Male–female differences in predicting displaced volume: Strategy usage, aptitude relationships, and experience influences.

Investigated the role of aptitudes and experiences in gender differences in scientific reasoning by using the Predicting Displaced Volume (PDV), a scientific reasoning task known to be solved by males more frequently than females. 778 7th–11th graders were administered the PDV in groups. Of the Ss, 90% consistently used 1 of 4 expectation-based strategies to solve the problems. Males used the correct strategy more frequently than females; males and females both used the same incorrect strategies. It was found that gender differences in PDV did not reflect gender differences in spatial ability, field dependence–independence (FDI), or Piagetian formal reasoning. In addition, gender differences in PDV were not accounted for by science and math course-taking experience. Factors such as spatial ability and FDI may correlate highly with scientific reasoning task performance but may not account for gender-related differences in that performance. (51 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Scoring procedure, performance factors, and magnitude of sex differences in spatial performance

The purpose of the present study was to demonstrate the influence of procedural factors on the magnitude of sex differences in a test of spatial ability. Two hundred and seven females and 155 males were administered the Mental Rotations Test (MRT) under timed and untimed conditions. Four different scoring procedures were used: total score, ratio of correct responses to the number of items attempted, score out of 24, and score out of 48. Significant sex differences were obtained in the timed condition but not in the untimed condition. Results also revealed that the magnitude of sex differences was reduced when a ratio score was used. Analysis of the pattern of responses provided insights into the causes of sex differences on the MRT. Results are interpreted in terms of their implications for research on sex differences in spatial ability.     

Performance of male and female children, adolescents and adults on spatial tasks that involve everyday objects and settings.

Administered 9 spatial tasks to 52 male and 52 female children (aged 7–9 yrs), 30 male and 33 female adolescents (aged 18–19 yrs), and 46 male and 48 female undergraduate (adult) Ss. Eight of the tests involved stimuli and settings with which Ss would have everyday experience. Significant sex differences were observed on 2 of the 9 tasks: estimating the length of a floor and identifying embedded figures. Adults performed better than other age groups on the embedded figures task and a wall height estimation task. In those cases where sex differences were observed, the effect sizes were well below .100, suggesting the magnitudes of sex differences were minimal. The fact that no sex differences were found on 7 or the 9 spatial tasks allows, at most, the statement that males perform better than females on some spatial tasks. There is no justification for the global statement that males excel in spatial abilities. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sex differences in learning and memory in mice: Effects of sequence of testing and cholinergic blockade.

Sexual dimorphism in spatial and cued navigation using the Morris water maze was examined in C57BL/6 mice both with and without administration of scopolamine, a cholinergic blocker. In Exp 1, female and male mice learned to perform first a spatial, then a cued, navigation task. Both performed a spatial task similarly; males, however, performed a cued task better than females. In Exp 2, the sequence of navigation testing was reversed. Both performed similarly on a cued task; however, males performed a spatial task better than females. In both experiments, females were more sensitive than males to the effects of scopolamine. No significant confounding sex differences were found in either spontaneous activity or passive avoidance retention. These data indicate that sex differences in spatial and cued tasks are dependent on the sequence of task presentation and implicate a role for the cholinergic system in these differences. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of aptitudes, strategy training, and task facets on spatial task performance.

A pilot study, with 8 high school students, demonstrated that 3 item characteristics accounted for most of the variation in item difficulty in a paper-folding task: number of folds, number of obscured folds, and number of asymmetric folds. Retrospective reports suggested that Ss employed 2 strategies when attempting to solve these items: a visualization strategy and an analytic strategy. In the main experiment, these 2 strategies were demonstrated via motion picture models; 24 Ss received visualization training, and 24 received analytic training. Training effects of the demonstration films were compared with a performance feedback condition given to 8 Ss. All Ss performed 74 paper-folding items and 60 surface development transfer items following treatment. Error and latency data suggested that the treatments affected strategy selection and efficiency on both tasks. Treatment effects depended on item characteristics and response mode as well as on Ss' fluid-analytic/visualization and verbal abilities, as assessed by the Concept Mastery Test, WAIS Vocabulary test, and Raven Progressive Matrices. Sex differences were also noted, with verbal ability being important in the performance of females but not males. Implications for a process theory of human abilities are discussed. (33 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sex, Age, and Training Modulate Spatial Memory in the Rhesus Monkey (Macaca mulatta).

