Face recognition impairments

Congenital prosopagnosia without object agnosia? A literature review

A longstanding controversy concerns the functional organization of high-level vision, and the extent to which the recognition of different classes of visual stimuli engages a single system or multiple independent systems. We examine this in the context of congenital prosopagnosia (CP), a neurodevelopmental disorder in which individuals, without a history of brain damage, are impaired at face recognition. This paper reviews all CP cases from 1976 to 2016, and explores the evidence for the association or dissociation of face and object recognition. Of the 238 CP cases with data permitting a satisfactory evaluation, 80.3% evinced an association between impaired face and object recognition whereas 19.7% evinced a dissociation. We evaluate the strength of the evidence and correlate the face and object recognition behaviour. We consider the implications for theories of functional organization of the visual system, and offer suggestions for further adjudication of the relationship between face and object recognition.

Electrophysiological studies of face processing in developmental prosopagnosia: neuropsychological and neurodevelopmental perspectives

People with developmental prosopagnosia (DP) show severe face-recognition deficits that typically emerge during childhood without history of neurological damage. We review findings from recent event-related brain potential (ERP) studies of face perception and face recognition in DP. The generic face-sensitivity of the N170 component is present in most DPs, suggesting rapid category-selective streaming of facial information. In contrast, DPs show atypical N170 face inversion effects, indicative of impaired structural encoding, specifically for upright faces. In line with neurodevelopmental accounts of DP, these effects are similar to those observed for other developmental disorders, as well as for younger children and older adults. Identity-sensitive ERP components (N250, P600f) triggered during successful face recognition are similar for DPs and control participants, indicating that the same mechanisms are active in both groups. The presence of covert face-recognition effects for the N250 component suggests that visual face memory and semantic memory can become disconnected in some individuals with DP. The implications of these results for neuropsychological and neurodevelopmental perspectives on DP are discussed.

Laterality in Familiar Face Recognition

An extensive series of experiments has recently led to the hypothesis that face recognition, which had been considered a right-hemisphere specialization, may actually be bilaterally processed in the two hemispheres. In the present study an attempt was made to solve the conundrum of the laterality of face recognition by performing a meta-analysis on studies of familiar face recognition. Results of six studies measuring reaction time of familiar face naming and of eleven studies measuring accuracy of familiar face naming were transformed to standard Z scores. The average Z scores for reaction time and for accuracy were then tested for their significance. The results suggested that face recognition is not lateralized. This conclusion is consistent with theories of bihemispheric cognitive resources and with the latest brain-imaging data.

Face perception: a very special issue

The perception of a face allows us to recognize the person, infer his or her emotional state, better understand what the person is saying, and derive general information, such as age and gender. This unique visual stimulus has generated a wealth of research, and subsequently theoretical and methodological debate. This special issue brings together 16 original papers that show the extraordinary diversity and fruitfulness of the approaches now being pursued. They are aimed at understanding different aspects of face perception in populations ranging from healthy children to adults with brain lesions and with techniques covering the entire spectrum from paper-and-pencil tests to functional brain imaging. Together, these contributions provide an insightful overview of the current state of research on face perception and exemplify the questions that dominate the field. To one such question, whether 'face perception' is a special issue in the broad field of the cognitive neurosciences, the answer is clearly yes!

Self-recognition in everyday life

INTRODUCTION

A sample of everyday difficulties was collected, encompassing errors and unusual experiences participants had encountered when recognising their own faces in everyday life, with the aim of characterising similarities and differences between the reported difficulties and the major forms of self-recognition impairments described in the neuropsychological and neuropsychiatric literatures (prosopagnosia, mirrored-self misidentification, and Capgras delusion).

METHOD

A total of 70 participants recalled experiences from memory. Incidents (n = 51) were recorded on questionnaire sheets that were filled out at home. Reports of three categories of incidents were analysed: misidentifications (the participant misidentified her/his own face as being that of another familiar person; n = 5), recognition failures (the participant judged that his/her own face was that of an unfamiliar person; n = 20) and perception of unusual aspects (the participant confidently recognised his/her own face but found that the seen face did not fit well the representation she/he had of his/her own face; n = 26).

RESULTS AND DISCUSSION

In the reported incidents, experiences showing some similarities to those of patients with prosopagnosia, Capgras delusion or mirrored-self misidentification were noted. However, across the whole study, no incident involved a failure of reality testing; in contrast to pathological forms of error, in all of the reported incidents from our study the participant realised that a mistake had been made. The importance of decision processes in pathological forms of own-face misrecognition is discussed.

