Event-related potentials during word-reading and figure-matching in left-handed and right-handed males and females

In two experiments, event-related potentials at left and right occipital, parietal, and temporal sites were studied in 16 left-handers (8 male, 8 female) and 16 right-handers (8 male, 8 female). Subjects displayed extreme handedness, had a normal writing hand position, reported no left-handed relatives, and reported no perinatal traumata. In Experiment 1, centrally presented words had to be read, and nonverbal stimuli had to be matched. Condition-dependent asymmetries were found for P340 and SW components. Word-reading elicited a N500 component, whereas figure-matching did not. In Experiment 2, words presented to either the left or right visual field had to be read. It was found that N160 measures were larger, and P240, P400, and SW measures were smaller to words presented in the contralateral visual field compared to words in the ipsilateral field. Sex affected these pathway effects. In both experiments, hand preference did not significantly influence the ERP results.     

Feature representations and analytic/nonanalytic processing.

Lee Brooks' original formulation of instance theory embedded the notion of an instance within the larger conception of a distinction between analytic and nonanalytic processing. Brooks has recently argued that features can be represented either in terms of their specific feature appearance, or in terms of the abstract information some particular instantiation embodies. This work reviews some recent studies that link reliance on different types of feature representations to different decision-making processes, and to different patterns of categorization behaviour. This in turn complicates the analytic/nonanalytic distinction, suggesting a more precise reformulation.     

The eec, eye-movements and dreams of the blind

It was found that characteristic frontal EEG waves significantly often precede the rapid eye movements of dreaming. The rapid eye movements were absent during dream periods of three men with life-long blindness, and of two men, 30 and 40 years blind respectively, but were present during dream periods in three men blind only 3, 10 and 15 years respectively.     

Early and late processes in syllogistic reasoning: evidence from eye-movements

An eye-movement monitoring experiment was carried out to examine the effects of the difficulty of the problem (simple versus complex problems) and the type of figure (figure 1 or figure 4) on the time course of processing categorical syllogisms. The results showed that the course of influence for these two factors is different. We found early processing effects for the figure but not for the difficulty of the syllogism and later processing effects for both the figure and the difficulty. These results lend support to the Model Theory (Johnson-Laird, P. N., Byrne, R. M. J. (1991). Deduction. Hillsdale, New Jersey: LEA.) as opposed to other theories of reasoning (Chater, N., Oaksford, M. (1999). The probability heuristics model of syllogistic reasoning. Cognitive Psychology, 38, 191-258; Rips, L. J. (1994). The psychology of proof. Cambridge, MA: MIT Press; Rips, L. J. (1994). The psychology of proof. Cambridge, MA: MIT Press).     

The effect of word position on eye-movements in sentence and paragraph reading

The present study explores the role of the word position-in-text in sentence and paragraph reading. Three eye-movement data sets based on the reading of Dutch and German unrelated sentences reveal a sizeable, replicable increase in reading times over several words at the beginning and the end of sentences. The data from the paragraph-based English-language Dundee corpus replicate the pattern and also indicate that the increase in inspection times is driven by the visual boundaries of the text organized in lines, rather than by syntactic sentence boundaries. We argue that this effect is independent of several established lexical, contextual, and oculomotor predictors of eye-movement behaviour. We also provide evidence that the effect of word position-in-text has two independent components: a start-up effect, arguably caused by a strategic oculomotor programme of saccade planning over the line of text, and a wrap-up effect, originating in cognitive processes of comprehension and semantic integration.     

Aphasia in left-handers. Comparison of aphasia profiles and language recovery in non-right-handed and matched right-handed patients.

The present retrospective analysis reports two studies. In Study 1, clinical aspects of aphasia are compared in right-handed (RH) and non-right-handed (NRH) patients; in Study 2, recovery from aphasia is compared in RH and NRH aphasic patients with a minimum of 5 months of daily language rehabilitation. From a continuous series of 1200 brain-damaged subjects, 24 NRH patients with a vascular lesion documented by computerized tomography were selected. In 19 cases the lesion was in the left hemisphere and in 5 cases in the right hemisphere. For 14 NRH patients, a RH subject with similar lesion, matched for age, education, length of illness, etiology (ischemic vs. hemorrhagic), and, when possible, sex was found. Presence and type of aphasia were compared in the two patients of the same pair and were found similar except for Pair 14; the RH subject had global aphasia and the NRH had conduction-like aphasia. Fifteen NRH patients were rehabilitated and reexamined at least 5 months after the first examination. Recovery of the 12 patients with a left-hemisphere lesion was compared with recovery of a group of RH subjects and no significant differences were found. Recovery of the three patients with right-hemisphere lesions is described. It is concluded that differences in type of aphasia and recovery between RHs and NRHs have been overemphasized in the past and must be reconsidered.     

