Reaction time and movement time as measures of stimulus evaluation and response processes

Reaction time has been divided into the time to initiate a response (RT) and the time to execute the motor response (MT) in many chronometric studies of intelligence. Our purpose was to determine which cognitive processes are reflected by RT and MT. To accomplish this, the latency of the P300 wave of the event-related potential was recorded concurrently with RT and MT measures in three experiments. P300 latency reflects the duration of stimulus evaluation relatively independently of response processes. In the first experiment, a Sternberg memory task was employed to manipulate stimulus classification requirements. In the second, the subjects' emphasis on either speed or accuracy of responding was examined during a task that also manipulated stimulus evaluation time. In the third experiment, a Stroop-like task was used to examine response processes. RT and P300 latency varied with manipulations of stimulus evaluation time, whereas MT varied with difficulty of motor execution. MT was also affected by stimulus classification processes. Both RT and MT were sensitive to processes involved in response bias and preparation. The possibility that the correlations of RT and MT with measures of intelligence are due to effects on a common stage of information processing cannot be rejected in the light of these results.     

Reaction time and movement time measured in a key-press and a key-release condition.

Reaction time (RT) and movement time (MT) are measured in two conditions, a key-press and a key-release condition. The latter makes a greater demand on perceptual feedback than the former. RT increases in the key-release condition and a fraction of MT denoted key-press time (KT) decreases in the key-press condition. It is argued that KT of a response button in the simple reaction-time experiment may serve as a proper measure of the motor component. The foreperiod prior to onset of the reacting stimulus affects RT, KT, and MT, suggesting that preparatory set or expectancy influences both the perceptual and motor components of simple human performance. The results indicate that the relation of RT and MT depends upon methodological conditions.     

Reaction time,evoked brain potentials,and psychometric g in the severely retarded

Measurements derived from reaction time (RT), movement time (MT), and an index of neural adaptability (NA) derived from averaged evoked potentials are significantly related to each other as well as to g factor scores extracted from a battery of 15 psychometric tests in a sample of 54 severely retarded adults. The RT-MT and NA variables show a shrunken multiple R of .64 (p < .001) with psychometric g.     

Reaction time to the offset of brief auditory stimuli

An earlier investigator has found that the time at which the offset of a stimulus is perceived depends on the time of stimulusonset, rather than on the time of stimulus offset, for stimuli briefer than a critical duration of the order of 100 msec. In an attempt to determine whether this effect extends to reaction time (RT), we have determined RT to the offset of brief noise bursts. RT was found to be essentially constant as a function of stimulus duration. Thus, RT to stimulus offset appears not to be related to the time of perception of offset, as determined in the earlier investigations.     

Use of a computer-controlled firearms training simulator in perception response time experiments

This paper describes the use of a custom-configured computer-controlled firearms training simulator to measure perception response (reaction) time (RT) to a stimulus in which the degree of threat presented is a manipulable variable across trials. The computer records the number of frames of videotape traversed between the point of presentation of the threat in the video stimulus and the point at which the subject responds by drawing the firearm. For the purposes of data analysis, these frame-count measures are converted to RT measurements. Example data are presented that capture perception RT at both thedraw-stimulus and thefire-stimulus points in situations for which either only one threat or more than one threat exists. Other elements, such as degree of threat and accuracy of response, provide additional data.     

The effect of cellular telephone conversation and music listening on response time in braking

Driver distraction contributes to vehicle accidents, with estimates as high as one-half of crashes being distraction-related. The purpose of this experiment was to explore potential distractions by testing the effects of cellular telephone conversation and music listening on response time and its subcomponents of reaction time (RT) and movement time (MT) in a simulated braking task. Participants (N = 27) sat at a simulated driving station and released the accelerator and depressed the brake pedal as quickly as possible following activation of a simulated brake lamp. The braking task was performed under each of six conditions including: (a) the control (braking task only); (b) music playing at 66 dBA; (c) music playing at 78 dBA; (d) cellular telephone conversation; (e) cellular telephone conversation and music at 66 dBA; and (f) cellular telephone conversation and music at 78 dBA. Cellular telephone conversation slowed response time, yet music had no effect on response time. While the RT results generally mirrored those of response time (i.e., RT was also slowed by the telephone conversation), interestingly, MT was actually faster when the cellular telephone conversation was present compared to when it was not. Participants appear to have anticipated slower RT in the presence of the cellular telephone conversation, and attempted to compensate by executing a more rapid movement to the brake pedal.     

