The temporal resolution power (TRP) hypothesis states that higher temporal acuity of the brain leads to better coordinated mental operations and, in turn, to better performance on tests of psychometric intelligence. Here, we examined this idea and concretized the vague construct "coordination of mental operations" through working memory (WM) updating. In 228 participants (age range: 18 to 30 years), TRP as derived from three timing tasks was significantly related to psychometric intelligence. Furthermore, WM updating was measured by Stankov's swaps task and depicted as a latent variable with increasing factor loadings to represent the increasing number of WM updates in different task conditions. WM updating correlated significantly with psychometric intelligence. In a latent mediation analysis, TRP and WM updating were still directly related to psychometric intelligence. Although the TRP-intelligence link did not substantially decrease in this model, the indirect path from TRP via WM updating to intelligence was statistically significant. This result suggests that higher TRP leads to temporally more precise mental representations in WM. Thereby, the present study provides a first answer to the question of how higher TRP translates into better performance and, eventually, to higher intelligence. Alternative views on the results are critically discussed.

As a measure of the brain’s temporal fine-tuning capacity, temporal resolution power (TRP) explained repeatedly a substantial amount of variance in psychometric intelligence. Recently, spatial suppression, referred to as the increasing difficulty in quickly perceiving motion direction as the size of the moving stimulus increases, has attracted particular attention, when it was found to be positively related to psychometric intelligence. Due to the conceptual similarities of TRP and spatial suppression, the present study investigated their mutual interplay in the relation to psychometric intelligence in 273 young adults to better understand the reasons for these relationships. As in previous studies, psychometric intelligence was positively related to a latent variable representing TRP but, in contrast to previous reports, negatively to latent and manifest measures of spatial suppression. In a combined structural equation model, TRP still explained a substantial amount of variance in psychometric intelligence while the negative relation between spatial suppression and intelligence was completely explained by TRP. Thus, our findings confirmed TRP to be a robust predictor of psychometric intelligence but challenged the assumption of spatial suppression as a representation of general information processing efficiency as reflected in psychometric intelligence. Possible reasons for the contradictory findings on the relation between spatial suppression and psychometric intelligence are discussed.

This paper reports an investigation of the influence of method effects on the measurement of reasoning and of the relationships of these effects to basic cognitive processes. For this purpose, the variation due to the item-position and difficulty effects was separated from the variation due to the measured latent source of inductive reasoning. Data were collected by means of inductive reasoning items and cognitive tasks measuring working memory (WM) updating, rule learning, and automatization. Confirmatory factor analysis models served the decomposition of the variation of inductive reasoning data into a purified version of inductive reasoning, item-position, and difficulty components. The investigation of the relationships of corresponding latent variables and basic cognitive processes revealed two major associations: (a) the purified version of reasoning correlated with WM updating and (b) the item-position effect correlated with variants of learning. These results could be interpreted as signifying a two-dimensional structure of reasoning associated with executive functioning and learning processes.

One of the best-established findings in intelligence research is the pattern of positive correlations among various intelligence tests. Although this so-called positive manifold became the conceptual foundation of many theoretical accounts of intelligence, the very nature of it has remained unclear. Only recently, Process Overlap Theory (POT) proposed that the positive manifold originated from overlapping domain-general, executive processes. To test this assumption, the functional relationship between different aspects of executive attention and the positive manifold was investigated by re-analyzing an existing dataset (N = 228). Psychometric reasoning, speed, and memory performance were assessed by a short form of the Berlin Intelligence Structure test. Two aspects of executive attention (sustained and selective attention) and speed of decision making were measured by a continuous performance test, a flanker task, and a Hick task, respectively. Traditional structural equation modeling, representing the positive manifold by a g factor, as well as network analyses, investigating the differential effects of the two aspects of executive attention and speed of decision making on the specific correlations of the positive manifold, suggested that selective attention, sustained attention, and speed of decision making explained the common but not the unique portions of the positive manifold. Thus, we failed to provide evidence for POT’s assumption that the positive manifold is the result of overlapping domain-general processes. This does not mean that domain-general processes other than those investigated here will not be able to show the pattern of results predicted by POT.

