Option 2
Compare and contrast Marr and Nishihara’s and Biederman’s theories of object recognition. How well do they explain how we are able to recognize three dimensional objects despite changes in viewing angle?
Humphreys and Bruce (1989) proposed a model of object recognition that fits a wider context of cognition. According to them, the recognition of objects occurs in a series of stages. First, sensory input is generated, leading to perceptual classification, where the information is compared with previously stored descriptions of objects. Then, the object is recognized and can be semantically classified and subsequently named. This approach is, however, over-simplified. Other theories like Marr and Nishihara’s and Biederman’s
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This description is then matched against those stored in memory. According to Biedermann, geons are detected on the basis of non-accidental properties such as collinearity, symmetry and parallelism. Like Marr and Nishihara, Biedermann sustains that primitives are invariant under changes in viewpoint.
Similarly, both theories are supported by research. Lawson and Humphreys (1996), for example, showed that recognition is affected more by tilt of major axis (foreshortening) than any other rotation, which endorses Marr’s and Nishihara prediction that establishing a central axis is crucial to the process of recognition. Warrington and Taylor (1978) reported that brain damaged patients could recognize objects presented in a typical view only. These patients found difficult to say if two photographs presented simultaneously were the same object when one image was a typical view and the other an unusual view. Although this could be explained as the patient’s inability to transform a 2D version of the atypical view into a 3D model, it could also be due to difficulty in establishing the central axis or due to some features of the object being hidden. In a later study, Humphreys and Riddoch (1984) used images where either the axis had been foreshortened through rotation or a critical feature was hidden. They found that patients had more problems recognizing the images with a foreshortened axis than the ones where a critical feature was hidden. Their
The first thing that I learned about perception was earlier discovered by a psychologist by the name of Max Wertheimer. He discovered that our body clearly separates images into figures
ABSTRACT: The aim of this paper is to defend a broad concept of visual perception, according to which it is a sufficient condition for visual perception that subjects receive visual information in a way which enables them to give reliably correct answers about the objects presented to them. According to this view, blindsight, non-epistemic seeing, and conscious visual experience count as proper types of visual perception. This leads to two consequences concerning the role of the phenomenal qualities of visual experiences. First, phenomenal qualities are not necessary in order to see something, because in the case of blindsight, subjects can see objects without experiences phenomenal
Powell (1986) conducted a study in which individuals viewed a photo or slide. Individuals were required to scan images and decide on an image for the entire display (Powell, 1986). Objects were pointed to, and subjects were asked to identify its location (Powell, 1986). The subject was asked to close his or her eyes and were shown another image. The subjects were to decide if the object was in the correct position (Powell, 1986). The subjects would hear one of the objects and was required to focus on the object while keeping the entire image in his or her mind (Powell, 1986). When the next object was identified, the subjects were to move from the first object to the second watching a black dot moving in a straight line (Powell, 1986).
Participants were shown each of the cards (a) to (d) in set 2, in order, for three seconds each. Participants were then asked to write down what they saw in each of the pictures, but their responses are not recorded by the experimenter. The purpose of this was to develop a perceptual set for faces based on the participant’s immediate past experience with the four pictures of faces.
In experiments of scene memory, subjects viewed hundreds of photographs of natural scenes. Afterward, they were asked to identify which photograph they had seen and which ones they had never viewed before. Even though subjects can recognize previously viewed pictures very well, the memories were not linked to the precise visual form. In addition, subjects failed to detect changes when the images were mirror-reversed. These
View-point dependence states that the way one recognized an object depends upon its viewpoint. It is more focused on remembering the image as a whole and the different ways it was viewed. It also states that how quickly or accurately one can recognize an object depends on its orientation, this point greatly differing with view-point invariance. This paper supports the statement, “object recognition is view-point dependent” and uses additional research to support it.
