Association vs dissociation and setting appropriate criteria for object agnosia

Familiarity enhances functional connectivity between visual and nonvisual regions of the brain during natural viewing

We explored the neural correlates of familiarity with people and places using a naturalistic viewing paradigm. Neural responses were measured using functional magnetic resonance imaging, while participants viewed a movie taken from Game of Thrones. We compared inter-subject correlations and functional connectivity in participants who were either familiar or unfamiliar with the TV series. Higher inter-subject correlations were found between familiar participants in regions, beyond the visual brain, that are typically associated with the processing of semantic, episodic, and affective information. However, familiarity also increased functional connectivity between face and scene regions in the visual brain and the nonvisual regions of the familiarity network. To determine whether these regions play an important role in face recognition, we measured responses in participants with developmental prosopagnosia (DP). Consistent with a deficit in face recognition, the effect of familiarity was significantly attenuated across the familiarity network in DP. The effect of familiarity on functional connectivity between face regions and the familiarity network was also attenuated in DP. These results show that the neural response to familiarity involves an extended network of brain regions and that functional connectivity between visual and nonvisual regions of the brain plays an important role in the recognition of people and places during natural viewing.

Disentangling developmental prosopagnosia: A scoping review of terms, tools and topics

The goal of this preregistered scoping review is to create an overview of the research on developmental prosopagnosia (DP). Through analysis of all empirical studies of DP in adults, we investigate 1) how DP is conceptualized and defined, 2) how individuals are classified with DP and 3) which aspects of DP are investigated in the literature. We reviewed 224 peer-reviewed studies of DP. Our analysis of the literature reveals that while DP is predominantly defined as a lifelong face recognition impairment in the absence of acquired brain injury and intellectual/cognitive problems, there is far from consensus on the specifics of the definition with some studies emphasizing e.g., deficits in face perception, discrimination and/or matching as core characteristics of DP. These differences in DP definitions is further reflected in the vast heterogeneity in classification procedures. Only about half of the included studies explicitly state how they classify individuals with DP, and these studies adopt 40 different assessment tools. The two most frequently studied aspects of DP are the role of holistic processing and the specificity of face processing, and alongside a substantial body of neuroimaging studies of DP, this paints a picture of a research field whose scientific interests and aims are rooted in cognitive neuropsychology and neuroscience. We argue that these roots - alongside the heterogeneity in DP definition and classification - may have limited the scope and interest of DP research unnecessarily, and we point to new avenues of research for the field.

What is developmental about developmental prosopagnosia?

Developmental prosopagnosia (DP) is characterised by difficulties recognising face identities and is associated with diverse co-occurring object recognition difficulties. The high co-occurrence rate and heterogeneity of associated difficulties in DP is an intrinsic feature of developmental conditions, where co-occurrence of difficulties is the rule, rather than the exception. However, despite its name, cognitive and neural theories of DP rarely consider the developmental context in which these difficulties occur. This leaves a large gap in our understanding of how DP emerges in light of the developmental trajectory of face recognition. Here, we argue that progress in the field requires re-considering the developmental origins of differences in face recognition abilities, rather than studying the end-state alone. In practice, considering development in DP necessitates a re-evaluation of current approaches in recruitment, design, and analyses.

Contrasting domain-general and domain-specific accounts in cognitive neuropsychology: An outline of a new approach with developmental prosopagnosia as a case

The backbone of cognitive neuropsychology is the observation of (double) dissociations in performance between patients, suggesting some degree of independence between cognitive processes (domain specificity). In comparison, observations of associations between disorders/deficits have been deemed less evidential in neuropsychological theorizing about cognitive architecture. The reason is that associations can reflect damage to independent cognitive processes that happen to be mediated by structures commonly affected by the same brain disorder rather than damage to a shared (domain-general) mechanism. Here we demonstrate that it is in principle possible to discriminate between these alternatives by means of a procedure involving large unbiased samples. We exemplify the procedure in the context of developmental prosopagnosia (DP), but the procedure is in principle applicable to all neuropsychological deficits/disorders. A simulation of the procedure on a dataset yields estimates of dissociations/associations that are well in line with existing DP-studies, and also suggests that seemingly selective disorders can reflect damage to both domain-general and domain-specific cognitive processes. However, the simulation also highlights some limitations that should be considered if the procedure is to be applied prospectively. The main advantage of the procedure is that allows for examination of both associations and dissociations in the same sample. Hence, it may help even the balance in the use of associations and dissociations as grounds for neuropsychological theorizing.

Not so fast! Response times in the computerized Benton Face Recognition Test may not reflect face recognition ability

Response times (RTs) are commonly used to assess cognitive abilities, though it is unclear whether face processing RTs predict recognition ability beyond accuracy. In the current study, we examined accuracy and RT on a widely used face matching assessment modified to collect meaningful RT data, the computerized Benton Facial Recognition Test (BFRT-c), and measured whether RTs predicted face recognition ability and developmental prosopagnosia (DP) vs. control group membership. 62 controls and 36 DPs performed the BFRT-c as well as validated measures of face recognition ability: the Cambridge Face Memory Test (CFMT) and a Famous Faces Memory Test (FFMT). In controls, BFRT-c accuracy robustly predicted CFMT (r = .49, p < .001), FFMT (r = .43, p < .001), and a CFMT-FFMT composite (r = .54, p < .001), whereas BFRT-c RT was not significantly associated with these measures (all r's  .21). We also found that BFRT-c accuracy significantly differed between DPs and controls, but RT failed to differentiate the groups.

