Examination for Professional Practice of Psychology (EPPP) Practice Test

Left-right confusion is most likely to be caused by a lesion in which area of the brain?

1. Corpus callosum

2. Basal forebrain

3. Left parietal region

4. Right occipital region

The correct answer is: Left parietal region

Left-right confusion is most commonly associated with lesions in the left parietal region of the brain. This area is crucial for spatial awareness and processing, particularly in distinguishing between the left and right sides of the body and the environment. Damage to the left parietal lobe can disrupt an individual's ability to understand and interpret spatial relationships, leading to difficulties when trying to identify or respond to the sides of their body, which manifests as left-right confusion. The right side of the brain, while not primarily assigned the tasks of left-right distinction, plays more of a role in holistic processing and attention to the left visual field. Thus, while the right occipital region concerns visual processing, it is not directly linked to the confusion of left and right. The corpus callosum facilitates communication between the brain's hemispheres, and lesions here can lead to various cognitive and perceptual disturbances, but not specifically to left-right confusion. The basal forebrain is associated more with executive functions and memory, and while it also plays a role in attention, it doesn't specifically lead to left-right confusion. Overall, lesions in the left parietal region most directly impact the understanding of spatial orientation, making it the correct choice for the cause of left-right confusion.