Differences In Base Rates Research Articles

MRI white matter hyperintensities and neuropsychological performance in a clinical sample

Objective White-matter hyperintensities (WMH) are commonly observed on MRI of non-demented patients. Findings are mixed regarding their association with neuropsychological test performance. The purpose of this study is to investigate the association of white-matter hyperintensities on routine clinical MRI and neuropsychological test performance in non-demented outpatients. Method Two groups were selected based on MRI results: (1) normal (n = 62, M age = 50.21, M edu = 14.89) and (2) WMH without other MRI abnormality (n = 56, M age = 55.43, M edu = 14.04). Neuropsychological tests assessed five cognitive domains for which index scores were calculated and categorized in the following clinical ranges: well below average, below average, low average, average, and above average. Results Likelihood ratios comparing base rates for the WMH and normal groups across these clinical ranges revealed significant base rate differences only for attention/processing speed (Lχ2 = 16.47, df = 4, p < .01), with more WMH patients in the below average range and fewer above average. Odds ratios were calculated using two z-score cutoffs: −1.67 and −1.00. While patients with WMH were significantly more likely to have an index z-score ≤ −1.00 on attention/processing speed tests (OR = 3.62, 95% CI: 1.08–12.19) and an executive function test of reasoning (OR = 4.63, 95% CI: 1.18–18.19), there was no difference in the likelihood the groups would have a z-score ≤ −1.67 in any cognitive domain. Conclusions Taken together, these findings indicate that among referred outpatients without dementia, WMH on routine clinical MRI are associated with relatively mild decreased attention and processing speed.

Does context recollection depend on the base-rate of contextual features?

Episodic recollection is defined by the re-experiencing of contextual and target details of a past event. The base-rate dependency hypothesis assumes that the retrieval of one contextual feature from an integrated episodic trace cues the retrieval of another associated feature, and that the more often a particular configuration of features occurs, the more effective this mutual cueing will be. Alternatively, the conditional probability of one feature given another feature may be neglected in memory for contextual features since they are not directly bound to one another. Three conjoint recognition experiments investigated whether memory for context is sensitive to the base-rates of features. Participants studied frequent versus infrequent configurations of features and, during the test, they were asked to recognise one of these features with (vs. without) another feature reinstated. The results showed that the context recollection parameter, representing the re-experience of contextual features in the dual-recollection model, was higher for frequent than infrequent feature configurations only when the binding of feature information was made easier and the differences in the base-rates were extreme, otherwise no difference was found. Similarly, base-rates of features influenced response guessing only in the condition with salient differences in base-rates. The Bayes factor analyses showed that the evidence from two of our experiments favoured the base-rate neglect hypothesis over the base-rate dependency hypothesis; the opposite result was obtained in the third experiment, but only when high base-rate disproportion and facilitated feature binding conditions were used.

A Comparison of Decision Rule Accuracy From Curriculum-Based Measurement of Reading and Nonsense Word Fluency

The transition from sounding out unfamiliar words to effortlessly reading connected text does not occur all at once nor at the same rate for students. The purpose of this study was to explore the accuracy of three decision rules (data point, median, and trend line) applied to progress monitoring outcomes of alphabetic principle (nonsense word fluency [NWF]) and oral reading rate (curriculum-based measurement of reading [CBM-R]). Outcomes from students receiving Tier-2 supports in oral reading and decoding were analyzed to generate model parameters. Scores were simulated for NWF and CBM-R and decision rules were applied to schedules where one observation was collected per week. The trend-line rule was viable with NWF after 7 weeks and 9 to 10 weeks with CBM-R. Differences in base rates of non-proficiency between measures call into question the utility of NWF to capture student improvement in alphabetic principle as they encounter increasingly complex word types.