When two fields collide: Identifying "super-recognisers" for neuropsychological and forensic face recognition research

In the last decade, a novel individual differences approach has emerged across the face recognition literature. While the field has long been concerned with prosopagnosia (the inability to recognise facial identity), it has more recently become clear that there are vast differences in face recognition ability within the typical population. "Super-recognisers" are those individuals purported to reside at the very top of this spectrum. On one hand, these people are of interest to cognitive neuropsychologists who are motivated to explore the commonality of the face recognition continuum, whereas on the other hand, researchers from the forensic face matching field evaluate the implementation of super-recognisers into real-world police and security settings. These two rather different approaches have led to discrepancies in the definition of super-recognisers, and perhaps more fundamentally, the approach to identifying them, resulting in a lack of consistency that prohibits theoretical progress. Here, we review the protocols used in published work to identify super-recognisers, and propose a common definition and screening recommendations that can be adhered to across fields.

The domain-specificity of face matching impairments in 40 cases of developmental prosopagnosia

A prevailing debate in the psychological literature concerns the domain-specificity of the face recognition system, where evidence from typical and neurological participants has been interpreted as evidence that faces are "special". Although several studies have investigated the same question in cases of developmental prosopagnosia, the vast majority of this evidence has recently been discounted due to methodological concerns. This leaves an uncomfortable void in the literature, restricting our understanding of the typical and atypical development of the face recognition system. The current study addressed this issue in 40 individuals with developmental prosopagnosia, completing a sequential same/different face and biological (hands) and non-biological (houses) object matching task, with upright and inverted conditions. Findings support domain-specific accounts of face-processing for both hands and houses: while significant correlations emerged between all the object categories, no condition correlated with performance in the upright faces condition. Further, a categorical analysis demonstrated that, when face matching was impaired, object matching skills were classically dissociated in six out of 15 individuals (four for both categories). These findings provide evidence about domain-specificity in developmental disorders of face recognition, and present a theoretically-driven means of partitioning developmental prosopagnosia.

Progress in perceptual research: the case of prosopagnosia

Prosopagnosia is an impairment in the ability to recognize faces and can be acquired after a brain lesion or occur as a developmental variant. Studies of prosopagnosia make important contributions to our understanding of face processing and object recognition in the human visual system. We review four areas of advances in the study of this condition in recent years. First are issues surrounding the diagnosis of prosopagnosia, including the development and evaluation of newer tests and proposals for diagnostic criteria, especially for the developmental variant. Second are studies of the structural basis of prosopagnosia, including the application of more advanced neuroimaging techniques in studies of the developmental variant. Third are issues concerning the face specificity of the defect in prosopagnosia, namely whether other object processing is affected to some degree and in particular the status of visual word processing in light of recent predictions from the "many-to-many hypothesis". Finally, there have been recent rehabilitative trials of perceptual learning applied to larger groups of prosopagnosic subjects that show that face impairments are not immutable in this condition.

Object recognition in acquired and developmental prosopagnosia

Whether face and object recognition are dissociated in prosopagnosia continues to be debated: a recent review highlighted deficiencies in prior studies regarding the evidence for such a dissociation. Our goal was to study cohorts with acquired and developmental prosopagnosia with a complementary battery of tests of object recognition that address prior limitations, as well as evaluating for residual effects of object expertise. We studied 15 subjects with acquired and 12 subjects with developmental prosopagnosia on three tests: the Old/New Tests, the Cambridge Bicycle Memory Test, and the Expertise-adjusted Test of Car Recognition. Most subjects with developmental prosopagnosia were normal on the Old/New Tests: for acquired prosopagnosia, subjects with occipitotemporal lesions often showed impairments while those with anterior temporal lesions did not. Ten subjects showed a putative classical dissociation between the Cambridge Face and Bicycle Memory Tests, seven of whom had normal reaction times. Both developmental and acquired groups showed reduced car recognition on the expertise-adjusted test, though residual effects of expertise were still evident. Two subjects with developmental prosopagnosia met criteria for normal object recognition across all tests. We conclude that strong evidence for intact object recognition can be found in a few subjects but the majority show deficits, particularly those with the acquired form. Both acquired and developmental forms show residual but reduced object expertise effects.

Over time, the right results will emerge

Scientific research involves going beyond the well-trodden and well-tested ideas and theories that form the core of scientific knowledge. During the time scientists are working things out, some results will be right, and others will be wrong. Over time, the right results will emerge. Lisa Randall (Frank B. Baird, Jr. Professor of Science, Physics Department, Harvard University) We are grateful to all the commentators for the important and thoughtful comments raised in response to the Geskin and Behrmann (G & B) literature survey. The issues raised in the introduction to this Special Issue and in these commentaries not only address and challenge aspects of the G & B literature review, but contribute perspectives and extensions that go well beyond the scope of the review. As is evident from G & B and from the 13 commentaries, many aspects of congenital prosopagnosia (CP) remain controversial. Adopting the language of the quote above, the intention of the G & B survey, along with the commentaries and this response, is to establish a collaborative process from which the right results (and right theory) will emerge in time. We are grateful to the editor of this Special Issue, Dr. Brad Mahon, for his support and for facilitating this collaborative exchange in Cognitive Neuropsychology.