ABSTRACT
Attention, which marks the first phase of all the processes of cerebral activity, is, then, a phenomenon similar to all those developed in the peripheral plexuses of the system when they are impressed by excitations from the external world. In all forms of mental disease the faculty of attention becomes gradually weaker, and presents, according to the intensity of the morbid process, different and fatally progressive modifications. In a general way, in persons with hallucinations, individuals attacked with acute or chronic mania., the forces of attention cease to take effect, the phenomena of the external world no longer produce in the sensorium anything more than an abortive impression. Patients with dementia, whose cortical substance is more or less profoundly degenerated, are in the same condition: they only lend a very limited degree of attention to words addressed to them, and cannot sustain a connected conversation for more than a very few minutes. "
