Sex differences in reaction time mean and intraindividual variability across the life span

Men are often found to have faster and less variable reaction times (RTs) than do women. However, it has not been established whether these differences occur in children. One suggestion is that sex differences in RT variability may be due to the effect of sex hormones on the brain and, by implication, may be expected in adults but not in children. The present study investigates sex differences in RT mean and intraindividual variability in a sample that includes both children and adults (age range = 4-75 years). Mean and intraindividual variability of simple RT (SRT) and 4-choice RT (CRT) were measured in 1,994 visitors to science festivals held in Edinburgh, Scotland, in 2008 and 2009 and in Cheltenham and Cambridge, England, in 2008. The commonly reported pattern of decreasing RT mean and variability in childhood and adolescence, followed by an increase in mean and variability through adulthood and into old age, was confirmed. Greater intraindividual variability for females in SRT and CRT was observed in adults but not in children. Males had significantly faster mean SRT than did females across the life span, but there were no sex differences in mean CRT. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

Sensorimotor Variables and Forced Expiratory Volume as Correlates of Speed,Accuracy, and Variability in Reaction Time Performance in Late Adulthood

The relationship between performance on measures of sensorimotor and physiological function and performance on measures of reaction time (RT) was investigated using an individual differences approach. Older participants showed greater intra-individual variability on the RT measures. They were also slower on measures of four choice visual RT but not on measures of three choice auditory RT. Sensorimotor and physiological variables explained nearly all the age differences in performance on the RT tasks and showed similar patterns of relationships with measures of speed, accuracy, and intra-individual variability. The results support a common factor interpretation of the relationships among these variables in old age.     

Effect of directional response variables on eye-hand reaction times and decision time

To determine if direction of response affects reaction time, we measured the time for hand response to a visual stimulus, using a sensitive, microprocessor-based testing device to determine simple reaction time (RT), choice RT, and decision time. Mean simple RT was 207 +/- 3.7 msec. (mean +/- SEM); mean choice RT was 268 +/- 4.2 msec; and mean decision time was 61 msec. No differences were noted for leftward versus rightward movements, or midline versus lateral movements. Choice RT increased by 1.49 msec./yr. of age. Simple RT increased significantly with age for the nondominant hand, but not for the dominant hand. Right-handed subjects were more rapid with the dominant hand for choice RT. We conclude that dominance of hand tested and test initiation mechanism have major effects, but direction of movement in the lateral plane has little effect on reaction 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.

     

Binary choice reaction time as a function of the relationship between durations and forms of responses

In a choice between responding with the left or right hand, some kinds of differences between the movements increase RT (Reaction Time) while others do not. Of the first kind are differences in form, while differences in the finger used are of the latter kind. In previous experiments differences in form were confounded with differences in duration. Since there is some indication that a difference in duration is sufficient to lengthen RT, both characteristics were varied separately. It turned out that a difference in form (duration being constant) has essentially the same effects as a difference in duration (form being constant): Mean RT is longer, variability of RT and MT (movement time) is larger, and frequency of choice errors is smaller than in choice between identical movements. These effects, which seem to be associated with choice between movements of different temporal patterns, are interpreted in terms of advance specification of movement parameters. Additional results on the relationship between response duration and RT suggest that RT does not depend on duration (or velocity) per se, but on how much the duration deviates from quickest performance.     

How normal and retarded individuals monitor and regulate speed and accuracy of responding in serial choice tasks