Development of criteria for cognitive dysfunction in post-COVID syndrome: the IC-CoDi-COVID approach

BackgroundWe aimed to develop objective criteria for cognitive dysfunction associated with the post-COVID syndrome. MethodsFour hundred and four patients with post-COVID syndrome from two centers were evaluated with comprehensive neuropsychological batteries. The International Classification for Cognitive Disorders in Epilepsy (IC-CoDE) framework was adapted and implemented. A healthy control group of 145 participants and a complementary data-driven approach based on unsupervised machine-learning clustering algorithms were also used to evaluate the optimal classification and cutoff points. ResultsAccording to the developed criteria, 41.2% and 17.3% of the sample were classified as having at least one cognitive domain impaired using -1 and -1.5 standard deviations as cutoff points. Attention/processing speed was the most frequently impaired domain. There were no differences in base rates of cognitive impairment between the two centers. Clustering analysis revealed two clusters, although with an important overlap (silhouette index 0.18-0.19). Cognitive impairment was associated with younger age and lower education levels, but not hospitalization. ConclusionsWe propose a harmonization of the criteria to define and classify cognitive impairment in the post-COVID syndrome. These criteria may be extrapolated to other neuropsychological batteries and settings, contributing to the diagnosis of cognitive deficits after COVID-19 and facilitating multicenter studies to guide biomarker investigation and therapies.

Association between recollection and familiarity‐based memory measures and plasma biomarkers for Alzheimer’s disease

AbstractBackgroundNormal aging and preclinical Alzheimer’s Disease (AD) share common features, such as structural changes to medial temporal lobe regions and declining episodic memory. However, prior work suggests qualitative differences between AD‐related memory changes and those due to aging. Specifically, recollection‐based, or contextual, memory declines with both normal aging and AD. Alternatively, familiarity‐based, or item, memory is more specific to preclinical AD and atrophy in the perirhinal cortex. In the current analysis, we examined the relationship between these forms of memory with plasma biomarkers associated with AD and neurodegeneration.MethodAt the Penn Alzheimer’s Disease Research Center, 127 cognitively‐normal participants (age=73.12±6.62, 59% female, years of education=16.40±2.62, 80% Caucasian) completed an experimental memory paradigm assessing recollection and familiarity along with standard neuropsychological testing. In this paradigm, pictures of common objects were presented in 80 pairs at study and participants were told to pick the object they preferred. At test, 40 intact, 40 re‐arranged, and 40 novel object pairs were presented. Recollection was defined as the probability(intact)–probability(rearranged), while familiarity was defined as the probability(rearranged)/(1‐R). To account for differences in base rates of false alarms (‘‘old’’ responses to novel pairs), familiarity was calculated using a measure of discrimination (d’) derived from signal detection theory. Whole blood samples were collected in EDTA‐tubes, spun‐down, and stored at ‐80°C. Measures of glial fibrillary acidic protein (GFAP), neurofilament light chain (Nfl), and plasma tau (p‐Tau181) were generated with the Simoa HD‐X analyzer system.ResultFamiliarity correlated with GFAP (r(125) =‐0.24, p&lt;0.05) (Figure 1) and NfL (r(125) =‐0.23, p&lt;0.05) (Figure 2). Further, a partial correlation controlling for age and days between the experimental and plasma measure remained significant for GFAP (r(125)=‐0.25, p&lt;0.05). Additionally, recollection correlated with Nfl (r(125) =‐0.25, p&lt;0.05) (Figure 3). Correlations with standard neuropsychological tests revealed no significant results.ConclusionThis study reveals that within the normal aging spectrum, familiarity‐based memory correlates with molecular measures that have been associated with amyloid (GFAP), while both measures correlated with a non‐specific measure of neurodegeneration (NfL). This supports the notion that familiarity may be sensitive to preclinical AD.

