Prosocial motives underlie scientific censorship by scientists: A perspective and research agenda

Science is among humanity's greatest achievements, yet scientific censorship is rarely studied empirically. We explore the social, psychological, and institutional causes and consequences of scientific censorship (defined as actions aimed at obstructing particular scientific ideas from reaching an audience for reasons other than low scientific quality). Popular narratives suggest that scientific censorship is driven by authoritarian officials with dark motives, such as dogmatism and intolerance. Our analysis suggests that scientific censorship is often driven by scientists, who are primarily motivated by self-protection, benevolence toward peer scholars, and prosocial concerns for the well-being of human social groups. This perspective helps explain both recent findings on scientific censorship and recent changes to scientific institutions, such as the use of harm-based criteria to evaluate research. We discuss unknowns surrounding the consequences of censorship and provide recommendations for improving transparency and accountability in scientific decision-making to enable the exploration of these unknowns. The benefits of censorship may sometimes outweigh costs. However, until costs and benefits are examined empirically, scholars on opposing sides of ongoing debates are left to quarrel based on competing values, assumptions, and intuitions.

Testing Environmental Effects on Age at Menarche and Sexual Debut within a Genetically Informative Twin Design

Life-history-derived models of female sexual development propose menarche timing as a key regulatory mechanism driving subsequent sexual behavior. The current research utilized a twin subsample of the National Longitudinal Study of Adolescent to Adult Health (Add Health; n = 514) to evaluate environmental effects on timings of menarche and sexual debut, as well as address potential confounding of these effects within a genetically informative design. Results show mixed support for each life history model and provide little evidence rearing environment is important in the etiology of individual differences in age at menarche. This research calls into question the underlying assumptions of life-history-derived models of sexual development and highlights the need for more behavior genetic research in this area.

Confirmatory Factor Analysis of the Coalitional Mate Retention Inventory (CMRI) and Evidence for Two Superordinate Domains

Abstract. The Coalitional Mate Retention Inventory (CMRI; Pham, Barbaro, Mogilski, & Shackelford, 2015 ) assesses the frequency with which individuals solicit allies to assist with mate retention efforts. The current study subjected the CMRI to confirmatory factor analyses (CFAs). A model comparison approach was employed using data from a large community sample of participants currently in a heterosexual romantic relationship ( n = 1,003, 54% male). The seven-factor structure of the CMRI demonstrates good model fit and provides significantly better fit than an alternative single-factor structure. The results also demonstrate that the seven tactics of the CMRI are subsumed by two superordinate domains of Benefit-Provisioning and Cost-Inflicting coalitional mate retention. Correlational analyses with the superordinate domains of coalitional mate retention are presented and highlight their predictive utility. We recommend the continued use of the CMRI in psychological research.

Environmental Unpredictability in Childhood Is Associated With Anxious Romantic Attachment and Intimate Partner Violence Perpetration

Human life history theory describes how resources are allocated among conflicting life tasks, including trade-offs concerning reproduction. The current research investigates the unique importance of environmental unpredictability in childhood in association with romantic attachment, and explores whether objective or subjective measures of environmental risk are more informative for testing life history hypotheses. We hypothesize that (1) unpredictability in childhood will be associated with greater anxious attachment, (2) anxious attachment will be associated with intimate partner violence (IPV) perpetration, and (3) anxious attachment will mediate the relationship between unpredictability in childhood and IPV perpetration. In two studies (total n = 391), participants in a heterosexual, romantic relationship completed self-report measures of childhood experiences, romantic attachment, and IPV perpetration. Study 1 provides support for Hypothesis 1. Hypothesis 1 is replicated only for men, but not women, in Study 2. Results of Study 2 provide support for Hypothesis 2 for men and women, and Hypothesis 3 was supported for men but not women. The findings contribute to the literature addressing the association of environmental risk in childhood on adult romantic relationship outcomes.

