A new selective developmental deficit: Impaired object recognition with normal face recognition

Introduction

Studies of developmental deficits in face recognition, or developmental prosopagnosia, have shown that individuals who have not suffered brain damage can show face recognition impairments coupled with normal object recognition ( [Duchaine and Nakayama, 2005] , [Duchaine et?al., 2006] and [Nunn et?al., 2001] ). However, no developmental cases with the opposite dissociation – normal face recognition with impaired object recognition – have been reported. The existence of a case of non-face developmental visual agnosia would indicate that the development of normal face recognition mechanisms does not rely on the development of normal object recognition mechanisms.

Methods

To see whether a developmental variant of non-face visual object agnosia exists, we conducted a series of web-based object and face recognition tests to screen for individuals showing object recognition memory impairments but not face recognition impairments. Through this screening process, we identified AW, an otherwise normal 19-year-old female, who was then tested in the lab on face and object recognition tests.

Results

AW’s performance was impaired in within-class visual recognition memory across six different visual categories (guns, horses, scenes, tools, doors, and cars). In contrast, she scored normally on seven tests of face recognition, tests of memory for two other object categories (houses and glasses), and tests of recall memory for visual shapes. Testing confirmed that her impairment was not related to a general deficit in lower-level perception, object perception, basic-level recognition, or memory.

Discussion

AW’s results provide the first neuropsychological evidence that recognition memory for non-face visual object categories can be selectively impaired in individuals without brain damage or other memory impairment. These results indicate that the development of recognition memory for faces does not depend on intact object recognition memory and provide further evidence for category-specific dissociations in visual recognition.     

Normal and abnormal face selectivity of the M170 response in developmental prosopagnosics

Developmental prosopagnosia is a lifelong impairment in face recognition despite normal low-level visual processing. Here we used magnetoencephalography (MEG) to examine the M170 response, a component occurring approximately 170 ms after stimulus onset, in a group of five developmental prosopagnosics. In normal subjects, the M170 is “face-selective”, with a consistently higher amplitude to faces than to a wide variety of other visual stimulus categories; the N170, a component recorded using event-related potentials (ERP) and thought to be analogous to the M170, also shows this “face selectivity”. Two previous ERP studies with developmental prosopagnosics have found attenuation or absence of face selectivity in the N170 response of these subjects [Bentin, S., Deouell, L. Y., & Soroker, N. (1999). Selective visual streaming in face recognition: Evidence from developmental prosopagnosia. Neuroreport, 10, 823–827; Kress, T., & Daum, I. (2003). Event-related potentials reflect impaired face recognition in patients with congenital prosopagnosia. Neuroscience Letters, 352, 133–136]. Three of our developmental prosopagnosic group showed this non-selective pattern at the M170 while the remaining two prosopagnosics were indistinguishable from normal controls. Thus, impaired face recognition is not necessarily correlated with an absence of the “face-selective” M170. Furthermore, ERP recordings collected simultaneously in the two developmental prosopagnosics with seemingly selective M170s also showed N170s within the same normal selective range, demonstrating that the face-selective signals found with MEG are not due to differences between MEG and ERP. While the presence of face selectivity at these neurophysiological markers is insufficient for predicting normal behavioral performance with faces, it could help to distinguish different classes of face recognition deficits.     

The fusiform face area is not sufficient for face recognition: evidence from a patient with dense prosopagnosia and no occipital face area

We tested functional activation for faces in patient D.F., who following acquired brain damage has a profound deficit in object recognition based on form (visual form agnosia) and also prosopagnosia that is undocumented to date. Functional imaging demonstrated that like our control observers, D.F. shows significantly more activation when passively viewing face compared to scene images in an area that is consistent with the fusiform face area (FFA) (p < 0.01). Control observers also show occipital face area (OFA) activation; however, whereas D.F.'s lesions appear to overlap the OFA bilaterally. We asked, given that D.F. shows FFA activation for faces, to what extent is she able to recognize faces? D.F. demonstrated a severe impairment in higher level face processing--she could not recognize face identity, gender or emotional expression. In contrast, she performed relatively normally on many face categorization tasks. D.F. can differentiate faces from non-faces given sufficient texture information and processing time, and she can do this is independent of color and illumination information. D.F. can use configural information for categorizing faces when they are presented in an upright but not a sideways orientation and given that she also cannot discriminate half-faces she may rely on a spatially symmetric feature arrangement. Faces appear to be a unique category, which she can classify even when she has no advance knowledge that she will be shown face images. Together, these imaging and behavioral data support the importance of the integrity of a complex network of regions for face identification, including more than just the FFA--in particular the OFA, a region believed to be associated with low-level processing.     

