An important open problem is how values are compared to make simple choices. A natural hypothesis is that the brain carries out the computations associated with the value comparisons in a manner consistent with the Drift Diffusion Model (DDM), since this model has been able to account for a large amount of data in other domains. We investigated the ability of four different versions of the DDM to explain the data in a real binary food choice task under conditions of high and low time pressure. We found that a seven-parameter version of the DDM can account for the choice and reaction time data with high-accuracy, in both the high and low time pressure conditions. The changes associated with the introduction of time pressure could be traced to changes in two key model parameters: the barrier height and the noise in the slope of the drift process.

Response time is used here to interpret choice in decision problems. I first establish that there is a close connection between short response time and choices that are clearly a mistake. I then investigate whether a correlation also exists between response time and behavior that is inconsistent with some standard theories of decision making. The lack of such a correlation could be interpreted to imply that such behavior does not reflect a mistake. It is also shown that a typology of slow and fast responders may, in some cases, be more useful than the standard typologies.

Internet-based surveys have expanded public opinion data collection at the expense of monitoring respondent attentiveness, potentially compromising data quality. Researchers now have to evaluate attentiveness ex-post. We propose a new proxy for attentiveness—response-time attentiveness clustering (RTAC)—that uses dimension reduction and an unsupervised clustering algorithm to leverage variation in response time between respondents and across questions. We advance the literature theoretically arguing that the existing dichotomous classification of respondents as fast or attentive is insufficient and neglects slow and inattentive respondents. We validate our theoretical classification and empirical strategy against commonly used proxies for survey attentiveness. In contrast to other methods for capturing attentiveness, RTAC allows researchers to collect attentiveness data unobtrusively without sacrificing space on the survey instrument.

‘Munchausen's syndrome by proxy’ characteristically describes women alleged to have fabricated or induced illnesses in children under their care, purportedly to attract attention. Where conclusive evidence exists the condition's aetiology remains speculative, where such evidence is lacking diagnosis hinges upon denial of wrong-doing (conduct also compatible with innocence). How might investigators obtain objective evidence of guilt or innocence? Here, we examine the case of a woman convicted of poisoning a child. She served a prison sentence but continues to profess her innocence. Using a modified fMRI protocol (previously published in 2001) we scanned the subject while she affirmed her account of events and that of her accusers. We hypothesized that she would exhibit longer response times in association with greater activation of ventrolateral prefrontal and anterior cingulate cortices when endorsing those statements she believed to be false (i.e., when she ‘lied’). The subject was scanned 4 times at 3 Tesla. Results revealed significantly longer response times and relatively greater activation of ventrolateral prefrontal and anterior cingulate cortices when she endorsed her accusers' version of events. Hence, while we have not ‘proven’ that this subject is innocent, we demonstrate that her behavioural and functional anatomical parameters behave as if she were.

Nonadjacent dependency learning is thought to be a fundamental skill for syntax acquisition and often assessed via an offline grammaticality judgment measure. Asking judgments of children is problematic, and an offline task is suboptimal as it reflects only the outcome of the learning process, disregarding information on the learning trajectory. Therefore, and following up on recent methodological advancements in the online measurement of nonadjacent dependency learning in adults, the current study investigates if the recording of response times can be used to establish nonadjacent dependency learning in children. Forty-six children (mean age: 7.3 years) participated in a child-friendly adaptation of a nonadjacent dependency learning experiment (López-Barroso, Cucurell, Rodríguez-Fornells, & de Diego-Balaguer, 2016). They were exposed to an artificial language containing items with and without nonadjacent dependencies while their response times (online measure) were measured. After exposure, grammaticality judgments (offline measure) were collected. The results show that children are sensitive to nonadjacent dependencies, when using the online measure (the results of our offline measure did not provide evidence of learning). We therefore conclude that future studies can use online response time measures (perhaps in addition to the offline grammaticality judgments) to further investigate nonadjacent dependency learning in children.

Introduction: EMS time factors such as total prehospital, activation, response, scene and transport intervals have been used as a measure of EMS system quality with the assumption that shorter EMS time factors save lives. The objective was to assess in adults and children accessing ground EMS (population), whether operational time factors (intervention and control) were associated with survival at hospital discharge (outcome). Methods: Medline, EMBASE, and CINAHL were searched up to January 2015 for articles reporting original data that associated EMS operational time factors and survival. Conference abstracts and non-English language articles were excluded. Two investigators independently assessed the candidate titles, abstracts, and full text with discrepant reviews resolved by consensus. Risk of bias was assessed using GRADE. Results: A total of 10,151 abstracts were screened for potential inclusion, 199 articles were reviewed in full-text, and 73 met inclusion criteria. Amongst included studies, 49 investigated response time, while 24 investigated other time factors. All articles were observational studies. Amongst the 14 (28.6%) studies where response time was the primary analysis, statistically significant associations between shorter response time and increased survival were found in 5 of 7 cardiac arrest, 1 of 5 general EMS population, and 0 of 2 trauma studies. Other time factors were reported in the primary analysis in 10 (41.7%) studies. One study reported shorter combined scene and transport intervals associated with increased survival in acute heart failure patients. Two studies in trauma patients had somewhat conflicting results with one study reporting shorter prehospital interval associated with increased survival whereas the other reported increased survival associated with longer scene and transport intervals. Study design, analysis, and methodological quality were of considerable variability, and thus, meta-analyses were not possible. Conclusion: There is a substantial body of literature describing the association between EMS time factors and survival, but evidence informing these relationships are heterogeneous and complex. Important details such as patient population, EMS system characteristics, and analytical approach must be taken into consideration to appropriately translate these findings to practice. These results will be important for EMS leaders wishing to create evidence-based time policies.

