What speeds up the internal clock? Effects of clicks and flicker on duration judgements and reaction time

Four experiments investigated the effect of pre-stimulus events on judgements of the subjective duration of tones that they preceded. Experiments 1 to 4 used click trains, flickering squares, expanding circles, and white noise as pre-stimulus events and showed that (a) periodic clicks appeared to “speed up” the pacemaker of an internal clock but that the effect wore off over a click-free delay, (b) aperiodic click trains, and visual stimuli in the form of flickering squares and expanding circles, also produced similar increases in estimated tone duration, as did white noise, although its effect was weaker. A fifth experiment examined the effects of periodic flicker on reaction time and showed that, as with periodic clicks in a previous experiment, reaction times were shorter when preceded by flicker than without.     

Stop the clock because I can’t stop: time pressure,but not monitoring pressure,impairs response inhibition performance

ABSTRACT

Psychological pressure can exert detrimental effects on cognitive tasks that depend on attentional control. However, the effect of psychological pressure on inhibitory cognitive processes has been relatively overlooked. The study purpose was to examine the effect of psychological pressure on response inhibition. In Experiment 1, participants (N?=?125) were assigned to a combined time and performance-based incentive pressure condition or control condition. In Experiment 2, participants (N?=?124) were allocated to a time pressure only or control condition. Participants (N?=?149) in Experiment 3 were assigned to either an explicit monitoring pressure condition in which their performance was video-recorded or control condition. Participants in all experiments completed a Go/NoGo Task to assess response inhibition performance. Pressure impaired performance in Experiments 1 and 2 but not Experiment 3. The results demonstrate that time pressure, but not explicit monitoring pressure, significantly impairs inhibition accuracy. These findings are consistent with the distraction theory of performance pressure.     

On the relation between stimulus intensity and processing time: Piéron’s law and choice reaction time

Piéron (1914, 1920, 1952) demonstrated that simple reaction time (SRT) decays as a hyperbolic function of luminance in detection tasks. However, whether such a relationship holds equally for choice reaction time (CRT) has been questioned (Luce, 1986; Nissen, 1977), at least when the task is not brightness discrimination. In two SRT and three CRT experiments, we investigated the function that relates reaction time (RT) to stimulus intensity for five levels of luminance covering the entire mesopic range. The psychophysical experiments consisted of simple detection, two-alternative forced choice (2 AFC) with spatial uncertainty, 2 AFC with semantic categorization, and 2 AFC with orientation discrimination. The results of the experiments showed that mean RT increases with task complexity. However, the exponents of the functions relating RT to stimulus intensity were found to be similar in the different experiments. This finding indicates that Piéron’s law holds for CRT as well as for SRT. It describes RT as a power function of stimulus intensity, with similar exponents, regardless of the complexity of the task.     

Is the reaction time-movement time relationship 'essentially zero'?

It was hypothesized that, if RM-MT correlations are "essentially zero," then the magnitude of that correlation should not be subject to variation due to the manipulation of various experimental variables. In this experiment, Ss were tested with either RT-MT together or done separately. Results indicated significant relationships for 18 males but not for 18 females. The "essentially zero" position was discussed as being procedurally specific.     

The “concept of time” and the “being of the clock”: Bergson, Einstein, Heidegger, and the interrogation of the temporality of modernism

The topic to be addressed in this paper, that is, the distinction between the “concept” of time and the being of the clock, divides into two parts: first, in the debate between Albert Einstein and Henri Bergson, one discovers the ground for the diverging concepts of time characterized by physics in its opposing itself to philosophy. Bergson’s durée or “duration” in opposition to Einstein’s ‘physicist’s time’ as ‘public time,’ one can argue, sets the terms for Martin Heidegger’s extending, his ontological analysis of Da-sein, as human being-in-the-world. Second, in this the ‘concept of time’ gives way to the analysis of the ‘being of the clock.’ What is this being of the clock that makes evident the fundamental temporality of Da-sein? This question is rehearsed in Division Two of Being and Time. My claim is that the fundamental insight into the nature of time revealed by the encounter between Bergson and Einstein is that time extemporizes itself. Temporality “is” not a being but a process that temporalizes itself, precisely because it “is not.”     