Life history correlates of human (Homo sapiens) ejaculate quality

Life history strategies reflect resource allocation decisions, which manifest as physiological, psychological, and behavioral traits. We investigated whether human ejaculate quality is associated with indicators of relatively fast (greater resource allocation to mating effort) or slow (greater resource allocation to parenting effort) life history strategies in a test of two competing hypotheses: (a) The phenotype-linked fertility hypothesis, which predicts that men pursuing a relatively fast life history strategy will produce higher quality ejaculates, and (b) the cuckoldry-risk hypothesis, which predicts that men pursuing a relatively slow life history strategy will produce higher quality ejaculates. Men (n = 41) completed a self-report measure assessing life history strategy and provided two masturbatory ejaculate samples. Results provide preliminary support for the cuckoldry-risk hypothesis: Men pursuing a relatively slow life history strategy produced higher quality ejaculates. Ejaculate quality may therefore reflect resource allocation decisions for greater parenting effort, as opposed to greater mating effort. The findings contribute informative data on correlations between physiological and phenotypic indicators of human life history strategies. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Associations of Attachment Anxiety and Avoidance With Male- and Female-Perpetrated Sexual Coercion in Romantic Relationships

Few studies have investigated the associations between romantic attachment dimensions and sexual coercion perpetration. The present study aimed to address methodological limitations in previous studies, and to more accurately identify the associations between romantic attachment and sexual coercion perpetration in romantic relationships. Data from 284 individuals (56% men) were secured via an online self-report survey. Participants completed assessments of romantic attachment to their current romantic partner, and reported the frequency with which they perpetrated 34 acts of sexual coercion against their romantic partner. Attachment anxiety was a positive predictor of sexual coercion perpetration for men and women. Additionally, for men only, the association between attachment anxiety and sexual coercion perpetration was stronger for individuals with greater attachment avoidance. The results of the study present a clearer picture of the associations between attachment and sexual coercion, and accord with modern theoretical perspectives positing that romantic attachment regulates reactions to acute and ongoing relationship threats.

Anxious and Hostile: Consequences of Anxious Adult Attachment in Predicting Male-Perpetrated Sexual Assault

Attachment theory has increasingly been utilized to understand the etiology of sexual violence, and anxious attachment appears to be especially informative in this domain. We investigate the influence of general anxious attachment and specific anxious attachment on hostile masculine attitudes to predict male-perpetrated sexual assault. We hypothesize that hostile masculinity will mediate the relationship between general anxious attachment style and sexual assault perpetration (Hypothesis 1) and the relationship between specific anxious attachment to the assaulted woman and sexual assault perpetration (Hypothesis 2). Men ( N = 193) completed the Sexual Experiences Survey (SES) to determine sexual assault history and completed measures of general attachment style, specific attachment to the woman involved in the sexual activity, and measures of hostile masculine attitudes. Results support the hypothesized mediation models, such that general anxious attachment and specific anxious attachment are significantly associated with hostile masculinity, which in turn, predicts the likelihood of male-perpetrated sexual assault. The findings suggest that the unique characteristics of anxious attachment may escalate into hostile masculinity, which then increases the likelihood of sexual assault perpetration. This research is the first to investigate attachment bonds to the woman involved in the sexual activity and likelihood of sexual assault perpetration against the same woman.

A People-as-Means Approach to Interpersonal Relationships

Interpersonal relationships and goal pursuit are intimately interconnected. In the present article, we present a people-as-means perspective on relationships. According to this perspective, people serve as means to goals-helping other people to reach their goals in a variety of ways, such as by contributing their time; lending their knowledge, skills, and resources; and providing emotional support and encouragement. Because people serve as means to goals, we propose that considering relationship processes in terms of the principles of goal pursuit can provide novel and important insights into the ways that people think, feel, and behave in these interpersonal contexts. We describe the principles of means-goals relations, review evidence for each principle involving people as means, and discuss implications of our approach for relationship formation, maintenance, and dissolution.

Do Men Produce Higher Quality Ejaculates When Primed With Thoughts of Partner Infidelity?