Selective effects of barbiturate and amphetamine on information processing and response execution

In a 3 × 2 × 2 factoral experiment, 12 subjects carried out a choice reaction task with reaction time (RT) and movement time (MT) as response measures.Independent variables were drug treatment (amphetamine, barbiturate, placebo), visual stimulus degradation and S-R compatibility. Visual stimulus degradation and S-R compatibility showed additive effect on the RT, but did not affect the MT. This confirms that stimulus encoding, response selection and response execution represent independent processing stages. The two drugs had selective effects on the RT and the MT. Barbiturate (as compared to placebo) had no effect on the MT, but it lengthened the RT, and this effect was additive with the effects of S-R compatibility but showed an interaction with the effects of stimulus degradation. Amphetamine (as compared to placebo) shortened the MT, but there was no significant main effect of amphetamine on the RT although the interaction with the effect of S— compatibility was significant. These results suggest that barbiturate affects stimulus encoding whereas amphetamine affects response-related processes..     

Reaction time,movement time,and intelligence: A replication and extension

The purpose of the investigation was to replicate and extend a study by Jensen and Munro which found reaction time (RT) and movement time (MT) parameters to correlate negatively and moderately with Raven matrices performance. A sample of 20 ninth-grade girls was used. Relationships between RT and MT and Raven scores were found to be negative and moderate to high, thus replicating the Jensen and Munro study. In addition, moderate to strong negative correlations were found between RT and MT parameters and reading comprehension and performance on the California Test of Basic Skills. Weaker relationships were found for mathematics and English grades although the direction was consistently negative.     

OSP parameters and the cognitive component of reaction time to a missing stimulus: Linking brain and behavior

This within-subjects experiment tested the relationship between the premotor (cognitive) component of reaction time (RT) to a missing stimulus and parameters of the omitted stimulus potential (OSP) brain wave. Healthy young men (N = 28) completed trials with an auditory stimulus that recurred at 2 s intervals and ceased unpredictably. Premotor RT and Motor RT were measured on active trials that required an immediate response to a missing stimulus. Passive trials required no response in order to measure the complete set of OSP parameters (i.e., onset, rate of rise, amplitude and peak latency). The results showed that faster Premotor RT was strongly associated with a faster rate of rise in the OSP wave. Motor RT was unrelated the OSP parameters. This new evidence is consistent with the occurrence of some common cognitive processes generating behavioral and brain reactions to a missing stimulus.     

Reaction time to the second of two shortly spaced auditory signals both varying in intensity

Six subjects participated in a reaction time (RT) task in which the stimulus events consisted of two sinusoidal waves presented in close succession. The leading stimulus (S₁) had a duration of 25 msec while the binary reaction stimulus (S₂) was 250 msec. Presentation of the interstimulus interval (ISI) was irregular. S₁ as well as S₂ varied in intensity and were assigned randomly the values of 45, 68, 85 and 105 db (SPL). RT to S₂ was examined as a function of the intensity of both stimuli. Generally RT varied inversely with the intensity of S₁ and the downward gradient of RT with ISI became steepened at least for ISIs shorter than 200–250 msec. Concerning S₂, RT grew shorter as the intensity increased up to 85 db. Probably due to startle, RT tended to lengthen at S₂ = 105 db. When both S₁ and S₂ were 105 db the startle effect upon RT seemed most evident. Then the elevation in RT took place at especially those ISIs for which he fastest RTs might have been expected (about 200 msec). For the remaining intensities no interaction between S₁ and S₂ upon RT was found even for the shortest ISIs, implying that the effects of S₁ and S₂ intensities upon RT were independent.     

Positive and negative stimuli in relation to tennis players' reaction time

Research has indicated that negative and positive thoughts may affect sport performance. The purpose of this analogue study was to assess whether negative and positive stimuli influenced tennis performance similar to positive and negative thought. The reaction time (RT) of 40 competitive tennis players was measured during a timed response to a tennis ball rotating in a topspin, sidespin, or backspin direction on the computer screen. Immediately prior to the ball presentation, a phrase (accessory stimulus) was presented visually or aurally. The accessory stimulus provided either positive (e.g., 'nice shot') or negative information (e.g., 'bad shot') followed by the subject's name. Analysis showed a main effect only for the type of spin. The slowest RT occurred when responding to a tennis ball rotating in a backspin direction. A significant interaction was found for the sensory modality (audition vs vision) and polarity (positive vs negative) of the accessory stimulus. RT to negative stimuli was slowest when the accessory stimulus was presented aurally. The quickest RT to positive stimuli occurred when the accessory stimulus was presented aurally. These results indicated that negative and positive stimuli, when presented aurally, affected performance as positive and negative thoughts measured in other studies. Not measured was whether negative and positive stimuli actually produce the negative and positive thoughts, respectively, that have been reported to affect performance.     

