Hemispheric, and Environmental Factors
نویسندگان
چکیده
This quantitative Golgi study extends our investigation of relationships between cortical dendrite systems in humans and higher cognitive functions. Here we examine the relationship between the basilar dendrites of supragranular pyramidal cells in Wernicke's area and selected intrinsic (i.e., gender and hemisphere) and extrinsic (i.e., education and personal history) variables. Tissue was obtained from 20 neurologically normal right-handers: 10 males (M, = 52.2) and 10 females (Mage = 47.8). Several independent variables were investigated: GENDER (male, female), HEMISPHERE (left, right), and EDUCATION (less than high school, high school, and university). These were evaluated according to Total Dendritic Length, Mean Dendritic Length, and Dendritic Segment Count. A distinction was made between proximal (lst, 2nd, and 3rd order) and ontogenetically later developing distal (4th order and above) branches. There was significant interindividual variation in dendritic measurements, which roughly reflected individuals' personal backgrounds. Females exhibited slightly greater dendritic values and variability than males across the age range examined. On the whole, the left hemisphere maintained a slight advantage over the right hemisphere for all dendritic measures when all subjects were pooled, but these differences were not in a consistent direction across individuals. Education had a consistent and substantial effect such that dendritic measures increased as educational levels increased. Dendritic differences between independent variable levels were most clearly illustrated in the total dendritic length of 3rd and 4th order branches. Distal dendritic branches appeared to exhibit greater epigenetic flexibility than proximal dendrites. The present findings concur with environmental enrichment research results in animals and suggest that dendritic systems in humans function as a sensitive indicator of an individual's (a)vocational activities. 'r) 1993 Wiley-Liss, Inc.
منابع مشابه
Study of anatomic location of blink reflex arch in patients with hemispheric strokes
Introduction: Blink reflex (BR) is a new electro diagnostic test mediated through a reflex arch with fifth cranial nerve in its afferent and seventh cranial nerve in its efferent side. BR responses are designed R1 , R2 and R2c responses. Anatomic locations of this reflex arch in central nervous system are still undefined and various results have been reported in different studies, for example...
متن کاملThe impact of asymmetrical light input on cerebral hemispheric specialization and interhemispheric cooperation.
Hemispheric specialization potentially provides evolutionary advantages by enhancing cognitive capacities. However, separation of function might be advantageous only with the presence of commissural systems allowing for efficient information exchange and cooperation between the hemispheres. Here we investigate hemispheric cooperation in pigeons as they possess an asymmetrically organized visual...
متن کاملSocioeconomic status predicts hemispheric specialisation of the left inferior frontal gyrus in young children
Reading is a complex skill that is not mastered by all children. At the age of 5, on the cusp of prereading development, many factors combine to influence a child's future reading success, including neural and behavioural factors such as phonological awareness and the auditory processing of phonetic input, and environmental factors, such as socioeconomic status (SES). We investigated the intera...
متن کاملتغییر سرعت و مقایسه جریان خون نیمکرههای تکلمی در افراد سالم چپ و راست دست با سونوگرافی داپلر ترانس کرانیال عملکردی
Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal" mso-tsty...
متن کاملPilot Study: The Role of the Hemispheric Lateralization in Mental Disorders by Use of the Limb (Eye, Hand, Foot) Dominance
Introduction: Based on the previous studies, we know that the hemispheric lateralization defects, increase the probability of psychological disorders. We also know that dominant limb is controlled by dominant hemisphere and limb preference is used as an indicator for hemisphere dominance. In this study we attempted to explore the hemispheric dominance by the use of three limbs (hand, foot...
متن کاملDirect and Indirect Timing Functions in Unilateral Hemispheric Lesions
Introduction: The neural substrates of temporal processing are not still fully known. The majority of interval timing studies have dealt with this subject in the context of “Explicit timing” (computing the time intervals explicitly). The hypothesis “Implicit timing” (implicitly using temporal processing to improve function) has also proposed. This lesion study addressed explicit and implicit ti...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2004