Perception is one of the major areas of study in cognitive psychology: Perception studies answer a variety of questions such as “How do you spot a plane on a radar?“, “What are the illusions; What affect us?“, “What perfume do 40-year-old women prefer?“,”Why do we see worse in the car at dusk?“, and on and on. In other words… It is our ability to sense things just before they happen or sense what has happened.
Perception is defined as the set of mechanisms by which the body becomes acquainted with the world, on the basis of the information of the subject (because the memory intervenes enormously!). It refers to all information-gathering operations: the perceptual system transforms stimulations into information, a transformation phenomenon which, moreover, takes time (and cognitive resources: it is the processing of information!).
The time for transformation and the perceptual storage of information, for example, occur when someone says something that we did not pay attention to. Words have not been transformed into information (making sense for our mind), like all noises we hear, non-important and therefore untreated. But when the person is asked to repeat, the words that have been heard, and to which we pay sudden attention, are immediately transformed into information even before the person has repeated. This phenomenon is a conclusive clue that every piece of information that we perceive is not only kept, at least for a short time, in memory but in addition, that this information must be processed for it to make sense (comprehension).
Perception may depend on information previously stored in memory (our knowledge!). For example, there may be a connection between place and recognition: if we expect to see some people in some places and not others, faces that we know … then we recognize them easily in these places. On the other hand, if we cross them in a place where we do not expect to see them, we sometimes do not even recognize them! (And the eternal question that everyone has already asked himself once in his life: “But where have I already seen this face that is familiar to me?”.
Thus, perception can be facilitated or dependent on memory, so it is customary to distinguish two major perceptual processes:
- The direct approach is called Bottom-up process: The environment imposes itself on knowledge. When we first perceive a stimulus, only the information of the environment is taken into account to form a mental representation (it can also be stored later in memory). Imagine for example – everyone has already experienced it! – an image game, with an image in which an object is hidden: the first time you see the image, you only perceive what it sends you, and you start a process of the visual search to find the image object. Once it is found, you have it in memory.
- The indirect approach or Top-down. Knowledge is imposed on the environment: in the previous example, if you are presented with the image again, you immediately find the hidden object. But the image has not changed! The only thing that could explain that you perceive it right away, and the representation that you had previously put in memory. It is a memory that influences your perceptions so that you interpret the image directly!
Definition of Perception in Psychology
In cognitive psychology, perception is defined as the person’s response to external stimulation manifested by chemical phenomena at the neurological level of the sense organs and central nervous system and by various mechanisms that tend to confuse this response with its object by processes such as the representation of the object, the differentiation of the object from other objects. In humans, there are five meanings to provide this information to perceive a given object and identify it, these five types of perception basics are the perception visual, the perception hearing, the perception olfactory, the perception touch and perception gustative. These five mechanisms of perception that the human body is naturally endowed, are added other types of perception that are not specific to particular sensory organs but related a level of psychological maturity linked to a level of development of the central nervous system or brain, it is about the perception of time, the perception of space and the audiovisual perception.
The tongue is the part of the body that allows knowing the taste. There are different areas of the tongue that allow the distinction between different tastes. Below the tongue, there is a median ridge that secures it in the mouth and extends to the back by a mucous fold. This is called the brake. Its flat upper surface is marked by the median groove (or multilingual axis of symmetry). The surface is rough by the presence of taste buds. The identification of different tastes is made by different areas: The salty taste is detected by the front and back of the tongue. Softness is detected by the tip of the tongue. The acid taste is marked on each side of the tongue. The bitter taste is detected by the base of the tongue. We also identify tastes in the brain that sends us information. The areas of the brain are numerous: the motor areas that control the muscular activity, the areas of association that relate to the emotion and intelligence and finally the sensitive areas. Among them, there are four areas: the visual area, the auditory area, the olfactory area and the tasting area.
Perception of time or temporal perception
If we have eyes to see, ears to hear and a nose to feel, we do not have the specific sensory receptors dedicated to the perception of time. However, we are able to perceive the passage of time. The study of the perception of time is thus confronted with a paradox, which refers to the nature of the time when psychological experiences that attempt to give answers, to philosophical thoughts, to our understanding of how the brain works and to our knowledge of circadian rhythms. The perception time has been the subject of many studies from early studies in the nineteenth century to psychophysical explorations through brain imaging. The experimenters have distinguished the different types of phenomena that are all of the perceptions of time: the perception of duration, the perception of rhythm, temporal order and simultaneity, the question remains whether these different domains of perception of time are carried out by the same mechanisms or not, in particular, other distinctions have been introduced on the basis of timescales considered.