Normative data for two neuropsychological tests sensitive to frontal dysfunction

Interest in frontal functions has progressively increased over recent years; however, despite this, there are only a few frontal tasks for which Italian normative data are available. The objective of this study was to obtain reference values for two frontal tests from a random sample of normal adults: the first (the Test of Classification and Recall of Pictures) has been shown to reveal selective impairment in patients with unilateral frontal excision; the second (the Odd-Man-Out Test) derives from tasks which have been used to evaluate frontal functions in animals and detect frontal impairment in Parkinson patients. We tested 100 normal subjects, aged 22 to 79 years, stratified by education according to the Italian school system. The correction grids for both tests are also presented. The usefulness of these tests is represented not only by their sensitivity to frontal impairment, but also by the possibility of dissociating the various cognitive aspects of frontal lobe dysfunction.

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Sommario L'interesse nei confronti delle funzioni frontali è progressivamente aumentato negli ultimi anni. Nonostante ciò, solo per pochi test frontali sono disponibili dati normativi italiani. Lo scopo di questo studio era ottenere valori normativi per due test frontali utilizzando un campione di soggetti normali selezionati in maniera casuale. Il primo test, ossia il Test di Classificazione e Rievocazione di Figure, risulta selettivamente compromesso in pazienti sottoposti a escissione frontale unilaterale; il secondo test, ossia il Test della Percora Nera, deriva da compiti utilizzati per rilevare la compromissione frontale negli animali ed è stato usato per individuare una disfunzione di tipo frontale nei parkinsoniani. Sono stati testati 100 soggetti normali, di età compresa fra i 22 e i 79 anni, stratificati per scolarità secondo il modello scolastico italiano. Vengono presentate le griglie di correzione per entrambi i test. La loro utilità consiste non solo nella loro sensibilità al danno frontale, ma anche nella possibilità di dissociare aspetti cognitivi differenti della disfunzione dei lobi frontali.

     

神经心理测验对痴呆诊断的贡献与误区

目的：评价神经心理测验（NPT）对痴呆诊断的作用及局限性。方法：痴呆组270例，非痴呆组617名，进行简易精神状态检查、Fuld物体记忆测验、言语流畅性测验、数字广度测验和积木测验。结果：痴呆和非痴呆组NPT得分差异有显著意义。4个测验特异性高在72％－99％之间，敏感性在22％－90％之间，随文化水平的增高而降低。在筛查的基础上加用NPT，诊断准确性由68％提高到80％－89％。文化、年龄、性别对NPT有显著影响。结论：NPT可提高痴呆诊断的准确性。本组NPT适合于我国低文化老人的痴呆调查，对高文化轻度痴呆应采用更敏感的测验。     

The Cambridge Face Memory Test: results for neurologically intact individuals and an investigation of its validity using inverted face stimuli and prosopagnosic participants

The two standardized tests of face recognition that are widely used suffer from serious shortcomings [Duchaine, B. & Weidenfeld, A. (2003). An evaluation of two commonly used tests of unfamiliar face recognition. Neuropsychologia, 41, 713-720; Duchaine, B. & Nakayama, K. (2004). Developmental prosopagnosia and the Benton Facial Recognition Test. Neurology, 62, 1219-1220]. Images in the Warrington Recognition Memory for Faces test include substantial non-facial information, and the simultaneous presentation of faces in the Benton Facial Recognition Test allows feature matching. Here, we present results from a new test, the Cambridge Face Memory Test, which builds on the strengths of the previous tests. In the test, participants are introduced to six target faces, and then they are tested with forced choice items consisting of three faces, one of which is a target. For each target face, three test items contain views identical to those studied in the introduction, five present novel views, and four present novel views with noise. There are a total of 72 items, and 50 controls averaged 58. To determine whether the test requires the special mechanisms used to recognize upright faces, we conducted two experiments. We predicted that controls would perform much more poorly when the face images are inverted, and as predicted, inverted performance was much worse with a mean of 42. Next we assessed whether eight prosopagnosics would perform poorly on the upright version. The prosopagnosic mean was 37, and six prosopagnosics scored outside the normal range. In contrast, the Warrington test and the Benton test failed to classify a majority of the prosopagnosics as impaired. These results indicate that the new test effectively assesses face recognition across a wide range of abilities.     