Common features of the “repetition” and “same-different” effects in reaction time experiments

Using comparable stimulus and response sets, and the same Ss, the “repetition” and “same-different” effects were studied in two experiments involving several reaction-time (RT) tasks. In Experiment 1, these effects were examined at a 2-sec interval between successive stimuli in the simple (SRT), the recognition (RRT), the choice (CRT), the same-different recognition(S-DRRT),and the same-different choice (S-DCRT) tasks. In Experiment 2, the effects were studied at a 1 O-sec interval in the CRT and S-DCRT tasks. The results suggest the following mainconclusions: (1)The positive repetition effect (i.e., shorter reaction times on “repeated” trials than on “nonrepeated” trials) is not only a feature of the CRT task but may also occur in the SRT and RRT tasks. (2) With increasing intertrial interval, the magnitude of the positive repetition effect diminishes and then reverses into a negative repetition effect. (3) The positive same-different effect (ie., shorter reaction times on “same” trials than on “different” trials) is affected by an increase in interstimulus interval ina manner that parallels the effect of intertrial interval on the positive repetition effect, suggesting that the processes underlying the two effects are mainly the same. (4) These changes in the magnitude and direction of the repetition and same-different effects are probably a function of discrimination difficulty.     

Pigeon reaction time, Hick’s law, and intelligence

Pigeons' choice reaction times (RTs) increased as a linear function of log2 number of potential target stimuli (Experiments 1-3), as would be predicted by Hick's law. The values of intercepts and slopes decreased with training (Experiments 2 and 3) and with differential reinforcement of short RTs under percentile reinforcement contingencies (Experiment 3). RT functions obtained from human subjects were also consistent with Hick's law, but slopes for pigeons were significantly lower than those for humans (Experiments 4 and 5). These results extend the generality of Hick's law to pigeons but are inconsistent with Jensen's claim that the parameters of the Hick function are related to intelligence.     

Does increasing the warning signal intensity decrease or increase simple reaction time?

The purpose of the study was to reconcile the contradictory evidence reporting either a shortening or lengthening of the simple reaction time (RT) as a function of the intensity of a warning signal. The lengthening of auditory RT is obtained when short visual or auditory warning signals are of constant intensity within a session and succeeded by a fore-period. Visual RT did not vary under similar circumstances. There was no effect when a warning signal of constant intensity overlapped in time with the response stimulus. The shortening of RT occurred with auditory warning signals of variable intensity and overlapping in time with the response stimulus. The shortening of RT was interpreted as facilitation-by-arousal. The lengthening of RT is a contextual effect but the data do not support accounts based on sensory-neural adaptation or criterion changes.     

Noogenesis—the fundamental problem of our time

The possibility of long wave economic cycles are considered under both market capitalism and command socialism. Capitalist long waves can be generated by a two‐stage multiplier‐accelerator model and socialist long waves can be generated by an equivalent model strictly for investment cycles. Under certain conditions chaotic dynamics can occur at turning points in both cases. It is argued that a systemic crisis leading to a systemic transformation is most likely to occur at such a point.     

What is the impact of the explicit knowledge of sequence regularities on both deterministic and probabilistic serial reaction time task performance?

The aim of this study was to explore the role of prior explicit sequence knowledge by comparing its influence on serial reaction time (SRT) performance with either a deterministic or a probabilistic sequence. The results confirm that, with a deterministic sequence, preliminary explicit learning improves SRT performance. On the other hand, with a probabilistic sequence, the results show no advantage for SRT performance in explicit-learning conditions. In addition, by using the process dissociation procedure (Jacoby, 1991), we show that performance on a subsequent generation task was more sustained by controlled processes for participants in the explicit-learning conditions than for those in the incidental condition. On the whole, these results, showing that the influence of explicit knowledge can be suppressed in certain specific conditions, are consistent with the intervention of both implicit and explicit mechanisms in SRT tasks, and the results also show that their relative influence can be modulated by the particular demands of the task.     

