Base rates of non-credible performance in a post-secondary student sample seeking accessibility accommodations.

Objective: Performance Validity Tests (PVTs) have been used to identify non-credible performance in clinical, medicolegal, forensic, and, more recently, academic settings. The inclusion of PVTs when administering psychoeducational assessments is essential given that specific accommodation such as flexible deadlines and increased writing time can provide an external incentive for students without disabilities to feign symptoms. Method: The present study used archival data to establish base rates of non-credible performance in a sample of post-secondary students (n = 1045) who underwent a comprehensive psychoeducational evaluation for the purposes of obtaining academic accommodations. In accordance with current guidelines, non-credible performance was determined by failure on two or more freestanding or embedded PVTs. Results: 9.4% of participants failed at least two of the PVTs they were administered, of which 8.5% failed two PVTs, and approximately 1% failed three PVTs. Base rates of failure for specific PVTs ranged from 25% (b Test) to 11.2% (TOVA). Conclusions: The present study found a lower base rate of non-credible performance than previously observed in comparable populations. This likely reflects the utilization of conservative criteria in detecting non-credible performance to avoid false positives. By contrast, inconsistent base rates previously found in the literature may reflect inconsistent methodologies. These results further emphasize the importance of administering multiple PVTs during psychoeducational assessments. The implications of these findings can further inform clinicians administering assessments in academic settings and aid in the appropriate utilization of PVTs in psychoeducational evaluation to determine accessibility accommodations.

Predictive value of performance validity testing and symptom validity testing in psychoeducational assessment.

Using archival data from 2463 psychoeducational assessments of postsecondary students we investigated whether failure on either symptom or performance validity tests (SVTs or PVTs) was associated with score differences on various cognitive, achievement, or executive functioning performance measures or on symptom report measures related to mental health or attention complaints. In total, 14.6% of students failed one or more PVT, 33.6% failed one or more SVT, and 41.6% failed at least one validity test. Individuals who failed SVTs tended to have the highest levels of self-reported symptoms relative to other groups but did not score worse on performance-based psychological tests. Those who failed PVTs scored worse on performance-based tests relative to other groups. Failure on at least one PVT and one SVT resulted in both performance and self-reported symptoms suggestive of greater impairment compared with those who passed all validity measures. Findings also highlight the need for domain-specific SVTs; failing ADHD SVTs was associated only with extreme reports of ADHD and executive functioning symptoms while failing mental health SVTs related only to extreme reports of mental health complaints. Results support using at least one PVT and one SVT in psychoeducational assessments to aid in diagnostic certainty, given the frequency of non-credible presentation in this population of postsecondary students.

The impact of depression and anxiety on speed of academic performance and retrieval fluency in postsecondary students.

Objective: This study evaluated the functional effects of severe mental health symptoms on speed of academic performance to assist clinicians and educators in determining whether extra time accommodations are evidence-based for students with such diagnoses. Method: Using archival data from 1476 post-secondary students, we examined the performance of students with existing mental health diagnoses who were also reporting extremely high levels of symptoms. Their performance on timed academic achievement and cognitive processing measures was compared with performance of students with learning disabilities, Attention Deficit Hyperactivity Disorder, and clinical controls. Students failing stand-alone performance validity and/or symptom validity measures were excluded from this investigation. Results: Students diagnosed with anxiety and/or depression did not differ from clinical controls on any timed performance measure, typically performing academic tasks within a normal amount of time. By contrast, those with reading disabilities were typically the slowest on all academic tasks. Conclusion: Across the range of timed tests, students with mental health diagnoses did not show functional impairments in tests with a speed component. As such, they would not typically require increased time to perform speeded academic tasks, but they might require alternative accommodations in their post-secondary programmes in order to participate equally.

Processing speed and timed academic skills in children with learning problems.

Information processing speed is commonly measured in intelligence and neuropsychological testing, and the scores from speed measures are considered in diagnostic and management recommendations for students with academic learning problems. However, this score usage often depends on assumptions about strong relationships between cognitive speed and the ability to perform actual academic tasks under time pressure. The primary purpose of the present study was to test the strength of these relationships empirically. In the present study, children with prior learning disability diagnoses (146 girls and 301 boys, ages 10-14 years old) completed diagnostic batteries that included measures of cognitive speed as well as timed academic skills. The relationships between the two types of measures were often modest (median r = 0.25), and the gap between processing speed and timed academic scores was typically approximately 1 standard deviation. The pattern of relationships suggested that superficial similarity in stimuli and task demands affected the strength of associations. These results suggest that timed academic skills cannot be reliably estimated based on processing speed scores, and there will often be significant gaps between the two. Therefore, making diagnostic judgments (e.g., learning disability diagnoses) or management recommendations (e.g., for extended time testing accommodations) should be based on more direct measures of relevant academic skills.