A tale of two recognition systems: implications of the fusiform face area and the visual word form area for lateralized object recognition models

Two areas of current intense interest in the neuroimaging literature are that of the visual word form area (VWFA) and of the fusiform face area (FFA) and their roles in word and face perception, respectively. These two areas are of particular relevance to laterality research because visual word identification and face identification have long been shown to be especially lateralized to the left hemisphere and the right hemisphere, respectively. This review therefore seeks to evaluate their significance for the broader understanding of lateralization of object recognition. A multi-level model of lateralized object recognition is proposed based on a combination of behavioral and neuroimaging findings. Rather than seek to characterize hemispheric asymmetries according to a single principle (e.g., serial-parallel), it is suggested that current observations can be understood in terms of three asymmetric levels of processing, using the framework of the Janus model of hemispheric function. It is suggested that the left hemisphere represents features using an abstract-category code whereas the RH utilizes a specific-exemplar code. The relationships between these features are also coded asymmetrically, with the LH relying on associative co-occurrence values and the RH relying on spatial metrics. Finally, the LH controlled selection system focuses on isolating features and the RH focuses on conjoining features. It is suggested that each hemisphere utilizes efficient (apparently parallel) processing when stimuli are congruent with its preferred processing style and inefficient (apparently serial) processing when they are not, resulting in the typical left-lateralization for orthographic analysis and right-lateralization for face analysis.     

不同记忆测验识别轻度认知损害的差异

目的分析不同的记忆测验对于轻度认知损害（MCI）的识别力的差异。方法2004年5月至2006年5月就诊于本院神经内科记忆障碍门诊的被试共712例，除了客观记忆指标，其余要求均符合MCI入组标准的有329例。全部入组者完成听觉词语学习测验（AVLT）、逻辑记忆测验（LM）、Rey-Osterrieth复杂图形测验（CFT）及MMSE、画钟测验、五点测验、言语流畅性测验、Stroop色词测验、连线测验、临床痴呆评定量表。结果对于MCI的识别率AVLT-Ⅱ（51％）〉AVLT-Ⅰ（31％）〉CFT回忆（27％）〉LM-Ⅰ（21％）=LM-Ⅱ（21％）。AVLT-Ⅱ与LM-Ⅱ均〉划界分者，为主观认知缺损（SCI）组，占47％（155／329）；AVLT-Ⅱ与LM-Ⅱ均≤划界分者，为确定MCI组，占19％（63／329）；AVLT-Ⅱ与LM-Ⅱ不一致，其中AVLT-Ⅱ≤划界分而LM-Ⅱ〉划界分者，为分歧组，占32％（104／329）。通过对各领域神经心理测验结果和临床表现进行比较，分歧组明显不同于SCI组，而是接近于确定MCI组，也就是说，分歧组是认知功能损害相对较轻的MCI。结论不同的情景记忆测验对于MCI的识别能力存在巨大的差异。AVLT延迟回忆最敏感，可以作为MCI“记忆减退的客观证据”。     

Abnormal face identity coding in the middle fusiform gyrus of two brain-damaged prosopagnosic patients