The perception of space
Like the duration, the distances between the objects can be a perception. Thus, it is possible to say whether such an object is closer to us than the other or that this is greater than the other. In any case, scientific research shows that the parietal lobe of the brain plays an important role in the perception of space.
The audio-visual perception
Apart from the natural situations for which we can always speak of a phenomenon of audio-visual perception, this type of perception is rather the result of the recent technological development of humanity with the cinema, the television and the digital camera and the computer and with such a technological development there has been a parallel development of the psychology of perception especially relating to information, communication, and advertising.
The tactile perception
Also known as, the perception of touch, is the perception by humans or animals by sensations touch transmitted through the skin, mucous membranes (tongue) or teeth (periodontal mechanical receptors). It includes not only the perception of touch in the narrow sense (recognition of the texture, elasticity, reading Braille, etc.) but also the perception of heat (feeling hot or cold), and even perception of emotional as pain or sensuality.
The olfactory perception
The nose is, of course, the sense organ that includes the mechanisms of reception and transmission of smell to the olfactory lobe of the brain for identification and interpretation, the smell is relatively neglected by many humans , and much more used by some animals especially dogs (it is well known that dogs are trained to help customs and police to detect prohibited products in vehicles and luggage of travelers). It is used, however, often without realizing it. It participates in the perception of taste to the sensation of taste.
The auditory perception
The branch of psychology that studies how we perceive sound is psychoacoustics. The chain of auditory perception sounds that are transmitted by the air is picked up and amplified by the auricle of the ear to concentrate them at the level of the auditory canal that leads them to the eardrum whose membrane begins to vibrate. The chain of ossicles transmits and amplifies these vibrations (mechanical conduction) and is transmitted to the inner ear. At the level of the inner ear, they cause pressure waves corresponding to sound waves. These pressure waves can communicate the vibrations to the deepest and most delicate part of the human ear, the cochlea. The mechanical waves move through the eyelashes of the inner ear, perception proper and interpretation or identification.
Psychology perception of forms
The retina is not a homogeneous structure because it contains a central zone, the fovea; everything else is called periphery. The fovea is in the middle of the retina and is characterized by an extremely small diameter of about 0.4 mm which covers only a visual angle of 2 degrees to 4 degrees but contains twenty-five thousand cones. Each cone, at the level of the fovea, is connected to the brain by direct wiring. This allows maximum discrimination: it is visual acuity. In humans, the sharpness is 1 arc minute (= l / 60th of a degree).
Conversely, the periphery covers almost the entire fundus of the eye (except the center = fovea) and it is populated mainly by sticks. The transmission structure is hierarchical, several photoreceptors are connected to an optical cable, as clusters become larger and larger out of the periphery. Thus, at 15 degrees from the optical axis, there are sixty rods for a fiber of the optic nerve while at the extreme edge (near the ciliary muscles), at 80 degrees, there are ten thousand rods for a fiber. The brain that is only informed at the end of wiring is therefore blurred when the images are projected on the periphery of the retina and all the more fuzzy as the image is far from the center. In some diseases where the fovea is destroyed, the patients see very roughly, for example,
Saccades and fixation
Given the smallness of the fovea, the brain controls eye movements to take “samples” of the visual scene and reconstructs it (hence the errors in ocular evidence). So when we read, our view is not panoramic and the eyes do not wander regularly along the lines of the text. The eye recordings show that the reading consists of jumps and breaks: jerks and eye fixations. The jerks are the jumps that have the function of bringing the gaze in front of the target (a word); the saccades are very short of the order of 20 ms (milliseconds) between each word and 80 ms for a change of line. The fixations are the breaks that allow the input of information: they last on average 250 ms (1/4 second). In general, for words or for the details of drawings, the vision is effective with good sharpness only at an angle of 2 degrees (1 degree on each side of the center of fixation); it is very small; practically that’s about the length of a word. Moreover, we note in the recordings during the reading that not all fixations are equally effective and there are a number of backtracks, or regressions, especially in children.
Eye Exploration Strategy and Shape Construction
The perception of forms is a paradox because most of the time the shape of a figure is too big for its entire image to be limited to the fovea. But the identification is very bad on the periphery (weak acuity). The perception of forms, which cannot be ensured by any one of the vision systems, is ensured by the coordination of the foveal vision (fixation) and the peripheral vision in real exploration strategies (saccades). The eye is the explorer and the brain is the cartographer. This explains that certain forms are required as good forms(gestalt) because the more the figure is simple, symmetrical, regular and more the mental construction (like a computer program) is simple. This explains why certain figures appear to us elementary, like the geometrical shapes, the circle, the square, the rectangle, the triangle, etc.