Numerical digits influence perceived duration; specifically, higher numerical digit values are perceived to be longer than lower ones that are presented for the same duration of time. To examine the functional relationship between digit value and perceived duration further, three models based on digit value and covered area were tested in two experiments. Unlike previous studies, each experiment utilised the entire digit range that spans from 1 to 9. In both experiments, digit values were presented visually during the target interval of a time reproduction task. Although numerical digits (i.e., Arabic digits) were used in Experiment 1, verbal digits (i.e., number words) were utilised in Experiment 2. In the case of the numerical digits, perceived duration increased as a function of digit value, while the effect of covered area failed to reach statistical significance. For verbal digits, however, the effects of both digit value and covered area were statistically significant. Overall, our findings support the existence of two distinct nontemporal processes that are involved in the modulation of perceived duration: one process that is based on a digit’s surface characteristics (i.e., covered area) and another process that is based on the digit’s numerical meaning (i.e., digit value).

Stimulus discriminability is often assessed by comparisons of two successive stimuli: a fixed standard (St) and a varied comparison stimulus (Co). Hellström’s sensation weighting (SW) model describes the subjective difference between St and Co as a difference between two weighted compounds, each comprising a stimulus and its internal reference level (ReL). The presentation order of St and Co has two important effects: Relative overestimation of one stimulus is caused by perceptual time-order errors (TOEs), as well as by judgment biases. Also, sensitivity to changes in Co tends to differ between orders StCo and CoSt: the Type B effect. In three duration discrimination experiments, difference limens (DLs) were estimated by an adaptive staircase method. The SW model was adapted for modeling of DLs generated with this method. In Experiments 1 and 2, St durations were 100, 215, 464, and 1,000 ms in separate blocks. TOEs and Type B effects were assessed with univariate and multivariate analyses, and were well accounted for by the SW model, suggesting that the two effects are closely related, as this model predicts. With short St durations, lower DLs were found with the order CoSt than with StCo, challenging alternative models. In Experiment 3, St durations of 100 and 215 ms, or 464 and 1,000 ms, were intermixed within a block. From the SW model this was predicted to shift the ReL for the first-presented interval, thereby also shifting the TOE. This prediction was confirmed, strengthening the SW model’s account of the comparison of stimulus magnitudes.

Background: For adult multiple sclerosis (MS) patients, impaired temporal processing of simultaneity/successiveness has been frequently reported although interval timing has been investigated in neither adult nor pediatric MS patients. We aim to extend previous research in two ways. First, we focus on interval timing (instead of simultaneity/successiveness) and differentiate between sensory-automatic processing of intervals in the subsecond range and cognitive processing of intervals in the one-second range. Second, we investigate whether impaired temporal information processing would also be observable in pediatric MS patients' interval timing in the subsecond and one-second ranges.Methods: Participants were 22 pediatric MS patients and 22 healthy controls, matched for age, gender, and psychometric intelligence as measured by the Culture Fair Test 20-R. They completed two auditory interval-timing tasks with stimuli in the subsecond and one-second ranges, respectively, as well as a frequency discrimination task.Results: Pediatric MS patients showed impaired interval timing in the subsecond range compared to healthy controls with a mean difference of the difference limen (DL) of 6.3 ms, 95% CI [1.7, 10.9 ms] and an effect size of Cohen's d = 0.830. The two groups did not differ significantly in interval timing in the one-second range (mean difference of the DL = 26.9 ms, 95% CI [−14.2, 67.9 ms], Cohen's d = 0.399) or in frequency discrimination (mean difference of the DL = 0.4 Hz, 95% CI [−1.1, 1.9 Hz], Cohen's d = 0.158).Conclusion: The results indicate that, in particular, the sensory-automatic processing of intervals in the subsecond range but not the cognitive processing of longer intervals is impaired in pediatric MS patients. This differential pattern of results is unlikely to be explained by general deficits of auditory information processing. A tentative explanation, to be tested in future studies, points to subcortical deficits in pediatric MS patients, which might also underlie deficits in speech and visuomotor coordination typically reported in pediatric MS patients.

