Griffin P. Sutton

Memory and Attention Profiles in Pediatric Traumatic Brain Injury

Traumatic brain injury (TBI) causes heterogeneous patterns of neurocognitive deficits. In an attempt to identify homogenous subgroups within this heterogeneity, cluster analysis was used to examine memory and attention abilities as measured by the Test of Memory and Learning (TOMAL) in 300 children, 150 with TBI and 150 matched nonbrain injured controls (standardization sample [SS]). Significant differences were present between the TBI and the SS groups on all TOMAL subscale and index scores, with the TBI groups performing approximately 1.3 SD below the SS. Factor analysis of the TOMAL indicated six factors that assessed various aspects of verbal and nonverbal learning and memory, as well as attention/concentration. Cluster analyses of TOMAL factor scores indicated that a four-cluster solution was optimal for the SS group, and a five-cluster solution for the TBI group. For the TBI clusters, differences were present for clinical, achievement, neurocognitive, and behavioral variables, providing some support for the validity of the cluster solution. These findings suggest that TBI results in unique patterns of neurocognitive impairment that are not accounted for by individual differences in test performance commonly observed in normal populations. Additionally, neurocognitive profiles identified using cluster analysis may prove useful for identifying homogeneous subgroups of children with TBI that are differentiated by a number of important clinical, cognitive, and behavioral variables associated with treatment and outcomes.

Differential impairment of social cognition factors in bipolar disorder with and without psychotic features and schizophrenia

While it is well-established that patients with schizophrenia and bipolar disorder exhibit deficits in social cognition, few studies have separately examined bipolar disorder with and without psychotic features. The current study addressed this gap by comparing patients with bipolar disorder with (BD+) and without (BD-) psychotic features, patients with schizophrenia (SZ), and healthy controls (NC) across social cognitive measures. Principal factor analysis on five social cognition tasks extracted a two-factor structure comprised of social/emotional processing and theory of mind. Factor scores were compared among the four groups. Results identified differential patterns of impairment between the BD+ and BD- group on the social/emotional processing factor while all clinical groups performed poorer than controls on the theory of mind factor. This provides evidence that a history of psychosis should be taken into account while evaluating social cognition in patients with bipolar disorder and also raises hypotheses about the relationship between social cognition and psychosis.

Emotion perception abnormalities across sensory modalities in bipolar disorder with psychotic features and schizophrenia

Emotion perception deficits are a well-established feature of schizophrenia (SZ). Individuals with SZ have difficulty labeling emotional stimuli across auditory, visual, and audio-visual modalities and also misattribute threat towards neutral stimuli. The relationship between a history of psychosis and similar abnormalities in bipolar disorder (BD) is less clear. The current study set out to examine emotion perception across sensory modalities in a sample of 24 stabilized individuals meeting criteria for SZ, 24 remitted individuals meeting criteria for BD with psychotic features, 24 remitted individuals meeting criteria for BD without psychotic features, and 24 healthy controls. Results indicated that the bipolar with psychotic features group had intermediary performance between the SZ group and the other two groups for auditory, visual, and audio-visual items, with particularly poor performance in identifying angry stimuli. The SZ group misattributed neutral stimuli as negative when they were in visual format, but as positive when they were in auditory or audio-visual formats. The bipolar with psychotic features group had a trend towards misattributing more neutral visual stimuli as negative. These findings indicate that emotion perception deficits are present in BD with psychotic features and comparatively spared in BD without psychotic features, and that a similar bias of misattributing negative emotions to neutral visual stimuli may be present across diagnostic boundaries.

Beery-Buktenica Developmental Test of Visual-Motor Integration performance in children with traumatic brain injury and attention-deficit/hyperactivity disorder.

Evaluation of visuoconstructional abilities is a common part of clinical neuropsychological assessment, and the Beery-Buktenica Developmental Test of Visual-Motor Integration (VMI; K. E. Beery & N. A. Beery, 2004) is often used for this purpose. However, few studies have examined its psychometric properties when used to assess children and adolescents with traumatic brain injury (TBI) or attention-deficit/hyperactivity disorder (ADHD), even though these are among the most common acquired and neurodevelopmental forms of brain dysfunction in children. This study examined the validity of VMI scores in 123 children with TBI and 65 with ADHD. The TBI and ADHD groups performed significantly worse than the standardization sample, obtaining VMI mean scores of 87.2 (SD = 13.7) and 93.5 (SD = 11.27). Previous research has noted decrements in visuoconstructional abilities in TBI but relative sparing in ADHD. To examine the criterion validity of VMI scores, the authors therefore compared these 2 groups. As anticipated, the TBI group performed significantly worse than the ADHD group, but receiver operator characteristic analysis indicated that VMI scores were poor at discriminating between groups. Nonetheless, convergent validity evidence supported interpretation of VMI scores as measuring perceptual organization in both groups. In particular, principal components analysis indicated that VMI total scores loaded with perceptual organization tests from the Wechsler Intelligence Scale for Children, 3rd ed. (WISC-III; D. Wechsler, 1997), and its highest correlation was with the WISC-III Perceptual Organization Index. Also, the VMI correlated significantly with the Grooved Pegboard test for the group with TBI. These findings suggest that VMI scores are sensitive to visuoconstructional and motor deficits in children with developmental and acquired brain dysfunction.

