1. Sensory Disorders – disorders that affect the sentient cognitive processes
a) Anaesthesia/ Anesthesia – loss of sensitivity that may either be due to a psychological or psychogenic cause.
Ex. Glove/ stocking anaesthesia – only specific parts of the body have anaesthesia, in this case in the hands and in the legs respectively.
b) Hyperesthesia – increased or higher than normal sensitivity
c) Hypoesthesia – decreased sensitivity
d) Paraesthesia – false/ perverted sensitivity
2. Perception Disorders – perception is sensation + meaning; any perceptual disturbance will cause an abnormality in the interpretation of sensed sensory stimuli.
a) Illusion – perceptual disturbance in the presence of stimulus; a distortion of perception and an erroneous interpretation of present stimulus
- Normal Illusion – this type of illusion is normal when everyone can sense the stimulus.
NOTE: Epicritic/ Discriminative sensibility – ability of locating stimuli that are applied on the body; this ability is normal to everyone.
- Abnormal Illusion – an illusion is abnormal when not everybody can experience the illusion
· Dyschiria – difficulty in localizing stimulus applied in the body.
b) Hallucination – the perceptual distortion in the absence of the stimulus.
c) Agnosia – the patient appears to be confused that he cannot see meaning or cannot identify and recognize the stimuli acting on the senses.
Reber, A. S., Allen, R., & Reber, E. S. (2009). Penguin dictionary of psychology. (4th ed.). London, England: Penguin Books Ltd.