The present study investigated the functional relationships among sexual orientation, masculine and feminine gender role orientation, and sociosexual orientation in 282 heterosexual and 282 homosexual young men. Homosexual men reported significantly more pronounced sociosexual behavior (d = 0.65) and desire (d = 0.31). Furthermore, homosexual men were characterized by lower masculine (d =-0.26) and higher feminine (d = 0.38) gender role orientation. Latent variable analyses revealed that homosexual men as well as more masculine men, irrespective of their sexual orientation, had more uncommitted sexual relations and more unrestricted sociosexual attitudes. A similar pattern could be identified for sociosexual desire. While homosexual men were more unrestricted in their sociosexual desire, this also held for more feminine men in general. Overall, findings indicated that homosexual orientation is positively associated with sociosexual orientation. In addition, masculine/feminine gender role orientations exert differential influences on the three facets of sociosexuality independent of sexual orientation.

The present study investigated the mutual interplay of sexual orientation, masculine and feminine gender role orientation, and sociosexual orientation in young women. To ensure cross-sample validity, 323 heterosexual women and 323 lesbian women, ranging in age from 18 to 29 years, were matched for possible confounding variables. Lesbian women scored significantly higher (d = 0.27) on the Desire subscale of the Revised Sociosexual Orientation Inventory, but not on the Behavior (d = 0.07) and Attitude subscales (d = 0.11). Concerning gender role orientation, heterosexual women were characterized by significantly higher scores on the Femininity scale (d = 0.20), whereas lesbian women showed more pronounced masculine gender role orientation (d = 0.16). Structural equation modeling revealed two functionally distinct relationships between sexual orientation and sociosexuality, on the one hand, and between gender role orientation and sociosexuality, on the other hand. Sociosexual desire was exclusively associated with a woman's sexual orientation with no indication of any mediating effect of gender role orientation. Sociosexual behavior was positively related to a woman's level of masculine gender role orientation, while sociosexual attitude was positively associated with masculine and negatively associated with feminine gender role orientation, irrespective of sexual orientation.

The ability to recognise others’ emotions from nonverbal cues (emotion recognition ability, ERA) is measured with performance-based tests and has many positive correlates. Although researchers have long proposed that ERA is related to general mental ability or intelligence, a comprehensive analysis of this relationship is lacking. For instance, it remains unknown whether the magnitude of the association varies by intelligence type, ERA test features, as well as demographic variables. The present meta-analysis examined the relationship between ERA and intelligence based on 471 effect sizes from 133 samples and found a significant mean effect size (controlled for nesting within samples) of r = .19. Different intelligence types (crystallized, fluid, spatial, memory, information processing speed and efficiency) yielded similar effect sizes, whereas academic achievement measures (e.g. SAT scores) were unrelated to ERA. Effect sizes were higher for ERA tests that simultaneously present facial, vocal, and bodily cues (as compared to tests using static pictures) and for tests with higher reliability and more emotions. Results were unaffected by most study and sample characteristics, but effect size increased with higher mean age of the sample. These findings establish ERA as sensory-cognitive ability that is distinct from, yet related to, intelligence.

The mental speed approach to individual differences in mental ability (MA) is based on the assumption of higher speed of information processing in individuals with higher than those with lower MA. Empirical support of this assumption has been inconsistent when speed was measured by means of the P3 latency in the event-related potential (ERP). The present study investigated the association between MA and P3 latency as a function of task demands on selective attention. For this purpose, 20 men and 90 women performed on a standard continuous performance test (CPT1 condition) as well as on two further task conditions with lower (CPT0) and higher demands (CPT2) on selective attention. MA and P3 latency negatively correlated in the standard CPT, and this negative relationship even increased systematically from the CPT1 to the CPT2 condition but was absent in the CPT0 condition. The present results indicate that task demands on selective attention are decisive to observe the expected shorter P3 latency in individuals with higher compared to those with lower MA.

