Broca's Motor Research Articles

Gender morphology of Broca's motor speech area

To study the general patterns and differences in the macroscopic structure of Broca's motor speech area in the left and right hemispheres of male and female brains. The study was conducted on MRI images of the brains of 9 men and 9 women (36 hemispheres in total). All the people were between the ages of 20 and 30, without any mental or neurological disorders. The localization and structure of the main sulci and gyri of Broca's area, namely the pars triangularis and pars opercularis, were studied. In addition, the topography of the main sulci in Broca's motor speech area, namely their shape, length, and relative position to the other sulci, was analyzed. The features of the localization of the sulci in Broca's area, the differences in the number of additional sulci in the pars triangularis and pars opercularis of male and female brains, as well as the degree of asymmetry of Broca's area in the left and right hemispheres of the brains of men and women were established.In modern neuroscience a new scientific direction of genderology, which studies the behavior and cognitive functions of males and females, is rapidly developing. Broca's motor speech area of the brain of men and women differs in macroscopic structure.

PTERION: A SITE FOR NEUROSURGICAL APPROACH

Pterion is defined as point of sutural confluence seen in the normal ateralis of the skull where frontal, parietal, temporal and sphenoid bones meet. It is a commonly used neurosurgical landmark. The anatomic location of the pterion is important in surgical interventions following surgical approaches to the anterior and middle cranial fossae, following extradural hemorrhage as well as tumors involving inferior aspects of the frontal lobe, such as olfactory meningioma, used in operations on the Broca's motor speech area and in repairing aneurysms of the middle cerebral artery as well as those of the upper basilar complex and also the anatomical varieties of the pterion, is of interest mainly to anthropologists and forensic pathologists, for assessing the location of the pterion in incomplete archeological remains or forensic materials. The pterion exhibits population-based variations. The aim of the study is to determine the position of the pterion using the midpoint of the zygoma (MPZ) and the frontozygomatic suture (FZS) as palpable points.In the present study seventy dry skulls (34 male and 36 female) were used. The dry skulls were obtained from the department of anatomy, K M C Mangalore, Manipal University. Only the intact skulls were included in the study. The sexing was done on the morphological basis. The Distance between pterion to FZS and pterion to MPZ of right and left side of the male skull bones when compared with the right and left side of female skull bones showed statistically significant side difference among male and female bones.

The pterion in Turkish male skulls.

This study was conducted to determine the location and type of pterion in Turkish males. The importance of the pterion is its relation to the middle meningeal artery, Broca's motor speech area on the left side, and surgical interventions relating to pathologies of the sphenoid ridge and optic canal. Specific measurements were taken on both sides of 26 Turkish human male skulls, none of which showed any obvious pathology or trauma. The sphenoparietal type of pterion was the most common (96% right side, 79% left side), followed by the frontotemporal (4% right side, 17% left side), and finally the epipteric type (4% left side only). The distances on the right and left sides respectively from the center of the pterion to the frontozygomatic suture were 3.30+/-0.40 cm and 3.44+/-0.39 cm, to the zygomatic arch 4.05+/-0.39 cm and 3.85+/-0.25 cm, to the optic canal 4.39+/-0.40 cm and 4.36+/-0.40 cm, and to the sphenoid ridge 1.40+/-0.33 cm and 1.48+/-0.32 cm. The thickness of the skull at the center of the pterion was 0.41+/-0.14 cm and 0.39+/-0.12 cm on the right and left sides respectively. These findings should be of use in surgical approaches and interventions via the pterion.

Book Review

Book Review

Studies on integrative functions of the human frontal association cortex with MEG

Our MEG studies on the human frontal association cortex are briefly reviewed. (1) The no-go potential was first found at go/no-go reaction-time hand movement task with discrimination between different colour light stimuli in the prefrontal cortex of monkeys. The potential was recorded in human subjects with EEG over the scalp, but its current dipoles could be localized only by use of MEG, in the dorsolateral part of the frontal association cortex in both cerebral hemispheres. The function for no-go decision and subsequent suppressor action was thus substantiated in the human frontal cortex. (2) Utterance of a short noun in Japanese was found to be initially preceded by an activity in the lower lateral part of the frontal lobe and then by that around the central sulcus. The area of the former, often in both hemispheres, appears to correspond to Broca's motor speech centre and that of the latter, always in both hemispheres, to correspond to the motor-somatosensory cortices. (3) Intensive and continuous concentration on mental calculation and some `abstract' thinking for a few minutes were often associated with magnetic theta (5–7 Hz) wave bursts in the frontal part of the scalp. Dipole fitting suggested that the electrical current dipoles occur successively and scattered in wide areas of the frontal lobe on both sides. They are to be called “frontal mental theta wave”, revealing dynamic and active participation of the frontal lobe in mental functions.

Developmental apraxia of speech and manual dexterity

A quantitative test of fine motor function was used to compare the dexterity of the right and left hands of normal children and children with developmental apraxia of speech (DAS). The results suggest that the left cerebral hemisphere of children with DAS is not predominantly impaired in regard to motor control of the upper extremities. In neither female nor male children with DAS was the manual dexterity of the right hand less than that of the left. In female but not male children with DAS, manual dexterity of both hands was impaired when compared to the normal control groups. Therefore, DAS is probably not due to a congenital or an acquired defect in Broca's motor speech area or adjacent brain area of the left hemisphere. The basis of this conclusion is discussed.