Sperm competition theory can be used to generate the hypothesis that men alter the quality of their ejaculates as a function of sperm competition risk. Using a repeated measures experimental design, we investigated whether men produce a higher quality ejaculate when primed with cues to sperm competition (i.e., imagined partner infidelity) relative to a control prime. Men ( n = 45) submitted two masturbatory ejaculates-one ejaculate sample for each condition (i.e., sperm competition and control conditions). Ejaculates were assessed on 17 clinical parameters. The results did not support the hypothesis: Men did not produce higher quality ejaculates in the sperm competition condition relative to the control condition. Despite the null results of the current research, there is evidence for psychological and physiological adaptations to sperm competition in humans. We discuss methodological limitations that may have produced the null results and present methodological suggestions for research on human sperm competition.

Endorsement of Social and Personal Values Predicts the Desirability of Men and Women as Long-Term Partners

A prospective romantic partner's desirability as a long-term partner may be affected by the values that he or she endorses. However, few studies have examined the effects of "values" on a person's desirability as a long-term partner. We hypothesized that individuals who endorse social values (vs. personal values) will be perceived as more desirable long-term partners (Hypothesis 1) and that the endorsement of social values will be especially desirable in a male (vs. female) long-term partner (Hypothesis 2). The current study employed a 2 (sex of prospective partner: male vs. female) × 2 (values of prospective partner: personal vs. social) × 2 (physical attractiveness of prospective partner: unattractive vs. highly attractive) mixed-model design. Participants were 339 undergraduates (174 men, 165 women), with ages varying between 18 and 33 years ( M = 19.9, SD = 3.6), and mostly in a romantic relationship (53.7%). Participants reported interest in a long-term relationship with prospective partners depicted in four scenarios (within subjects), each varying along the dimensions of values (personal vs. social) and physical attractiveness (unattractive vs. highly attractive). Individuals endorsing personal values (vs. social values) and men (vs. women) endorsing personal values were rated as less desirable as long-term partners. The current research adds to the partner preferences literature by demonstrating that an individual's ascribed values influence others' perceptions of desirability as a long-term partner and that these effects are consistently sex differentiated, as predicted by an evolutionary perspective on romantic partner preferences.

Post-Fight Respect Signals Valuations of Opponent's Fighting Performance

The current research explores whether humans process inputs about combat (e.g., assessments of formidability) that produce outputs of post-fight respect (e.g., shaking an opponent's hand when the fight ends). Using an online questionnaire (Study 1, n = 132), an in-person questionnaire (Study 2, n = 131), and an in-lab fight simulation (Study 3, n = 58), we investigated whether participants were more likely to receive (Studies 1 and 3) and display (Studies 2 and 3) post-fight respect as a function of the fight outcome (Hypothesis 1), use of fight tactics (Hypothesis 2), fighter asymmetries (Hypothesis 3), fighter ranking (Hypothesis 4), and the presence of witnesses (Hypothesis 5). The results support Hypotheses 1 to 4 concerning expectations of receiving post-fight respect, and support only Hypotheses 2 and 3 concerning displays of post-fight respect. We suggest that post-fight respect signals positive valuations of fighting performance that may function to maintain valuable relationships within the social group.

Consideration of Cosmetic Surgery As Part of Women's Benefit-Provisioning Mate Retention Strategy

Individuals perform mate retention behaviors to minimize the risk of partner infidelity and relationship dissolution. The current study investigates whether consideration of cosmetic surgery can be conceptualized as part of a broader strategy of mate retention for women, but not men. We hypothesized that women's consideration of cosmetic surgery would be positively associated with performance frequencies of Benefit-Provisioning and Cost-Inflicting mate retention behaviors. We recruited 203 individuals (54% women) in committed heterosexual relationships from Tehran, Iran. Results indicate a positive association between consideration of cosmetic surgery and Benefit-Provisioning mate retention behaviors for women, but not men. There was no association between consideration of cosmetic surgery and Cost-Inflicting mate retention behaviors. Women therefore may consider cosmetic surgery to improve their physical attractiveness as part of a Benefit-Provisioning strategy to retain a long-term mate. We discuss limitations of the study and highlight future directions for research from an evolutionary perspective.