Rapid extraction of emotional expression: evidence from evoked potential fields during brief presentation of face stimuli

Although the emotional expression of faces is believed to be accessed rapidly, previous ERP studies hardly found correlates of these processes. Here, we report findings from a study that investigated dichoptic binocular interaction using emotional face stimuli. Thirty-one subjects were briefly presented with schematic normal and scrambled faces (of neutral, positive, or negative expression) that occurred simultaneously in the left and right visual fields. Stimuli for both eyes could be congruent (control) or incongruent (dichoptic). Subjects decided which of the superimposed images in both hemi-fields appeared more "face-like" and during this task, the EEG was recorded from 30 channels. VEPs were analysed topographically according to the influence of the different experimental conditions (defined by presentation form, emotional expression, and location). Behavioural responses to the ambiguous dichoptic stimuli demonstrated a functional eye dominance not related to visual acuity and conventional eye preference. Electrophysiological data revealed three components with mean latencies of 85, 160, and 310 ms. Topography of the second component (equivalent to the face-related N170) differed in left-right and anterior-posterior direction compared with simple checkerboard stimuli. Dichoptic presentation caused reduced field strength of all three, and increased latency of the first component. Faces with negative expression yielded largest field strength of the second and third components. Besides that, emotional expression affected topography not only of late, but also the first component. This provides new evidence about the timing of perceptual processes related to facial expression, indicating that already VEP components occurring at 80-90 ms are sensitive to emotional content.

Cognitive vision, its disorders and differential diagnosis in adults and children: knowing where and what things are

As ophthalmologists we need a basic model of how the higher visual system works and its common disorders. This presentation aims to provide an outline of such a model. Our ability to survey a visual scene, locate and recognise an object of interest, move towards it and pick it up, recruits a number of complex cognitive higher visual pathways, all of which are susceptible to damage. The visual map in the mind needs to be co-located with reality and is primarily plotted by the posterior parietal lobes, which interact with the frontal lobes to choose the object of interest. Neck and extraocular muscle proprioceptors are probably responsible for maintaining this co-location when the head and eyes move with respect to the body, and synchronous input from both eyes is needed for correct localisation of moving targets. Recognition of what is being looked at is brought about by comparing the visual input with the "image libraries" in the temporal lobes. Once an object is recognised, its choice is mediated by parietal and frontal lobe tissue. The parietal lobes determine the visual coordinates and plan the visually guided movement of the limbs to pick it up, and the frontal lobes participate in making the choice. The connection between the occipital lobes and the parietal lobes is known as the dorsal stream, and the connection between the occipital lobes and the temporal lobes, comprises the ventral stream. Both disorders of neck and extraocular muscle proprioception, and disorders leading to asynchronous input along the two optic nerves are "peripheral" causes of impaired visually guided movement, while bilateral damage to the parietal lobes can result in central impairment of visually guided movement, or optic ataxia. Damage to the temporal lobes can result in impaired recognition, problems with route finding and poor visual memory. Spontaneous activity in the temporal lobes can result in formed visual hallucinations, in patients with impaired central visual function, particularly the elderly. Deficits in cognitive visual function can occur in different combinations in both children and adults depending on the nature and distribution of the underlying brain damage. In young children the potential for recovery can lead to significant improvement in parietal lobe function with time. Patients with these disorders need an understanding of their deficits and a structured positive approach to their rehabilitation.

A serial test of the laterality of familiar face recognition

The purpose of the present study was to address the issue of laterality of familiar face recognition. Seventy-two participants judged familiar faces presented laterally or centrally for their "faceness," familiarity, occupation, and name (which represent four stages of familiar face processing) using one of three response modes-verbal, manual, or combined. The pattern of reaction times (RTs) implied a serial process of familiar face recognition. Centrally presented stimuli were recognized faster than laterally presented stimuli. No RT differences were found between the left and right visual fields (VFs) across all judgments and response modes. The findings were interpreted as supporting the notion that there are no significant hemispheric differences in familiar face recognition.