The effects of contralateral noise on reaction time to monaural stimuli

Experiment I measured reaction time (RT) to monaural tones of six frequencies presented along with white noise to the contralateral ear. RT with the hand ipsilateral to the stimulus was an average of 9.63 msec faster than RT with the contralateral hand. Contralateral RT was significantly affected by the stimulus frequency. Experiment II measured ipsilateral and contralateral RT to monaural tones with and without contralateral noise. Noise-on results agreed with the results of Experiment I, while noise-off results showed no difference between ipsilateral and contralateral RT. No right-ear advantage was found. The ipsilateral-contralateral RT difference found with noise on is interpreted as being due to callosal transmission time as well as other factors. The finding of no right-ear advantage is discussed in relation to other studies which did report a right-ear advantage.     

The location-, word-, and arrow-based Simon effects: An ex-Gaussian analysis

Task-irrelevant spatial information, conveyed by stimulus location, location word, or arrow direction, can influence the response to task-relevant attributes, generating the location-, word-, and arrow-based Simon effects. We examined whether different mechanisms are involved in the generation of these Simon effects by fitting a mathematical ex-Gaussian function to empirical response time (RT) distributions. Specifically, we tested whether which ex-Gaussian parameters (μ, σ, and τ) show Simon effects and whether the location-, word, and arrow-based effects are on different parameters. Results show that the location-based Simon effect occurred on mean RT and μ but not on τ, and a reverse Simon effect occurred on σ. In contrast, a positive word-based Simon effect was obtained on all these measures (including σ), and a positive arrow-based Simon effect was evident on mean RT, σ, and τ but not μ. The arrow-based Simon effect was not different from the word-based Simon effect on τ or σ but was on μ and mean RT. These distinct results on mean RT and ex-Gaussian parameters provide evidence that spatial information conveyed by the various location modes are different in the time-course of activation.     

The theory of intelligence and its measurement

Mental chronometry (MC) studies cognitive processes measured by time. It provides an absolute, ratio scale. The limitations of instrumentation and statistical analysis caused the early studies in MC to be eclipsed by the ‘paper-and-pencil’ psychometric tests started by Binet. However, they use an age-normed, rather than a ratio scale, which severely limits the ability of IQ tests to probe the physical basis of differences in cognition. For this reason, Arthur Jensen reinitiated mental chronometry in the 1970s. He designed an apparatus that measures reaction time to a task known as the Hick paradigm that requires the testee to respond to a display of 1 to 8 lights. Faster decision times were related to psychometric g, with theoretically important consequences. He was able to do this, where many other studies had failed, mainly because his apparatus clearly separated movement (MT) from reaction time (RT, also called ‘decision time’.) Interestingly, while RT is clearly related to IQ, MT is not. Principal components analysis reveals RT to be a cognitive variable and MT a motor variable. Failure to distinguish between them drastically obscures the correlation between composite RT (i.e., RT + MT) and cognitive variables. When Jensen (2006) reviewed the literature on MC he found there was a shocking lack of standardization in the administration, recording, and analysis. Consequently, the results of a study conducted in one lab, even though measured in absolute time, could not be compared directly against those from another. Termed “method variance,” this is a major obstacle to the advancement of MC. For that reason, Jensen's Institute of Mental Chronometry commissioned a leading electronics firm to construct a state-of-the-art apparatus to administer, record, and analyze MC experiments.     

Effects of foreperiod interval upon reaction time, alpha blocking, and heart rate under variable conditions with reduced learning factors

The present experiment was to investigate the effects of foreperiod interval upon reaction time (RT), alpha blocking, and heart rate (HR) under conditions in which learning factors and conditional probability were minimized. Twenty college students were given a series of 44 randomized foreperiod intervals (0–30 sec). The fastest RT was obtained at 0.6 sec foreperiod. Alpha blocking provided the same trend as that of RT, showing that the 0.6 sec foreperiod yielded the largest alpha blocking. Positive correlation was observed between the speed of RT and alpha blocking (r = 0.56, p<0.001). HR curve was different from those of RT and alpha blocking. No significant correlation was obtained between RT and HR. The results were discussed, particularly, in terms of the theory of classical conditioning.     