These experiments investigate whether or not differences in the way that retarded and nonretarded individuals monitor and regulate speed and accuracy of responding contribute to the slower and more variable performance of retarded subjects on choice reaction time (RT) tasks. Rabbitt (1979, 1981) suggested that efficient choice RT performance is mediated by subjects tracking increasingly faster RT bands on successive trials until, by making and recognizing errors, they discover those very fast RT levels that should be avoided and those safe bands, just above typical error levels, that should be tracked. Experiments 1A and 1B established that most retarded subjects detect their errors as efficiently as nonretarded controls, a finding that excludes the possibility that retarded subjects do not monitor accuracy efficiently but achieve comparable levels of accuracy by consistently responding within very slow RT bands that minimize likelihood of errors. Experiment 2 showed that while a qualitatively similar trial-by-trial tracking mechanism mediates the performance of both groups, retarded subjects are less efficient at constraining RTs within very fast, but safe, bands. Increasing error probabilities at longer RTs suggest that momentary fluctuations in stimulus discriminability and/or attention are factors affecting RT variability in retarded subjects. The RT patterns for various sequences of correct responses initiated and terminated by errors suggest that the effective past experience (EPEX) guiding trial-by-trial RT adjustments of retarded subjects is short and inadequate, and it was argued that this can account for much of the remaining RT variability contributing to retarded-nonretarded differences. Not only does a short EPEX increase variability by giving rise to long error-free sequences of slower than average RT but also, when combined with occasional specified random fluctuations, it suggests why retarded subjects can achieve, but not sustain, RT levels maintained by nonretarded subjects.     

Binary Choice Reaction Time as a Function of the Relationship between Durations and Forms of Responses

In a choice between responding with the left or right hand, some kinds of differences between the movements increase RT (Reaction Time) while others do not. Of the first kind are differences in form, while differences in the finger used are of the latter kind. In previous experiments differences in form were confounded with differences in duration. Since there is some indication that a difference in duration is sufficient to lengthen RT, both characteristics were varied separately. It turned out that a difference in form (duration being constant) has essentially the same effects as a difference in duration (form being constant): Mean RT is longer, variability of RT and MT (movement time) is larger, and frequency of choice errors is smaller than in choice between identical movements. These effects, which seem to be associated with choice between movements of different temporal patterns, are interpreted in terms of advance specification of movement parameters. Additional results on the relationship between response duration and RT suggest that RT does not depend on duration (or velocity) per se, but on how much the duration deviates from quickest performance.     

Simulation analyses of space use: Home range estimates,variability, and sample size

Simulations of space use by animals were run to determine the relationship among home range area estimates, variability, and sample size (number of locations). As sample size increased, home range size increased asymptotically, whereas variability decreased among mean home range area estimates generated by multiple simulations for the same sample size. Our results suggest that field workers should ascertain between 100 and 200 locations in order to estimate reliably home range area. In some cases, this suggested guideline is higher than values found in the few published studies in which the relationship between home range area and number of locations is addressed. Sampling differences for small species occupying relatively small home ranges indicate that fewer locations may be sufficient to allow for a reliable estimate of home range. Intraspecific variability in social status (group member, loner, resident, transient), age, sex, reproductive condition, and food resources also have to be considered, as do season, habitat, and differences in sampling and analytical methods. Comparative data still are needed.     

Reaction Time,Age, and Cognitive Ability: Longitudinal Findings from Age 16 to 63 Years in Representative Population Samples

Reaction time variables are used widely in studies of human cognitive ageing and in research on the information processing foundations of psychometric intelligence. The research is largely based on biased population samples. In the present study, large (500+), representative samples of the population of the West of Scotland were tested at ages 16, 36 and 56 years on simple and choice reaction time. Participants were re-tested eight years later, at which time they also took the Paced Auditory Serial Addition Test (PASAT). We report simple and choice reaction time means and their variabilities, their stability across 8 years, and their correlations with the PASAT. Simple and choice reaction times become slower and more variable with age. Women from age 36 to 63 show more variability in choice reaction times than men, an effect which remains after controlling for mean reaction time. Reaction time differences largely account for age differences, but not sex differences, in PASAT scores.     