The experiment was to study color and orientation of encoding from different parts of objects. Color feature was altered in 50% of the trials and participants were asked to detect this change. The stimuli presented to each participant in on feature consisted visually a small circle with an oriented bar crossing in the middle of circle, forming a Saturn-like object. Each stimulus was displayed on a gray background and used black oriented bars with the small colored circles using 4 colors. Six display types were utilized: single-feature with 5 color, single-feature with 10 color displays, all contained the 5 and 10 circles with the colors being the main focus of this condition. The next two conditions were; single-feature with 5 orientation and single-feature with 10 orientation displays, however these features are focusing on the orientation of each of the bars that are being displayed. The final two displays are that of the
Chapter 4 (63-85): Chapter 4, ‘The Zombie in the Brain’ moves from phantom limbs to a new focus on perception and how each person can view things differently, and similarly. Every few pages Dr. Ramachandran inserts diagrams meant to trick the human mind and the readers in order for us to get first hadn experience and understanding of the topic being studied and discussed. Besides the images, Ramachandran goes more in depth with the eye and how different parts of it affect perception for our brains. Like the optic pathway, which is the pathway in which the optic nerve/eye has information travel through to our brain, like colors, shapes, distances, and width of something. Our brain then makes reason out of this information that was sentic in
Earlier research with similar goals argues that context plays a role in recognition. Sinha’s research provides direct evidence of contextual cues eliciting object-specific neural responses in the brain.
Our brains can process perceptions in two ways: Bottom up and top down. In bottom up processing, there are 3 different ways that a person interprets or perceives what they see. Template matching uses prior knowledge of an object and creates a template using that prior knowledge. For example, the brain can use a template of the letter A in order to perceive an A. Template matching is very particular and uses every detail to create a template. However, prototype is a more generic type of matching. Prototype uses an idealized representation of an object or event. For example, to perceive a dog, the brain uses a generic idea of a dog (head, pointy ears, wet nose, big jowls). The third type of bottom up processing is called categorical perception.
High-level feature extraction concerns finding shapes in computer images. To be able to recognize faces automatically, for example, one approach is to extract the component features. This requires extraction of, say, the eyes, the ears and the nose, which are the major facial features. To find them, we can use their shape: the white part of the eyes is ellipsoidal; the mouth can appear as two lines, as do the eyebrows. Shape extraction implies finding their position, their orientation and their size. This feature extraction process can be viewed as similar to the way in which we perceive the world: many books for babies describe basic geometric shapes such as triangles, circles and squares. More complex pictures can be decomposed into a structure
Agnosia is defined as the inability to recognize objects through the processing of sensory information, which means there is no deficit in semantic memory or problems with naming objects. An individual suffering from agnosia still possesses all the relevant semantic information tied to a precept, but they cannot recognize the precept when it is presented to them and therefore trigger the recall of said information. There are many types of agnosia, but this essay will focus on visual object agnosia and prosopagnosia. The former is the inability to recognise objects: patients suffering from visual object agnosia do not have impaired vision, and in some cases can even copy the object they are seeing (patient H.J.A., Humphreys & Riddoch, 1987) or draw it from memory (patient D.F., Milner & Goodale, 1992), but are unable to recognize it when they see it. In the latter, prosopagnosia, patients cannot recognise faces of familiar individuals, and have to rely on other characteristics such as their voice or clothing to recognize them. Patients suffering from prosopagnosia can either acquire it through a lesion in relevant brain areas (acquired prosopagnosia) or for less understood reasons have it from birth, in which case it is termed developmental prosopagnosia. The study of patients with agnosia is integral to the field of visual recognition, as the specifics of their deficits can provide great insight into the ways our brain processes information; for example, the location of
Studies comparing the gender and visual spatial recognition along with different fields of study; Peters, Laeng, Jackson, Zaiyouna, and Richardson (1995) conducted a spatial visualization test using a duplicated version of Vandenberg and Kuse's (1978), MRT test and several different groups. In one test they compared male's performance to female's performance between students from the
‘Size constancy’ is the perception of an object as having a fixed size, regardless of the change in size of the retinal image & the visual angle which accompanies changes in distances (i.e. as an objects moves into the distance, the retinal image decreases yet the object size remains the same). It is thus possible to accurately
Binocular cues are the reason we are able to see things in three dimensions rather than just two. Binocular cues are what enable us to establish where in space an object sits and its size compared to our own body. By seeing things through both of your eyes and then conjoining it your brain is then able to see the world three dimensions. Binocular disparity is there because since our eyes are a certain distance apart form each other it means that the right eye sees the world from a marginally different angle the left eye. Binocular disparity allows our eyes to see the object from different angles so then we can see slightly different parts of the object which help us to determine its shape and size. Binocular Convergence as Sternberg, R. J. (1998) explains is because ‘your two eyes are in slightly different places on your head, when you rotate your eyes so that the image of an object that is in front of you falls directly on each fovea, each eye must turn inward slightly to registrar the same image. Our brains receive neural information from the eye muscles about the convergence of the eyes, and they assume that the more the eyes converge, the close the perceived object must