Advanced information about target location facilitates movement planning: More evidence using a deadline procedure on movement time

It was recently shown that in a multiple choice aiming task the knowledge of the target location prior to stimulus introduction, even though the trajectory to follow was still uncertain, facilitated movement planning and execution (Girouard et al. 1987). In that particular study, the subjects had, in the first condition, knowledge about the target location prior to the stimulus presentation. In that condition, they started their movements in the direction indicated by one of four possible stimuli. However, they always ended their movements on the same target (single-target condition). In a second condition, there was always a one-to-one mapping between the stimuli and the targets (multiple-target condition). The facilitating effects of knowing target location were found for both the movement planning time or reaction time (RT) and movement time (MT). A possible explanation of the latter effect was that the subjects, somewhere along the movement path, made a check to see if their movement was carried out as expected and corrected it accordingly. The purpose of the present experiment was to see if knowing the target to reach before the stimulus presentation, even though the trajectory to follow is uncertain, could override the well-known effect of stimulus-response uncertainty on RT (Hick 1952) when the possibility of making a check during MT was reduced. To reach that goal the methodology used by Girouard et al. (1987) was modified by limiting the time permitted to execute the required response. The effect of this manipulation was that it almost tripled the target location effect on RT found in the previous study. Furthermore, the significant effect found on MT disappeared for the single-target condition whilst it remained significant for the multiple-target condition. Different interpretations are offered to take into account the latter result.     

Testing the hypothesized effect of dysgenic fertility on intelligence with existing reaction time data: A comment on Woodley,te Nijenhuis,and Murphy (2013)

Dysgenic fertility has supposedly resulted in a decline in general intelligence (g) over time. In light of evidence that simple visual reaction time (RT) is inversely related to IQ, Woodley et al. (2013) tested the hypothesized dysgenic effect by subjecting to a meta-regression simple visual RT data collected over 100 years in 15 studies. This analysis found that RT had significantly increased according to a linear function over this time period. Woodley et al. then used this result to estimate the rate at which g had declined over the same period. The present comment points out that there are large gaps in the distribution of RTs analyzed by Woodley et al. with respect to year tested, and that RT in males did not vary as a function of year in the 13 studies published from 1941 on. It is concluded that although existing data are consistent with the idea that g has been adversely affected by dysgenic fertility, it cannot be determined at what rate g has fallen over time.     

Probability effects in choice reaction time tasks

This paper contains a short review of the main results that were obtained by the author in a series of experiments that constituted a study of the effects of signal probability on choice reaction time. The effects of stimulus probability are shown to be influenced by the following variables: (1) differences in the method of varying stimulus probability, (2) differences in task complexity, (3) differences in S-R code, and (4) differences in Ss’ motivation. The data that are considered here are the overall mean RT for particular signals and the mean RT for sequential repetitions. Two questions, related to the psychological “nature” of the probability effects in choice RT are discussed: (1) The question of the relationship between the relative frequency and the number of alternatives as two different ways of determining the probability effect in choice RT; and (2) the question of identifying the main determinants of the trial-to-trial variability of RT in such experiments.

     

Unilateral versus bilateral presentation methods in the reaction time paradigm

The use of bilateral presentation in lateralized tachistoscopic reaction time (RT) tasks has been precluded by problems of how to instruct the subject to respond to the left visual field (LVF) or right visual field (RVF) stimulus and by the necessity of fixation control with bilateral presentation. Schmuller and Goodman, 1979 and Schmuller and Goodman, 1980, Brain and Language, 11, 12–18) offered a method, applied to date only in recognition accuracy studies, which can overcome these problems. They used an “arrowhead pointer” at fixation. This instructs the subject as to which stimulus to report first and also controls fixation. We adapted the method to the RT paradigm by having subjects report only the stimulus indicated and applied it in a bilateral presentation version of the Object Naming Latency Task (W. F. McKeever & T. L. Jackson, 1979, Brain and Language, 7, 175–190). Fifty subjects received the unilateral task and 50 received the bilateral task. The bilateral task yielded right visual field superiority in 98% of the subjects and the magnitude of the superiority was over three times as large as in the unilateral task. Different sex × familial sinistrality × VHF interactions obtained on the tasks. Combining the advantages of reaction time and bilateral presentation methods may substantially increase the resolving power of lateralized tachistoscopic tasks.     

Effects of a coactor's prediction on latencies to predict and indentify stimuli

On each of 300 trials E's confederate (C) verbalized which of two stimuli would occur; then S made a prediction. Following each presentation, S and C pulled a trigger to identify the stimulus. Two latencies were measured: the interval between C's and S's prediction (prediction time), and the interval between stimulus presentation and S's identification response (choice RT). Prediction times were significantly shorter when S's prediction agreed rather than disagreed with C's prediction, when S's preceding prediction was correct rather than incorrect, and when S was female rather than male. Choice RT was influenced by distributions of C's stimulus predictions and C's prediction outcomes in directions supporting an expectancy model.