Thinking is the mental activity that makes use of ideas or symbols instead of overt activity. The types of thinking are (i) Perceptual (concrete) thinking, (ii) Conceptual (abstract) thinking (iii) Reflective thinking, (iv) Creative thinking.

The core elements in thinking are- 

(i) Mental representation – It is a coded internal sensation acquired by direct experiences through the sense organs or by indirect experiences such as narrations, pictures, etc. Mental representation is the mental imagery with the help of which the brain codes and stores the information. It is like a hypothetical internal cognitive symbol used by the brain to represent external reality. Example: a child is asked to imagine a peacock. The visual image of a peacock with its colourful plumage immediately comes to mind. This refers to “mental imagery” of an object.

(ii) Concepts – They form the basis for all cognitive processes, acting as building blocks by connecting with each other to form more complex concepts. Concepts involve extraction of some ‘idea’ on the basis of similarities and differences among the sensations. A concept is an idea which represents a class of objects, situations, etc which differentiates it from other classes of objects, situations, etc., for e.g. a child forms a mental image of a ‘dog’. He derives an idea of something similar in all examples of ‘dog’ that he has seen i.e. tail, fur, barking, etc. Thus, he has formed concept of dog. If he mistakenly identifies as a cat as a dog. he is corrected by others. So he tries to compare the mental images of dogs and cats. He has now learned and refined two concepts viz. dog and cat.

(iii) Schema – It is an internal representation that organizes knowledge about related concepts and relationships among them. Schema involves arranging many concepts in a particular system or organisation. It describes a pattern of thought or behavior that organises categories of information and the relationships among them. A child tries to organise the concepts that he has learned in a systematic way to generate a higher order understanding of patterns about information collected, for e.g. when a child visits a ‘zoo’ for the first time, images and concepts such as of different animals, caves/cages, etc., are activated in the brain simultaneously. Thus, he is forming the schema of ‘zoo.

Conclusion:- Mental representation is sensory experiences in the form of mental images in the brain. Many similar mental representations denote concepts while many concepts put in a particular relationship to each other is schema.