A cognitive tool to diagnose predominantly inattentive ADHD behavior

Not All Differences between Patients with Schizophrenia and Healthy Subjects Are Pathological: Performance on the Conners' Continuous Performance Test

OBJECTIVE

This study analyzed attentional performance in patients with schizophrenia during a continuous performance task requiring a high response rate.

METHOD

The Conners' Continuous Performance Test-II (CPT-II) was administered to 64 patients with schizophrenia and 64 healthy comparison subjects. A cross-sectional design was used in order to allow analysis of the means between patients and healthy subjects. Differences in performance were assessed for significance using ANCOVA. Percentiles were also analyzed in order to determine whether a participant showed normal or pathological performance. Pearson's correlation was used to detect possible relationships between attentional performance and psychopathology.

RESULTS

Of the 12 CPT-II measures, response style and slowing of reaction time (RT) between targets increased to similar extents between patients and healthy comparison subjects. Patients performed significantly less well than non-patient group on all other measures. Nevertheless, patient's performance on four of these measures remained within the normal range, and patient's performance on the remaining measures qualified as pathological only in the case of variability in hit RT. No significant correlations between attention performance and symptoms were found.

CONCLUSIONS

These results suggest that although patients may show lower attentional functioning than non-patients on tasks requiring a high response rate, their attentional performance remains within the normal range on most dimensions.

Differences in Speech Recognition Between Children with Attention Deficits and Typically Developed Children Disappear When Exposed to 65 dB of Auditory Noise

The most common neuropsychiatric condition in the in children is attention deficit hyperactivity disorder (ADHD), affecting ∼6–9% of the population. ADHD is distinguished by inattention and hyperactive, impulsive behaviors as well as poor performance in various cognitive tasks often leading to failures at school. Sensory and perceptual dysfunctions have also been noticed. Prior research has mainly focused on limitations in executive functioning where differences are often explained by deficits in pre-frontal cortex activation. Less notice has been given to sensory perception and subcortical functioning in ADHD. Recent research has shown that children with ADHD diagnosis have a deviant auditory brain stem response compared to healthy controls. The aim of the present study was to investigate if the speech recognition threshold differs between attentive and children with ADHD symptoms in two environmental sound conditions, with and without external noise. Previous research has namely shown that children with attention deficits can benefit from white noise exposure during cognitive tasks and here we investigate if noise benefit is present during an auditory perceptual task. For this purpose we used a modified Hagerman’s speech recognition test where children with and without attention deficits performed a binaural speech recognition task to assess the speech recognition threshold in no noise and noise conditions (65 dB). Results showed that the inattentive group displayed a higher speech recognition threshold than typically developed children and that the difference in speech recognition threshold disappeared when exposed to noise at supra threshold level. From this we conclude that inattention can partly be explained by sensory perceptual limitations that can possibly be ameliorated through noise exposure.

Validity of the factor structure of Conners' CPT

OBJECTIVE

A previous factor analysis of the Conners' Continuous Performance Test (CCPT) indicates that the test measures 5 sub-functions of attention, namely focused attention, hyperactivity/impulsivity, sustained attention, vigilance, and change in control. The present study further analyzes the results from Egeland & Kowalik-Gran to test the construct- and criterion-validity of these factors.

METHOD

Construct validity is tested by analyzing whether clinical groups known to be impaired in specified subprocesses actually differ with regard to factor scores. Comparison of CCPT factor scores from 282 individuals with ADHD, schizophrenia, affective disorders, brain injury, language disorders, and normal individuals gives validity to 4 factors, but not to the vigilance factor.

RESULTS

Other tests of controlled attention correlate only with focused attention, thus giving criterion validity to this factor and differential validity to the remaining 4 factors.

CONCLUSION

Grouping scores on the CCPT into 4 or 5 sub-functions of attention may provide the clinician with a tool to differentiate between clinical groups.

Measuring several aspects of attention in one test: the factor structure of conners's continuous performance test

OBJECTIVE

Continuous performance tests are known to typically measure sustained attention but usually also yield parameters that potentially measure other subprocesses of attention. The aim of the present study was to test the factor structure of the Conners's Continuous Performance Test (CCPT) in a heterogeneous clinical sample consisting of subjects considered to fail in different subfunctions of attention.