We report a functional magnetic resonance imaging (fMRI) adaptation study of two well-described patients, DF and PS, who present face identity recognition impairments (prosopagnosia) following brain-damage. Comparing faces to non-face objects elicited activation in all visual areas of the cortical face processing network that were spared subsequent to brain damage. The common brain lesion in the two patients was in the right inferior occipital cortex, in the territory of the right “occipital face area” (‘OFA’), which strengthens the critical role of this region in processing faces. Despite the lesion to the right ‘OFA’, there was normal range of sensitivity to faces in the right “fusiform face area” (‘FFA’) in both patients, supporting a non-hierarchical model of face processing at the cortical level. At the same time, however, sensitivity to individual face representations, as indicated by release from adaptation to identity, was abnormal in the right ‘FFA’ of both patients. This suggests that the right ‘OFA’ is necessary to individualize faces, perhaps through reentrant interactions with other cortical face sensitive areas. The lateral occipital area (LO) is damaged bilaterally in patient DF, who also shows visual object agnosia. However, in patient PS, in whom LO was spared, sensitivity to individual representations of non-face objects was still found in this region, as in the normal brain, consistent with her preserved object recognition abilities. Taken together, these observations, which fruitfully combine functional imaging and neuropsychology, place strong constraints on the possible functional organization of the cortical areas mediating face processing in the human brain.     

An event-related brain potential study of explicit face recognition

To determine the time course of face recognition and its links to face-sensitive event-related potential (ERP) components, ERPs elicited by faces of famous individuals and ERPs to non-famous control faces were compared in a task that required explicit judgements of facial identity. As expected, the face-selective N170 component was unaffected by the difference between famous and non-famous faces. In contrast, the occipito-temporal N250 component was linked to face recognition, as it was selectively triggered by famous faces. Importantly, this component was present for famous faces that were judged to be definitely known relative to famous faces that just appeared familiar, demonstrating that it is associated with the explicit identification of a particular face. The N250 is likely to reflect early perceptual stages of face recognition where long-term memory traces of familiar faces in ventral visual cortex are activated by matching on-line face representations. Famous faces also triggered a broadly distributed longer-latency positivity (P600f) that showed a left-hemisphere bias and was larger for definitely known faces, suggesting links between this component and name generation. These results show that successful face recognition is predicted by ERP components over face-specific visual areas that emerge within 230 ms after stimulus onset.     

健康成人事件相关电位与神经心理学测验的相关性研究

目的 探讨事件相关电位P300的四个主要成分是否反映特定的认知功能。方法 将120名正常受试者按年龄分为三组，即20～34岁组、35～54岁组和55～70岁组，对所有受试者采用全套韦氏成人智力测验(WAIS-RC)等多项神经心理学测验以及P300进行测评，将神经心理学测验结果与P瑚结果进行Spearman等级相关分析。结果 三个年龄组中的N2潜伏期、P2波幅、N2波幅均与反映注意、短时记忆的神经心理学测验存在以下相关：在20～34岁组中，N2潜伏期与即刻视觉再生呈负相关(r=-0．352)，P2波幅与即刻视觉再生呈正相关(r=0．339)，N2波幅与即刻视觉再生呈正相关(r=0．331)。在35～54岁组中，N2潜伏期与数字广度、数字符号、词汇流畅均呈负相关(r分别=-0．357、-0．385、-0．316)；P2波幅与延线测验B呈负相关(r=-0．427)；Nl波幅与即刻逻辑记忆呈正相关(r=0．343)。在55～70岁组中，N2潜伏期与数字符号、词汇流畅呈负相关(r分别=-0．488和-0．321)，与延线测验B呈正相关(r=0．366)；P2波幅与数字符号呈正相关(r=0．314)；N2波幅与词汇流畅呈正相关(r=0．437)。在不同的年龄组中，P300的其他指标与神经心理学测验相关性不一致。结论 P300的四个主要成分可反映一定的认知功能，但不具有特异性，部分P300指标所反映的认知功能受年龄的影响。     

