Locus of the intensity effect in simple reaction time tasks

Evidence is still inconclusive regarding the locus of the stimulus intensity effect on information processing in reaction tasks. Miller, Ulrich, and Rinkenauer (1999) addressed this question by assessing the intensity effect on stimulus- and response-locked lateralized readiness potentials (LRPs) as indices of the sensory and motor parts of reaction time (RT). In the case of visual stimuli, they observed that application of brighter stimuli resulted in a shortening of RT and stimulus-locked LRP (S-LRP), but not of response-locked LRP (R-LRP). The results for auditory stimuli, however, were unclear. In spite of a clear RT reduction due to increased loudness, neither S-LRP nor R-LRP onset was affected. A reason for this failure might have been a relatively small range of intensity variation and the type of task. To check for this possibility, we performed three experiments in which broader ranges of stimulus intensities and simple, rather than choice, response tasks were used. Although the intensity effect on the R-LRP was negligible, S-LRP followed RT changes, irrespective of stimulus modality. These findings support the conclusion that stimulus intensity exerts its effect before the start of motoric processes. Finally, S-LRP and R-LRP findings are discussed within a broader information-processing perspective to check the validity of the claim that S-LRP and R-LRP can, indeed, be considered as pure estimates of the duration of sensory and motor processes.     

Generational Differences in Work Ethic: Fact or Fiction?

Even though stereotypes suggest that older generational cohorts (e.g., Baby Boomers) endorse higher levels of work ethic than younger generations (e.g., Millennials), both the academic literature and popular press have found mixed evidence as to whether or not generational differences actually exist. To examine whether generational differences exist in work ethic, a dataset was compiled (k = 105) of all published studies that provided an average sample age and average work ethic score, with each sample becoming an observation, and being assigned a generational cohort based upon the average age of the sample. Three hierarchical multiple regressions found no effect of generational cohort on work ethic endorsement. In two of the three phases, results found a main effect of sample type, such that industry samples had higher work ethic endorsement than student samples. Implications for applied practitioners and future research streams for generational and work ethic research are discussed.     

Gender and lexical access in Bulgarian

Two procedures were used to explore the effects of semantic and grammatical gender on the recognition and processing of Bulgarian nouns, in relation to other factors that are known to affect lexical access. This study in a three-gender language was modeled on previous work in Italian, a two-gender language (Bates, Devescovi, Pizzamiglio, D'Amico, & Hernandez, 1995). Words were presented auditorily in randomized lists in two tasks: (1) repeat the word as quickly as possible and (2) determine the grammatical gender of the noun as soon as possible and indicate the decision by pressing a button. Reaction times in both tasks were influenced by phonological factors, word frequency, and irregularity of gender marking, but semantic and grammatical gender affected only gender monitoring. The significant contribution of semantic gender to processing in Bulgarian contrasts with previous findings for Italian. Also, we obtained an interaction between sex of the subject and noun gender, reflecting a bias toward one's own grammatical gender "counterpart" (especially for females). Reanalysis of the prior study in Italian showed a similar interaction but confirmed no effects of the semantic gender of the noun, suggesting that these two natural gender effects can dissociate. Possible reasons for cross-linguistic differences are discussed, with implications for comparative studies of gender and lexical access.     

Music preferences and tobacco smoking

This study investigated the association of music preferences with tobacco smoking in a group of 152 high school and college students. Both the questionnaire and the listening survey indicated a higher preference for music associated with anxiety and depressed mood among smokers. These findings may reflect a common etiology of tobacco addiction and a specific type of music preferences. To elucidate this phenomenon further studies are needed.     

Grammaticality sensitivity in children with early focal brain injury and children with specific language impairment

Grammaticality judgments and processing times associated with violation detection were examined in typically developing children, children with focal brain lesions (FL) acquired early in life, and children with specific language impairment (SLI). Grammatical sensitivity in the FL group, while below typically developing children, was above levels seen in children with SLI. Age effects were noted with developmental changes in sensitivity extending into adolescence. Developmental delays in grammatical processing were particularly pronounced for children with SLI, who showed sensitivity levels below those of younger typically developing children. Sensitivity to agreement violations was also protracted in the SLI group providing further evidence of the vulnerability of morphology, a pattern not unlike that seen in adult aphasics. Findings for the FL group provide compelling evidence of neural and behavioral plasticity in children with early unilateral brain injury. Moreover, results from these children underscore how very different compensatory organization may be compared to profiles seen in adult aphasics who have comparable lesions. In contrast, although it was expected that the SLI children would perform below the typically developing children, the disadvantage seen with respect to the FL group suggests that the underlying pathology responsible for SLI may be more pervasive and less plastic than the focal pathology of children with early brain damage.     