Rethinking the transmission gap: What behavioral genetics and evolutionary psychology mean for attachment theory: A comment on Verhage et al. (2016)

Traditional attachment theory posits that attachment in infancy and early childhood is the result of intergenerational transmission of attachment from parents to offspring. Verhage et al. (2016) present meta-analytic evidence addressing the intergenerational transmission of attachment between caregivers and young children. In this commentary, we argue that their appraisal of the behavioral genetics literature is incomplete. The suggested research focus on shared environmental effects may dissuade the pursuit of profitable avenues of research and may hinder progress in attachment theory. Specifically, further research on the "transmission gap" will continue to limit our understanding of attachment etiology. We discuss recent theoretical developments from an evolutionary psychological perspective that can provide a valuable framework to account for the existing behavioral genetic data. (PsycINFO Database Record

Mothers and Fathers Perform More Mate Retention Behaviors than Individuals without Children

Human life history is unique among primates, most notably the extraordinary length of infant dependency and the formation of long-term pair-bonds. Men and women are motivated to remain pair-bonded to maintain the distribution of male-provisioned resources to a woman and her offspring, or to protect offspring from infanticide. Men and women can employ several strategies to retain their mate and prevent their partner from defecting from the relationship, including individual mate retention (behaviors performed alone) and coalitional mate retention (behaviors performed by a close ally). The current research investigates whether men and women with children perform more frequent mate retention behaviors than men and women without children. Participants (n = 1003) currently in a heterosexual romantic relationship completed a survey, reporting whether they had genetic children with their current romantic partner and how frequently they performed various mate retention behaviors. The results indicate that men (n = 262) and women (n = 234) who share genetic children with their current partner performed more frequent individual mate retention behaviors and requested more frequent coalitional mate retention behaviors than men (n = 280) and women (n = 227) who do not share genetic children with their current partner. The results are interpreted as they relate to hypotheses concerning the evolution of pair-bonding in humans, and mate retention behaviors more generally. Limitations of the current research are discussed, and profitable avenues for future research in this domain are suggested.

Husband's Reaction to His Wife's Sexual Rejection Is Predicted by the Time She Spends With Her Male Friends but Not Her Male Coworkers

Males among many species, including humans, evaluate cues of sperm competition risk and adjust accordingly their sperm competition tactics. The number of potential sexual rivals can serve as an index of sperm competition risk. Therefore, men may adjust their in-pair copulatory interest in accordance with the presence of sexual rivals. Using self-reports from 45 married men, we test the hypotheses that the time a man's wife spends with other men-either male friends or male coworkers-will positively predict a man's copulatory interest in his wife (Hypothesis 1) and his anger (Hypothesis 2), upset (Hypothesis 3), and frustration (Hypothesis 4) in response to his wife's sexual rejection. The results show that the time wives spend with male friends (but not male coworkers) predicts their husbands' anger, upset, and frustration in response to sexual rejection, providing support for Hypotheses 2-4. Discussion highlights novel contributions of the current research and provides a potential explanation for the discrepant findings regarding male friends versus male coworkers.

Psychometric Evaluation and Cultural Correlates of the Mate Retention Inventory-Short Form (MRI-SF) in Iran

The current study investigated the psychometric properties of the Persian translation of the Mate Retention Inventory-Short Form (MRI-SF) in Iran. We also investigated sex differences in the use of mate retention tactics and investigated the relationships between mate retention behaviors and a number of related cultural constructs. Participants ( N = 308) ranged in age from 18 to 57 years. All participants were in a committed romantic relationship, with mean relationship length of 63.5 months ( SD = 73.8). Participants completed the Persian translation of the MRI-SF and measures of religiosity, relationship satisfaction, self-esteem, and socioeconomic status. Cultural measures specific to Iran were also included, such as Mahr (for married individuals), self-perceived Qeiratiness (for men), and self-perceived jealousy (for women). Mahr is a mandatory amount of money or possessions paid or promised to be paid by the groom to the bride at the time of the marriage contract. Qeirati is a male-specific adjective in Persian meaning protective against unwanted attention toward a man's romantic partner. Female jealousy is usually regarded the counterpart of male Qeiratiness in Iranian culture. The 19 mate retention tactics formed a two-component structure, consistent with previous research. Results demonstrate adequate internal consistency of 2-item assessments of mate retention tactics. Observed sex differences accorded with previous mate retention research and are discussed in reference to evolutionary perspectives on human mating. Several significant associations emerged between mate retention tactics and Iranian culture-specific variables and are discussed from a cross-cultural perspective.

