delivery of the stimulus as experienced by the subject. This problem was experimentally approached from two directions: (1) by varying the objective probability, in which case the reaction times should change inversely with the objective probability, and (2) by keeping the objective probability constant (by using the Bernoulli process), in which case the reaction times should not change. Eight male subjects were used. The first assumption proved to be correct, whereas the second held only when certain mean inter-stimulus intervals were used.     

Cardiac activity in a simple reaction time task

Twenty subjects, half having high extraversion and the other half having low extraversion scores on the Eysenck Personality Inventory, performed a simple reaction time task in which the warning stimulus was a light and the imperative stimulus was a tone. Beat-by-beat analysis showed significantly different response patterns between the two groups in time of onset, magnitude, and duration of the cardiac responses. The extraversion measures were found to relate to central-nervous-system-strength types and to indicate relative strength of central inhibitory processes, as reflected by cardiac activity.     

Visual temporal integration and simple reaction time

Intensity-time reciprocity for simple RT to foveal pulses of light was demonstrated up to 11 msec by using two experimental paradigms. The first paradigm was designed to separate two possibly confounded factors displayed by previous studies investigating the effects of increased stimulus duration on RT: (1) an asymptotic RT as a function of the increasing energy of a pulse as its duration is increased, and (2) the breakdown of integration as the pulse duration is increased. The second paradigm was designed to avoid the first factor so as to maximize the possibility of finding partial integration at long durations. In this paradigm, partial integration was demonstrated for additional light input presented as long as 64 msec after stimulus onset. The failure of other studies to demonstrate temporal integration for RT is discussed in terms of these paradigms.     

Wavelength effects on simple reaction time

Simple reaction time was measured to spectral lights matched photometrically in luminance. When these lights were presented on a dimmer achromatic background, reaction time did not vary as a function of wavelength. Moreover, reaction times to white and chromatic lights were the same. When the luminance of the background was the same as that of the chromatic lights, reaction time increased and showed a strong effect of wavelength. Reaction time in this condition appeared to follow a saturation function. The results are described in terms of the operation of achromatic and chromatic processing channels.     

Cardiac-somatic changes during a simple reaction time task: A developmental study

The relationship during a simple reaction time task between heart rate and four measures of task irrelevant somatic activity was evaluated in four age groups of children, i.e., 4-, 5-, 8-, and 10-year-olds and young adults, in order to evaluate further a hypothesized coupling of cardiac and somatic activity. At all age levels, phasic decreases in both heart rate and somatic activity coincident with performance were found with the magnitude of the effect increasing with age only on three somatic measures. However, tonic levels of both heart rate and somatic activity decreased with age. Performance on the reaction task was found to be inversely related to the age-related phasic somatic effects as well as age-related tonic heart rate and somatic activity.     

Performance on a simple reaction time task while sleep deprived

Divergent results have been reported on the effect of a night's sleep loss on performance of a single monotonous task. The present experiment examined the effect that partial sleep deprivation had on 10 participants' performance on a simple reaction time task requiring low responding for 120 min. compared to performance on the same task when well rested. Participants missed significantly more signals and had slower reaction times when sleep deprived. Reaction times increased with time when participants were both sleep deprived and rested, but the number of misses did not significantly change over time. Reaction time was significantly correlated with subjective ratings of sleepiness and heart rate in both conditions. EEG and heart-rate variability measures did not correlate significantly with reaction time. Misses correlated significantly with subjective ratings and heart rate but only in the rested condition.     

A free, easy-to-use, computer-based simple and four-choice reaction time programme: the Deary-Liewald reaction time task

Reaction time tasks are used widely in basic and applied psychology. There is a need for an easy-to-use, freely available programme that can run simple and choice reaction time tasks with no special software. We report the development of, and make available, the Deary-Liewald reaction time task. It is initially tested here on 150 participants, aged from 18 to 80, alongside another widely used reaction time device and tests of fluid and crystallised intelligence and processing speed. The new task’s parameters perform as expected with respect to age and intelligence differences. The new task’s parameters are reliable, and have very high correlations with the existing task. We also provide instructions for downloading and using the new reaction time programme, and we encourage other researchers to use it.     

On the peculiarity of simple reaction time

Two experiments are reported in which high-compatibility reaction time (RT) tasks were performed with, and without, a concurrent secondary task. In both experiments, the secondary task interfered to a greater extent with simple RT than with choice RT. In fact, the effect of adding a secondary task was to eliminate the advantage of simple RT over two-alternative-choice RT. Previous studies of this phenomenon employed a task in which subjects raised a finger when it received tactile stimulation, while engaging in continuous reading aloud. The present experiments show that the effect can be obtained using a different stimulus modality (vision) as well as other responses (vocal) and secondary tasks (shadowing, auditory step-tracking). The paradigm provides a means of isolating preparatory processes that are peculiar to the simple RT task.     