Amid the recent interest in the role of membrane viscosity in the deformation of a fluid-filled capsule, we consider the role of various capsule properties (shear elasticity, membrane bending stiffness and viscosity) in determining the response and recovery times of a spherical capsule in shear flow. These times are determined by fitting exponential functions to results for the Taylor deformation parameter Dxy. We focus on the relationship between the membrane and fluid viscosity ratios, as suggested by Diaz et al, and whether adjustments to the fluid viscosity ratio may be used to approximate the effects of membrane viscosity. Based on its ability to reproduce response and recovery times, our results suggest that such an approach holds promise.

The Implicit Association Test (IAT) is a computerized two-choice discrimination task in which stimuli have to be categorized as belonging to target categories or attribute categories by pressing, as quickly and accurately as possible, one of two response keys. The discrimination association model has been recently proposed for the analysis of reaction time and accuracy of an individual respondent to the IAT. The model disentangles the influences of three qualitatively different components on the responses to the IAT: stimuli discrimination, automatic association, and termination criterion. The article presents General Race (GRace), a MATLAB-based application for fitting the discrimination association model to IAT data. GRace has been developed for Windows as a standalone application. It is user-friendly and does not require any programming experience. The use of GRace is illustrated on the data of a Coca Cola-Pepsi Cola IAT, and the results of the analysis are interpreted and discussed.

The study of the effects of typographical factors on lexical access has been rather neglected in the literature on visual-word recognition. Indeed, current computational models of visual-word recognition employ an unrefined letter feature level in their coding schemes. In a letter recognition experiment, Pelli, Burns, Farell, and Moore-Page (2006), letters in Bookman boldface produced more efficiency (i.e., a higher ratio of thresholds of an ideal observer versus a human observer) than the letters in Bookman regular under visual noise. Here we examined whether the effect of bold emphasis can be generalized to a common visual-word recognition task (lexical decision: “is the item a word?”) under standard viewing conditions. Each stimulus was presented either with or without bold emphasis (e.g., actor vs. actor). To help determine the locus of the effect of bold emphasis, word-frequency (low vs. high) was also manipulated. Results revealed that responses to words in boldface were faster than the responses to the words without emphasis –this advantage was restricted to low-frequency words. Thus, typographical features play a non-negligible role during visual-word recognition and, hence, the letter feature level of current models of visual-word recognition should be amended.

Linkages between neuropsychological functioning (i.e., response inhibition, processing speed, reaction time variability) and word reading have been documented among children with attention-deficit/hyperactivity disorder (ADHD) and children with Reading Disorders. However, associations between neuropsychological functioning and other aspects of reading (i.e., fluency, comprehension) have not been well-documented among children with comorbid ADHD and Reading Disorder. Children with ADHD and poor word reading (i.e., ≤25th percentile) completed a stop signal task (SST) and tests of word reading, reading fluency, and reading comprehension. Multivariate multiple regression was conducted predicting the reading skills from SST variables [i.e., mean reaction time (MRT), reaction time standard deviation (SDRT), and stop signal reaction time (SSRT)]. SDRT predicted word reading, reading fluency, and reading comprehension. MRT and SSRT were not associated with any reading skill. After including word reading in models predicting reading fluency and reading comprehension, the effects of SDRT were minimized. Reaction time variability (i.e., SDRT) reflects impairments in information processing and failure to maintain executive control. The pattern of results from this study suggest SDRT exerts its effects on reading fluency and reading comprehension through its effect on word reading (i.e., decoding) and that this relation may be related to observed deficits in higher-level elements of reading. (JINS, 2014, 20, 1–10)

Information processing speed is frequently cited as the primary cognitive domain impacted by multiple sclerosis (MS) and is usually evaluated with reaction time (RT) or rapid serial processing (RSP) measures. The present study compared the efficacy of RT and RSP measures to distinguish between patients with MS (N = 42) and healthy controls (N = 40). The RT measure was patterned after the Computerized Tests of Information Processing and included measures of simple, choice, and semantic RT. The RSP measures consisted of the Symbol Digit Modalities Test (SDMT) and the Stroop Test. Substantial differences in information processing speed between patients and controls were found on all tests, with slightly larger effect sizes for RSP measures than RT measures and for the SDMT than the Stroop Test. Binary logistic regression analyses showed RSP measures performed better than RT measures at distinguishing patients from controls, and likewise, the SDMT score performed better than the scores derived from the Stroop Test. Results are discussed in the context of three effects associated with common measures of processing speed: complexity, compounding, and augmentation. (JINS, 2011, 17, 1113–1121)

Focusing on symptoms of attention deficit hyperactivity disorder (ADHD) in a sample obtained from the general population, we aimed to investigate the effects of incentives and event rate on reaction time (RT) performance and response inhibition. We assessed 1156 children, at a mean age of 8 years, on their performance on an inhibition task and a RT task under different experimental conditions that manipulated event rate and incentives. Children with high ADHD (ADHD-H) symptoms showed cognitive performance deficits only under some of the experimental conditions compared to a control group. The fast-incentive condition of the RT task succeeded in normalizing the RT variability, as well as the slow overall speed, in the ADHD-H group. Analyses of ADHD symptom scores as a quantitative trait in the total sample were overall consistent with these findings. The findings suggest that at least some cognitive performance deficits in children with high ADHD symptoms do not reflect stable cognitive deficits. The degree to which cognitive impairments in ADHD can be modulated by energetic or motivational factors has important implications for clinical and educational interventions. (JINS, 2009, 15, 570–579.)