Certified Ophthalmic Medical Technologist (COMT) Practice Exam

Which lesions can result in visual field inattention in simultaneous targets but not when presented individually?

1. Occipital lobe lesions

2. Parietal lobe lesions

3. Frontal lobe lesions

4. Temporal lobe lesions

The correct answer is: Parietal lobe lesions

Visual field inattention, or neglect, often arises from parietal lobe lesions, particularly in the right hemisphere, which are crucial for spatial attention and the integration of sensory information. When there are simultaneous targets presented, individuals with parietal lobe damage may fail to attend to one side of the visual field due to impaired processing of bilateral spatial stimuli. This is often referred to as hemineglect, where the patient may ignore or have difficulty perceiving stimuli on the side opposite to the lesion. However, when targets are presented individually, the patient can process them normally since there is no competition for attention that leads to neglect. This phenomenon shows that the parietal lobe is fundamentally involved in assessing and directing attention to visual stimuli in a spatial context, allowing the patient to focus on one object at a time but struggle with multiple objects due to the limited capacity of attention when competing for focus simultaneously. The other regions mentioned, such as the occipital, frontal, and temporal lobes, do not typically cause this specific pattern of neglect. Occipital lesions primarily affect visual processing but do not lead to inattention per se. Frontal lobe lesions might impact executive functions and attention, but in a different manner. Temporal l