Unstable in more ways than one: reaction time variability and the neuroticism/distress relationship

The authors hypothesized that a greater degree of stimulus-response variability could either serve adaptive or maladaptive control purposes, depending on levels of Neuroticism. Specifically, a more variable relation between stimulus and response may be emotionally beneficial if such flexibility is used to support non-neurotic forms of self-regulation, but costly if it is used to support neurotic forms of self-regulation. To investigate these ideas, the authors asked 232 college undergraduates within three studies to perform several choice reaction time (RT) tasks. On the basis of performance, we could quantify stimulus-response variability in terms of RT variability from trial to trial. Such a measure of stimulus-response variability interacted with Neuroticism in predicting momentary negative affect (Study 1), informant judgments of negative affect (Study 2), and informant judgments of anxious symptoms (Study 3). As hypothesized, greater stimulus-response variability tended to be associated with less distress among individuals low in Neuroticism, but more distress among individuals high in Neuroticism. The results highlight the manner in which Neuroticism may "taint" control functions, in turn reinforcing Neuroticism-linked outcomes.     

Choice reaction times in children: Error and post-error responses,and the repetition effect

Analysis of the frequency and nature of error and post-error responses in the serial choice reaction times (RTs) of children between 5 and 12 years essentially replicate findings in adults. Errors are few and fast, tend to be made on fingers closely related to the correct responding finger, and are followed by a marked slowing in response rate. This pattern of results is interpreted in terms of a strategy to optimize performance with respect to instructions emphasizing both speed and accuracy. Importantly, this may be seen to reflect the activity, even in the youngest of children, of a finely-tuned feedback mechanism for error detection. Only the extent of immediate post-error slowing shows a decline with age, and is referred to improvements in response programming. Repetition RT is much faster than alternation RT (the “Repetition Effect”) and improves much less rapidly with age. Reduction of the Repetition Effect with age is consistent with theories of RT in which signals are categorized by retrospective search in short-term memory. The girls' advantage in gross RT is found to be confined to alternation RT only. The particular contribution of alternation RT both to the development of, and sex difference in, gross RT is related to the greater response organization involved in rapidly switching between fingers and hands.     

Sex differences in face cognition

Although there is abundant evidence for female superiority in Face Cognition (FC), a number of questions regarding sex differences remain to be addressed. Here we report a reanalysis of data on the level of latent factors, modeled on the basis of an extensive test battery applied to three samples of over 800 adults in all. In independent samples the measurement structure of FC was invariant for both sexes, indicating that the measurement of the construct does not depend on the context variable sex, and investigating mean performance differences will not be biased by measurement issues — a neglected aspect in previous studies. We confirmed female superiority for face perception (FP) and face memory (FM). For the first time we could show that these sex differences prevailed after accounting for sex differences in broadly measured general cognitive functioning and in object perception. Across adult age, sex differences in FM increased due to the rapid decline of this ability in men, whereas performance in women remained stable across adult age. Self-reported social involvement and things-oriented activities moderated sex-differences in FM. Results show that sex differences are salient at the level of specific FC constructs and that they can be partially explained by social involvement.     

Practice effects on fractionated response time related to age and activity level

Two days of practice on simple and choice reaction (RT) and movement time (MT) were studied using 60 males placed into four groups based upon age and physical activity level. Practice effects upon simple and choice RTs were different for young and old groups. Only the two inactive groups improved on simple and choice MT, with greatest improvement occurring on simple MT. Old Actives had true-score variance than the Old Inactives, but much greater than the two young groups. Intraindividual variability was greater for the two older groups even in the absence of practice effects. Results support the claim that a life style or regular physical activity may lessen aging effects upon RT and MT as well as attenuating interindividual variability.     

Developmental change in speed of processing during childhood and adolescence

Throughout childhood and adolescence, there are consistent age differences in speed of processing. Here 72 published studies yielded 1,826 pairs of response times (RTs) in which each pair consisted of adults' mean RT for a condition and the corresponding mean RT for a younger group. The primary results were that (a) children's and adolescents' RTs increase linearly as a function of adult RTs in corresponding conditions and (b) the amount of increase becomes smaller with age in a manner that is well described by an exponential function. These results are consistent with the view that age differences in processing speed reflect some general (i.e., nontask specific) component that changes rapidly during childhood and more slowly during adolescence. Possible candidates for the general component are discussed.     

