Recognition Of Other Objects Research Articles

Prosopagnosia: current perspectives.

Prosopagnosia is a selective visual agnosia characterized by the inability to recognize the identity of faces. There are both acquired forms secondary to brain damage and developmental forms without obvious structural lesions. In this review, we first discuss the diagnosis of acquired and developmental prosopagnosia, and the challenges present in the latter case. Second, we discuss the evidence regarding the selectivity of the prosopagnosic defect, particularly in relation to the recognition of other objects, written words (another visual object category requiring high expertise), and voices. Third, we summarize recent findings about the structural and functional basis of prosopagnosia from studies using magnetic resonance imaging, functional magnetic resonance imaging, and event-related potentials. Finally, we discuss recent attempts at rehabilitation of face recognition in prosopagnosia.

Experience moderates overlap between object and face recognition, suggesting a common ability.

Some research finds that face recognition is largely independent from the recognition of other objects; a specialized and innate ability to recognize faces could therefore have little or nothing to do with our ability to recognize objects. We propose a new framework in which recognition performance for any category is the product of domain-general ability and category-specific experience. In Experiment 1, we show that the overlap between face and object recognition depends on experience with objects. In 256 subjects we measured face recognition, object recognition for eight categories, and self-reported experience with these categories. Experience predicted neither face recognition nor object recognition but moderated their relationship: Face recognition performance is increasingly similar to object recognition performance with increasing object experience. If a subject has a lot of experience with objects and is found to perform poorly, they also prove to have a low ability with faces. In a follow-up survey, we explored the dimensions of experience with objects that may have contributed to self-reported experience in Experiment 1. Different dimensions of experience appear to be more salient for different categories, with general self-reports of expertise reflecting judgments of verbal knowledge about a category more than judgments of visual performance. The complexity of experience and current limitations in its measurement support the importance of aggregating across multiple categories. Our findings imply that both face and object recognition are supported by a common, domain-general ability expressed through experience with a category and best measured when accounting for experience.

Impaired holistic and analytic face processing in congenital prosopagnosia: Evidence from the eye-contingent mask/window paradigm

There is abundant evidence that face recognition, in comparison to the recognition of other objects, is based on holistic processing rather than analytic processing. One line of research that provides evidence for this hypothesis is based on the study of people who experience pronounced difficulties in visually identifying conspecifics on the basis of their face. Earlier, we developed a behavioural paradigm to directly test analytic vs. holistic face processing. In comparison to a to be remembered reference face stimulus, one of two test stimuli was either presented in full view, with an eye-contingently moving window (only showing the fixated face feature, and therefore only affording analytic processing), or with an eye-contingently moving mask or scotoma (masking the fixated face feature, but still allowing holistic processing). In the present study we use this paradigm (that we used earlier in acquired prosopagnosia) to study face perception in congenital prosopagnosia (people having difficulties recognizing faces from birth on, without demonstrable brain damage). We observe both holistic and analytic face processing deficits in people with congenital prosopagnosia. Implications for a better understanding, both of congenital prosopagnosia and of normal face perception, are discussed.

Facial Coding is Disrupted at Equiluminance

Human face recognition is disrupted by the reversal of luminance contrast polarity (ie photo negatives--see Galper 1970 Psychonomic Science 19 207-208; Johnston et al 1992 Perception 21 365-375), while recognition of other objects is less impacted (Nederhouser et al 2007 Vision Research 47 2134-2142; Subramaniam and Biederman 1997 Investigative Ophthalmology & Visual Science 38 998). This suggests that correct patterns of luminance contrast are important for facial coding. Here we investigate this further by minimising luminance contrast. We contrast peoples' ability to categorise cars and faces when images vary in luminance and when images are altered to predominantly contain differences in colour (equiluminance). Eliminating luminance contrast had a greater adverse impact on facial classifications relative to car categorisations. This was true even though precautions were taken to equate visibility, and despite equal levels of performance when images contained luminance contrast. These results were not due to images containing markedly different spectra, as the effect persisted for facial images altered to match car images in this regard, and performance in both tasks dropped off proportionally with increasing levels of image blur. Finally, consistent with previous observations, we show that facial coding is not only adversely impacted at equiluminance but becomes even worse when the polarity of luminance contrast is reversed. Our data show that the correct pattern of luminance contrast is very important for facial coding. We suggest that this is related to the role of luminance contrast in signalling 3-D shape from shading.

