Methods for improving the signal-to-noise ratio of endogenous-evoked potentials.

A stimulus leads to a cortical response (i.e., evoked potential [EP]) which may be recorded from electrodes attached to the scalp. However, background cortical activity, considered as noise (n), is typically of equal or greater magnitude than the response, which is considered as signal (s). This situation leads to the masking of the presence of the electrocortical signal. Two methods are described which enable the enhancement of the signal with respect to the noise. The first method outlined is time-domain averaging. Its relation to Fourier averaging is also presented. Time averaging can lead to an enhancement of the signal with respect to the noise, known as the signal-to-noise ratio (SNR), by a factor of root N; N being the number of trials recorded. However, latency variability (i.e., jitter) present in the signal leads to a decrement in this maximal potential enhancement. The second technique is an adaptive filter method of averaged cross-correlations, developed by Woody (1967), which deals with the variable latency problem. The development of a latency corrected average developed by McGillem and Aunon (1977) is also presented. The final section describes methods for data handling once the electrocortical signal has been enhanced. It is then necessary to describe the EP quantitatively. Principal Components Analysis (PCA) allows for the quantitative compact representation of the evoked potential waveform. The method also allows for the testing of the effects of explanatory variables on the EP.     

Brief report: Measuring self-efficacy with female adolescents who are conduct disordered: Validation of the program efficacy scale

This study focused on measuring self-efficacy with 44 female conduct disordered youth involuntarily placed in a long-term residential setting. The Program Efficacy Scale (PES) was developed as a measure of self-efficacy linked specifically to program completion. Construct validity for this measure was assessed by correlating it to the Generalized Self-Efficacy Scale (GSE) developed by Tipton and Worthington (1984) and other measures of program success. The PES was found to be significantly related to the GSE, length of placement, level of program achievement, and effort ratings by staff. Possible uses for the PES in predicting success or failure with youth in residential settings are discussed.     

Correlates of loneliness in nonreferred and psychiatrically hospitalized children

We investigated psychosocial correlates of loneliness using self- and caretaker-reports in 6–12 year old nonreferred and psychiatrically hospitalized children. In Phase 1, 109 nonreferred children completed self-report measures of internalizing problems, mothers completed the Child Behavior Checklist (CBCL), and teachers completed the CBCL-Teacher's Report Form. In Phase 2, a similar assessment battery was completed for 109 psychiatrically hospitalized children. Results indicated a moderate to strong relationship between loneliness and self-reported depression, hopelessness, low self-esteem, and anxiety. Children reporting high and low levels of loneliness were not differentiated by parent or teacher reports. Lonely children had lower IQs than their non-lonely peers.     

Another Round for the Brewers: Television Ads and Children's Alcohol Expectancies1

In an experimental study of how beer commercials affect alcohol expectancies, 92 fifth graders watched 40 television ads that included either five beer commercials, five soft-drink commercials, or five beer commercials plus two antidrinking messages. Afterwards, as an unrelated task, they completed the Alcohol Expectancy Questionnaire-Adolescent Form (AEQ-A; Christiansen, Goldman, & Inn, 1982). Exposure to different commercials produced no differences in drinking expectancies. The experiment was repeated on 74 eighth graders with similar null results; however, eighth-grade girls more strongly believed (p <.02) that alcohol leads to deteriorated cognitive and behavioral function. In a comparison of fifth and eighth graders from the same school, eighth graders had significantly more positive scores on three AEQ-A scales that tapped social/emotional expectancies. The failure of beer commercials to create positive alcohol expectancies is consistent with limited and null findings of previous investigations. Research to date does not support a ban on alcohol advertising.     

Murray A. Rae,Kierkegaard's Vision of the Incarnation: By Faith Transformed

International Journal for Philosophy of Religion -     

Cortical malformations and epilepsy

Brain malformations, resulting from aberrant patterns of brain development, are highly correlated with childhood seizure syndromes, as well as with cognitive disabilities and other neurological disorders. The structural malformations, often referred to as cortical dysplasia, are extremely varied, reflecting diverse underlying processes and critical timing of the developmental aberration. Recent studies have revealed a genetic basis for many forms of dysplasia. Gene mutations responsible for such common forms of dysplasia as lissencephaly and tuberous sclerosis have been identified, and investigators are beginning to understand how these gene mutations interrupt and/or misdirect the normal developmental pattern. Laboratory investigations, using animal models of cortical dysplasia, are beginning to elucidate how these structural malformations give rise to epilepsy and other functional pathologies.     

Family Centred Brief Solution-focused Therapy with Chronic Schizophrenia: a Pilot Study

The purpose of the study was to pilot a family centred brief solution-focused therapy model (BSFT) with families and clients diagnosed with schizophrenia. A control group of clients and their families received traditional outpatient therapy, while an experimental group of clients and their families were treated with a BSFT model. All participants were pre-tested and then post-tested with the Family Environment Scale after five therapy sessions over a ten-week period. Significant differences between the groups were found on expressiveness, active-recreational orientation, moral-religious emphasis and family incongruence. The participation of families and clients with schizophrenia in family centred brief solution-focused therapy produced encouraging results and demonstrated the need for expanded studies using BSFT with other chronically mentally ill clients and their families.     

OBJECT SUBSTITUTION:

Abstract —Can four dots that surround, but do not touch, a target shape act as a mask to reduce target discriminability? Although existing theories of metacontrast and pattern masking say "no." we report this occurs when targets appear in unpredictable locations. In three experiments, a four-dot mask was compared with a standard metacontrast mask that surrounded the target. Although accuracy was predictably different for the two masks at a central display location in Experiment I. both masks had similar strong effects on accuracy in parafoveal locations. Experiment 2 revealed that both four-dot and metacontrast masking were insensitive to contour proximity in parafoveal display locations, and Experiment 3 showed that four-dot masking could occur even at a central location if attention was distributed among several targets. We propose that targets in unattended locations are coded with low spotiotemporal resolution, leaving them vulnerable to substitution by the four dots when attention is directed to them.