两种遗忘型轻度认知损害患者的随访比较

目的 比较单纯遗忘型轻度认知功能损害(aMCI-s)和多个认知领域损害遗忘型轻度认知功能损害(aMCI-m)患者的2年随访转归结果并分析其神经心理学变化.方法 采用MMSE、听觉词语学习测验(AVLT)、逻辑回忆测验(LMT)、连线测验(TMT)、Stroop色词测验(CWT)、Rey复杂图形测验(CFT)、五点连线测验(FPT)、画钟测验(CDT)、言语流畅性测验(VF)和临床痴呆量表(CDR)等一系列神经心理测验评估记忆障碍门诊130例遗忘型轻度认知功能损害(aMCI)就诊者(其中aMCI-s 66例和aMCI-m 64例),并进行平均2年的随访,MCI及AD的诊断标准分别参照美国Petersen等及美国神经病学、语言障碍和卒中-老年性痴呆和相关疾病学会(NINCDS-ADRDA)有关诊断标准.结果 aMCI的阿尔茨海默病(AD)总转化率为33.8%(44/130);aMCI-s和aMCI-m的AD转化率分别为26.2%(17/65)和42.9%(27/63),差异有统计学意义(x2=3.957,P=0.047).随着aMCI发展为AD,aMCI-s和aMCI-m组在记忆和执行功能方面的减退幅度接近,aMCI-s组的视空间结构能力相对保留,语言和注意力的减退更快,aMCI-m组的视空间结构能力衰退更为显著.结论 aMCI-m比aMCI-s更容易发展为AD,aMCI分为aMCI-s和aMCI-m对判断认知功能减退的速度是有必要的,有助于判断预后.     

A comparative case study of face recognition: The contribution of configural and part-based recognition systems, and their interaction

Understanding the interaction between the configural and part-based systems in face recognition is the major aim of this study. Specifically, we established whether configural representation of faces contribute to aspects of face recognition that depend on part-based processes, such as identifying inverted or fractured faces. Using face recognition tasks that require part-based or configural processing, we compared the results of CK—a man who has object agnosia and alexia [Moscovitch, M., Winocur, G., & Behrmann, M. (1997). What is special about face recognition? Nineteen experiments on a person with visual object agnosia and dyslexia but normal face recognition. Journal of Cognitive Neuroscience, 9(5), 555–604] but normal upright face recognition, to those of DC—a man who has prosopagnosia but normal object recognition. CK was normal at recognizing faces if configural processing was sufficient, but poor at recognizing faces that were modified so as to alter their gestalt, and require part-based processing (Moscovitch et al.). DC was impaired at recognizing upright faces and his performance declined in all tasks involving recognition of modified faces, including those that depend on part-based and on configural processing. Nevertheless, DC was normal on tasks involving perception of generic faces and face imagery. These results show that although configural face perception can proceed without part-based processing, the reverse is not the case. Our results suggest that the configural system is always necessary for face recognition, and appears to support what remains of face identification even in prosopagnosic people who have an intact part-based system.     

Human brain potential correlates of repetition priming in face and name recognition

We investigated repetition priming in the recognition of famous people by recording event-related brain potentials (ERPs) and reaction times (RTs). Participants performed speeded two-choice responses depending on whether or not a stimulus showed a famous person. In Experiment 1, a facilitation was found in RTs to famous (but not to unfamiliar) faces when primed by the same face shown in an earlier priming phase of the experiment. In ERPs, an influence of repetition priming was observed neither for the N170 nor for a temporal N250 component which in previous studies had been shown to be sensitive to immediate face repetitions. ERPs to primed unfamiliar faces were more negative over right occipitotemporal areas than those to unprimed faces, but this effect was specific for repetitions of the same image, consistent with recent findings. In contrast, ERPs to primed familiar faces were more positive than those to unprimed faces at parietal sites from 500-600 ms after face onset, and these priming effects were comparable regardless of whether the same or a different image of the celebrity had served as prime. In Experiment 2, similar results were found for name recognition-a facilitation in RTs to primed familiar but not unfamiliar names, and a parietal positivity to primed names around 500-600 ms. ERP repetition effects showed comparable topographies for faces and names, consistent with the idea of a common underlying source. With reference to current models of face recognition, we suggest that these ERP repetition effects for familiar stimuli reflect a change in post-perceptual representations for people, rather than a neural correlate of recognition at a perceptual level.     

The role of lateral occipital face and object areas in the face inversion effect

Stimulus inversion impairs face discrimination to a greater extent than discrimination of other non-face object categories. This finding has led to suggestions that upright faces are represented by mechanisms specialized for upright faces whereas inverted face representation depends on more general object recognition mechanisms. In the present study we tested the causal role of face-selective and object-selective cortical areas for upright and inverted face discrimination by transiently disrupting neural processing using transcranial magnetic stimulation (TMS). Participants matched upright and inverted faces while TMS was delivered over each participant's functionally localized right occipital face area (rOFA) or right lateral occipital area (rLO). TMS delivered over rOFA disrupted the discrimination of upright and inverted faces while TMS delivered over rLO impaired inverted face discrimination only. These results provide causal evidence that upright faces are represented by face-specific mechanisms whereas inverted faces are represented by both face-specific and object-specific mechanisms. The similar sensitivity of the OFA to upright and inverted faces is consistent with the hypothesis that the OFA processes facial features at an early stage of face processing.     

