Jerilyn Higa

Continuous-processing-related event-related potentials in children with attention deficit hyperactivity disorder

Visual information processing in children with attention deficit hyperactivity disorder (ADHD) was studied using event-related potentials recorded during two versions of the Continuous Performance Task (CPT). ADHD children made more errors, and had longer reaction times than normal children on both the single- and dual-target CPT. Event-related potential waveforms were normal in the ADHD children with reference to early processing stages, i.e., contingent negative variation, P1-N1 laterality, and processing negativities, suggesting that ADHD children did not differ in their level of preparedness or their ability to mobilize resources for target identification and categorization. With respect to later processing, P3 amplitude was reduced in the ADHD group, whereas P3 latency was longer than normal. ADHD children had a diminished late frontal negative component, suggestive of reduced involvement in postdecisional processing.

Cognitive function, mood and P3 latency: effects of the amelioration of anemia in dialysis patients.

Attention difficulties and psychomotor slowing associated with depressed mood affect the ability of individuals to perform on most neuropsychological tests. It has been suggested that latency of the P3 (P300) component of the event-related EEG potential is an index of neurocognitive status which is not affected by mood. Dialysis patients, who experience diminished dysphoric mood with the reversal of anemia when treated with recombinant human erythropoietin (rHuEPO), were tested for neurocognitive performance, mood and latency of P3. Prior to rHuEPO treatment mood was dysphoric, and neurocognitive testing showed mild deficits, but P3 latency was normal. After treatment, mood improved and neurocognitive test performance was normal. P3 amplitude increased over frontal areas, while P3 latency remained unchanged. Thus, in the case of dysphoric mood, P3 latency may provide a more accurate index of cognitive capacity (as opposed to level of functioning) than neurocognitive test measures.

Event-related potentials in high-functioning adult autistics: Linguistic and nonlinguistic visual information processing tasks

Event-related potentials (ERPs) were recorded from high-functioning adult autistics and age- and IQ-matched normal controls during performance of two non-linguistic information processing tasks, the Continuous Performance Task (CPT) and Span of Apprehension (SPAN), and an Idiom Recognition Task (IRT) involving idiomatic, literal and nonsense phrases. The autistics exhibited behavioral deficits only when attempting to identify idiomatic phrases. The ERP correlate of that deficit was greatly reduced N400 to idioms. In addition, autistics produced larger N1 amplitudes in all tasks, and larger P3s in the IRT and CPT.

Development of a health risk appraisal for the elderly (HRA-E).

The purpose of this project is to develop a health risk appraisal for the elderly (HRA-E) and test its application in both medical and nonmedical settings. The HRA-E system consists of a questionnaire and software for computer-generation of personalized reports to participants, 55 years and older, and their physicians. Items in the questionnaire cover a comprehensive range of content domains relevant to health promotion in the elderly. The goal of the HRA-E system is to prevent functional decline. Samples of eligible subjects from the American Association of Retired Persons (AARP), a group practice, and a senior center were extended invitations to participate. Those responding affirmatively to the invitation were given a questionnaire and evaluation form. Each person who returned the questionnaire received his or her personal report and a second evaluation form. Four months after receiving their reports, respondents were questioned about behavior changes during the interim. Preliminary findings, based on 1895 respondents, indicate that nearly all participants found the questionnaire easy to complete and were pleased with its overall length. In addition, most participants read their reports, and many planned to take action, based on report recommendations. In the next phase of this project, the intent is to refine the questionnaire, extend the intervention protocols for longitudinal application, and evaluate its impact on health-related behaviors, medical care utilization, and functional decline.

Event-Related Potential Correlates of Impaired Attention in Schizophrenic Children

Electrophysiological correlates of focused attention were studied in 13 schizophrenic and 19 age- and gender-matched children. Subjects performed a version of the Continuous Performance Task (CPT) in which a target was designated as any digit from 0 through 9 occurring on two successive stimulus presentations. Signal digits were surrounded by distractor digits which varied in position, value, and number. Event-related potentials (ERPs) elicited by each stimulus of a target pair were recorded from midline and homologous parietal, temporal, and occipital electrode placements. Schizophrenic children made significantly more errors of omission and commission than normal children. The amplitude and time course of the intertrial CNV was the same for both groups. There was a circumscribed amplitude asymmetry, left smaller than right, for the P1/N1 and P2 measures which was greater in normal than in schizophrenic children. The P3 component was significantly larger to the second stimulus of the target pair than to the first for both groups, and larger for the normal than the schizophrenic children to both stimuli.

