_After-image._--A retinal picture of an object seen after removing the gaze from the object.
_Agent._--The person who seems to initiate a telepathic transmission.
_Agraphia._--Lack of power to write words.
_Alexia_ or _Word-blindness_.--Lack of power to understand words written.
_Anæsthesia_, or the loss of sensation generally, must be distinguished from _analgesia_, or the loss of the sense of pain alone.
_Aphasia._--Incapacity of coherent utterance, not caused by structural impairment of the vocal organs, but by lesion of the cerebral centres for speech.
_Aphonia._--Incapacity of uttering sounds.
_Automatic._--Used of mental images arising and movements made without the initiation, and generally without the concurrence, of conscious thought and will. _Sensory automatism_ will thus include visual and auditory hallucinations. _Motor automatism_ will include messages written and words uttered without intention (automatic script, trance-utterance, etc.).
_Automnesia._--Spontaneous revival of memories of an earlier condition of life.
_Autoscope._--Any instrument which reveals a subliminal motor impulse or sensory impression, _e.g._, a divining rod, a tilting table, or a planchette.
_Bilocation._--The sensation of being in two different places at once, namely where one's organism is, and in a place distant from it.
_Catalepsy._--"An intermittent neurosis producing inability to change the position of a limb, while another person can place the muscles in a state of flexion or contraction as he will." (Tuke's _Dictionary of Psychological Medicine_.)
_Centre of Consciousness._--The place where a percipient imagines himself to be. The point of view from which he seems to himself to be surveying some phantasmal scene.
_Chromatism._--See _Secondary Sensations_.
_Clair-audience._--The sensation of hearing an internal (but in some way veridical) voice.
_Clairvoyance_ (_Lucidité_).--The faculty or act of perceiving, as though visually, with some coincidental truth, some distant scene.
_Cænesthesia._--That consensus or agreement of many organic sensations which is a fundamental element in our conception of personal identity.
_Control._--This word is used of the intelligence which purports to communicate messages which are written or uttered by the _automatist_, _sensitive_ or _medium_.