According to Gibson’s direct theories of perception, the array of our information in our sensory receptors is all we need to perceive anything. Meaning, we don’t really need to rely on past experiences to mediate between sensory experiences and perception. Gibson believes that it is vital to study perception in real world environments. According to Gibson, perception is based on four things. One of the theories states that the pattern of light that reaches into our eyes can be thought of as an optic array which may contain data necessary for perception. Secondly, it states that it is important information is provided by the movement of the observer. Thirdly, the optic array contains invariant information.

The optic array is known to contain all the visual information from the environment that strikes the eye. He also believes that the starting point for perception is the structure of the light that reaches the retinas of the observer. To be able to perceive objects, it is vital for the light to be structured by the presence of the objects, surfaces and textures. The structure itself can be very complex because these rays of light converging on the observer from every part of the surrounding environment and also this structure will change every time the individual makes a move therefore his or her own perspective changes too.

Optic flow is the changes in the light patterns that reach an observer when the individual moves. Flow patterns are created when objects in the visual environment flow past a moving observer. The nature of the flow provides information to the observer about position and depth. For example, a motorway sign, first seen as a distant feature on the horizon, eventually passes to the left of you as you drive forward.

Texture gradient is seen as one of the important aspects of Gibson’s theory of perception. Our perceptual world is made up of surfaces of different textures and these textures can be used to assist the perception of depth and orientation. A visual texture can be broadly defined as a collection of objects in the visual field and the gradient refers to the change in relative size and compactness of these elements.

Affordance is simply recognising what an object simply mean. We know the meaning as what Gibson’s suggest by perceiving them directly. That means everything afford certain responses ie. Chair affords sitting etc. According to McGrenere and Ho Gibson has explained affordance as an action possibility available in the environment to an individual, independent of the individual’s ability to perceive this possibility. This means we acquire direct perception if there is an affordance and enough information in the environment is present to specify the affordance.

Last but not the least; Gibson has suggested that our perception is mainly influenced by our evolutionary past enabling our perception to be received by our developed nervous system which allows us to make sense and receive the rich environmental data around us. Humans are equipped to make direct use of data from the environment without the need of constant judgement and hypothesis testing which is implied by constructivists theorist called Gregory. Furthermore, he assumes that we operate as a single unit, and if one part of our nervous system goes off or becomes impaired, the system won’t work at all.

One study that supports Gibson’s Bottom-up theory is Warren and Hannon produced films consisting of patterns of moving dots simulating the optic flow that would be produced if someone were moving in a given direction. As predicted by Gibson, observers used the optic-flow information to make accurate judgements of the direction in which they were heading.
One criticism on Gibson’s theory of perception was he was unable to explain visual illusions- in situations where an individual’s perception of a stimulus does not correspond to the physical properties of the stimulus, which shows us that perception isn’t always accurate. On the other hand, Gibson himself has said how much the importance of studying perception in real life situations where movement and passage of time are important. He also recognises the fact that most studies based on the perception of illusions carried out in an artificial laboratory conditions where participants were stationary had little or no relevance to real life situations.

However, studies suggest that Gibson has exaggerated the role of optic flow and that we use more than one method to move around and perceive in our highly complex environment. Such information is sometimes used, but it is much less important than what he has assumed, as there are other factors such as visual direction and binocular disparity.

In relation to one research against Gibson’s theory of perception is done by Van den Berg and Brenner provide evidence that optic flow doesn’t sufficiently account for depth perception. We only need one eye to use optic-flow information. However, judgements about the direction in which observers were moving were more accurate when they used two eyes rather than only one. This happened because of what is known as binocular disparity—the slight difference in images on the retina of each eye allows observers to obtain additional information about the relative depths of objects.

One of the positive aspects of Gibson’s theory is that it has allowed practical application on training programmes for pilots. This made sure better lighting and markings are installed in airports to enhance optical flow patterns for incoming pilots. Another practical application can be seen on approach roads to busy roundabouts where a set of parallel lines is painted closer together as the road approaches the roundabout. This gives an impression that they are accelerating. Hampson and Morris have pointed out, this traffic control technique changes perception by changing the structure of the perceptual or cognitive mechanisms with a reduce speed sign. These applications illustrate the importance of Gibson’s work in helping people act more safely in their everyday lives in low-key yet important ways.

This is a reductionist study because studies suggest that few cells or neural networks have been found that pick up the very complex features of the world. It may be that we have the innate capability to directly perceive something very basic and essential for survival, such as depth, but we may not have cells that respond to a particular object, such as a goose. Menzel have done some research and found evidence criticising Gibson’s theory as he ignores the idea of cognition. Chimpanzees were carried around a field, and were shown the locations of 20 pieces of food. When each chimpanzee was then released, it moved around the field picking up the food efficiently. There could be no relevant information in the light reaching the chimpanzees because they were now moving independently rather than being carried, and so they must have made use of stored information in long-term memory to guide their search, which Gibson did not account for.