Q: I GET car sick and sea sick quite often. With the junk season coming up I would like to know what to do. Is there anything you can recommend? I'd also like to know what actually causes the motion sickness? Dr Rose writes: Motion sickness is a result of conflicting sensory input into your brain. Nausea, vomiting, dizziness and breaking into a cold sweat are the main symptoms. Milder forms of the sickness are uneasiness and a headache. The only relief is to get away from the cause. It helps to avoid big meals and alcohol before travelling. When on the junk, focus on the horizon or another fixed point in the distance, and try to stay on the top of the boat. Dramamine and Benadryl are two over-the-counter drugs that can be used for motion sickness. They are most effective if you take them half an hour to one hour before you leave. These medications alleviate the nausea but often cause drowsiness. If these over-the-counter remedies are ineffective, your doctor can provide you with a prescription. The most commonly used is Scopolamine or transderm Scop, a skin patch which you place behind the ear about five to six hours before embarking on a journey. Its only major side effect is a dry mouth. Q: SOMETIMES when I eat out at the cheaper restaurants, they serve fake fish and crab sticks. Exactly what are in these things and what is their nutritional value? Dr Rose writes: Many restaurants use surimi, a shellfish substitute, for expensive crabmeat, lobster and scallops. The Japanese have been making surimi for centuries from a lean, white-fleshed fish. They debone, skin, grind and repeatedly wash the fish to remove the blood, pigment and fishy odour. The washing also removes fat, niacin and potassium. Then sugar and/or sorbitol and MSG are added to enhance the flavour and texture of the pulp before it is shaped into lobster tails or crab legs. Surimi is low in cholesterol (as much as 75 per cent lower than shellfish), rich in high quality protein and is rated highly in terms of taste and texture. Its main disadvantage is its high sodium content. Surimi contains up to 10 times more salt than real shellfish and as many as 25 per cent more calories than the shellfish which it is replacing. You should avoid surimi if you are on a low sodium diet. However, it is a good way to add low-cholesterol fish protein to your diet. Q: ONE of my neighbours has a mentally retarded teenage son. Although he is very well-behaved I sometimes worry about leaving my young children alone with him. I don't want to hurt his feelings, but I must admit that my main concern is for my children. I also heard somewhere that the mentally retarded have higher sex drives than the normal population. Is this true? Dr Rose writes: About three per cent of the population is mentally retarded, most of them mildly. And, unless they have a particular physical handicap, their sexual development will not be affected. However, they may find it more difficult than normal adolescents to deal with the physical and emotional changes that puberty brings. Statistics indicate that the mentally retarded are more often victims than perpetrators of sexual exploitation. This is because they are often extremely trusting and naive and find it difficult to evaluate the motives of others. There is also no evidence to support the myth that the mentally disabled have higher than normal sex drives or no control over their sexuality. When they do get into trouble it is usually for non-violent behaviour such as ''indecent exposure''. You should not have any reason to worry any more than if your neighbour was a normally intelligent adolescent boy. Dealing with adolescent sexuality can be challenging for any parent. Disabled children need extra help in coping during the adolescent years because it takes them longer than average to learn basic social rules and practices. You do not indicate if your neighbour's son has attended a special school for the mentally retarded. Schools of this type provide special training to enhance the skills of mentally retarded individuals and routinely cover basic sex education. Dr Rose Ong is a certified family physician licensed in the United States. She welcomes enquiries but cannot answer them individually. Specific questions should be addressed to your own physician. Additional enquiries: Peak Corporate Health Management, 525-6600, fax 525-8100.