The roulette wheel: an aid to informed decision making.

The authors outline a new visual tool that can help patients assess the benefits and risks of different treatments.

Reduced attention-related negative potentials in schizophrenic children ☆

ERPs were recorded from normal and schizophrenic children during performance of a reaction time task (RT) followed by a complex visual discrimination, the span of apprehension task (Span), sensitive to vulnerability factors in schizophrenia. Subjects responded rapidly to the onset of the visual arrays in the RT condition and differentially to the presence of 1 of 2 target letters in the Span condition. The EEG was recorded at 19 scalp sites and ERPs included activity 1 sec before through 1 sec after Span array onset. Difference potentials (Span-RT) were computed to remove unvarying exogenous activity, thus isolating endogenous activity associated with the processing demands of the Span task. When RT and Span task ERPs are compared, schizophrenic children produced a significantly smaller than normal increment in endogenous negative activity. This endogenous negativity differed in its topography and time course from the exogenous components (P1, N1 and P2), and most likely reflects attentional effort associated with serial search, pattern recognition and stimulus identification. We believe that the current results support the position that schizophrenics are impaired in their ability to allocate adequate attentional resources for the processing of the Span stimuli. It is important to note that this deficit is apparent quite early in discriminative processing.

Are older hazardous and harmful drinkers less likely to participate in health-related behaviors and practices as compared with nonhazardous drinkers?

OBJECTIVES: To describe the (1) prevalence of at‐risk drinking and participation in health‐related behaviors and practices and (2) associations of at‐risk drinking with other health‐related behaviors and practices among older persons completing a health‐risk appraisal for the elderly (HRA‐E).

Continuous-processing related ERPS in schizophrenic and normal children

The continuous performance task (CPT) has proven to be sensitive to schizophrenic impairments. Multichannel event-related potential (ERP) data were recorded from schizophrenic and normal children during performance of easy and hard versions of the CPT. Schizophrenics produced fewer hits, more false alarms, and prolonged reaction times. Poor performance in schizophrenics was associated with four ERP abnormalities: (1) Schizophrenics did not exhibit the normal increase in amplitude of an early-onset, processing-related negativity from nontarget to target stimuli, suggesting a failure to appropriately allocate attentional resources to discriminative processing. (2) Although P3 amplitude to targets was not significantly smaller in schizophrenic children, the distribution of P3 amplitude between target and nontarget responses in the easy and hard versions of the CPT was abnormal, suggesting that schizophrenics differed in the strategic allocation of resources in later stages of CPT processing. (3) In all task conditions schizophrenics showed a parietal negative component with a latency of 400 msec seen in younger, but not older normal children, suggestive of maturational lag. (4) ERP data demonstrated absence of right-lateralized P1/N1 amplitude in schizophrenic children. Taken together these data indicate that at several stages of information processing, schizophrenics are deficient in the control and strategic allocation of processing resources.

A test of knowledge about prostate cancer screening. Online pilot evaluation among Southern California Physicians.

AbstractBACKGROUND: Although the benefits of prostate cancer screening are uncertain and guidelines recommend that physicians share the screening decision with their patients, most U.S. men over age 50 are routinely screened, often without counseling. OBJECTIVE: To develop an instrument for assessing physicians’ knowledge related to the U.S. Preventive Services Task Force recommendations on prostate cancer screening. PARTICIPANTS: Seventy internists, family physicians, and general practitioners in the Los Angeles area who deliver primary care to adult men. MEASUREMENTS: We assessed knowledge related to prostate cancer screening (natural history, test characteristics, treatment effects, and guideline recommendations), beliefs about the net benefits of screening, and prostate cancer screening practices for men in different age groups, using an online survey. We constructed a knowledge scale having 15 multiple-choice items. RESULTS: Participants’ mean knowledge score was 7.4 (range 3 to 12) of 15 (Cronbach’s α=0.71). Higher knowledge scores were associated with less belief in a mortality benefit from prostate-specific antigen (PSA) testing (r=−.49, P<.001). Participants could be categorized as low, age-selective, and high users of routine PSA screening. High users had lower knowledge scores than age-selective or low users, and they believed much more in mortality benefits from PSA screening. CONCLUSIONS: Based on its internal consistency and its correlations with measures of physicians’ net beliefs and self-reported practices, the knowledge scale developed in this study holds promise for measuring the effects of professional education on prostate cancer screening. The scale deserves further evaluation in broader populations.