Hippocampal underactivation in an fMRI study of word and face memory recognition in schizophrenia

Schizophrenia is a major mental disorder which is characterized by several cognitive deficits. Investigations of the neural basis of memory dysfunctions using neuroimaging techniques suggest that the hippocampus plays an important role in declarative memory impairment. The goal of this study was to investigate possible dysfunctions in cerebral activation in schizophrenic patients during both word and face recognition memory tasks. We tested 22 schizophrenics and 24 controls matched by gender, age, handedness and parental socioeconomic status. Compared to healthy volunteers, patients with schizophrenia showed decreased bilateral hippocampal activation during word and face recognition tasks. The whole brain analysis also showed a pattern of cortical and subcortical hypoactivation for both verbal and non-verbal recognition. This study provides further evidence of hippocampal involvement in declarative memory impairments of schizophrenia.     

Automated scoring of novel object recognition in rats

The object recognition task (ORT) has become increasingly popular as a memory test in neuroscience research. Scoring of ORT performance is still mostly done by hand, which can be liable to subjective scoring. To our knowledge, no suited software is available yet since the direction of the nose of the animal cannot be tracked reliably. We have developed a software paradigm that reliably tracks the nose of the rats and have conducted a series of experiments to evaluate the reliability of this newly developed program. We used Wistar rats, which showed good object memory after 1 h interval. Subsequently, we used scopolamine (SCOP) to impair the memory performance of the rats. The object exploration was scored by two observers and the automated system. Both observers and the automated system found an impairing drug effect of scopolamine on ORT performance. When using large objects the correlation between the discrimination index d2 of observers was: 0.60 (SCOP) and 0.79 (SAL). However, the correlation between observers and the automated system was quite low: 0.41 (SCOP) and 0.40 (SAL). Reducing the size of the objects increased the reliability between observers and the automated system substantially (0.82–0.87). We conclude that the use of small objects in combination with our program enables reliable automated scoring in the ORT, thus increasing the objectivity and validity of this task.     

脑血管性痴呆与帕金森病神经心理学测验和脑单光子发射计算机断层扫描的对照研究

目的　研究脑血管性痴呆（ Ｖ Ｄ） 与帕金森病（ Ｐ Ｄ） 在神经心理学测验及脑单光子发射计算机断层扫描（ Ｓ Ｐ Ｅ Ｃ Ｔ） 的诊断和鉴别诊断的意义。方法　对３０ 例 Ｖ Ｄ、３１ 例 Ｐ Ｄ 和３０ 名正常老年人（ Ｎ Ａ） 进行神经心理学测验和 Ｓ Ｐ Ｅ Ｃ Ｔ 检查并比较检测结果。结果　神经心理学各项总分 Ｖ Ｄ 组最低［ 除积木测验（ Ｂ Ｄ） 外］ , Ｐ Ｄ 组次之, Ｎ Ａ 组最高;３ 组间差异均有非常显著性（ Ｆ＝ １８６７ ～６３９５ , Ｐ＜００１） 。在 Ｓ Ｐ Ｅ Ｃ Ｔ的检查中, Ｖ Ｄ 除额叶、左丘脑和右枕叶外余各脑区血流灌注均低于 Ｎ Ａ 组（ Ｐ＜００５） , Ｐ Ｄ 则为顶叶、颞叶、基底节和丘脑血流灌注低于 Ｎ Ａ 组（ Ｐ＜ ００５） 。结论　 Ｖ Ｄ 和 Ｐ Ｄ 的神经心理学测验和脑 Ｓ Ｐ Ｅ Ｃ Ｔ各有其特点,这两项检查可作为诊断和鉴别诊断 Ｖ Ｄ 和 Ｐ Ｄ 的辅助手段。