Utility of CVLT–3 response bias as a measure of performance validity after traumatic brain injury

Objective We sought to determine the utility of a new performance validity index that was recently proposed. In particular, we wanted to determine if this index would be associated with a specificity of at least .90, a sensitivity of at least .40, and an Area Under the Curve of at least .70 in a traumatic brain injury (TBI) sample. Method We used logistic regression to investigate how well this new index could distinguish persons with TBI (n = 148) who were evaluated within 1–36 months after injury. All participants had been classified on the basis of at least two independent performance validity tests as having provided valid performance (n = 128) or invalid performance (n = 20). Results The new performance validity index had acceptable specificity (.96) but had suboptimal sensitivity (.35) and Area Under the Curve (.66). It was concerning that almost half (5/12) of the cases that were identified by this index as providing invalid effort were false positives. Although a slightly more liberal cut-off improved sensitivity, the problem with poor positive predictive power remained. The conventional Forced Choice index had relatively better classification accuracy. Conclusion Differences in base rates between the original sample of Martin et al. and the current one most likely affected positive predictive power of the new index. Although their performance validity has excellent specificity, the current results do not support the application of this index in the clinical evaluation of patients with traumatic brain injury when base rates of invalid performance differ markedly from those in the original study.

Attention biases in the inverse base-rate effect persist into new learning.

The inverse base-rate effect is a tendency to predict the rarer of two outcomes when presented with cues that make conflicting predictions. Attention-based accounts of the effect appeal to prioritised attention to predictors of rare outcomes. Changes in the processing of these cues are predicted to increase the rate at which they are learned about in the future (i.e., their associability). Our previous work has shown that the development of the inverse base-rate effect is accompanied by greater overt attention to the rare predictor while participants made predictions, and during feedback, and these biases change in different ways depending on the stage of training and global base-rate differences. It is unknown whether these gaze patterns reflect the manner in which cues are prioritised for learning or are merely a consequence of learning what the cues predict. This study tested whether the associability of common and rare predictors differed, and if so, how this difference changed as a function of training length and the presence of base-rate differences in the outcomes. Experiment 1 tested cue associability using a second learning task presented after either short or long training. The results suggest an associability advantage for rare predictors that weakens with extended training and is not strongly affected by the presence of global base-rate differences. However, Experiment 2 showed a clear effect of base-rate differences on choice after very brief training, indicating that attention biases as measured by associability change are not sufficient to produce the inverse base-rate effect.

Emotion regulation and relations to well-being across the lifespan.

The specific strategies that individuals use to regulate their emotions have shown strong associations with various indices of well-being. However, theoretical accounts suggest that strategy use, and the associations between strategy use and well-being, may change across the life span. Attempts have been made to assess whether levels of strategy use, and the association between strategy use and well-being, change across development; however, studies typically do not take into account potential differences in base rates of item endorsement across the life span. Therefore, the current study had two objectives. First, we sought to examine whether relative ER strategy reliance, or the proportional degree to which an individual relies on various ER strategies, varied across three developmental periods: early adolescence, young adulthood, and adulthood. Second, we sought to identify whether the associations between relative strategy use and well-being differed significantly across these developmental periods. Results showed that relative reliance on distraction, rumination, relaxation, and suppression differed significantly across age groups. Moreover, results showed that the association between relative use of reappraisal and suppression interacted with age group to predict relationship quality. Relative strategy use and age did not interact significantly to predict anxiety and depressive symptoms. Theoretical and practical implications are discussed. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Evaluating the Prevalence of Low Factor Scores on the ImPACT™ Quick Test in Adolescents and Adults using Multivariate Base Rates

Abstract Purpose The ImPACT™ Quick Test (QT) is a brief iPad-based battery of neurocognitive tests that has been standardized on a sample of children, adolescents, and adults (ages 12-70). We sought to provide information regarding the prevalence of low ImPACT™ QT scores in the normative sample to improve clinical interpretation and reduce the risk of over-interpreting, or misinterpreting, a single low score. Methods Participants included 616 individuals ranging in age from 12 to 70, who were assessed individually. The ImPACT QT includes five subtests, contributing to three factor scores: Motor Speed, Memory, and Attention Tracker. The prevalence of low factor scores, stratified by age and gender, were calculated using multivariate base rates. Results In the total sample, obtaining 1 score below the 25th percentile was common (base rate, BR=31.8%), but obtaining 2 or more scores in this range was uncommon (BR=13.3%). Similarly, obtaining 1 score below the 16th percentile was common (BR=22.3%), but obtaining two or more scores in this range was very uncommon (BR=5.4%). There were small differences in base rate between genders and the number of low scores were fairly similar across the age groups. Conclusion Results from this study parallel previous work illustrating that a substantial percentage of healthy individuals will obtain one or more low test score when administered a battery of multiple cognitive test measures. Given that some healthy, non-concussed individuals will obtain a single score below expected cut-offs, clinicians should caution against overinterpreting a single low test score.