Discriminating malingered attention Deficit Hyperactivity Disorder from genuine symptom reporting using novel Personality Assessment Inventory validity measures.

It is now widely understood that ADHD can be feigned easily and convincingly. Despite this, almost no methods exist to assist clinicians in identifying when such behavior occurs. Recently, new validity indicators specific to feigned ADHD were reported for the Personality Assessment Inventory (PAI). Derived from a logistic regression, these algorithms are said to have excellent specificity and good sensitivity in identifying feigned ADHD. However, these authors compared those with genuine ADHD only to nonclinical undergraduate students (asked to respond honestly or asked to simulate ADHD); no criterion group of definite malingerers was included. We therefore investigated these new validity indicators with 331 postsecondary students who underwent assessment for possible ADHD and compared scores of those who were eventually diagnosed with ADHD (n = 111) to those who were not [Clinical controls (66), Definite malingerers (36); No diagnosis (117)]. The two proposed PAI algorithms were found to have poor positive predictive value (.19 and .17). Self-report validity measures from the Connors' Adult Attention Rating Scale, and the Negative Impression Management scale on the PAI returned more positive results. Overall, more research is needed to better identify noncredible ADHD presentation, as the PAI-based methods proposed by Aita et al. appear inadequate as symptom validity measures.

What can we learn about performance validity from TOVA response profiles?

Given the functional impairments associated with Attention Deficit/Hyperactivity Disorder (AD/HD), a valid diagnosis is important. However, particularly when carried out in adulthood, the diagnostic process can be challenging and is complicated by conclusive evidence that a proportion of individuals referred for evaluation of AD/HD exaggerate or feign their symptoms. Relatively few methods, however, exist to identify such feigning. While continuous performance tests (CPTs) may provide useful information regarding performance validity, the question remains as to whether there are consistent patterns of exaggeration demonstrated by those feigning AD/HD. Thus, this study used cluster analysis to determine whether valid and reliable performance clusters would emerge based on CPT performance. Using archival data from a university-based AD/HD screening clinic, we investigated the performance of 305 adults on the Test of Variables of Attention (TOVA). Three profiles emerged, including one cluster who demonstrated exceptionally low performance on the TOVA, exceptionally high reports of AD/HD symptomology, and higher rates of failure on symptom and performance validity tests. The implication from our analysis is that this group most likely represents individuals who were exaggerating or magnifying their difficulties. The results reaffirm previous research showing that performance profiles on a continuous performance test can be used as an indicator of credible performance.

Learning disability documentation submitted by osteopathic medical students.

An increasing number of individuals are requesting disability accommodations on high-stakes licensing examinations, and neuropsychological evaluation reports are a frequent component of disability documentation. This study reviewed 103 requests for accommodations based on a learning disability (LD), submitted to the National Board of Osteopathic Medical Examiners between 2013 and 2016 for accommodation on the licensure exams for osteopathic physicians. Depending on criteria employed, anywhere from 84 to 97% of applicants failed to meet recognized criteria for a LD diagnosis, with the vast majority demonstrating academic functioning that was average or better relative to most other individuals in the general population. Thus, although given a disability diagnosis, the majority lacked evidence of substantial impairment that would require accommodations under the Americans with Disabilities Act. Additionally, no significant differences were found between the academic achievement or fluency scores of those requesting 50% as compared to 100% extra time. Finally, many evaluators employed grade-based assessment measures to demonstrate academic impairment, even when candidates' functioning using age-based comparisons was unimpaired. Recommendations for future research and practice based on these and other findings are discussed.

A comparison of the self-report patterns of analog versus real-world malingerers of attention deficit hyperactivity disorder.