The effect of task-irrelevant numerical values on perceived duration is well established. More precisely, higher numerical values (e.g., ‘9’) correspond to longer estimated durations than lower numerical values (e.g., ‘1’). So far, sparse evidence for two moderators, physical context and stimulus salience, has been provided. The contextual effect refers to an increased difference between estimated durations for low and high numerical values when Arabic digits are presented simultaneously with large physical quantities (e.g., ‘kg’), instead of small physical quantities (e.g., ‘g’). Similarly, the salience effect refers to the observation that differences in time estimations increase when attention is directed to numerical values’ magnitude. Using a time reproduction paradigm, we conducted four experiments to further investigate these two moderators and their possible interaction. In Experiments 1a and 1b, target intervals differed in duration (800, 1000, 1200 ms), numerical value (1, 2, 8, 9), and physical quantity (mg, kg, without). Experiments 2 and 3 additionally included the manipulation of the attentional focus (numerical value or physical quantity) and further quantities (cm, km). Our results supported the positive effect of numerical values on reproduced durations. This was also true for the moderating effect of stimulus salience, which was always significant. In contrast, no evidence for a contextual effect was observed even when participants’ attention was directed on the difference in physical quantity. In conclusion, our data challenge the existence of a moderating contextual effect, while supporting the moderating effect of stimulus salience.

Spatial suppression refers to the increasingly difficult identification of motion direction with increasing size of the moving stimulus. Previous research indicated a close association between stronger spatial suppression and higher psychometric intelligence. Since the measurement of spatial suppression is based on the time needed to correctly identify the motion direction of small vs. large stimuli, the present study aimed to elucidate the unique and shared effects of mental speed, as assessed by reaction times from the Hick task, and spatial suppression on psychometric intelligence. In 177 young adults, neither manifest nor latent variables representing spatial suppression were related to psychometric intelligence. Irrespective of stimulus size, however, individuals with higher intelligence detected motion direction faster than individuals with lower intelligence. While we cannot fully rule out stimulus and apparatus differences as being behind this discrepancy with prior work, our results indicate that the link between spatial suppression and intelligence is at best confined to a specific range of stimulus parameters. The relation between intelligence and speed of motion direction detection (independent from stimulus size) overlapped with the relation between psychometric intelligence and reaction times in the Hick task. This latter result is consistent with the assumption that there is a general (task-independent) speed of information processing, which is robustly related to psychometric intelligence.

The importance of sex as a biological variable has recently been emphasized by major funding organizations [1] and within the neuroscience community [2]. Critical sex-based neural differences are indicated by, for example, conditions such as autism spectrum disorder (ASD) that have a strong sex bias with a higher prevalence among males [51, 3]. Motivated by this broader context, we report a marked sex difference in a visual motion perception task among neurotypical adults. Motion duration thresholds [4, 5] the minimum duration needed to accurately perceive motion direction were considerably shorter for males than females. We replicated this result across three laboratories and 263 total participants. This type of enhanced performance has previously been observed only in special populations including ASD, depression, and senescence [6-8]. The observed sex difference cannot be explained by general differences in speed of visual processing, overall visual discrimination abilities, or potential motor-related differences. We also show that while individual differences in motion duration thresholds are associated with differences in fMRI responsiveness of human MT+, surprisingly, MT+response magnitudes did not differ between males and females. Thus, we reason that sex differences in motion perception are not captured by an MT+fMRI measure that predicts within-sex individual differences in perception. Overall, these results show how sex differences can manifest unexpectedly, highlighting the importance of sex as a factor in the design and analysis of perceptual and cognitive studies.

The present study investigated whether the relationship between temporal resolution power (TRP) and general intelligence (g) is more fundamental than the relationship between speed of information processing (SIP) and g when a) TRP and SIP are assessed with an equally effective test battery, and b) when the relationship between SIP and g is strengthened by an increase of task demands. A heterogeneous sample of 110 male and 118 female participants completed a short version of the Berlin Intelligence Structure test as a measure of g. TRP was assessed with three psychophysical timing tasks and SIP with three different reaction time tasks in which cognitive task demands were systematically increased across task conditions. SIP variance was divided into a component representing speed of processing increasing cognitive task demands and a component representing processing speed independent of the experimental manipulation. The relationship between TRP and g was robust and unaffected by both SIP components. SIP caused by the enhanced cognitive task demands explained variance in g irrespective of TRP, whereas TRP completely accounted for the relationship between speed unaffected by the experimental manipulation and g. In contrast to previous findings, however, the effect of TRP on the SIP-g relationship ceases when SIP is derived from cognitively more demanding reaction time tasks.