Discrimination and Calibration Properties of the Level of Service Inventory–Ontario Revision in a Correctional Mental Health Sample

We examined the predictive properties of the Level of Service Inventory–Ontario Revision (LSI-OR) in a sample of 604 provincially incarcerated men with mental illness from a correctional mental health facility followed up nearly 2 years after release. Recidivism base rates and LSI-OR scores were relatively consistent across major mental disorder categories, but higher among individuals with personality disorder, substance use disorder, or dual diagnosis. LSI-OR scores predicted general and violent recidivism in the overall sample and among specific diagnostic groups. Calibration analyses were conducted to model 1-year recidivism estimates for the overall sample and among individual diagnostic groups associated with individual LSI-OR scores. Good correspondence was observed among the different diagnostic groups, with some difference in recidivism trajectories given the differences in base rate. The results support the predictive properties of the LSI-OR with correctional mental health samples and inform the recidivism estimates associated with LSI-OR scores in this population.

To Change is Human: "Abnormal" Reliable Change Memory Scores are Common in Healthy Adults and Older Adults.

The rate at which people obtain reliably improved or declined cognitive test scores when retested, in the absence of a change in clinical condition, is largely unknown. The purpose of this study was to illustrate the prevalence of statistically reliable change scores on memory test batteries in healthy adults and older adults. Participants included three adult and older adult test-retest samples from memory test batteries. Reliable change scores (reliable change index with 90% confidence interval and practice effects) were calculated for the indexes and subtests of each battery. Multivariate analyses involved calculating the frequencies of healthy people obtaining one or more reliably declined or one or more reliably improved scores when considering all change scores simultaneously within each battery. Across all batteries, having one or more reliably changed index or subtest score on retest was common. With most batteries, having two or more reliably changed scores was uncommon. Those with higher intellectual abilities were more likely to have a change on retest; however, no significant differences in base rates were found based on education level, sex, or ethnic minority status. Those older adults who did not have any low memory scores were more likely to improve than decline on retest. Having a single reliably changed score on retest is common when interpreting a battery of memory measures. This has implications for determining cognitive decline and cognitive recovery, suggesting that multivariate interpretation is necessary.

Predictive brain signals best predict upcoming and not previous choices.

Predictive brain signals best predict upcoming and not previous choices.

Auditors’ Use Of Base Rate Evidence: Insights From A Cognitive Styles Model

Good auditors sometimes draw different conclusions from quite similar audit evidence. This may result from differences in auditors’ information gathering and processing styles. In particular, differences in auditors’ cognitive styles preferences may lead to differential reliance on base rate evidence. Base rate evidence -- such as information from auditors’ past judgments -- is important because it is both relevant and inexpensive. One line of research suggests under-utilization of such evidence in the opinion forming process; another suggests the opposite. A comparison of methodological differences indicates that the framing of the experimental tasks may be contributing to the conflicting results. This paper presents the results of an empirical investigation of framing effects in evidence use and provides support for the proposition that framing may be an important factor. In addition, the use of cognitive styles models is proposed as a possible basis for explaining individual differences in base rate and sample evidence use.