Much of what we know about malingering of attention deficit hyperactivity disorder (ADHD) has been learned from the performance of analog malingerers, typically first-year psychology students given credit for study participation. It is not clear, however, whether their performance is similar to that found in actual clinical settings. Indeed, past research suggests that analog malingerers may overexaggerate deficits relative to real-world malingerers, making them easier to identify in controlled studies. The purpose of the current study was, therefore, to compare the performance of analog malingers to post-secondary students strongly suspected of malingering ADHD on a self-report measure of ADHD symptoms. Their scores were, in turn, compared to those returned by students with genuine ADHD and clinical controls. Results demonstrated that, apart from analog subjects overexaggerating symptoms of hyperactivity, few differences exist between the scores returned by analog malingerers relative to clinical malingerers. While newly devised symptom validity measures show promise in identifying malingered ADHD, neither the analog nor the clinical malingers consistently failed these symptom validity scales. Furthermore, a good portion in both malingering groups failed to endorse high levels of ADHD symptoms in general. Clinical implications are discussed.

Differences in performance on the test of variables of attention between credible vs. noncredible individuals being screened for attention deficit hyperactivity disorder.

Measuring performance validity in Attention Deficit Hyperactivity Disorder (ADHD) assessments is essential, with multiple studies identifying how easily young adults can feign symptoms on self-report measures. Few methods, however, exist to identify such feigning when it occurs. While some clinicians include computerized tests of attention (e.g., Test of Variables of Attention [TOVA]) when assessing for possible ADHD, it is unclear how symptom exaggerators perform, and whether the TOVA Symptom Exaggeration Index (SEI) adequately identifies performance-based exaggeration when it occurs. Using archival data from a university-based ADHD screening clinic we investigated the performance of 245 late adolescents/emerging adults. Three groups were created: (1) Good effort but not ADHD (n = 183); (2) Good effort and diagnosed ADHD (n = 13); and (3) suspect effort (n = 49), based on final diagnosis and performance on an existing validity measure. Results showed clearly that those with suspect effort performed more poorly than the other two groups on all but second-half commission errors on the TOVA. Similar to Nicholls et al., the suspect effort group showed significantly subaverage (i.e., greater than two standard deviations below the mean) scores in Omission errors; in this replication, however, this was true for both the first and second half of the test. Response time variability was similarly exaggerated, with the suspect effort group again returning extreme scores in both halves of the test. Suspect effort students were indistinguishable from those with genuine ADHD when looking solely at self-reported symptoms; however, embedded symptom validity measures on an ADHD rating scale discriminated well between groups. Overall, results support the use of the TOVA as an embedded performance validity measure in the assessment of late adolescents/emerging adults and support previous findings that symptom report alone cannot distinguish credible from noncredible ADHD presentation.

Diagnostic Accuracy of the Conners' Adult ADHD Rating Scale in a Postsecondary Population.

Objective: Clinicians frequently rely upon the results of self-report rating scales when making the diagnosis of ADHD; however, little research exists regarding the ability of self-report measures to accurately differentiate ADHD from other disorders. Method: This present study investigated the ability of the Conners' Adult ADHD Rating Scale (CAARS) to discriminate between 249 postsecondary students with carefully diagnosed ADHD and 507 clinical controls. Results: The overall discriminant validity of the CAARS was 69%, and it had an unacceptably high false positive and false negative rate. At lower prevalence rates, a high score on the CAARS has only a 22% chance of accurately identifying individuals with ADHD. Conclusion: Although the CAARS is an adequate screening measure, it should not be the main method by which a diagnosis is made, as it frequently misidentifies individuals with other psychological complaints as having ADHD. Implications for clinical practice are discussed.

Development of a symptom validity index to assist in identifying ADHD symptom exaggeration or feigning.

OBJECTIVE: Concerns have been identified regarding the ease with which students and young adults can feign or exaggerate symptoms of ADHD, and no formal measures exist to identify such behavior when it occurs. This article describes the development and initial validation of a new symptom validity measure designed to detect feigned or exaggerated ADHD symptom reporting. METHOD: Employing items from a commonly used self-report measure of ADHD (Conners' Adult ADHD Rating Scale [CAARS]) and select items from a scale measuring symptoms of dissociation, we assessed students diagnosed with ADHD, students with other diagnoses, and student volunteers with no psychopathology. RESULTS: This new measure (Exaggeration Index or EI) demonstrated excellent specificity (.97) and adequate sensitivity (.24) in discriminating between those who are suspected of or instructed to feign or exaggerate symptoms of ADHD and all other clinical groups. CONCLUSION: The results strongly suggest that the EI may be a useful adjunct to existing validity measures when identifying exaggerated or implausible symptoms of ADHD.

Comparing Canadian and American normative scores on the Wechsler Adult Intelligence Scale-Fourth Edition.