Auditory stream segregation impairments in schizophrenia

We used behavior and event-related potentials (ERPs) to examine auditory stream segregation in people with schizophrenia and control participants. During each trial, a context pattern was presented, consisting of low (A) and high (B) tones and silence (-) in a repeating ABA- pattern, with a frequency separation (Δf) of 3, 6, or 12 semitones. Next, a test ABA-pattern was presented that always had a 6-semitone Δf. Larger Δf during the context resulted in more perception of two streams and larger N1 and P2 ERPs, but less perception of two streams during the test pattern. These effects of Δf were smaller in schizophrenia. Individuals with schizophrenia also showed a reduced effect of prior perceptual judgments. Overall, the findings demonstrate that people with schizophrenia have abnormalities in segregating sounds. These abnormalities result from difficulties utilizing frequency cues in addition to reduced temporal context effects.

Application of a standardized assessment methodology within the context of an evidence-based treatment for substance abuse and its associated problems.

Administrators of community-based treatment programs are increasingly being required to utilize psychometrically validated instruments to measure the effectiveness of their interventions. However, developers of psychometric measures have often failed to report strategies relevant to the administration of these measures in nontraditional settings outside the therapy office. Moreover, with few exceptions, developers of evidence-based treatments (EBTs) have insufficiently disseminated methods for integrating assessment measures into treatment planning. Therefore, the purpose of this article is to review an assessment methodology that may be utilized to support EBT for individuals who are identified for substance abuse or related problem behaviors. The application of this methodology is demonstrated utilizing Family Behavior Therapy to exemplify “real world” scenarios involving adolescents and adults. Although many of these strategies are evidence supported, most are based on clinical experiences occurring in clinical trials and dissemination efforts within community settings.

Auditory processing deficits in bipolar disorder with and without a history of psychotic features

Auditory perception deficits have been identified in schizophrenia (SZ) and linked to dysfunction in the auditory cortex. Given that psychotic symptoms, including auditory hallucinations, are also seen in bipolar disorder (BD), it may be that individuals with BD who also exhibit psychotic symptoms demonstrate a similar impairment in auditory perception.

Validity of the RIAS for assessing children with traumatic brain injury: Sensitivity to TBI and comparability to the WISC-III and WISC-IV

Intelligence tests are commonly administered to children following moderate-to-severe traumatic brain injury (TBI). The Reynolds Intellectual Assessment Scales (RIAS) is a recently developed measure of intellectual ability that has a number of appealing features for assessing individuals with brain damage, but as yet has little validity information when applied to children with TBI or other forms of brain injury. It is therefore unclear whether RIAS scores are sensitive to brain injury and how they compare to older more well-established tests such as the Wechsler scales. The current article reports two studies that examine these matters in youth with TBI. The first study examined sensitivity of the RIAS to TBI in 110 children. Results indicated the TBI sample performed significantly worse compared with the standardization sample on all RIAS index scores. The second study included 102 children who were administered either the RIAS, Wechsler Intelligence Scale for Children-Third Edition (WISC-III), or WISC-Fourth Edition (WISC-IV; 34 children in each group). Comparisons among the RIAS, WISC-III, and WISC-IV groups indicated no significant differences among the measures on verbal, nonverbal, and Composite Index/Full-Scale IQs. Results provide support for the sensitivity of the RIAS to TBI in children and also suggest that IQs produced by the RIAS, WISC-III, and WISC-IV do not significantly vary from one test to the other, which is particularly true of the verbal and Composite Index/Full-Scale IQs.

Preliminary evidence for reduced auditory lateral suppression in schizophrenia

BACKGROUND Well-documented auditory processing deficits such as impaired frequency discrimination and reduced suppression of auditory brain responses in schizophrenia (SZ) may contribute to abnormal auditory functioning in everyday life. Lateral suppression of non-stimulated neurons by stimulated neurons has not been extensively assessed in SZ and likely plays an important role in precise encoding of sounds. Therefore, this study evaluated whether lateral suppression of activity in auditory cortex is impaired in SZ. METHODS SZ participants and control participants watched a silent movie with subtitles while listening to trials composed of a 0.5s control stimulus (CS), a 3s filtered masking noise (FN), and a 0.5s test stimulus (TS). The CS and TS were identical on each trial and had energy corresponding to the high energy (recurrent suppression) or low energy (lateral suppression) portions of the FN. Event-related potentials were recorded and suppression was measured as the amplitude change between CS and TS. RESULTS Peak amplitudes of the auditory P2 component (160-260ms) showed reduced lateral but not recurrent suppression in SZ participants. CONCLUSIONS Reduced lateral suppression in SZ participants may lead to overlap of neuronal populations representing different auditory stimuli. Such imprecise neural representations may contribute to the difficulties SZ participants have in discriminating complex stimuli in everyday life.

Concurrent sound segregation impairments in schizophrenia: The contribution of auditory-specific and general cognitive factors

The present study sought to test whether perceptual segregation of concurrently played sounds is impaired in schizophrenia (SZ), whether impairment in sound segregation predicts difficulties with a real-world speech-in-noise task, and whether auditory-specific or general cognitive processing accounts for sound segregation problems. Participants with SZ and healthy controls (HCs) performed a mistuned harmonic segregation task during recording of event-related potentials (ERPs). Participants also performed a brief speech-in-noise task. Participants with SZ showed deficits in the mistuned harmonic task and the speech-in-noise task, compared to HCs. No deficit in SZ was found in the ERP component related to mistuned harmonic segregation at around 150ms (the object-related negativity or ORN), but instead showed a deficit in processing at around 400ms (the P4 response). However, regression analyses showed that indexes of education level and general cognitive function were the best predictors of sound segregation difficulties, suggesting non-auditory specific causes of concurrent sound segregation problems in SZ.