Selective attention to facial emotion and identity in schizophrenia

The selective attention to facial emotion and identity was investigated in 12 patients with schizophrenia and 12 healthy participants. Both patients and controls were required to perform two classification tasks (according either to identity or emotion). Two separate values for identity (person A/person B) and for emotion (fear/anger) were used. When the classification task was on one dimension, the other dimension was either correlated, constant, or orthogonal (Garner WR. The Processing of Information and Structure. Potomac, MD: Erlbaum, 1974, Garner WR. Interaction of stimulus dimensions in concept and choice processes. Cognitive Psychology 1976;8:98-123). Results indicated that both patients and healthy participants had an asymmetrical pattern of performance: they were able to selectively attend to the identity of the face presented, regardless of the emotion expressed on the face, but variation in identity interfered with the classification of facial emotion. Moreover, a correlational study indicated that the identity interference on emotion classification for schizophrenic patients covaried with the severity of their negative symptoms. The selective attention competencies in schizophrenia and the independence hypothesis of emotion and face recognition are discussed in the framework of current face recognition models.

Neuropsychological impairments in the recognition of faces, voices, and personal names

In order to determine the dissociability of face, voice, and personal name recognition, we studied the performance of 36 brain-lesioned patients and 20 control subjects. Participants performed familiarity decisions for portraits, voice samples, and written names of celebrities and unfamiliar people. In those patients who displayed significant impairments in any of these tests, the specificity of these impairments was tested using corresponding object recognition tests (with pictures of objects, environmental sounds, or written common words as stimuli). The results showed that 58% of the patients were significantly impaired in at least one test of person recognition. Moreover, 28% of the patients showed impairments that appeared to be specific for people (i.e., performance was preserved in the corresponding object recognition test). Three patients showed a deficit that appeared to be confined to the recognition of familiar voices, a pattern that was not described previously. Results were generally consistent with the assumption that impairments in face, voice, and name recognition are dissociable from one another. In contrast, there was no clear evidence for a dissociability between deficits in face and voice naming. The results further suggest that (a) impairments in person recognition after brain lesions may be more common than was thought previously and (b) the patterns of impairment that were observed can be interpreted using current cognitive models of person recognition (Bruce & Young, 1986; Burton, Bruce, & Johnston, 1990).

Knowing about people and naming them: can Alzheimer's disease patients do one without the other?

It has recently been suggested that patients with semantic breakdown may show the phenomenon of so-called "naming without semantics". If substantiated, this finding would clearly have a major impact on theories of face and object processing, all of which assume that access to semantic knowledge is a prerequisite for successful naming. In order to investigate this issue, we studied recognition, identification (the ability to provide accurate information), and naming of 50 famous faces by 24 patients with mild to moderate dementia of Alzheimer type (DAT) and 30 age-matched controls. The DAT group was impaired in all three conditions. An analysis of the concordance between identification and naming by each patient, for each stimulus item, established that naming a famous face was possible only with semantic knowledge sufficient to identify the person. Our data support the hypothesis that naming is not possible unless semantic information associated with the target is available. Naming without semantics, therefore, did not occur in patients with DAT. By contrast, there were 206 instances (17% of the total responses) in which the patients were able to provide detailed, accurate identifying information yet were unable to name the person represented. The implication of these findings for models of face identification and naming are discussed.

What's wrong and what's right in neuropsychology and neuropsychiatry

There has been a recent converging of interests by psychiatrists and psychologists in subjective mental phenomena. Examples of topics where these converging interests arise include the relationship of confabulation and delusional memories, the nature of face-processing deficits in prosopagnosia and the Capgras delusion, and hierarchial models of psychological function. These developments are very much welcomed; but the over-interpretation of neuropsychological test findings in neuropsychiatry, and the occasional failure to take account of clinical context (particularly the psychiatric background) in neuropsychology, are also noted. Cognitive neuropsychiatry appears to have emerged as a label to identify this converging of interests, modelling itself on cognitive neuropsychology. The potential benefits and limitations of such an approach are discussed.

Facial expression processing after amygdalotomy

Facial expression processing impairments were studied in D.R., a 51-year-old woman with a partial bilateral amygdalotomy. D.R. was poor at recognising emotional facial expressions, both in static and moving stimuli. In identity matching tasks (same vs different person) and expression matching tasks (same vs different expression), D.R. was impaired at expression matching with simultaneously or successively presented faces; she experienced difficulties whenever the faces' identities were discrepant with their expressions. For identity matching, she also had problems when simultaneously presented images showed the same face with two different expressions; her deficit in interpreting facial expressions could lead her to mistake differences in expression for a difference in identity. In imagery tasks, D.R. was able to answer questions about the appearance of familiar people, yet she was very poor at imaging facial expressions of emotion. We suggest that her problems in processing facial expressions included impaired knowledge of the patterning of facial features in each emotion; without this, remembering or reconstructing what emotional facial expressions look like is as impaired as perceptual recognition. These findings are consistent with the hypothesis of a role for the amygdala in social behaviour.