Female-directed violence as a form of sexual coercion in humans (Homo sapiens)

Male-perpetrated female-directed violence (FDV) may be associated with greater sexual access to a female. Accordingly, FDV is expected to be associated with greater copulation frequency. Research on nonhuman primates affirms this hypothesis, but no previous research has investigated this relationship in humans (Homo sapiens). The current research tests the hypothesis that FDV is associated with in-pair copulation frequency and, thus, may function as a form of sexual coercion. It was predicted that men who perpetrate FDV will secure more in-pair copulations than men who do not perpetrate violence (Prediction 1a), and that average monthly rates of FDV would positively correlate with in-pair copulation frequency (Prediction 1b). Male participants (n = 355) completed a survey, reporting limited demographic information (e.g., age, relationship length), in-pair copulation frequency, and history of physical violence perpetration. As predicted, violent men secured more in-pair copulations, on average, than nonviolent men, and monthly rates of violence positively correlated with in-pair copulation frequency. In humans, as in nonhuman primates, FDV by males may facilitate greater sexual access to a female. We discuss the implications of the current research for an evolutionary perspective on partner violence, and draw on research on nonhuman primates to highlight profitable avenues of research on FDV in humans. (PsycINFO Database Record

Sperm Competition Risk and Sexual Coercion Predict Copulatory Duration in Humans

A man whose romantic partner is sexually unfaithful is at risk of sperm competition and cuckoldry-unwitting investment in offspring to whom he is genetically unrelated. Men, therefore, may have evolved mechanisms to solve the adaptive problems of sperm competition and cuckoldry. The current research investigates another potential anti-cuckoldry tactic: reducing in-pair copulation (IPC) duration, thereby more quickly placing his sperm into competition. We hypothesize that IPC duration will be negatively correlated with female infidelity (Hypothesis 1). We further hypothesize that IPC duration will be negatively correlated with sexual coercion (Hypothesis 2). Results of Study 1 (men's reports, n = 410) indicate that both men's perceptions of female infidelity and men's sexual coercion predict shorter IPC duration. Results of Study 2 (women's reports, n = 455) did not provide statistical support for the study hypotheses. The current research provides an initial investigation of men's adjustment of copulatory duration and suggests that men reduce IPC duration and ejaculate more quickly at the couple's most recent copulation, in response to greater risk of sperm competition and in the context of sexual coercion.

The relationship between subjective sleep disturbance, sleep quality, and emotion regulation difficulties in a sample of college students reporting trauma exposure

Sleep disturbance and poor sleep quality has been associated with trauma exposure and posttraumatic stress disorder (PTSD) symptoms; however, the associated emotional consequences of sleep disturbance have not been examined within this context (i.e., emotional reactivity, emotion modulation). The current study examined the relationship between sleep disturbance, poor sleep quality, and emotion regulation difficulties. In a sample of college students reporting exposure to at least 1 traumatic event, online survey methodology was used to assess PTSD symptom severity (PTSS), sleep disturbances, including PTSD-specific sleep disturbances, and emotion regulation difficulties. After controlling for PTSS, sleep disturbance and poor sleep quality domains were related to both global and specific difficulties in emotion regulation domains. The findings suggest that sleep disturbance and emotion regulation difficulties associated with PTSD may not be a mere extension of the clinical picture of PTSD. Sleep disturbances following trauma exposure may contribute to emotion regulation difficulties and exacerbate negative consequences. Future research should examine the effects of treatments that simultaneously address sleep disturbances and PTSD symptoms on emotion regulation processes.

