Conditional error variance in the WISC-IV

Measurement error at different ability levels in the WISC-IV was studied to empirically test the conditional error variance hypothesis. Graduate students in clinical psychology at a Midwestern university scored fictitious WISC-IV Vocabulary subtests constructed to yield actual scaled scores of 4, 10, and 16. Classical measurement theory assumes error rate will be constant across the three conditions. Modern test theories (Item Response Theory), however, predict that the precision of a measurement instrument will change as a function of the examinee\u27s ability level. Data supported the conditional error variance hypothesis. Scorers made significantly more errors in the low- and high-abilitylevel conditions than they did in the average ability condition. Implications of these findings for intelligence testing are discussed

Memory consolidation in developmental disorders

The relationship between memory and adaptive functioning was studied in sample of 268 children with attention deficit/hyperactivity disorder (ADHD, n = 83), autism spectrum disorder (ASD, n = 62), velo-cardio-facial syndrome (VCFS, n = 21), and low birth weight (LBW, n = 38) and neurotypicals (n = 64). Children with ASD and VCFS demonstrated a relative weakness in facial and visual memory, while no between-group differences were found during the auditory verbal learning task of the TOMAL. Learning curve analyses showed that after the first trial of the visual span test, all groups performed at the same level, but the performance of the clinical samples dropped after each subsequent trials. However, during the delayed recall, no between-group differences were evident. On the word memory test, the groups were significantly different after the first trial, but during delayed recall their performance converged. When memory functioning was used to predict academic achievement, TOMAL scores explained 37% of the variance in math scores, 22% in reading, and 13% in spelling scores. The same models did not predict social skills as measured by the CBCL. When age, gender, and FSIQ were added to memory scores to the regression model, the adjusted R2 value doubled for achievement scores, with IQ clearly driving the age effect. However, IQ was not a significant predictor of social skills. With that criterion, age became the only significant predictor, explaining 39% of the variance. The clinical implications of the findings on diagnostic (nonverbal memory and math seem to be a relative weakness in neurodevelopmental disorders; repeated learning trials may be needed to allow diagnosis-specific deficits to emerge; cognitive variables predict academic, but not social functioning; consolidation could be treated as a separate, emergent variable and normed separately to enhance its diagnostic utility) and treatment (visual cuing may be less effective in ASD and especially VCFS than a verbally mediated one) considerations are discussed

Observational study of visual testing efficacy in detecting cannabis usage

Drug recognition and examination programs are widely used to detect drug impairment in motor vehicle operators. Visual tests are a key assessment in the detection of cannabis-related impairment. Participants were recruited via social media from the medical cannabis community in Southwestern Ontario, Canada. Twenty-two participants completed the full observational trial design. The majority (n = 13 or 59.1%) were male, with a mean age of 36 years (SD = 9.4; range: 24–59). Participants underwent the following protocol: 1) First round of testing (vital signs, bio sample collection, visual tests, subjective data, neurocognitive testing) (Baseline phase); 2) Consumption of cannabis via inhalation; 3) Second round of testing 30 minutes following consumption (THC phase); 4) Additional rounds of testing at 90, 150, and 210 minutes following consumption (Recovery phase). Visual assessment data and vital signs did not follow typical patterns associated with acute cannabis intoxication. With blood THC levels more than double the Canadian legal limit (5 ng/mL), visual testing results were not diagnostic for cannabis impairment, as participants maintained normal pupil sizes and normal ocular convergence patterns. Visual testing is a key component in standardized examinations used for detecting cannabis-related impairment in Canadian drivers; however, our data indicate that visual testing may not be an effective diagnostic tool for the specific population of medical cannabis users

Neural Synchrony Examined with Magnetoencephalography (MEG) During Eye Gaze Processing in Autism Spectrum Disorders: Preliminary Findings

Gaze processing deficits are a seminal, early, and enduring behavioral deficit in autism spectrum disorder (ASD); however, a comprehensive characterization of the neural processes mediating abnormal gaze processing in ASD has yet to be conducted. This study investigated whole-brain patterns of neural synchrony during passive viewing of direct and averted eye gaze in ASD adolescents and young adults (M Age  = 16.6) compared to neurotypicals (NT) (MAge  = 17.5) while undergoing magnetoencephalography. Coherence between each pair of 54 brain regions within each of three frequency bands (low frequency (0 to 15 Hz), beta (15 to 30 Hz), and low gamma (30 to 45 Hz)) was calculated

Neural Synchrony Examined with Magnetoencephalography (MEG) During Eye Gaze Processing in Autism Spectrum Disorders: Preliminary Findings

Gaze processing deficits are a seminal, early, and enduring behavioral deficit in autism spectrum disorder (ASD); however, a comprehensive characterization of the neural processes mediating abnormal gaze processing in ASD has yet to be conducted. This study investigated whole-brain patterns of neural synchrony during passive viewing of direct and averted eye gaze in ASD adolescents and young adults (M Age  = 16.6) compared to neurotypicals (NT) (MAge  = 17.5) while undergoing magnetoencephalography. Coherence between each pair of 54 brain regions within each of three frequency bands (low frequency (0 to 15 Hz), beta (15 to 30 Hz), and low gamma (30 to 45 Hz)) was calculated

The Importance of Relying on the Manual: Scoring Error Variance in the WISC-IV Vocabulary Subtest

Classical test theory assumes that ability level has no effect on measurement error. Newer test theories, however, argue that the precision of a measurement instrument changes as a function of the examinee’s true score. Research has shown that administration errors are common in the Wechsler scales and that subtests requiring subjective scoring are the most prone to errors. In this study, graduate students scored fictitious Wechsler Intelligence Scale for Children— Fourth Edition Vocabulary subtests that were constructed to yield actual scaled scores of 4, 10 and 16. Results support the conditional error variance hypothesis: Participants made significantly more scoring errors in the low and high ability conditions than they did in the average ability condition. Implications of these findings with regard to the interpretation of extreme scores are discussed