Psychologists practicing in Canada must decide which set of normative data to use for the Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV). The purpose of this study was to compare the interpretive effects of applying American versus Canadian normative systems in a sample of 432 Canadian postsecondary-level students who were administered the WAIS-IV as part of an evaluation for a learning disability, attention-deficit hyperactivity disorder, or other mental health problems. Employing the Canadian normative system yielded IQ, Index, and subtest scores that were systematically lower than those obtained using the American norms. Furthermore, the percentage agreement in normative classifications, defined as American and Canadian index scores within five points or within the same classification range, was between 49% and 76%. Substantial differences are present between the American and Canadian WAIS-IV norms. Clinicians should consider carefully the implications regarding which normative system is most appropriate for specific types of evaluations.

Waiting for a hand: saccadic reaction time increases in proportion to hand reaction time when reaching under a visuomotor reversal.

Although eye movement onset typically precedes hand movement onset when reaching to targets presented in peripheral vision, arm motor commands appear to be issued at around the same time, and possibly in advance, of eye motor commands. A fundamental question, therefore, is whether eye movement initiation is linked or yoked to hand movement. We addressed this issue by having participants reach to targets after adapting to a visuomotor reversal (or 180° rotation) between the position of the unseen hand and the position of a cursor controlled by the hand. We asked whether this reversal, which we expected to increase hand reaction time (HRT), would also increase saccadic reaction time (SRT). As predicted, when moving the cursor to targets under the reversal, HRT increased in all participants. SRT also increased in all but one participant, even though the task for the eyes-shifting gaze to the target-was unaltered by the reversal of hand position feedback. Moreover, the effects of the reversal on SRT and HRT were positively correlated across participants; those who exhibited the greatest increases in HRT also showed the greatest increases in SRT. These results indicate that the mechanisms underlying the initiation of eye and hand movements are linked. In particular, the results suggest that the initiation of an eye movement to a manual target depends, at least in part, on the specification of hand movement.

Relation between reaction time and reach errors during visuomotor adaptation.

Adaptation of reaching movements to visuomotor transformations is generally thought to involve implicit or procedural learning. However, there is evidence that explicit or cognitive processes can also play a role (Redding and Wallace, 2006 [31]). For example, the early phase of adaptation to a visuomotor rotation appears to involve spatial working memory processes linked to mental rotation (Anguera et al., 2010 [11]). Since it is known that cognitive processes like mental rotation lead to larger reaction times (Georgopoulos and Massey, 1987 [12]), here we explored the relation between reaction time (RT) and reach error reduction. Two groups of subjects adapted their reaching movements to a 60° visuomotor rotation either without RT constraints or with RT limited to 350 ms. In the unconstrained group, we found that adaption rate varied widely across subjects and was strongly correlated with RT. Subjects who decreased hand direction error (DE) rapidly exhibited prolonged RTs whereas little RT cost was seen in subjects who decreased DE gradually. RTs were also correlated with after-effects seen when the visuomotor rotation was removed. Subjects with the longest RTs exhibited the smallest after-effects. In the RT constrained group, all subjects exhibited gradual DE adaptation and large after-effects, similar to the fast responders in the free group. These results suggest that adaptation to a visuomotor rotation can involve processes that produce faster error reductions without increasing after-effects, but at an expense of larger reaction times. Possible candidates are processes related to spatial working memory, and more specifically, to mental rotation.

The influence of stimulus direction and eccentricity on pro- and anti-saccades in humans.

We examined the sensory and motor influences of stimulus eccentricity and direction on saccadic reaction times (SRTs), direction-of-movement errors, and saccade amplitude for stimulus-driven (prosaccade) and volitional (antisaccade) oculomotor responses in humans. Stimuli were presented at five eccentricities, ranging from 0.5 degrees to 8 degrees , and in eight radial directions around a central fixation point. At 0.5 degrees eccentricity, participants showed delayed SRT and increased direction-of-movement errors consistent with misidentification of the target and fixation points. For the remaining eccentricities, horizontal saccades had shorter mean SRT than vertical saccades. Stimuli in the upper visual field trigger overt shifts in gaze more easily and faster than in the lower visual field: prosaccades to the upper hemifield had shorter SRT than to the lower hemifield, and more anti-saccade direction-of-movement errors were made into the upper hemifield. With the exception of the 0.5 degrees stimuli, SRT was independent of eccentricity. Saccade amplitude was dependent on target eccentricity for prosaccades, but not for antisaccades within the range we tested. Performance matched behavioral measures described previously for monkeys performing the same tasks, confirming that the monkey is a good model for the human oculomotor function. We conclude that an upper hemifield bias lead to a decrease in SRT and an increase in direction errors.