The impact of a history of sexual abuse on high-risk sexual behaviors among females attending alternative schools

The goal of this study was to explore whether a history of sexual abuse is associated with high-risk sexual behaviors among female adolescents attending alternative schools in a large urban city in the southwestern United States, and to examine the role of depression and substance abuse in explaining this association. One hundred eighty-four sexually active female adolescents constituted the sample for this analysis. Forty-nine (26.6%) reported that they were forced to have sex. Having a history of sexual abuse substantially increased sexual risk behaviors. Adolescents reporting a history of sexual abuse, compared to those who did not report such a history, were significantly more likely to have initiated sexual activity (intercourse) before age 14, to have had three or more sexual partners in the last 3 months, and to have had a history of sexually transmitted diseases. These associations remained significant after controlling for age, ethnicity, and family income. Depression and substance abuse did not explain the association between sexual abuse and high-risk sexual behaviors. It seems reasonable to conclude that adolescents with a history of sexual abuse have greater difficulty practicing safe sexual behaviors than do those who have not been sexually abused. Given the prevalence of child sexual abuse and the extent of its impact, it is critical that intervention strategies for adolescent females address the issue of abuse and help them adopt self-protective sexual behaviors. The findings also highlight the importance of targeting adolescents who attend alternative schools.     

The MMPI'S of left- and right-handed subjects

Previous research has suggested that left-handedness relates to delinquency and violence. In an effort to pinpoint the nature of this apparent relationship, we compared the MMPIs of 72 left- and 687 right-handed men 60 yr. old or less on an alcohol treatment ward. No significant differences appeared. The results are compared to earlier research and hypotheses for further research are suggested.     

On the representation of language in the right hemisphere of right-handed people.

Laterality experiments using reaction time were conducted to assess the performance of the right hemisphere of normal people on verbal tasks. The results show that if the task calls for pictorial encoding of visually presented verbal material, then the right hemisphere's performance is superior to that of the left. When the task calls for linguistic analysis, the minor hemisphere displays no aptitude in dealing with the task. The latter finding is at variance with data from split-brain research. To reconcile these differences, it was proposed that language functions, though represented in the right hemisphere of normal people, are functionally localized in the left. When the control which the left hemisphere exerts over the right is weakened or removed, e.g., by commissurotomy, right hemisphere language is released. The application of this model to other neurological phenomena is briefly discussed.     

Investigating effects of selectional restriction violations and plausibility violation severity on eye-movements in reading

This paper presents a study investigating whether and how different kinds of knowledge affect the detection of plausibility and possibility violations. Readers’ eye-movements were monitored while reading sentences describing impossible events cued by selectional restriction violations, extremely implausible events without selectional restriction violations, and plausible events, in order to determine whether the time course of disruption is determined by overall implausibility/unlikelihood, or whether impossibility cued by selectional restriction violations additionally affects disruption. Both early and late fixation measures showed stronger disruption in the impossible/selectional restriction violation condition. However, measures indexing regressive eye-movements showed similar disruption in both extremely implausible conditions. This suggests that the magnitude and latency of disruption to possibility and plausibility violations is not a simple function of the overall implausibility/unlikelihood of the resulting event, but that selectional restriction violations influence the early and late time course of disruption.     

Single-sex versus coeducational environment and achievement in adolescent females.

For women, the nature and range of experiences during the high school years take on special significance, since it is during this period that they usually weigh their various roles and adjust their levels of aspirations accordingly. If the high school environment is successful in reducing the discrepancy between what are often viewed as conflicting roles, adolescent females may place greater emphasis on achievement. It is within this context that the present paper explored the differential benefits of single-sex and coeducational schooling. The issue explored is not whether one is preferable for females; rather, the concern here is how each of these settings influences both achievement and personal fulfillment.     