The authors tested 90 rhesus monkeys (Macaca mulatta) on a task of spatial memory, the spatial Delayed Recognition Span Test. The results showed that performance declined significantly with age, males had greater scores than females, and the rate of apparent decline with age was greater in males than in females. Both working and reference memory declined with age, but only working memory showed sex differences. The authors compared these data with that of 22 monkeys who were trained on a simpler version of the task before formal testing. Training had no effect on males but dramatically improved working memory in young females. The results confirm a male advantage in spatial working memory at a young age and confirm a greater decline with age in males than in females. It is important to note that prior training completely reverses the deficits of young females. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sex-related differences in cortical function after medial frontal lesions in rats.

The effects of sex on the performance of 4 spatial mazes (Morris water task, landmark task, radial arm maze, and egocentric radial arm maze) were studied in male and female rats given medial frontal lesions. Operated rats from both sexes were impaired at all of the tasks, but the frontal males were much less impaired than frontal females on the Morris task and the radial arm maze, both of which require animals to use multiple visual-spatial cues for their successful solution. Males also performed better on the egocentric maze. In contrast, frontal females performed better than frontal males at the landmark task, which is best solved by using a single spatial cue. The only sex difference in unoperated rats was a small advantage for females on the egocentric task. The sex differences may reflect an underlying difference in cortical organization or a differential response to cortical lesion in males and females. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sex differences in performance in the Morris water maze and the effects of initial nonstationary hidden platform training.

Sex differences in rats' performance on a stationary hidden-platform task (spatial task) in the Morris water maze and the effects of initial nonstationary hidden platform training (NSP training) were examined. The NSP training was designed to familiarize rats with the general requirements of the water-maze task without providing spatial information. NSP training led to faster acquisition and improved retention of the subsequent spatial task in both males and females. There was a sex difference favoring males on acquisition and retention of the spatial task only in rats that had not received previous NSP training. Moreover, there was an apparent reversed sex difference favoring females on some measures of spatial performance in NSP-trained rats. These results suggest that performance on the water-maze task, including the expression of sex differences, can be altered by previous familiarization with nonspatial aspects of the task. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spatial abilities, sex differences, and lateral eye movements.

Conducted 2 experiments with 91 female and 50 male undergraduates to examine relationships among the ability to determine horizontality, a general test of spatial abilities, and hemispheric activation measured lateral eye movements. Females who could determine horizontality were more likely to demonstrate a right-hemispheric mode of processing indexed by direction of lateral eye movements. Overall, the ability to determine horizontality was positively correlated with a general measure of spatial ability for the right-hemispheric females but not for the left-hemispheric females. For males, there was a high positive correlation between the horizontality task and the spatial ability measure, regardless of hemispheric mode of processing. (12 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mental rotation of facial profiles: Age-, sex-, and ability-related differences.

48 adults (mean age 28 yrs 4 mo), 48 8th graders, and 48 4th graders determined what the left–right orientations of rotated facial profiles would be were the profiles upright. There were 24 males and 24 females in each group. Ss were all administered the Raven Standard Progressive Matrices and the Picture Vocabulary and Spatial Ability subtests of the Woodcock-Johnson Psycho-Educational Battery. Results indicate that rate of mental rotation and combined rate of encoding, comparison, and response increased with age. Findings are consistent with a speed–accuracy tradeoff explanation of previous discrepancies in developmental studies of mental rotation. Female Ss' rates of mental rotation were slower on average and more variable than male Ss. Within the entire sample, there was a modest correlation between the ability test scores and both latency and error parameters derived from the rotation task. Only error rate was discriminantly related to spatial ability, however. Patterns of correlations between processing parameters and test scores differed between age groups and, within age groups, between sexes. Mental rotation showed a significant relation to spatial ability only in 4th graders. (32 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sexual maturation and spatial ability in college students.

194 female and 80 male undergraduates completed mental rotation and card rotation tests of spatial ability and a vocabulary test. Ss were also asked to indicate on a 5-point rating scale when they reached puberty in relation to others of the same sex. Findings provide evidence that the maturation related difference in spatial ability found in adolescents persists into adulthood. Regression analyses demonstrated a significant relation between puberty ratings and performance on the mental rotation test, with later maturers scoring higher than earlier maturers. There were no maturation-related differences on the other tests. Significant sex differences were found on all tests. Consistent with previously reported cognitive differences between males and females, females scored higher on the verbal test, and males scored higher on the 2 spatial tests. (15 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Early hormonal influences on cognitive functioning in congenital adrenal hyperplasia.

