Sex Differences In Processing Research Articles

The ventral hippocampal muscarinic cholinergic system plays a key role in sexual dimorphisms of spatial working memory in rats

Sex differences in cognitive processing and function have been documented in human and animal studies. Females have been found to perform better than males on non-spatial memory tasks, while males tend to outperform females on spatial memory tasks. The neural mechanisms underlying these sexual dimorphisms are unclear. However, it is known that the cholinergic system is critically involved in memory processes, and there are notable differences between males and females in cholinergic system function and receptor expression. In particular, there are sex differences in the processing of information in the frontal cortex and hippocampus. In this study, we examined the roles of muscarinic and nicotinic acetylcholine receptors in the medial frontal cortex (MfC) and ventral hippocampus (VH) on spatial working memory in male and female rats. Local infusions of scopolamine (SCOP) and mecamylamine (MEC) (10, 20, 50 μg/side) were used to antagonize these receptors in each respective brain region during performance in the 16-arm radial arm maze. Infusions of SCOP into the VH caused a significant increase in memory errors in female rats, but had no significant effect on males, while infusions of MEC into the VH had no effect on either sex. Infusions of both SCOP (50 μg/side) and MEC (20 μg/side) into the MfC caused working memory impairments in both sexes. These results show that muscarinic acetylcholine receptors in the VH are differentially vulnerable to spatial memory impairments in females. Ventral hippocampal muscarinic acetylcholine receptors may play a key role in male-female differences in spatial memory.

He hears, she hears: are there sex differences in auditory processing?

Songbirds learn individually unique songs through vocal imitation and use them in courtship and territorial displays. Previous work has identified a forebrain auditory area, the caudomedial nidopallium (NCM), that appears specialized for discriminating and remembering conspecific vocalizations. In zebra finches (ZFs), only males produce learned vocalizations, but both sexes process these and other signals. This study assessed sex differences in auditory processing by recording extracellular multiunit activity at multiple sites within NCM. Juvenile female ZFs (n = 46) were reared in individual isolation and artificially tutored with song. In adulthood, songs were played back to assess auditory responses, stimulus-specific adaptation, neural bias for conspecific song, and memory for the tutor's song, as well as recently heard songs. In a subset of females (n = 36), estradiol (E2) levels were manipulated to test the contribution of E2, known to be synthesized in the brain, to auditory responses. Untreated females (n = 10) showed significant differences in response magnitude and stimulus-specific adaptation compared to males reared in the same paradigm (n = 9). In hormone-manipulated females, E2 augmentation facilitated the memory for recently heard songs in adulthood, but neither E2 augmentation (n = 15) nor E2 synthesis blockade (n = 9) affected tutor song memory or the neural bias for conspecific song. The results demonstrate subtle sex differences in processing communication signals, and show that E2 levels in female songbirds can affect the memory for songs of potential suitors, thus contributing to the process of mate selection. The results also have potential relevance to clinical interventions that manipulate E2 in human patients.

Inhibition of contralateral premotor cortex delays visually guided reaching movements in men but not in women

The premotor-parietal network for preparation of visually guided reaching demonstrates activity mainly contralateral to the reaching arm in men but bilaterally in women. These sex differences are most prominent in the dorsal premotor cortex (PMd); however, the functional implications of these differences remain unclear. Therefore, in the experiments described here, we used continuous theta burst stimulation (cTBS) to test hypotheses regarding the roles of PMd both contralateral and ipsilateral to the reaching arm in men and in women. Inhibitory cTBS of the ipsilateral PMd did not have a significant effect on reaction time in either men or women. However, cTBS of the contralateral PMd resulted in a slowed mean reaction time in men but not in women. Movement times were unaffected by stimulation applied to either hemisphere. These results suggest the presence of sex differences in processing within the left PMd during visually guided reaching movements using the right arm. Further, when taken together, the results suggest that ipsilateral PMd activity in women may not be functionally necessary for reaching movements. Rather, this ipsilateral activity may provide a protective redundancy that can compensate for decreased activity from the contralateral PMd. The observation of sex differences in reaction times but not in movement times following cTBS to the contralateral hemisphere suggests that these sex differences are more strongly associated with movement planning than with motor execution.

A sex difference in visual influence on heard speech

Reports of sex differences in language processing are inconsistent and are thought to vary by task type and difficulty. In two experiments, we investigated a sex difference in visual influence onheard speech (the McGurk effect). First, incongruent consonant-vowel stimuli were presented where the visual portion of the signal was brief (100 msec) or full (temporally equivalent to the auditory). Second, to determine whether men and women differed in their ability to extract visual speech information from these brief stimuli, the same stimuli were presented to new participants with an additional visual-only (lipread) condition. In both experiments, women showed a significantly greater visual influence on heard speech than did men for the brief visual stimuli. No sex differences for the full stimuli or in the ability to lipread were found. These findings indicate that the more challenging brief visual stimuli elicit sex differences in the processing of audiovisual speech.

Sex Differences in Processing Printed Advertisements

The success of using biological sex to divide or segment markets requires a thorough understanding of how men and women process and respond to advertisements and other persuasive communications. Toward this end, this research (N=64; 32 men and 32 women) studied how college-age men and women respond to printed advertisements. There were no differences between the sexes in recall and recognition of claims in advertisements, but men and women generated different types of message relevant thoughts-women generated more category thoughts and men generated more attribute thoughts, suggesting that, while women and men might not differ in the depth of processing, they might use different processing styles.

ALPHA Asymmetry for Audio-Visual and Auditory Processing of Continuous Linguistic Information by Children

Four male and four female children from each of the ages four through ten with normal speech, hearing and language abilities participated. The study involved bilateral hemispheric recording of alpha wave activity from the temporo-parietal region during the processing of connected language in the form of a story presented either auditorily or audiovisually. No hemispheric asymmetry, developmental changes or sex differences in processing were found nor did processing patterns vary with the presentation format. Idiosyncratic processing was demonstrated in the children from all age groups. Hemispheric involvement in processing information during a naturalistic versus highly specific tasks is discussed and comparisons with previous literature are made.

Human intelligence: sex differences.

An extensive review of the literatureon sex differences in human intelligence leads to the conclusion that there is stron evidence for sex differences in processing both verbal and spatial information. The few genetic studies that there are all point toward a sex-link mode of inheritance of certain spatial abilities.