Violent Behavior and Gender of Swedish Psychiatric Patients: A Prospective Clinical Study

This study was designed to investigate the base rate of violent behavior, the predictive validity of the Classification of Violence Risk (COVR) software, and specific risk factors for violence among nonforensically involved psychiatric patients in Sweden. On discharge from two psychiatric hospitals in Stockholm, 331 patients were interviewed. Telephone interviews with the patients and supportive others, as well as data from a national criminal register, were used to measure violent behavior 20 weeks after discharge. After the baseline interview, patients were assigned to different risk groups by the COVR software. Predicted risk was compared with the occurrence of actual acts of violence during the follow-up. Gender differences in base rates of violent behavior among the general psychiatric population were not found during the 20 weeks of follow-up after discharge. Violent behavior was significantly predicted by young age of males and by level of anger, violent thoughts, and victimization of females. The predictive validity of the COVR software was comparable between females (area under the curve [AUC]=.78) and males (AUC=.76). Violent behavior was uncommon for all patients. Although several risk factors were significantly associated with violence by each gender, the COVR software could predict violence equally well for both genders.

The effects of age on initiation of mental health treatment after positive PTSD screens among Veterans Affairs primary care patients

ObjectiveThe objective was to examine differences by age in mental health treatment initiation in Veterans Health Administration (VA) primary care patients after positive posttraumatic stress disorder (PTSD) screens. MethodsThis was a retrospective cohort study of 71,039 veterans who were administered PTSD screens during primary care encounters in 2007 at four Pacific Northwest VA medical center sites and who had no specialty mental health clinic visits or PTSD diagnoses recorded in the year before screening. Main outcome measures were attendance of any specialty mental health clinic visits or receipt of any antidepressant medication in the year after a positive PTSD screen. ResultsOlder veterans, compared with veterans less than 30 years old, were less likely to attend any specialty mental health visits after positive PTSD screens [adjusted odds ratios (ORs) ranged from .57 to .12, all P<.001], and veterans 75 years and older were less likely to receive any antidepressant medication (adjusted OR=.56, P<.001). ConclusionsInitiation of mental health treatment among veterans who screen positive for PTSD varies significantly by age. Further research should examine whether this is due to differences in base rates of PTSD, treatment preferences, provider responses to screens or other age-related barriers to mental health treatment.

Base Rates of Post-concussive Symptoms in a Nonconcussed Multicultural Sample

The purpose of this preliminary study was to investigate differences in base rates of post-concussion syndrome (PCS) symptomatology in healthy individuals separated by cultural identity and language. In this study, we sought to determine if differences exist in terms of base-rate endorsement of PCS symptomatology in healthy individuals and whether culture and language-based specific clusters of PCS symptomatology exist in healthy individuals. A total of 151 participants, consisting of 33 Caucasians, 49 Chinese, Filipinos, and Southeast Asians, 43 Arabs, West Asians, and South Asians, and 26 participants of African descent completed four questionnaires and two subtests of a test of verbal ability. We found that the occurrence of PCS symptoms did not differ by culture and language-based groups in general, but that there were differences between groups in the base rates of individual symptom endorsement. Our preliminary findings illustrate that cultural and linguistic background may play a moderating role in the endorsement of PCS symptomatology and that false-positive conclusions may be reached disproportionally between groups. Our results underscore the importance of considering the influence of culture and language, in conjunction with a growing list of factors that can influence, maintain, and/or mimic persistent PCS.

Enhanced old–new recognition and source memory for faces of cooperators and defectors in a social-dilemma game

A popular assumption in evolutionary psychology is that the human mind comprises specialized cognitive modules for social exchange, including a module that serves to enhance memory for faces of cheaters. In the present study, participants played a trust game with computerized opponents, who either defected or cooperated. In a control condition, no interaction took place. In a surprise memory test, old–new recognition for faces and source memory for the associated cooperative or non-cooperative behavior were assessed. A multinomial model was used to measure old–new discrimination, source memory, and guessing biases separately. Inconsistent with the assumption of a memory mechanism that focuses exclusively on cheating, the present study showed enhanced old–new discrimination and source memory for both cooperators and defectors. Rarity of the behavior strategies within the experiment modulated source memory, but only when the differences in base rates were extreme. The findings can be attributed to a mechanism that focuses on exchange-relevant information and flexibly adapts to take into account the relative significance of this information in the encoding context, which may be more beneficial than focusing exclusively on cheaters.