Deficits in saccadic eye-movement control in Parkinson's disease.

In contrast to their slowed limb movements, individuals with Parkinson's disease (PD) produce rapid automatic eye movements to sensory stimuli and show an impaired ability to generate voluntary eye movements in cognitive tasks. Eighteen PD patients and 18 matched control volunteers were instructed to look either toward (pro-saccade) or away from (anti-saccade) a peripheral stimulus as soon as it appeared (immediate, gap and overlap conditions) or after a variable delay; or, they made sequential saccades to remembered targets after a variable delay. We found that PD patients made more express saccades (correct saccades in the latency range of 90-140 ms) in the immediate pro-saccade task, more direction errors (automatic pro-saccades) in the immediate anti-saccade task, and were less able to inhibit saccades during the delay period in all delay tasks. PD patients also made more directional and end-point errors in the memory-guided sequential task. Their inability to plan eye movements to remembered target locations suggests that PD patients have a deficit in spatial working memory which, along with their deficit in automatic saccade suppression, is consistent with a disorder of the prefrontal-basal ganglia circuit. Impairment of this pathway may release the automatic saccade system from top-down inhibition and produce deficits in volitional saccade control. Parallel findings across various motor, cognitive and oculomotor tasks suggest a common mechanism underlying a general deficit in automatic response suppression.

Sensory biases produce alternation advantage found in sequential saccadic eye movement tasks.

In two-choice reaction time tasks, participants respond faster when the correct decision switches across consecutive trials. This alternation advantage has been interpreted as the guessing strategies of participants. Because the participants expect that the correct decision will switch across consecutive trials, they respond faster when this expectation is confirmed and they respond more slowly when it is disconfirmed. In this study, we evaluated the veracity of this expectancy interpretation. After replicating a long-lasting alternation advantage in saccadic reaction times (Experiment 1), we show that reducing the participants' ability to guess with a challenging mental rotation task does not change the alternation advantage, which suggests that expectancy is not responsible for the effect (Experiment 2). Next, we used prosaccade and antisaccade responses to dissociate between the sensory and motor contributions of the alternation advantage (Experiment 3) and we found that the alternation advantage originates from sensory processing. The implications of these findings are discussed with regard to guessing strategies, sensory processing, and how these findings may relate to inhibition of return.

Altered control of visual fixation and saccadic eye movements in attention-deficit hyperactivity disorder.

Attention-deficit hyperactivity disorder (ADHD) is characterized by the overt symptoms of impulsiveness, hyperactivity, and inattention. A frontostriatal pathophysiology has been hypothesized to produce these symptoms and lead to reduced ability to inhibit unnecessary or inappropriate behavioral responses. Oculomotor tasks can be designed to probe the ability of subjects to generate or inhibit reflexive and voluntary responses. Because regions of the frontal cortex and basal ganglia have been identified in the control of voluntary responses and saccadic suppression, we hypothesized that children and adults diagnosed with ADHD may have specific difficulties in oculomotor tasks requiring the suppression of reflexive or unwanted saccadic eye movements. To test this hypothesis, we measured eye movement performance in pro- and anti-saccade tasks of 114 ADHD and 180 control participants ranging in age from 6 to 59 yr. In the pro-saccade task, participants were instructed to look from a central fixation point toward an eccentric visual target. In the anti-saccade task, stimulus presentation was identical, but participants were instructed to suppress the saccade to the stimulus and instead look from the central fixation point to the side opposite the target. The state of fixation was manipulated by presenting the target either when the central fixation point was illuminated (overlap condition) or at some time after it disappeared (gap condition). In the pro-saccade task, ADHD participants had longer reaction times, greater intra-subject variance, and their saccades had reduced peak velocities and increased durations. In the anti-saccade task, ADHD participants had greater difficulty suppressing reflexive pro-saccades toward the eccentric target, increased reaction times for correct anti-saccades, and greater intra-subject variance. In a third task requiring prolonged fixation, ADHD participants generated more intrusive saccades during periods when they were required to maintain steady fixation. The results suggest that ADHD participants have reduced ability to suppress unwanted saccades and control their fixation behavior voluntarily, a finding that is consistent with a fronto-striatal pathophysiology. The findings are discussed in the context of recent neurophysiological data from nonhuman primates that have identified important control signals for saccade suppression that emanate from frontostriatal circuits.