Sex Differences in Simple Visual Reaction Time: A Historical Meta-Analysis

To test the hypothesis that the magnitude of sex differences in simple visual reaction time (RT) has narrowed across time, a meta-analysis was conducted on 72 effect sizes derived from 21 studies (n=15,003) published over a 73-year period. The analysis provided strong evidence for the hypothesized change. In addition, the analysis indicated that the sex difference in RT was on average smaller with non-U.S. samples than with U.S. samples. No relation was found between the magnitude of the sex difference in RT and age or presence vs. absence of a warning signal. Two factors–-participation in fast-action sports and driving–-are proposed as having been responsible for the decrease in the magnitude of the sex differences in simple visual RT across time.     

Sex differences in reinforcement and punishment on prime-time television

Prime-time television programs were analyzed for frequencies of positive reinforcement and punishment exchanged among performers varying in age and sex. Results indicated that most responses were given by and directed to adult males. Moreover, while adult males exhibited and received similar frequencies of reinforcement and punishment, adult females were likely to give and to be the recipients of more reinforcement than punishment. Proportional analyses which controlled for sex differences in frequencies of responses revealed that females more often exhibited and received reinforcement, whereas males more often exhibited and received punishment. Results are interpreted from a social learning theory perspective and the implications for children's learning of positive and negative behaviors are explored.     

On the rate of gain of information in children

Previous studies of the development of information processing in children have frequently been methodologically suspect and inconclusive in outcome. A study was designed to overcome some of the difficulties encountered in earlier studies. Six boys and six girls at each year of age from 5 to 11 inclusive were tested for one week on a serial, numerals-keys choice reaction time task with 2, 4, and 8 alternatives. Results were consistent with Hick's (1952) law. Both reaction time (RT) and the rate of gain of information improved with age, but the intercept constant, a more labile index, did not. These findings suggest that development is largely restricted to the process of response selection within a 4-stage decomposition of RT. Girls consistently exhibited both faster RTs and higher rates of gain of information than boys. These sex differences are interpreted in relation to recent notions of cerebral maturation in males and females.     

Song perception during the sensitive period of song learning in zebra finches (Taeniopygia guttata)

The sensitive period is a special time for auditory learning in songbirds. However, little is known about perception and discrimination of song during this period of development. The authors used a go/no-go operant task to compare discrimination of conspecific song from reversed song in juvenile and adult zebra finches (Taeniopygia guttata), and to test for possible developmental changes in perception of syllable structure and syllable syntax. In Experiment 1, there were no age or sex differences in the ability to learn the discrimination, and the birds discriminated the forward from reversed song primarily on the basis of local syllable structure. Similar results were found in Experiment 2 with juvenile birds reared in isolation from song. Experiment 3 found that juvenile zebra finches could discriminate songs on the basis of syllable order alone, although this discrimination was more difficult than one based on syllable structure. The results reveal well-developed song discrimination and song perception in juvenile zebra finches, even in birds with little experience with song.     

Sex differences in the Schizotypal Personality Questionnaire Brief among Japanese employees and undergraduates: A cross-sectional study

Schizotypal personality may be seen as an indicator predisposition to schizophrenia and psychosis proneness. Schizotypal personality traits behave differently depending on a person’s age and sex, but few studies have examined the causal relationship between age-related sex differences and schizotypal personality traits. The aim of the present study was to examine the relationship between the schizotypal personality and sex in different age groups. In our study, we used the Schizotypal Personality Questionnaire Brief (SPQ-B). Participants were 371 college students (107 men) with an age range from 18 to 25 years, and 322 working people (156 men) with an age range of 22–67 years. The results showed that the young adult males in the college student group had tendencies to score higher than females in the same group on the SPQ-B total score and its two subscale scores (the cognitive-perceptual and the interpersonal scores). In the adult sample taken in the working people group, the total score and subscale scores of the SPQ-B did not significantly discriminate male subjects from female subjects. These findings indicate that sex differences of schizotypal personality traits may reflect differential age-related variation.