Recognition of faces and complex objects in younger and older adults

We examined whether (1) age-associated impairments in face recognition are specific to faces or also apply to within-category recognition of other objects and (2) age-related face recognition deficits are related to impairments in encoding second-order relations and holistic information. In Experiments 1 and 2, we found reliable age differences for recognition of faces, but not of objects. Moreover, older adults (OAs) and younger adults (YAs) displayed similar face inversion effects. In Experiment 3, unlike YAs, OAs did not show the expected decline in performance for recognition of composites (Young, Hellawell, and Hay, 1987). In Experiment 4, both OAs and YAs showed a whole/part advantage (Tanaka and Farah, 1993). Our results suggest that OAs have spared function for processing of second-order relations and holistic information. Possible explanations for the finding that OAs have greater difficulty recognizing faces than recognizing other objects are proposed.

A neural basis for expert object recognition.

Although most adults are considered to be experts in the identification of faces, fewer people specialize in the recognition of other objects, such as birds and dogs. In this research, the neurophysiological processes associated with expert bird and dog recognition were investigated using event-related potentials. An enhanced early negative component (N170, 164 ms) was found when bird and dog experts categorized objects in their domain of expertise relative to when they categorized objects outside their domain of expertise. This finding indicates that objects from well-learned categories are neurologically differentiated from objects from lesser-known categories at a relatively early stage of visual processing.

Object recognition: Holistic representations in the monkey brain

Cognitive-psychological and neuropsychological studies suggest that the human brain processes facial information in a distinct manner, relying on mechanisms that are anatomically and functionally different from those underlying the recognition of other objects. Face recognition, for instance, can be disrupted selectively as a result of localized brain damage, and relies strongly on holistic information rather than on the mere processing of local features. Similarly, in the non-human primate, distinct neocortical and limbic structures have cell populations responding specifically to face stimuli and only weakly to other visual patterns. Moreover, such cells tend to respond to the entire configuration of a face rather than to individual facial features. But are faces the only objects represented in this way? Here I present some evidence suggesting that at least one aspect of facial processing, the processing of holistic information, may be employed by the primate brain when recognizing any arbitrary homogeneous class of even artificial objects, which the monkey has to individually learn, remember, and recognize again and again from among a large number of distractors sharing a number of common features with the target. Acquiring such an expertise can induce configurational selectivity in the response of neurons in the visual system. Our findings suggests that regarding their neural encoding faces are unlikely to be 'special', but they rather are the default 'special class' of the primate visual system.

Attention to faces in the fusiform gyrus

Face recognition represents one of the most expert skills of the human visual/memory system. It has been proposed to rely on a highly specific, modular system distinct from the system(s) involved in recognition of other objects. A recent imaging study has shown face-specific activations in the ventral occipito-temporal pathway, in particular, in the fusiform gyrus[1xCovert visual attention modulates face-specific activity in the human fusiform gyrus: fMRI study. Wojciulik, E., Kanwisher, N., and Driver, J. J. Neurophysiol. 1998; 79: 1574–1578PubMedSee all References][1]. In this blocked-design functional magnetic resonance imaging study, the authors investigate whether fusiform gyrus activity in response to faces is modulated by attention. They show that the same stimuli containing a pair of houses plus a pair of faces activate face-specific fusiform areas more strongly when the task focuses subjects' attention on faces relative to houses. Consequently, this study supports the idea that fusiform gyrus activation in response to faces is not merely driven by the visual characteristics specific to these stimuli relative to other objects, but is also modulated by attentional processes. This result has implications for a strictly modular view of the face-recognition system. Because it shows that face-specific fusiform gyrus activations are not purely automatic and unmodulated, this study throws doubt on such a strict modular view of face recognition.

Spatial context in recognition.

