The Separation-Individuation Test of Adolescence

The procedures undergone to establish the validity of the Separation- Individuation Test of Adolescence (SITA) are described. The test consists of six scales designed to measure key dimensions of adolescent separation-individuation. Each scale was subjected to three stages of validation: theoretical-substantive, internal-structural, and external-criterion. The results of data with 305 adolescents are reported. Although particular modifications from the original form are planned, appreciative levels of validity were established for the SITA's various scales.     

The three-factor structure of the Eysenck personality inventory revealed by a two-step confirmatory procedure

Evidence for the existence of the assumed three-subscale structure of the Eysenck Personality Inventory has been persistent but tenuous. It was suggested that a substantial reason for this may be the discrepancy between the numbers of items in the Lie (L) scale (9 items) and those in the other two scales [Neuroticism (N) and Extraversion (E)] which have 24 items in each. A two-step confirmatory procedure to circumvent this problem was proposed, involving a two-factor analysis of the Neuroticism and Extraversion items, followed by a three-factor analysis of equal numbers of N, E and L scale items. An analysis of the responses of 386 undergraduates demonstrating the proposed procedure revealed in the first step, quite unequivocally, the presence of Neuroticism and Extraversion factors, and in the second step, a third factor clearly congruent with the L scale.     

A time sharing cross-sectional study of monolinguals and bilinguals at different levels of second language acquisition

Several methodological factors associated with the concurrent activities (finger-tapping) paradigm were considered in a cross-sectional study investigating cerebral patterns of asymmetry in three groups of English-speaking non-Hispanic dextral males at three levels of second language (Spanish) acquisition and one control group of monolinguals. Results revealed the fluent bilinguals to be bilateral and significantly different from other groups for native language tasks in English. Moreover, a priori contrasts indicate that greater right- than left-hand disruption in concurrent tapping may be typical of monolinguals, but can be influenced by other factors. Monolingual reliability test-retest correlations were .77 and .47.     

Effects of intrahemispheric interference on reaction times to lateral stimuli

Earlier work (Green, 1977) indicated that response by a given hand was slower when stimuli occurred in the visual half field ipsilateral to the body side of hand origin. It was hypothesized that this was due to interference between processing demands originating within the same hemisphere. The present experiments provide evidence regarding the relationship between such interference and the magnitude and type of processing demands. The eight experiments indicate that intrahemispheric interference affects a variety of tasks, including letter shape, letter name, or face matching. The results indicate that reduction in response processing demands reduces the interference. Evidence of interference appeared with a more demanding choice response, but not with a simpler go-no-go response. Manipulations hypothesized to reduce initial, perceptual stimulus processing demands did not reduce the magnitude of interference, possibly because the level of more central stimulus processing demands was still sufficient to interfere with response processing. Interference tended to be minimal on right-hand, match trials, which are hypothesized to involve reduced response processing and reduced central stimulus processing demands. Further investigation of the effects of stimulus processing demands is required.     

Evidence for the involvement of brain GABA and serotonin systems in the anticonflict effects of chlordiazepoxide in rats

Using male hooded Lister rats the effects of GABAergic and serotonergic treatments alone and with chlordiazepoxide (CDP) were compared with the behavioral effects of CDP in a conditioned conflict procedure with three components; Reward, Time Out, and Conflict. CDP (2.5, 5.0, and 10.0 mg/kg ip) dose- relatedly increased punished and time out responding, but increased rewarded responding in an inversely dose-related manner. Punished responding was enhanced by chronic treatment to a rate which remained stable between 9 and 19 injections. The GABA transaminase inhibitor ethanolamine-O-sulfate (EOS), given chronically in drinking water (5.0 mg/ml), increased punished responding linearly to a high stable level after 2-3 weeks. Rewarded and time out responding were less substantially increased. CDP given with EOS dose- relatedly increased time out and punished responding substantially above the rates found with either treatment alone. The GABA antagonist picrotoxin blocked the increase in punished and time out responding found with EOS and CDP alone. The tryptophan hydroxylase inhibitor p-chlorophenylalanine (PCPA; 100 mg/kg x 3) linearly increased punished responding for the first week of treatment. CDP with PCPA selectively and significantly increased punished responding above the rates for either treatment alone, but the increases were not as substantial as those with EOS + CDP. The serotonin reuptake inhibitor Wy 25093 reduced increases in time out and punished responding under CDP, and the precursor 5-hydroxytryptophan (5-HTP) counteracted increases in punished responding under PCPA but also substantially reduced rewarded responding. These results provide evidence that both increased GABA and decreased serotonin transmission are involved in the anticonflict effects of CDP, as EOS and PCPA both mimicked and potentiated effects of CDP, while picrotoxin, Wy 25093, and 5-HTP counteracted them.(ABSTRACT TRUNCATED AT 250 WORDS)