Input-output relations in simple reaction time experiments

The isotonic muscular effort was measured from the thenar muscles of human subjects during simple reaction time experiments. It was found that the output (θ) was related to the input (φ) by a simple power law, i.e. θ = φⁿ for visual, auditory and electrical stimuli applied to the digits. The exponents found were 0.21, 0.11 and 1.04 for auditory, visual and electrical stimuli respectively. Although different from those determined by Stevens for the transformation of the input energy to a psychological magnitude, their relative values are almost identical.     

On the ability to inhibit simple and choice reaction time responses: a model and a method

This article reports four experiments on the ability to inhibit responses in simple and choice reaction time (RT) tasks. Subjects responding to visually presented letters were occasionally presented with a stop signal (a tone) that told them not to respond on that trial. The major dependent variables were (a) the probability of inhibiting a response when the signal occurred, (b) mean and standard deviation (SD) of RT on no-signal trials, (c) mean RT on trials on which the signal occurred but subjects failed to inhibit, and (d) estimated RT to the stop signal. A model was proposed to estimated RT to the stop signal and to account for the relations among the variables. Its main assumption is that the RT process and the stopping process race, and response inhibition depends on which process finishes first. The model allows us to account for differences in response inhibition between tasks in terms of transformations of stop-signal delay that represent the relative finishing times of the RT process and the stopping process. The transformations specified by the model were successful in group data and in data from individual subjects, regardless of how delays were selected. The experiments also compared different methods of selecting stop-signal delays to equate the probability of inhibition in the two tasks.     

Binaural loudness gain measured by simple reaction time

In order to yield equal loudness, different studies using scaling or matching methods have found binaural level differences between monaural and diotic presentations ranging from less than 2 dB to as much as 10 dB. In the present study, a reaction time methodology was employed to measure the binaural level difference producing equal reaction time (BLDERT). Participants had to respond to the onset of 1-kHz pure tones with sound pressure levels ranging from 45 to 85 dB, and being presented to the right, the left, or both ears. Equal RTs for monaural and diotic presentation (BLDERTs) were obtained with a level difference of approximately 5 dB. A second experiment showed that different results obtained for the left and right ear are largely due to the responding hand, with ipsilateral responses being faster than contralateral ones. A third experiment investigated the BLDERT for dichotic stimuli, tracing the transition between binaural and monaural stimulation. The results of all three RT experiments are consistent with current models of binaural loudness and contradict earlier claims of perfect binaural summation.     

The motor system in simple reaction time experiments

In this paper evidence is presented that the variability of the motor system does not play an important role in the variability of simple reaction time. Many studies refer to this fact which, however, seems contradictory to electrophysiological data. A model is proposed for the operation of the motor system in simple reaction time experiments which consistently links single cell neuronal activity with electromyographic activity and with response time. It appears that the motor system subserving simple reactions consists of many elements which once triggered produce a mechanical response well defined in time despite the fact that the elements themselves show a rather large time jitter.     

On measuring the minimum detection time: A simple reaction time study in the time estimation paradigm

Kornblum's time estimation paradigm, together with the so‐called ‘race model’, provides an appealing alternative for measuring the ‘cut‐off’ which separates ‘true’ reaction times from anticipatory reaction times. However, the model is not precise enough to reveal the relation between the signal intensity and the ‘cut‐off’. Accordingly, Kornblum's model is extended with an emphasis on the measure of the ‘cut‐off’. Another aspect of the extension is to use a parametric method to analyse the data. In particular, it is assumed that the time estimation‐induced latency is gamma distributed and the signal‐induced latency is Weibull distributed, with the latter shifted by the ‘cut‐off’. The rationale behind the parametric assumption is discussed. For illustrative purposes, two pieces of experimental work are presented. Since the core of the race model is the assumption of an independent race between the time estimation process and the detection process, the first experiment tests whether, for the same signal intensity, the signal‐induced latency distribution is invariant across different time intervals; the second experiment tests whether, for the same time interval, the time estimation‐induced latency distribution is invariant across different signal intensity conditions. The data from the second experiment are also used to test various parametric assumptions in the model, which include the signal effect on the ‘cut‐off’. The new model fits the data well.