Administered a cognitive test battery that emphasized spatial ability, verbal fluency, and perceptual speed and accuracy to 17 females (aged 12.7–23.2 yrs) and 8 males (aged 13–29.9 yrs) with congenital adrenal hyperplasia (CAH) and 13 normal female relatives (aged 11.4–31.1 yrs) and 14 unaffected male relatives (aged 12.5–28.8 yrs). In addition, 13 fathers and 15 mothers of CAH patients participated. Ss also completed the Progressive Matrices, a vocabulary test, and an early life activities questionnaire (ELAQ). Findings indicate that CAH females, as compared with normal females, showed significantly enhanced performance on hidden pattern, card rotation, and mental rotation tests of spatial ability. On the ELAQ, CAH females, relative to normal females, showed significantly lower frequencies of participation in activities involving verbal expression and a trend toward greater participation in spatial manipulation activities. However, differences between CAH females and normal females in early childhood activities did not account for observed differences in spatial ability, given the absence of a significant correlation between the spatial manipulation activity scale and spatial ability. There was an absence of reliable differences between male CAH patients and controls across spatial tasks. Results are consistent with an effect of pre- and perinatal androgenizing hormones on the development of spatial ability. (58 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sex differences in object location memory

The ability to remember where objects were is thought to require multiple separate processes. One has to encode the precise positions occupied, assign the various objects to the correct (relative) locations, and achieve an integration of both types of spatial information. This study examined whether sex differences exist for these selective components of object location memory. Twenty males and 20 females participated in the following task. On a PC screen, they were shown a square with 10 different objects for 30 s. Subsequently, the objects disappeared from the screen, reappeared in a row above the square, and subjects were asked to relocate them in three different conditions. In the object-to-position-assignment condition, the original positions were premarked in the square, so subjects needed only to assign the correct object to the correct position. In the positions-only condition, all objects assumed the same identity. Therefore, subjects had only to reproduce the precise positions. Finally, in the combined condition, subjects were required to replace all the different objects in the square without any of object positions premarked. The absolute displacements between an object's original and its relocated position reflect the integration mechanism. Females did as well as males in the object-to-position-assignment condition and on the absolute displacements in the combined condition, but they were less efficient than males in positional reconstruction per se. Thus, it seems that the male advantage in spatial memory is not a general effect but applies only to certain specific processing components. Moreover, the employment of a dual task during encoding, concurrent articulatory suppression, yielded no significant interactions with sex. This suggests that females' weaker positional encoding does not derive from the use of an inefficient verbal strategy.     

DNA-protein interactions in the proximal zeta-globin promoter: identification of novel CCACCC- and CCAAT-binding proteins

The present study assessed whether prenatal androgen and estrogen exposure affected adult spatial learning and hippocampal morphology. Water maze performance, the CA1 and CA3 pyramidal cell field, and the dentate gyrus-granule cell layer (DG-GCL) morphology were assessed at adulthood (70+ days of age) in males, females, androgen-treated (testosterone propionate, TP, or dihydrotestosterone propionate, DHTP) females (2-4 mg/day), estradiol benzoate (EB)-treated females (100 microgram/day), and males treated with the antiandrogen flutamide (8 mg/day). Pregnant rats were injected daily (sc) between Embryonic Day 16 and birth; all pups were delivered by cesarean section. Flutamide-treated males were castrated upon delivery, and adult castrates were used to control for activational effects. Steroid-sensitive sex differences were observed in water maze performance in favor of males. Males had larger CA1 and CA3 pyramidal cell field volumes and soma sizes than females, which were feminized with flutamide treatment. TP and EB, but not DHTP, masculinized CA1 pyramidal cell field volume and neuronal soma size; CA3 was masculinized in both TP- and DHTP-treated females, while EB was ineffective. No effects were observed in cell density, number, or DG-GCL volume or due to adult hormone levels. Thus, prenatal androgens and estrogen influence sex differences in adult spatial navigation and exert differential effects on CA1 and CA3 pyramidal cell morphology. Hence, in addition to the previously reported postnatal component, there is also a prenatal component to the critical period in which gonadal steroids organize the neural mechanisms underlying sex differences in adult spatial ability.     

Sex differences in the effects of captivity on hippocampus size in brown-headed cowbirds (Molothrus ater obscurus).