Immediate and remote time estimation — A comparison

The influence of the length of time elapsing between the termination of an interval on its estimated duration was tested in three experiments. In the first experiment, 89 subjects performed the W, C, and CW tasks of the Stroop color-word test. The duration of each of these three tasks, which was 10 second in reality, was estimated twice by every subject. Once, immediately upon completion of the task (IE), and a second time 90 seconds later (RE), both under prospective paradigm. The nature of the relationship between task difficulty and its estimated duration was found to be different in IE and RE. A negative relationship was found in IE while in RE no significant difference was found between difficulty levels. In the second experiment it was found that RE's trend was not caused by estimation order. In the third experiment IE and RE were tested under prospective and retrospective paradigms. In the perspective paradigm the results obtained in experiment 2 were replicated. In the retrospective paradigm the relationship between task difficulty and time estimation was, unlike the prospective paradigm, negative in both IE and RE. The significance of the results to time estimation theory was discussed.     

Conscious intention and human action: Review of the rise and fall of the readiness potential and Libet’s clock

Is consciousness—the subjective awareness of the sensations, perceptions, beliefs, desires, and intentions of mental life—a genuine cause of human action or a mere impotent epiphenomenon accompanying the brain’s physical activity but utterly incapable of making anything actually happen? This article will review the history and current status of experiments and commentary related to Libet’s influential paper (Brain 106:623–664, 1983) whose conclusion “that cerebral initiation even of a spontaneous voluntary act …can and usually does begin unconsciously” has had a huge effect on debate about the efficacy of conscious intentions. Early (up to 2008) and more recent (2008 on) experiments replicating and criticizing Libet’s conclusions and especially his methods will be discussed, focusing especially on recent observations that the readiness potential (RP) may only be an “artifact of averaging” and that, when intention is measured using “tone probes,” the onset of intention is found much earlier and often before the onset of the RP. Based on these findings, Libet’s methodology was flawed and his results are no longer valid reasons for rejecting Fodor’s “good old commonsense belief/desire psychology” that “my wanting is causally responsible for my reaching.”.     

Attentional bias toward low-intensity stimuli: an explanation for the intensity dissociation between reaction time and temporal order judgment?

If two stimuli need different times to be processed, this difference should in principle be reflected both by response times (RT) and by judgments of their temporal order (TOJ). However, several dissociations have been reported between RT and TOJ, e.g., RT is more affected than TOJ when stimulus intensity decreases. One account for these dissociations is to assume differences in the allocation of attention induced by the two tasks. To test this hypothesis, different distributions of attention were induced in the present study between two stimulus positions (above and below fixation). Only bright stimuli appeared in one position and either bright or dim stimuli in the other. In the two RT experiments, participants had to respond to every stimulus appearing in one of the two positions. Reaction times to bright stimuli were faster when they appeared in the position where dim stimuli were likely to occur. This finding suggests that the allocation of attention was adapted to the asymmetrical arrangement of stimuli, not suggested by explicit instruction. In the two TOJ experiments, the temporal order of stimuli appearing in the two positions had to be judged. Although bright stimuli appearing at the bright-and-dim location were judged to be earlier, this effect was small and insignificant. Further, the intensity dissociation between RT and TOJ was insensitive to random vs blockwise presentations of intensities, therefore was not modified by attentional preferences. Thus, asymmetrical arrangement of stimuli has an impact on the allocation of attention, but only in the RT task. Therefore dissociations between TOJ and response times cannot be accounted for by an attentional bias in the TOJ task but probably by different use of temporal information in the two tasks.     

Measurement and comparative analysis of driver’s perception–reaction time to green phase at the intersections with and without a countdown timer

This paper proposes a method based on digital image processing for measuring drivers’ perception–reaction time (PRT) to the green phase. The detection of the onset of a green signal was based on the RGB color model. The detection of the start of the vehicle was based on the frame difference. The driver’s perception–reaction time was equal to the difference between the frame of the onset of the green signal and the frame of the start of the vehicle divided by the video frame rate. Drivers’ PRT with and without a countdown timer were comparatively analyzed. First, the means and variances of drivers’ PRT with a timer and without a timer were compared. Second, Normal, Lognormal, Gamma and Weibull distributions were used to fit the PRT data. Third, the fuzzy c-means clustering was utilized for PRT classification and comparison. The results show that the method for measuring drivers’ PRT based on digital image processing was effective. The drivers’ PRT was decreased from 2.12 s to 1.48 s with countdown signals. Weibull distribution appeared to best fit the PRT with No-Timer and Lognormal distribution appeared to best fit the PRT with Timer. The PRT data were classified into three groups: “Fast”, “Moderate” and “Slow”. Clustering centers without Timer were 1.16 s, 2.47 s and 3.98 s respectively. Clustering centers with Timer were 0.95 s, 1.64 s and 2.70 s respectively. The clustering centers can be regarded as reference values of drivers’ starting response for microscopic traffic simulation software.     