Test of a potential link between analytic and nonanalytic category learning and automatic, effortful processing

The link between automatic and effortful processing and nonanalytic and analytic category learning was evaluated in a sample of 29 college undergraduates using declarative memory, semantic category search, and pseudoword categorization tasks. Automatic and effortful processing measures were hypothesized to be associated with nonanalytic and analytic categorization, respectively. Results suggested that contrary to prediction strong criterion-attribute (analytic) responding on the pseudoword categorization task was associated with strong automatic, implicit memory encoding of frequency-of-occurrence information. Data are discussed in terms of the possibility that criterion-attribute category knowledge, once established, may be expressed with few attentional resources. The data indicate that attention resource requirements, even for the same stimuli and task, vary depending on the category rule system utilized. Also, the automaticity emerging from familiarity with analytic category exemplars is very different from the automaticity arising from extensive practice on a semantic category search task. The data do not support any simple mapping of analytic and nonanalytic forms of category learning onto the automatic and effortful processing dichotomy and challenge simple models of brain asymmetries for such procedures.     

Interhemispheric EEG coherence during sleep and wakefulness in left- and right-handed subjects

REM sleep is associated with the production of complex imagery sequences. Yet research is divided as to whether different brain regions are more or less coordinated in their functioning at this time. Some research suggests that there may occur a functional disconnection of the left and right cerebral hemispheres during REM sleep which is similar to the disconnection syndrome seen after corpus callosotomy. Other research suggests that an increase in interhemispheric coordination occurs. On the assumption that hemispheric coordination is reflected in the EEG coherence measure, we explored differences in interhemispheric coherence recorded in six left- and six right-handed normal subjects during periods of wakefulness, stage REM, stage 2, and stage 3/4 sleep. Strong evidence was found that mean EEG coherence values are larger during sleep than during waking and that they are approximately equal for the different stages of sleep. Frontal electrode placements demonstrated a slightly different pattern of coherence than central, parietal, or occipital placements. Furthermore, coherence values were larger for left-handed subjects over the occipital region during wakefulness, stage 2, and stage REM sleep, but not during stage 3/4 sleep. Coherence was not different for male and female subjects. These findings oppose the interpretation that a functional disconnection of hemispheres occurs during REM sleep and favor the interpretation that sleep in general is a state of heightened cortical coordination. Moreover, greater interhemispheric coherence over occipital brain regions in left-handed subjects suggests possible differences in the cognitive processes of these subjects during waking and dreaming states.     

Cultural differences in drawing movements between right-handed Japanese and German participants

Differences in drawing movements with the dominant and nondominant hands by 41 right-handed students from Japan (9 men, 12 women; M age = 20.3 yr., SD = 1.4) and Germany (13 men, 7 women; M age = 23.4 yr., SD = 3.0) were investigated. Participants were asked to use each hand to draw a circle, a pentagon, and a rhombus in one stroke. Analysis showed that Japanese participants drew a circle clockwise with the dominant right hand, starting from 6 or 7 o'clock on the face of a clock, while the German participants drew the circle counterclockwise, starting from 11 or 12 o'clock. Moreover, when drawing a pentagon and a rhombus with the right hand, Japanese participants drew counterclockwise from the top-center vertex, whereas almost half of German participants drew clockwise from the left side and others drew counterclockwise from the top-center vertex. Using the left hand, no significant difference was found in starting positions or directionality. Cultural differences in the starting positions and directionality when using the dominant right hand probably reflect the influence of writing habits on the drawing movement of the dominant hand.     

Unilateral nostril breathing in intraocular pressure of right-handed healthy subjects

The effects of unilateral forced nostril breathing on the intraocular pressures of right and left eyes was studied in 24 male and 26 female right-handed adults. In men, the forced breathing through both the right and left nostrils significantly decreased the intraocular pressures of both right and left eyes. For women, the forced breathing through right nostril did not affect the intraocular pressures of right and left eyes, and the forced breathing through left nostril also had no effect on the intraocular pressure of right eye, although it decreased the intraocular pressure of left eye significantly. These results show that unilateral forced nostril breathing decreases intraocular pressure especially in men, perhaps increasing sympathetic nervous system activity.     

A study of sexual offenses against females.

The objective of this study was to obtain information on sexual offenses against females. Data were obtained from 103 females in two university classes. Eighty-four percent reported having been the victim of a sexual offense. The offenses experienced were obscene telephone calls (61%), sexual molestation (44%), exhibitionism (27%), being followed (24%), attempted rape (16%) and rape (1%). Most offenses were discussed with friends while very few were reported to parents, police or social workers.     

Competitiveness in males and in females

Male and female undergraduates performed a task at which they either succeeded or failed in competition with either a male or female partner who subsequently either accepted or rejected them. Subjects who were rejected by a male partner following success or accepted following failure performed less well on a subsequent anagram task than did those who were accepted following success or rejected following failure. These results suggest the importance of situational factors as determinants of fear of success behavior.