The first process of perception is sensation at the sensory cells of the perceptual structures. To the recognition of a perception, a comparison is made in the brain between currently perceived stimuli and stimuli from the perceptual memory. Only this matching enables the human being to interpret.
What is recognition?
Recognition takes place on the basis of previous perceptions stored in the brain for comparison with each new perception. The anatomical sensory systems of humans enable them to receive stimuli from the environment and from within themselves. The reception of stimuli takes place through the sensory cells of the respective perceptual system. In order to get a picture of one’s own environment or processes within one’s own body, stimulus reception is, however, only the first instance of perception. Via afferent nerve pathways, perceptual information reaches the brain via the spinal cord, where the interpretation, classification and recognition of the stimuli only begins. In the brain, the image is assembled. Perceptual psychology divides the process of perception into three distinct stages: sensation, organization, and classification. In visual perceptions, for example, the first stage gives rise to an image of the object. The step of organization organizes the image into a solid form made of individual shapes. Only in the last step is meaning assigned to the sensory impression: the perception is thus recognized. Recognition takes place on the basis of previous perceptions, which are stored in the brain and serve for comparison with each new perception. Only by comparing, categorizing and assessing his perception does the human being recognize, in the case of the sense of sight, for example, a certain image as a person or an object. Recognition is thus one of the final steps in the perceptual chain.
Function and task
Like all living things, humans perceive the physical properties of their environment and their own bodies with their senses. However, there are differences of greater or lesser magnitude between what is recognized and what is actually perceived. What the sensory organ detects does not necessarily correspond to what is ultimately recognized. This phenomenon can be reproduced, for example, by optical illusions. Moreover, subjective perception does not always correspond to the objectively acting stimuli from the physical world that trigger perception in the first place. On the way between grasping the sensory organ and the step of recognition, the brain filters out information from a perception, summarizes information, divides the perception into categories and orders the individual areas of perception according to their experiential importance. In the case of perceptions of the visual system, for example, on the way to recognition the brain must first filter out individual objects from the overall perception, recognize these objects by matching them with perceptual memories, and in the final step understand the overall picture. Object recognition, for example, relies on conciseness as a principle. Figures are perceived according to the principle of conciseness with a structure that is as simple as possible. The principle of proximity also lets people perceive picture elements as belonging together as soon as they are particularly close to each other. In addition, the principle of similarity allows people to perceive all picture elements with the same shape or color as a whole. Symmetrical structures belong to the same object for people. Identical movements or an appearance and disappearance at the same time create as much togetherness as closed lines of a surface, common regions as delimited areas or continuous image continuations of interrupted elements. A visual impression is transformed by these and other principles from an overall impression to many extracted gestalt information. Only after these processes are the individual objects recognized and given interpretive meaning. Thus, for object recognition and interpretation, in visual impressions the brain extracts information about the location of objects and the relatedness of recognized lines. In object recognition, interpretation of the extracted objects follows by matching them with visual memory. This matching is done by feature analysis. Each object represents a certain set of abstract features and can be recognized based on these features.The actual recognition of a perception thus corresponds first to the assignment, in which an object is classified and thus becomes the representative of a certain category. In the case of complex objects, recognition is achieved by breaking them down into simpler components. The recognition of the sub-objects and their arrangement to each other lets the person recognize the total object. Recognition in all other sensory systems works on a similar principle.
Diseases and ailments
Perception is a complex process. Different perceptual abnormalities in different sensory structures can cause subjective perception to differ to a greater or lesser degree from objectively acting stimuli. If lesions in nerve structures impair perception, there is an underlying physical condition. If this is not the case, there is probably a mental perceptual disorder. Experiences, interests and attention can influence sensory impressions, for example. The integrity of anatomical perceptual structures enables objective stimulus reception. However, experiences, interests and attention enable subjective recognition and interpretation of a perception. Disturbances can be present in every subarea of perception. Thus, even a person with intact sensory organs can suffer from perceptual disorders. Visual perception disorders often manifest themselves in the inability to recognize the same shapes or spatial location. Other disorders from the field of visual perception have to do with face recognition. Auditory perceptual disorders often involve an inability to classify sounds or recognize sounds individually. Many recognition disorders are momentary perceptual weaknesses. Sometimes perceptual disorders are effects of overlapping developmental disorders and are due to a lack of support. However, a disturbed connection between the perceptual content and its representation within the perceptual memory is also a possible cause. Recognition disorders may also be due to physical diseases such as Alzheimer’s disease or triggered by mental illness.
