Context reinstatement in recognition: memory and beyond

Context effects in recognition tests are twofold. First, presenting familiar contexts at a test leads to an attribution of context familiarity to a recognition probe, which has been dubbed ‘context-dependent recognition’. Second, reinstating the exact study context for a particular target in a recognition test cues recollection of an item-context association, resulting in 'context-dependent discrimination'. Here we investigated how these two context effects are expressed in metacognitive monitoring (confidence judgments) and metacognitive control ('don’t know' responding) of retrieval. We used faces as studied items, landscape photographs as study and test contexts and both free- and forced-report 2AFC recognition tests. In terms of context-dependent recognition, the results document that presenting familiar contexts at test leads to higher confidence and lower rates of 'don’t know responses compared to novel contexts, while having no effect on forced-report recognition accuracy. In terms of context-dependent discrimination, the results show that reinstated contexts further boost confidence and reduce 'don’t know' responding compared to familiar contexts, while affecting forced-report recognition accuracy only when contribution of recollection to recognition performance is high. Together, our results demonstrate that metacognitive measures are sensitive to context effects, sometimes even more so than recognition measures

A Foot in Both Worlds: Asian Americans' Perceptions of Asian, White, and Racially Ambiguous Faces

Past research on racial perception has often focused on responses from White participants, making it difficult to determine the role of perceiver race in the perception of others. Similarly, studies examining perceptions of individuals whose racial category membership is unclear have not systematically examined responses from non-Whites. This was addressed by showing Asian participants pictures of Whites, Asians, and racially ambiguous White-Asian faces. Event-related potentials were recorded to measure early attention responses. Participants initially oriented more to outgroup White than ingroup Asian or racially ambiguous faces. Shortly after that, they showed sensitivity to the racial context in which the faces were presented, more deeply processing ingroup Asian and racially ambiguous faces when they were seeing lots of other Asians, but more deeply processing outgroup White and racially ambiguous faces when they were seeing lots of other Whites. Still later, responses were more sensitive to the objective physical properties of the faces, with racially ambiguous faces differentiated from both Whites and Asians. These results demonstrate the fluidity of racial processing, and when compared to responses obtained from White participants, show how perceiver race and racial context influences attention to racial cues

Reference face graph for face recognition

Face recognition has been studied extensively; however, real-world face recognition still remains a challenging task. The demand for unconstrained practical face recognition is rising with the explosion of online multimedia such as social networks, and video surveillance footage where face analysis is of significant importance. In this paper, we approach face recognition in the context of graph theory. We recognize an unknown face using an external reference face graph (RFG). An RFG is generated and recognition of a given face is achieved by comparing it to the faces in the constructed RFG. Centrality measures are utilized to identify distinctive faces in the reference face graph. The proposed RFG-based face recognition algorithm is robust to the changes in pose and it is also alignment free. The RFG recognition is used in conjunction with DCT locality sensitive hashing for efficient retrieval to ensure scalability. Experiments are conducted on several publicly available databases and the results show that the proposed approach outperforms the state-of-the-art methods without any preprocessing necessities such as face alignment. Due to the richness in the reference set construction, the proposed method can also handle illumination and expression variation

Species sensitivity of early face and eye processing

The final publication is available at Elsevier via http://dx.doi.org/10.1016/j.neuroimage.2010.07.031. © 2011. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/Humans are better at recognizing human faces than faces of other species. However, it is unclear whether this species sensitivity can be seen at early perceptual stages of face processing and whether it involves species sensitivity for important facial features like the eyes. These questions were addressed by comparing the modulations of the N170 ERP component to faces, eyes and eyeless faces of humans, apes, cats and dogs, presented upright and inverted. Although all faces and isolated eyes yielded larger responses than the control object category (houses), the N170 was shorter and smaller to human than animal faces and larger to human than animal eyes. Most importantly, while the classic inversion effect was found for human faces, animal faces yielded no inversion effect or an opposite inversion effect, as seen for objects, suggesting a different neural process involved for humans faces compared to faces of other species. Thus, in addition to its general face and eye categorical sensitivity, the N170 appears particularly sensitive to the human species for both faces and eyes. The results are discussed in the context of a recent model of the N170 response involving face and eye sensitive neurons (Itier et al., 2007) where the eyes play a central role in face perception. The data support the intuitive idea that eyes are what make animal head fronts look face-like and that proficiency for the human species involves visual expertise for the human eyes

The Semantic Error Problem for Epistemic Contextualism

Epistemic Contextualism is the view that “knows that” is semantically context-sensitive and that properly accommodating this fact into our philosophical theory promises to solve various puzzles concerning knowledge. Yet Epistemic Contextualism faces a big—some would say fatal—problem: The Semantic Error Problem. In its prominent form, this runs thus: speakers just don’t seem to recognise that “knows that” is context-sensitive; so, if “knows that” really is context-sensitive then such speakers are systematically in error about what is said by, or how to evaluate, ordinary uses of “S knows that p”; but since it's wildly implausible that ordinary speakers should exhibit such systematic error, the expression “knows that” isn't context-sensitive. We are interested in whether, and in what ways, there is such semantic error; if there is such error, how it arises and is made manifest; and, again, if there is such error to what extent it is a problem for Epistemic Contextualism. The upshot is that some forms of The Semantic Error Problem turn out to be largely unproblematic. Those that remain troublesome have analogue error problems for various competitor conceptions of knowledge. So, if error is any sort of problem, then there is a problem for every extant competitor view

Multiple Faces of Power and Learning

Power relations are seen by many as an obstacle to reducing poverty and inequality. There is a growing appetite for understanding power and for being more strategic about it, and a number of useful frameworks are now available. But the complexity of power makes it difficult to know which concepts to use, or how to develop capacities to put them into practice. This article argues that these questions need to be answered together: the multiple faces of power require multiple faces of learning. The case is made for using ‘deep’, experiential and reflective approaches that combine rational reflection and technical analysis with more embodied, emotional and creative methods of sense?making. Such capacities also need to be supported through adaptive, context?sensitive and applied methods, not imparted in abstract or instrumental ways. Emerging thinking about capacity supports this view, and could benefit from traditions of adult education and reflective learning

The N170 event-related potential differentiates congruent and incongruent gaze responses in gaze leading

To facilitate social interactions, humans need to process the responses that other people make to their actions, including eye movements that could establish joint attention. Here, we investigated the neurophysiological correlates of the processing of observed gaze responses following the participants’ own eye movement. These observed gaze responses could either establish, or fail to establish, joint attention. We implemented a gaze leading paradigm in which participants made a saccade from an on-screen face to an object, followed by the on-screen face either making a congruent or incongruent gaze shift. An N170 event-related potential was elicited by the peripherally located gaze shift stimulus. Critically, the N170 was greater for joint attention than non-joint gaze both when task-irrelevant (Experiment 1) and task-relevant (Experiment 2). These data suggest for the first time that the neurocognitive system responsible for structural encoding of face stimuli is affected by the establishment of participant-initiated joint attention