I Know Just How Yon Feel Do you feel sad? Happy? Angry? You may think that the way you show these emotions is unique．Well，think again．Even the expression of the most personal feelings can be classified，according to Mind Reading，a DVD displaying every possible human emotion．It demonstrates 412 distinct ways in which we feel：the first visual dictionary of the human heart．Attempts to classify expressions began in the mid-1800s，when Darwin divided the emotions into six types-anger，fear，sadness，disgust，surprise and enjoyment．【46】______Every other feeling was thought to derive from Darwin's small group．More complex expressions of emotion were probably learned and therefore more specific to each culture．But now it is believed that many more facial expressions are shared worldwide．【47】______The Mind Reading DVD is a systematic visual record of these expressions． The project was conceived by a Cambridge professor as an aid for people with autism(孤独症)，who have difficulty both reading and expressing emotions．But it quickly became apparent that it had broader uses．Actors and teachers，for example，need to understand a wide range of expressions．The professor and his research team first had to define an“emotion”．【48】______Using this definition，1，512 emotion terms were identified and discussed．This list was eventually reduced to 412，from“afraid”to“wanting”． Once these emotions were defined and classified，a DVD seemed the clearest and most efficient way to display them．In Mind Reading，each expression is acted out by six different actors in three seconds．【49】______The explanation for this is simple：we may find it difficult to describe emotions using words，but we instantly recognise one when we see it on someone's face．“It was really clear when the actors had got it right，”says Cathy Collis，who directed the DVD．“Although they were given some direction，”says Ms Collis，“the actors were not told which facial muscles they should move．【50】______”For example，when someone feels contempt，you can't say for certain that their eyebrows always go down． Someone who has tried to establish such rules is the American，Professor Paul Ekman，who has built a database of how the face moves for every emotion．The face can make 43 distinct muscle movements called “action units”．These can be combined into more than 10，000 visible facial shapes．Ekman has written out a pattern of facial muscular movements to represent each emotion．