The paper investigates why the virtual correspondence of the ability component of fluid reasoning scores and general intelligence observed by Schweizer, Troche, and Rammsayer (2011) was not replicated by Lozano (2015). It is shown that the time limit of the scale used in the former study caused a speed effect that strengthened the relationship, whereas the scale used by Lozano (2015) that was considered as unspeeded did not cause such an effect. Modifying the statistical model to eliminate this effect resulted in similar estimates of the relationship between the ability component of fluid reasoning and general intelligence.

Functional near infrared spectroscopy (fNIRS) is increasingly used for investigating cognitive processes. To provide converging evidence for the validity of fNIRS recordings in cognitive neuroscience, we investigated functional activation in the frontal cortex in 43 participants during the processing of a visuospatial working memory (WM) task and a sensory duration discrimination (DD) task functionally unrelated to WM. To distinguish WM-related processes from a general effect of increased task demand, we applied an adaptive approach, which ensured that subjective task demand was virtually identical for all individuals and across both tasks. Our specified region of interest covered Brodmann Area 8 of the left hemisphere, known for its important role in the execution of WM processes. Functional activation, as indicated by an increase of oxygenated and a decrease of deoxygenated hemoglobin, was shown for the WM task, but not in the DD task. The overall pattern of results indicated that hemodynamic responses recorded by fNIRS are sensitive to specific visuospatial WM capacity-related processes and do not reflect a general effect of increased task demand. In addition, the finding that no such functional activation could be shown for participants with far above-average mental ability suggested different cognitive processes adopted by this latter group.

Inspired by Robert Stelmack's research on the electrophysiological foundation of mental ability (MA), the present study investigated whether the well-established negative relation between reaction times (RTs) and MA in four conditions of the Hick task can be explained by faster stimulus classification and consolidation in working memory as measured by the P300 latency in the event-related potential. RTs of 113 female participants aged from 17 to 38years increased with increasing number of response alternatives in the Hick task. Except for one condition, RTs were negatively and significantly related to MA but this relationship did not increase with task complexity. This pattern of results suggests that speed of response selection does not account for shorter RTs in individuals with higher than lower MA. Against our expectations, however, in none of the four conditions, P300 latency was related to MA. Thus, the negative association between RTs and MA cannot be explained in terms of faster stimulus evaluation and consolidation in working memory. As a tentative explanation of this lack of association, even the most complex condition was not demanding enough to require the inhibitory processes underlying the P300 component in a sufficient extent to reveal MA-related individual differences in P300 latency.

The ability to recognize emotions from nonverbal cues (emotion recognition ability, ERA) is a core component of emotional intelligence, which has recently been conceptualized as a second-stratum factor of intelligence (MacCann et al., 2014). However, only few studies have empirically investigated the link between ERA, intelligence, and other mental abilities. The present study examined the associations between ERA, fluid intelligence, and sensory sensitivity in a sample of 214 participants. Results showed that both fluid intelligence and sensory sensitivity explained unique portions of variance in ERA. These findings suggest that future studies on ERA should include intelligence measures to assess the incremental validity of ERA above and beyond intelligence.

The present study was designed to systematically investigate the functional relationships among biological sex; masculine and feminine gender-role characteristics; and sociosexual behavior, attitude toward, and desire for uncommitted casual sex as three facets of sociosexual orientation. For this purpose, facets of sociosexuality were assessed by the Revised Sociosexual Orientation Inventory (SOI-R) and masculine and feminine gender-role characteristics were assessed by a revised German version of the Bem Sex-Role Inventory in 499 male and 958 female heterosexual young adults. Confirmatory factor analysis (CFA) and structural equation modeling (SEM) revealed differential mediating effects of masculine and feminine gender-role characteristics on the relationship between biological sex and the three facets of sociosexual orientation. Sociosexual behavior was shown to be primarily controlled by an individual's level of masculine gender-role characteristics irrespective of biological sex. Sociosexual desire was identified as being a sole function of biological sex with no indication for any effect of masculine or feminine gender-role characteristics, while sociosexual attitude was influenced by biological sex as well as by masculine and feminine gender-role characteristics to about the same extent.