Macaques are often used as a model system for invasive investigations of the neural substrates of cognition. However, 25 million years of evolution separate humans and macaques from their last common ancestor, and this has likely substantially impacted the function of the cortical networks underlying cognitive processes, such as attention. We examined the homology of frontoparietal networks underlying attention by comparing functional MRI data from macaques and humans performing the same visual search task. Although there are broad similarities, we found fundamental differences between the species. First, humans have more dorsal attention network areas than macaques, indicating that in the course of evolution the human attention system has expanded compared with macaques. Second, potentially homologous areas in the dorsal attention network have markedly different biases toward representing the contralateral hemifield, indicating that the underlying neural architecture of these areas may differ in the most basic of properties, such as receptive field distribution. Third, despite clear evidence of the temporoparietal junction node of the ventral attention network in humans as elicited by this visual search task, we did not find functional evidence of a temporoparietal junction in macaques. None of these differences were the result of differences in training, experimental power, or anatomical variability between the two species. The results of this study indicate that macaque data should be applied to human models of cognition cautiously, and demonstrate how evolution may shape cortical networks.

SIGNIFICANCE:Ptosis is often the hallmark finding in ocular and general myasthenia gravis. Reduction of ptosis has been achieved with oral and topical ocular medications. However, these medications can result in systemic and ocular adverse effects. A novel eye drop seems to be effective in reducing ptosis while minimizing adverse effects. PURPOSE: This case report aimed to demonstrate the efficacy of topical oxymetazoline hydrochloride 0.1%, an αadrenergic agonist, in temporary elimination of ptosis associated with myasthenia gravis.CASE REPORT: A 68-year-old woman with a history of myasthenia gravis and long-standing ptosis in the right eye presented to improve the asymmetrical appearance of her eyelids. One drop of oxymetazoline hydrochloride 0.1% was instilled in the right eye of the patient. Within 2 hours, the ptosis was eliminated, the margin-reflex distance 1 increased by 2.0 mm, and the superior visual field measured by a superior 36-point screening test increased by 15 points. The effect lasted for at least 7 hours. Of note, there was a decrease in elevation of the contralateral nonptotic eyelid that did not receive a drop of oxymetazoline, which might occur only in myasthenia gravis. Further evaluation is warranted.CONCLUSIONS: Oxymetazoline 0.1% is effective in reducing and potentially eliminating ptosis related to ocular myasthenia gravis for up to 7 hours.