Calcifying pseudoneoplasms of the neuraxis: CT, MR imaging, and histologic features

BACKGROUND AND PURPOSE

Non-neoplastic, calcified, fibro-osseous lesions known as "calcifying pseudoneoplasms of the neuraxis" (CAPNON) are rare and can occur anywhere within the neuraxis. The radiologic and histopathologic characteristics of this unusual entity are not well understood. We present the largest series reviewing the MR imaging features of CAPNON.

MATERIALS AND METHODS

The MR and CT imaging features in 4 patients with a pathologic diagnosis of "calcifying pseudoneoplasms of the neuraxis" were retrospectively reviewed. A neuropathologist also analyzed the histopathologic features for typical and atypical patterns.

RESULTS

Imaging features were strikingly similar for all 4 patients. All lesions appeared T1 and T2 hypointense without vasogenic edema. All tumors had dense calcification, and 3 tumors showed minimal linear internal or rim enhancement on MR imaging.

CONCLUSIONS

CAPNON may mimic more common vascular malformations or neoplasms and are often not considered in the differential diagnosis of calcified lesions. CAPNON should be included in the differential diagnosis of a calcified mass with marked T1 and T2 hypointensity and limited to no enhancement. Careful CT and MR imaging evaluation can suggest this entity, and this preoperative recognition may help subsequent management decisions.

In vivo hippocampal glucose metabolism in mesial temporal lobe epilepsy

BACKGROUND

The appearance of decreased 2-[(18)F]fluoro-2-deoxy-D-glucose (FDG) uptake in the mesial temporal region in temporal lobe epilepsy may simply reflect loss of gray matter due to hippocampal atrophy. Increased partial volume effects due to atrophic hippocampi may further increase appearance of hypometabolism.

METHODS

The authors used a combination of MRI-PET coregistration, with MRI-based gray matter segmentation, and partial volume correction to improve the examination of hippocampal specific glucose uptake in FDG PET. The goal was to determine 1) if relative mesial temporal hypometabolism is an artifact of gray matter (hippocampal) atrophy, 2) whether hippocampal metabolism correlates with atrophy evaluated on MRI, and 3) if MRI-based partial volume correction influences measurement of hippocampal metabolic-volume relationships, including epilepsy lateralization.

RESULTS

Findings showed that ipsilateral hippocampi of mesial temporal lobe epilepsy (MTLE) are relatively hypometabolic per unit of gray matter volume, and that hippocampal metabolism directly correlates with hippocampal volume. Specifically, partial volume corrected hippocampal metabolism correlated strongly (r = 0.613, p < 0.001) with hippocampal volume. Without partial volume correction, a weaker, but still significant, correlation was present (r = 0.482, p < 0.001). Degree of asymmetry was consistently greater and provided higher sensitivity of lateralization with partial volume vs non-partial volume corrected metabolic measurements.

CONCLUSIONS

Although, decreased metabolism may occur in the absence of neuronal cell loss, hippocampal atrophy and presumed degree of neuronal cell loss appears to be a primary factor involved in the cause of decreased metabolism in epileptogenic hippocampi. Partial volume correction is recommended for optimal interpretation of hippocampal structure and function relationships.

Spontaneous intracranial hypotension resulting in stupor caused by diencephalic compression

A 51-year-old man had a 4-month history of progressive headache and gradual onset of somnolence. MRI suggested spontaneous intracranial hypotension (SIH) with diencephalic compression, but he did not improve after three epidural blood patches. He became alert following intrathecal saline infusion that normalized his CSF pressure. A CSF leak was noted on spinal MRI and confirmed with CT contrast myelography. Surgical ligation of a torn dural root sleeve isolating a ruptured Tarlov's cyst resulted in permanent cure.

