background: learning disability is one of the most noticed subjects for behavioral specialists. most of the learning difficulties are caused by senso-motor development and neurological organization. the main purpose of the present research is to examine the role of delayed perceptual-motor development and brain damage in origination of expressive writing disorder (ewd).   methods: the studied s...

Optimal Brain Damage (OBD) is a method for reducing the number of weights in a neural network. OBD estimates the increase in cost function if weights are pruned and is a valid approximation if the learning algorithm has converged into a local minimum. On the other hand it is often desirable to terminate the learning process before a local minimum is reached (early stopping). In this paper we sh...

We have used information-theoretic ideas to derive a class of practical and nearly optimal schemes for adapting the size of a neural network. By removing unimportant weights from a network, several improvements can be expected: better generalization, fewer training examples required, and improved speed of learning and/or classification. The basic idea is to use second-derivative information to ...

When our experience of infants with hypernatraemic dehydration was reported 6 years ago from this hospital, the comment was made that, 'the follow-up period was, for many patients, too short to permit any evaluation of ultimate neurological status' (Macaulay and Blackhall, 1961). As far as we are aware no long-term studies of such patients have yet been published. This paper is a record of our ...

objectives : the study was designed to investigate the impairment of the ability to discriminate between nouns and verbs, resulting from the damage to the left-hemisphere, a condition which could lead to linguistic disorders proportionate to the depth and extent of the damage. various experimental and clinical investigations have demonstrated that nouns and verbs may, independent of one another...

introduction: the role of ovarian hormones and nitric oxide (no) on oxidative damage in brain tissues as well as learning and memory has been widely investigated.the present study was carried out to evaluate the effect of the precursor of no, l-arginine on learning and brain damage due to oxidative stress in ovariectomized (ovx) rats.methods: thirty -two rats were divided into four groups: 1) s...

introduction: cypermethrin causes its neurotoxic effect through voltage-dependent sodium channels and integral protein atpases in the neuronal membrane. brain and nerve damage are often associated with low residual level of pesticides. in vitro and in vivo studies have also shown that pesticides cause free radical-mediated tissue damage in brain. propolis has antioxidant properties. the main ch...

alcohol directly affects astroglial cell function, including inflammation-related activity.  and it also affects microglial cell development and function in specific ways that interfere with microglial interactions with the immune system and with neurons. neuroinflammatory processes might be involved in alcohol-induced brain damage. alcohol use, misuse and getting used to it causes different ki...