METHOD AND RESULTS

CCPT records from 376 patients were factor analyzed, yielding five factors indicating a differentiation between focused attention, hyperactivity-impulsivity, sustained attention, vigilance, and change in control.

CONCLUSION

The study warns against reducing CCPT performance to one overall score of attention. The study further emphasizes the need to reserve the concept of sustained attention for measures of change as a function of time on task. The differentiation between sustained attention and vigilance and the concept of change in mental control during the test are possible methodological contributions of the study.

Focus on words: a twin study of reading and inattention

The etiology of variation in reading ability and its relationship to inattention, impulsivity, and general cognitive ability were investigated within a large, population-based sample of 9- to 10-year-old twins. Phenotypic and genetic analyses were performed on word-level reading, full-scale IQ, and measures of inattention and impulsivity derived from the Go-NoGo task (i.e., Go errors and NoGo errors, respectively). Moderate and significant phenotypic correlations were found among reading, inattention and IQ, but not between impulsivity and the other variables. Genetic modeling revealed that genetic and shared environmental influences largely accounted for variation in reading, inattention, and IQ and covariation among them, whereas specific environmental influences contributed primarily to variation in impulsivity. Acting through a common factor, a portion of the genetic influences on reading ability appeared to be shared with influences affecting IQ as well as those affecting inattention. The contribution of phonological awareness to the remaining unique genetic influences on reading was explored through additional analyses. A two-common-factor model was revealed, with a strongly genetic general cognitive ability factor affecting reading, inattention, and IQ, and an equally strongly genetic second common factor, which captured the variability in reading ability that was related specifically to phonological processing. The processes involved in reading, therefore, seem to involve genetic and environmental influences that are part of both a general cognitive system and a system more specific to reading and phonology.

Attention-deficit disorder (attention-deficit/ hyperactivity disorder without hyperactivity): a neurobiologically and behaviorally distinct disorder from attention-deficit/hyperactivity disorder (with hyperactivity)

Most studies of attention-deficit/hyperactivity disorder (ADHD) have focused on the combined type and emphasized a core problem in response inhibition. It is proposed here that the core problem in the truly inattentive type of ADHD (not simply the subthreshold combined type) is in working memory. It is further proposed that laboratory measures, such as complex-span and dual-task dichotic listening tasks, can detect this. Children with the truly inattentive type of ADHD, rather than being distractible, may instead be easily bored, their problem being more in motivation (underarousal) than in inhibitory control. Much converging evidence points to a primary disturbance in the striatum (a frontal-striatal loop) in the combined type of ADHD. It is proposed here that the primary disturbance in truly inattentive-type ADHD (ADD) is in the cortex (a frontal-parietal loop). Finally, it is posited that these are not two different types of ADHD, but two different disorders with different cognitive and behavioral profiles, different patterns of comorbidities, different responses to medication, and different underlying neurobiologies.

Attention-deficit disorder (attention-deficit/ hyperactivity disorder without hyperactivity): a neurobiologically and behaviorally distinct disorder from attention-deficit/hyperactivity disorder (with hyperactivity)

Most studies of attention-deficit/hyperactivity disorder (ADHD) have focused on the combined type and emphasized a core problem in response inhibition. It is proposed here that the core problem in the truly inattentive type of ADHD (not simply the subthreshold combined type) is in working memory. It is further proposed that laboratory measures, such as complex-span and dual-task dichotic listening tasks, can detect this. Children with the truly inattentive type of ADHD, rather than being distractible, may instead be easily bored, their problem being more in motivation (underarousal) than in inhibitory control. Much converging evidence points to a primary disturbance in the striatum (a frontal-striatal loop) in the combined type of ADHD. It is proposed here that the primary disturbance in truly inattentive-type ADHD (ADD) is in the cortex (a frontal-parietal loop). Finally, it is posited that these are not two different types of ADHD, but two different disorders with different cognitive and behavioral profiles, different patterns of comorbidities, different responses to medication, and different underlying neurobiologies.