Simultaneity constancy

Sound and light take different amounts of time to reach their respective receptors, to be transduced, and to be transmitted to the cortex. Their processing times also vary with factors such as intensity and retinal eccentricity. We assessed the capability of subjects to perceive simultaneity correctly despite these variations. Temporal asynchronies of up to 200 ms were introduced between the components of sound/light pairs. Using the method of constant stimuli, seven subjects judged which came first. Distance, and hence the times of arrival of paired visual and auditory targets, was varied from 1 to 32 m. Visual intensity was varied by viewing the target through 1.8 dB attenuating glasses, and a retinal eccentricity of 20 degrees was compared to central presentation. Despite large differences in reaction times, which varied in a predictable way with the stimulus parameters, the timing of sound/light pairings judged as simultaneous corresponded to when the light and sound left the source simultaneously. Almost complete compensation was found in all conditions tested, showing that these substantial but predictable variations in timing can be taken into account in creating simultaneity constancy.     

Suicidality in adolescence: review and legal considerations

Adolescence is a unique developmental stage in which suicidality first emerges as a public health problem. The increasing trend of teenage suicide since the 1950s has only relented in the past ten years. The risk factors for adolescent suicide, suicidal ideation, and suicide attempts and an approach to assessing the suicidal adolescent for risk of future self-harm are reviewed. Treatment consists of ensuring safety and then treating the underlying psychiatric, psychological, and interpersonal disturbances. Issues of consent, confidentiality, and malpractice actions are addressed.     

Brain potentials implicate temporal lobe abnormalities in criminal psychopaths

Psychopathy is associated with abnormalities in attention and orienting. However, few studies have examined the neural systems underlying these processes. To address this issue, the authors recorded event-related potentials (ERPs) while 80 incarcerated men, classified as psychopathic or nonpsychopathic via the Hare Psychopathy Checklist--Revised (R. D. Hare, 1991, 2003), completed an auditory oddball task. Consistent with hypotheses, processing of targets elicited larger frontocentral negativities (N550) in psychopaths than in nonpsychopaths. Psychopaths also showed an enlarged N2 and reduced P3 during target detection. Similar ERP modulations have been reported in patients with amygdala and temporal lobe damage. The data are interpreted as supporting the hypothesis that psychopathy may be related to dysfunction of the paralimbic system--a system that includes parts of the temporal and frontal lobes.     

Confirmatory factor analysis of the three-factor structure of the schizotypal personality questionnaire and Chapman schizotypy scales

We examined the factor structure of the Schizotypal Personality Questionnaire (SPQ; Raine, 1991), using confirmatory factor analysis in 3 experiments, with an aim to better understand the construct of schizotypy. In Experiment 1 we tested the fit of 2-, 3-, and 4-factor models on SPQ data from a normal sample. The paranoid 4-factor model fit the data best but not adequately. Based on the strong basis for the Raine 3-factor model we attempted to improve the fit of the 3-factor model by making 3 modifications to the Raine model. These modifications produced a well-fitting model. In Experiment 2 the good fit of this modified 2-factor model to SPQ scores was replicated in an independent normal sample. In Experiment 3, the modified 3-factor model was successfully extended to include the 3 Chapman schizotypy scales. Together these 3 experiments indicate that the 3-factor model of the SPQ, albeit with some slight modifications, is a good model for schizotypy structure that is not restricted to 1 measure of schizotypal personality traits.     

Developmental trajectories of childhood disruptive behaviors and adolescent delinquency: a six-site,cross-national study

This study used data from 6 sites and 3 countries to examine the developmental course of physical aggression in childhood and to analyze its linkage to violent and nonviolent offending outcomes in adolescence. The results indicate that among boys there is continuity in problem behavior from childhood to adolescence and that such continuity is especially acute when early problem behavior takes the form of physical aggression. Chronic physical aggression during the elementary school years specifically increases the risk for continued physical violence as well as other nonviolent forms of delinquency during adolescence. However, this conclusion is reserved primarily for boys, because the results indicate no clear linkage between childhood physical aggression and adolescent offending among female samples despite notable similarities across male and female samples in the developmental course of physical aggression in childhood.