In recognizing objects and scenes, partial recognition of objects or their parts can be used to guide the recognition of other objects. Here, the role of individual objects in the recognition of complete figures and the influence of contextual information on the identification of ambiguous objects were investigated. Configurations of objects that were placed in either proper or improper spatial relations were used, and response times and error rates in a recognition task were measured. Two main results were obtained. First, proper spatial relations among the objects of a scene decrease response times and error rates in the recognition of individual objects. Second, the presence of objects that have a unique interpretation improves the identification of ambiguous objects in the scene. Ambiguous objects were recognized faster and with fewer errors in the presence of clearly recognized objects compared with the same objects in isolation or in improper spatial relations. The implications of these findings for the organization of recognition memory are discussed.

The inverted face inversion effect in prosopagnosia: Evidence for mandatory, face-specific perceptual mechanisms

Does the human visual system contain a specialized system for face recognition, not used for the recognition of other objects? This question was addressed using the “face inversion effect” which refers to the loss of our normal proficiency at face perception when faces are inverted. We found that a prosopagnosic subject paradoxically performed better at matching inverted faces than upright faces, the opposite of the normal “face inversion effect”. The fact that his impairment was most pronounced with the stimuli for which normal subjects show the greatest proficiency in face perception provides evidence of a neurologically localized module for upright face recognition in humans. An additional implication of these data is that specialized systems may control behavior even when they are malfunctioning and therefore maladeaptive, consistent with the mandatory operation of such systems according to the “modularity” hypothesis of the cognitive architecture.

Learning mutually dependent relations

So far, the task of learning relations has been concerned with the acquisition of intensional descriptions of unrelated concepts. However, in many real domains concepts are strictly related to each other and the instances of one of them cannot possibly be recognized without previous recognition of other objects as instances of related concepts. A typical case is the problem of labeling parts of a scene in order to interprete it. This paper extends in several ways the learning relations paradigm; in particular, a new methodology, allowing a recursive theory to be inferred from a set of examples, is presented. Each example may contain instances of several relations at the same time. The learning algorithm works bottom up, creating first an acyclic graph that classifies all the instances in the training set. Afterward, a recursive theory is synthesized from the graph. A prototype implementation of the algorithm has been realized by extending the program ML-SMART. The results obtained for an artificial labeling problem are described and discussed.

The effect of race, inversion and encoding activity upon face recognition

Recognition of faces has been shown to be more impaired by inversion than recognition of other objects normally only seen upright (Yin 1969).> Experiment 1 explores the possibility that this result is explicable in terms of the familiarity of the recognition tasks rather than a ‘face-specific’ factor. However, a less familiar task (recognizing other race faces) was more disrupted by inversion than recognizing own race faces. In experiment 2, Yin's (1969) finding was replicated using a different view of items at test, a task which is more representative of everyday face recognition. Yin (1970) suggested that the disproportionate effect of inversion may be due to difficulty in perceiving facial expression in an'inverted face. However, in experiment 3, subjects encouraged to make personality judgements on initial viewing of the faces were no more impaired by inversion at test than subjects encouraged to name distinctive physical features. These results imply that the disproportionate effect of inversion upon face recognition cannot be explained in terms of the extra familiarity of the task or the use of identical photographs at test. Furthermore, it appears that the role of facial expression is not sufficient to account for this effect. However, the results of experiment 3 are also discussed in terms of the effectiveness of specific encoding instructions to enhance expression analysis selectively.

Theory and measurement of self-esteem

An earlier paper (Dickstein, 1972) identified five forms of self-concept. The nature self-esteem was postulated to vary with age, with a different type of self-esteem being appropriate to each form of the self-concept. On the basis of this theory, a measure of self-esteem for school-age children was designed. The rationale for the new measure was derived from the writings of James (1890) and Mead (1934). The self-concept of the school-age child falls within the from of self called the "self-as-object." Through his recognition of other objects and people in the world, the child comes, in time, to see himself as an object. The self is created through experience, and knowledge of the self is limited to that which the child learns through interaction with others. For the individual whose self-concept falls at this level, self-esteem should be based on his perceived success at the various thing he does, with his overall level of self-esteem being determined by the degree to which he perceives himself to be successful at those particular activities which are most important to him.