Developmental trajectories of boys' and girls' delinquency: sex differences and links to later adolescent outcomes.

This study examined gender differences in trajectories of delinquent behaviors over a 6-year period in adolescence and differential outcomes of these diverse developmental pathways. Participants were 754 children who were part of a longitudinal study of the development of early starting conduct problems. Four trajectory patterns were identified across grades 7-12: increasing, desisting, chronic, and nonproblem groups. Although the proportion of boys and girls varied across the pathways, both genders were represented on these trajectories. Boys were more represented on the chronic and desisting trajectories; girls were more represented in the nonproblem group. However, the proportion of boys and girls was similar in the increasing trajectory. Trajectory membership significantly predicted age 19 outcomes for partner violence, risky sexual behavior and depression, and the risk conferred on these negative adjustment outcomes did not vary by gender. The overall pattern was characterized by poor outcomes at age 19 for youth in both the chronic and the increasing trajectories. The major conclusion is that, other than base rate differences, developmental patterns and outcomes for girls mimic those previously found for boys.

Toward Improved Ecological Validity in the Acoustic Measurement of Overall Voice Quality: Combining Continuous Speech and Sustained Vowels

To improve ecological validity, perceptual and instrumental assessment of disordered voice, including overall voice quality, should ideally sample both sustained vowels and continuous speech. This investigation assessed the utility of combining both voice contexts for the purpose of auditory-perceptual ratings as well as acoustic measurement of overall voice quality. Sustained vowel and continuous speech samples from 251 subjects with (n=229) or without (n=22) various voice disorders were concatenated and perceptually rated on overall voice quality by five experienced voice clinicians. After removing the nonvoiced segments within the continuous speech samples, the concatenated samples were analyzed using 13 acoustic measures based on fundamental frequency perturbation, amplitude perturbation, spectral and cepstral analyses. Stepwise multiple regression analysis yielded a six-variable acoustic model for the multiparametric measurement of overall voice quality of the concatenated samples (with a cepstral measure as the main contributor to the prediction of overall voice quality). The correlation of this model with mean ratings of overall voice quality resulted in r(s)=0.78. A cross-validation approach involving the iterated internal cross-correlations with 30 subgroups of 100, 50, and 10 samples confirmed a comparable degree of association. Furthermore, the ability of the model to distinguish voice-disordered from vocally normal participants was assessed using estimates of diagnostic precision including receiver operating characteristic (ROC) curve analysis, sensitivity, and specificity, as well as likelihood ratios (LRs), which adjust for base-rate differences between the groups. Depending on the cutoff criteria employed, the analyses revealed an impressive area under ROC=0.895 as well as respectable sensitivity, specificity, and LR. The results support the diagnostic utility of combining voice samples from both continuous speech and sustained vowels in acoustic and perceptual analysis of disordered voice. The findings are discussed in relation to the extant literature and the need for further refinement of the acoustic algorithm.

Sex differences in the longitudinal relations among family risk factors and childhood externalizing symptoms.

Despite potential sex differences in base rates, predictors, and maintaining processes for children's externalizing behaviors, little prospective research has examined sex differences in the relations between concurrent, proximal family risk factors and children's externalizing behaviors. The current study examined the relations among maternal depressive symptoms, maternal parenting behaviors (i.e., negativity and low warmth), and child externalizing symptoms at 24 months and first grade in a community-based sample of 1,364 children enrolled in the National Institute of Child Health and Human Development Study of Early Child Care and Youth Development. Structural equation modeling revealed that maternal depression and negative parental behaviors were associated with concurrent externalizing behaviors, though maternal depression may be differentially linked to boys' and girls' externalizing problems. The relation between depression and boys' externalizing symptoms was more pronounced at 24 months, and over time, the relation between maternal depression and boys' externalizing symptoms decreased in magnitude, whereas this relation increased among girls.