Facial expressions and speechreading performance

In the present study, the role of facial expressions in visual speechreading (lipreading) was examined. Speechreading was assessed by three different tests: sentence-based speechreading, word-decoding, and word discrimination. Twenty-seven individuals participated as subjects in the study. The results revealed that no general improvement as a function of expression was obtained across all tests. Nevertheless, skilled speechreaders could significantly improve their performance as a function of emotional expression in the word-decoding and word-discrimination conditions. Furthermore, a correlational analysis indicated that there was a significant relationship between the subjects' rating of confidence regarding their responses to each test-item and performance on speechreading tests where lexical analysis is a necessary task-demand. The results are discussed with respect to how information from facial expressions is integrated with the information given by the lip movements in visual speechreading, and also with respect to general models of face-processing (i.e., Bruce & Young, 1986; Young & Bruce, 1991).

The self, attributional processes and abnormal beliefs: towards a model of persecutory delusions

In this paper we review a series of recent investigations into cognitive abnormalities associated with persecutory delusions. Studies indicate that persecutory delusions are associated with abnormal attention to threat-related stimuli, an explanatory bias towards attributing negative outcomes to external causes and biases in information processing relating to the self-concept. We propose an integrative model to account for these findings in which it is hypothesized that, in deluded patients, activation of self/ideal discrepancies by threat-related information triggers defensive explanatory biases, which have the function of reducing the self/ideal discrepancies but result in persecutory ideation. We conclude by discussing the implications of this model for the cognitive-behavioural treatment of paranoid delusions.

Face-processing impairments and the Capgras delusion

Investigations of two cases of the Capgras delusion found that both patients showed face-processing impairments encompassing identification of familiar faces, recognition of emotional facial expressions, and matching of unfamiliar faces. In neither case was there any impairment of recognition memory for words. These findings are consistent with the idea that the basis of the Capgras delusion lies in damage to neuro-anatomical pathways responsible for appropriate emotional reactions to familiar visual stimuli. The delusion would then represent the patient's attempt to make sense of the fact that these visual stimuli no longer have appropriate affective significance.

Memory and imagery in the temporal lobe

Experimental and clinical studies in primates indicate that visual information is stored and retrieved by interactions between the temporal association area and the medial temporal lobe structures. Recent findings from single-neuron recordings have provided new evidence that perceptual aspects of the temporal neocortex are closely related to its memory function based on association. They further suggest that imagery is also implemented by the same neural mechanism that subserves memory retrieval.

Impaired discrimination of familiar from unfamiliar faces

We report investigations of the face processing abilities of J.T., a man who had suffered a right hemisphere stroke. J.T. showed a marked problem in discriminating between familiar and unfamiliar faces, with no corresponding problem in discriminating familiar from unfamiliar names. The problem with faces was still found 2 years after the stroke, but had resolved at long-term follow-up (9 years post stroke). When given unlimited time to respond, J.T. did not show any problem in recognising familiar faces, but tended to think that he recognised unfamiliar faces. When under time pressure, however, J.T. also failed to recognise a number of familiar faces which he could readily identify when the time pressure was removed. J.T.'s ability to remember a face and to think of other people who might be similar in appearance was affected by whether or not the face seemed familiar or unfamiliar to him. Hence, whatever underlay the spurious sense of familiarity was sufficient to produce real differences between the way in which genuinely unfamiliar and spuriously familiar faces were seen, leading us to suggest that his impaired discrimination of unfamiliar from familiar faces reflected a malfunction of face recognition units.

Cotard delusion after brain injury

A right-handed young man with contusions affecting temporo-parietal areas of the right cerebral hemisphere and some bilateral frontal lobe damage became convinced that he was dead (the Cotard delusion), and experienced difficulties in recognizing familiar faces, buildings and places, as well as feelings of derealization. Neuropsychological investigation while these symptoms were resolving revealed impairment on face processing tests. We suggest that these impairments contributed to his Cotard delusion by heightening feelings of unreality, and that the underlying pathophysiology and neuropsychology of the Cotard delusion may be related to other problems involving delusional misidentification.

Face recognition

The study of face-selective neurons in the monkey temporal lobe, and face recognition deficits in humans after brain damage have both become very active fields of investigation. Face-selective neurons appear to be members of ensembles for coding faces rather than individual face detectors or grandmother cells. They reflect the more general role of temporal cortex in pattern recognition. In humans there are a variety of face-processing impairments that result from damage to different areas, and which reflect interference at different levels of processing of the facial image.