Spatio-temporal correlations in human gamma band electrocorticograms

Animal electrocorticogram (ECoG) studies have shown that spatial patterns in the gamma band (>20 Hz) reflect perceptual categorization. Spatio-temporal correlations were investigated in the 20-50 Hz range in search for similar phenomena in human ECoG. ECoGs were recorded in a somatosensory discrimination task from 64-electrode subdural grid arrays, with inter-electrode spacing of 1 cm, overlying somatosensory, motor and superior temporal cortices in 2 patients with intractable epilepsy. Bootstrap techniques were devised to analyze the spatial and temporal characteristics of the correlations. Despite an extensive search, no evidence was found for globally correlated activity related to behavior either in narrow (1.e., 35-45 Hz) or broad (i.e., 20-50 Hz) bands. Spatial patterns, extracted using principal component analysis, could not be classified with respect to stimulus type in any time interval. Instead, spatially and temporally intermittent synchronization was observed between pairs of electrodes in 1 cm X 1 cm regions with high variability within and across trials. The distribution of correlation coefficients differed substantially from background levels at inter-electrode distances of 1 cm and 1.4 cm but not 2 cm or more. The minimum duration of correlation, the decorrelation time, of the ECoG was about 50 msec; the average correlation duration at 1 cm inter-electrode distance was about 150 msec; and the recurrence rate of significant correlation peaks was about 1.3/sec. The findings suggest that the surface diameters of domains of spatially correlated activity underlying perceptual categorization in human gamma band ECoG are limited to less than 2 cm and that the intermittent synchronization observed across separations of 1 cm and 1.4 cm is not solely due to volume conduction. Thus, if such gamma band spatial patterns exist in the human brain, no existing technology would be capable of measuring them at the scalp, and subdural electrode arrays for cortical surface recording would have to have spacings under 5 mm.

Correlation of functional magnetic source imaging with intraoperative cortical stimulation in neurosurgical patients

This study compared noninvasive preoperative functional imaging by using magnetoencephalography (MEG) with intraoperative direct cortical stimulation in ten patients undergoing neurosurgery. The goal was to assess the accuracy and reliability of MEG-based functional imaging in these patients as a possible replacement or adjunct for direct cortical stimulation with electrocorticography. Objective comparison of intraoperative mapping with preoperative MEG procedures was achieved by intraoperative recording of mapped cortical locations for motor responses using an interactive image-guided surgical device, the ISG viewing wand, with which mapping points could be marked on a previously acquired (MRI) set. In all ten patients, at least one stimulation site elicited a response during both MEG and intraoperative mapping. The central sulcus ipsilateral to the lesion was only directly visible on high-resolution MRIs in 3/10 cases and equivocally in 2/10. Coregistered with MRI to form magnetic source images (MSIs), MEG predictions of the postcentral gyrus were possible in all 10 cases. In all 10 cases, these were in agreement with intraoperative estimation of the precentral gyrus. Functional mapping of somatosensory cortex was achieved noninvasively in surgical patients by using MSI. The accuracy, compared with cortical stimulation, was always sufficient to define motor and somatosensory strips.

MDR1 gene expression in brain of patients with medically intractable epilepsy

Why some patients with seizures are successfully treated with antiepileptic drugs (AEDs) and others prove medically intractable is not known. Inadequate intraparenchymal drug concentration is a possible mechanism of resistance to AEDs. The multiple drug resistance gene (MDR1) encodes P-glycoprotein, an energy-dependent efflux pump that exports planar hydrophobic molecules from the cell. If P-glycoprotein is expressed in brain of some patients with intractable epilepsy and AEDs are exported by P-glycoprotein, lower intraparenchymal drug concentrations could contribute to lack of drug response in such patients. Eleven of 19 brain specimens removed from patients during operation for intractable epilepsy had MDR1 mRNA levels > 10 times greater than those in normal brain, as determined by quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) method. Immunohistochemistry for P-glycoprotein from 14 of the patients showed increased staining in capillary endothelium in samples from epileptic patients as compared with staining in normal brain samples. In epileptic brain specimens with high MDR1 mRNA levels, expression of P-glycoprotein in astrocytes also was identified. Last, steady-state intracellular phenytoin (PHT) concentrations in MDR1 expressing neuroectodermal cells was one fourth that in MDR1-negative cells. MDR1 expression is increased in brain of some patients with medically intractable epilepsy, suggesting that the patients' lack of response to medication may be caused by inadequate accumulation of AED in brain.