They may explicitly deny a hemiplegia, or fail to recognize that they have had a stroke. Neglect is more frequent and more severe with right than with left hemisphere lesions. Unless you specifically test memory, they may appear to be normal. These spared functions are thus mediated by different brain structures. It is thought, for example, that motor memories and habits may be mediated through the basal ganglia, but this remains to be clarified.
Frontal lobe syndromes The frontal lobes have a high-order executive role in behavior.
Without their guidance, we are left at the mercy of immediate stimuli. Patients with frontal dementias also fail to organize their experience, and do not plan for the future. They often forget things, not because they cannot encode new memories, but because they fail to initiate memory searches when appropriate. For example, the patient may be told to go to the store to buy five items, but when he gets to the store he is attracted to a magazine, reads it, and then comes home with nothing. Patients with orbitofrontal lesions appear to have most difficulty inhibiting inappropriate behavior.