In brood parasitic cowbirds, hippocampus (Hp) size is correlated with environmental spatial memory demands. Searching for host nests is the presumed causal factor influencing cowbird Hp size, because Hp volumes vary across species, sexes, and seasons according to nest-searching participation. Brown-headed cowbirds have female-only nest searching and, at least in the eastern subspecies, a larger Hp in females than in males, suggesting that nest searching influences cowbird Hp size. We predicted that female brown-headed cowbirds housed in aviaries lacking host nests would have a smaller Hp than wild-caught females whereas males would be unaffected. We found that the Hp was smaller in captive females, but not males, compared to their wild-caught counterparts. This did not appear to be due to general effects of an impoverished environment on all brain regions. Our results imply that interruption of nest searching in cowbirds prevents seasonal increase in Hp size in females. Future studies should isolate which behavioral differences between wild and captive birds contributed to captivity-induced changes in Hp volume in females while not affecting males. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Gender and reporting differences in measures of depression.

135 female and 75 male undergraduates (aged 18–30 yrs) responded to the Beck Depression Inventory and to 9 items assessing depression from the Hopkins Symptom Checklist. The hypothesis was explored that males particularly would endorse test items in a less "depressed" direction when presented explicitly as constituting a test of depression, but would endorse more depressive content when items were presented in a context not portrayed as measuring depression. Some support was obtained for the view that males may approach and respond differently to depression inventories compared to females. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Early sex differences in spatial skill.

This study investigated sex differences in young children's spatial skill. The authors developed a spatial transformation task, which showed a substantial male advantage by age 4 years 6 months. The size of this advantage was no more robust for rotation items than for translation items. This finding contrasts with studies of older children and adults, which report that sex differences are largest on mental rotation tasks. Comparable performance of boys and girls on a vocabulary task indicated that the male advantage on the spatial task was not attributable to an overall intellectual advantage of boys in the sample. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sex differences in reward allocation: Subjects, partners, and tasks.

Numerous studies have shown that males tend to allocate a reward equitably, whereas females will divide the same reward equally. This result has been attributed to a fundamental difference in the preferred social orientations of the sexes. Two studies (156 female and 143 male undergraduates) hypothesized and found that this difference may be due to the use of masculine sex-linked tasks in prior research. In both studies, males allocated equitably and females equally with same-sex partners on a masculine task. On a sex-appropriate task, both sexes allocated equitably. Questionnaire measures suggested that this effect stemmed from differences in how male and female Ss evaluated their performance, depending on whether the task was congruent or incongruent. It was also found that both sexes allocated more generously to an opposite-sex partner than a same-sex partner regardless of task type or success/failure. These findings are interpreted in terms of the implications of viewing sex differences as situation-specific rather than general. (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Magnesium and the transport system

For the purpose of studying the sex differences of the human face we collected five separate images, which consist of several parts of the face, from frontal view photographs of 48 male and 52 female college students. We traced outlines of their faces with simple lines (traced items), and made reproductions of the photographs of their eyes, mouth and nose by using a copying machine (reproduced items). The test subjects were 16 males and 8 females. They looked at parts of the face shown in each image, and categorized them individually by judging on their sex. Then, we calculated the percentages of correct judgments (percentage correct) for each image. By comparing the percentage correct between male and female we concluded that the sex of the subjects did not affect the results of their judgments. In the traced items the percentage correct for the face as a whole, which contained the outlines of the eyes, mouth, nose and the lower jaw, was 69%, but it decreased to 61% when the outline of the lower jaw was removed. Hence, the outline of the lower jaw apparently has a characteristic shape easily noticed by males. In the reproduced items the percentage correct was 65% for the eyes, 68% for the mouth and 58% for the nose. The mouth, therefore, has more distinguishing characteristics than the eyes or nose, especially with females. On the other hand, there is no correlation between the percentage correct for the eye, mouth and nose items. Hence, we concluded that the sexual specificity for the shape of the young Japanese face appears on their parts independently.     

Handedness, sex, and eyedness as moderating variables in the relation between hypnotic susceptibility and functional brain asymmetry.

The number of eye movements to the right in response to verbal and spatial questions in an E-facing-S situation correlated moderately with measured hypnotic responsiveness for a sample of 30 male and 30 female right-handed undergraduates. This finding confirms earlier indications that hypnotic responsiveness may be a right hemisphere function in right-handed Ss. The correlation was not significant for 19 male and 11 female left-handed Ss. Further breakdowns of the sample produced much higher correlations with hypnotizability, indicating the roles of sex, handedness, and eyedness as moderating variables. Right-handed males yielded a correlation of -.68 and left-handed females a correlation of .58, while the correlations for right-handed females and left-handed males were nonsignificant. Left-handed males, if also left-eyed, showed a correlation of .52. Left-handed males who were right-eyed, however, showed a correlation of -.41. Right-handed females who were left-eyed and right-eyed produced correlations with appropriate opposite signs, but the differences were not significant. (45 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)