Does functional performance and upper body strength predict upper extremity reaction and movement time in older women?

BackgroundReaction time to initiate upper limb movement and movement time to place hands on the landing surface may be important factors in forward fall landing and impact, contributing to injury reduction. The aim was to investigate the relationship of physical function and upper body strength to upper limb reaction and movement time in older female participants.Methods75 female participants (72 ± 8 yrs) performed 5 arm response trials. Reaction time (signal to initiation of movement), and movement time (initial movement to contact), were collected using 3D motion capture. Additional variables were: handgrip; sit-to-stand; shoulder flexion and elbow extension strength measured by hand-held dynamometry; one-legged balance; fall risk; and physical activity scores. Prediction variables for reaction and movement time were determined in separate backward selection multiple regression analyses. Significance was set at P < 0.05.FindingsSignificant regression equations for RT (r² = 0.08, P = 0.013) found a relationship between stronger handgrip (Beta = −0.002) and faster reaction time, accounting for 8% variance. For movement time (r² = 0.06, P = 0.036) greater shoulder flexion strength (Beta = −0.04) was related to faster movement time, explaining 6% variance. Stronger SF strength was related to a decrease in MT by 4%.DiscussionA relationship between arm strength measures and faster upper body reaction and movement time was shown, with 10–20% higher strength associated with a 5% faster response time. Even though this was a relatively weak relationship, given that strength is a modifiable component this provides a potential avenue for future intervention efforts. This in turn could have an impact on forward fall landing and potential reduction of injury risk.     

Bloch’s law and a Poisson counting model for simple reaction time to light

A series of three experiments was conducted with identical design as an earlier series (Hildreth, 1973). Its purpose was (1) to determine whether Bloch’s law holds for simple reaction time (RT) to still lower intensity visual stimuli, and (2) to provide data for testing a stochastic generalization of the temporal integration model (TI-ED) reported earlier. RT means were found to agree with Bloch’s law for durations below 48 msec. By a statistical test, Bloch’s law was shown to hold for both means and standard deviations below about 65 msec. Latency statistics—means and standard deviations—were predicted by a Poisson process counting model. This model assumes that a number of identical, parallel Poisson processes, activated by light, with pulse interarrival times decreasing with light intensity, trigger light detection when a critical number of pulses arrive at a counting center. For the intensities investigated, both the estimated number of Poisson processes and critical number of pulses required for detection range between 8 and 13. The model predicts the Broca-Sulzer effect for mean RTs which is observed in several of these experiments.     

Bloch’s law and a temporal integration model for simple reaction time to light

In a series of experiments designed to determine whether Bloch’s law holds for simple RT to low-energy visual stimuli, mean RTs were found to agree with Bloch’s law to a close approximation only when a narrow range of stimulus intensities is used. However, they could be accounted for more generally by (1) assuming that detection depends on a “visual response function” (VRF) initiated and maintained by the light stimulus (when the time integral of the VRF reaches a criterion, S detects the light and initiates a response): and (2) the fact that VRF generated by a square-wave flash rises quickly to its maximum, remains at this value for the duration of the flash, and then decays exponentially to zero after flash offset. S continues to integrate the VRF throughout its lifetime, and consequently for a brief stimulus, detection will occur during the exponentially decaying portion of the response-the portion corresponding to “visual persistence.” Finally. when luminances used vary by more than a factor of four. Bloch’s law fails to hold, while the model succeeds, implying that the temporal integration model more generally accounts for RTs.     

Empirical approaches to information processing: Speed-accuracy tradeoff functions or reaction time — a reply

This papers prsents a reply to Schmitt and Scheirer's (1977) criticism of recent work using the speed-accuracy tradeoff methodology. Several factual and conceptual errors in Schmitt and Scheirer's reporting of the empirical speed-accuracy tradeoff papers on recognition memory are corrected and a short discussion of the speed-accuracy method is presented