Our perception of external features comprises, among others, functional and phenomenological levels. At the functional level, the perceiver’s mind processes external features according to its own causal- functional organization. At the phenomenological level, the perceiver has consciousness of external features. The question of this paper is: How do the functional and the phenomenological levels of perception relate to each other? The answer I propose is that functional states of specifically perceptual attention constitute the necessary basis for the arising of consciousness (...) in a perceiver. -/- Widely studied within cognitive psychology, perceptual attention is still awaiting a thoroughgoing philosophical treatment. The paper presents and draws upon Anne Treisman’s feature-integration theory of attention (cf. A. Treisman & G. Gelade, “A Feature-Integration Theory of Attention,” Cognitive Psychology, 12, 1980. Pp. 97-136). According to this theory, attentional mechanisms are responsible for the binding of perceptual features into coherent and stable objects of perception. By itself, I will claim, the theory of feature integration does not allow a straightforward reduction of consciousness to the functional processing underlying it. However, on the basis of Treisman’s theory we can produce a methodological argument for endorsing the non-reductivist thesis that attentional states constitute the necessary basis for the arising of consciousness in a perceiver. The paper closes by presenting this argument, according to which the thesis is implied by a unified account of the common representational natures of attentional and conscious states. (shrink)

The Macpherson :24–62, 2012) argued that the perceptual experience of colors is cognitively penetrable. Macpherson also thinks that perception has nonconceptual content because this would provide a good explanation for several phenomena concerning perceptual experience. To have both, Macpherson must defend the thesis that the CP of perception is compatible with perception having NCC. Since the classical notion of CP of perception does not allow perception to have NCC, Macpherson proposes CP-lite. CP-lite makes room for an experience to have content (...) determined by concepts because the perceptual processes that produce the experience are affected by concepts rendering the experience, CP, while the same type of experience could have been had without any conceptual influences, in which case it would be CI. Macpherson then proceeds to show that CP-lite is compatible with some of the definitions of NCC. To do so, she argues that even when an experience is CP owing to the fact that it is produced by means of the mechanism posited by CP-lite, that is, through the interaction between bottom–up pure perception and top–down perceptual imagery, its content is NCC because it has the basic properties that characterize NCC. Based on this, Macpherson proceeds to criticize and undermine the definitions of NCC that are incompatible with CP-lite. In this paper, I argue that the possibility of CP-lite rests on the erroneous assumption that a state with conceptual content and a state with NCC can have the same phenomenology or content, and that the compatibility of CP-lite with NCC presupposes a view of NCC that does not conform to the usual construal of NCC. (shrink)

Inverting a face impairs perception of its features and recognition of its identity. Whether faces are special in this regard is a current topic of research and debate. Kanizsa studied the role of facial features and environmental context in perceiving the emotion and identity of upright and inverted faces. He found that observers are biased to interpret faces in a retinal coordinate frame, and that this bias is readily overruled by increased realism of facial features, but not easily overruled by (...) environmental context. An additional factor contributing to a retinal coordinate-frame interpretation may be the ambiguous nature of the face stimuli. Since his facial expressions are interpretable both upright and inverted, they may in both orientations activate an endogenous attentional process for faces. We present visual search and change-blindness experiments that explore how inversion, negation, and facial emotion affect visual attention to static faces. We find that attention to faces is impaired by inversion and negation. We also find that the parts of the face that receive greater attention can be influenced by the emotional expression of the face. We propose to extend these experiments to dynamic faces. To this end, we develop a theory of the visual representation of dynamic faces, in which faces are represented by classes of `spacetime fragments'-moving regions of the face with high informational content. We then present ideas for future experiments which are motivated by the spacetime fragment theory, and which should serve to constrain its further development. (shrink)

The present empirical study investigates limitations of human visual working memory. The experiments of the present work involve the experimental paradigm of change detection using simple geometrical objects in the form of rectangles of different colour, length, and orientation. It can be shown, that a limited performance in the temporary storage of visual information has multiple sources. Limitations of VWM can be attributed to a limited capacity or a limited duration, but also to limitations in retrieval, which so far has (...) found only little attention. Key findings of the present study show, that a capacity limitation cannot be described by a simple and generally valid size of the store. It is in fact generally acknowledged that the capacity limitation of VWM is object-based, which means that the capacity can roughly be determined by the number of visual objects. However, it could be shown that the complexity of the objects has an influence on memory performance: Experimental evidence shows, e.g., that memory performance decreases, when an object is characterized not only by one feature, but by a number of features. The results are explained by increased storage demands for the binding of the features. Other key findings of the present study relate to the process of retrieval of information from VWM. For example, an asymmetric performance pattern could be observed: In a change detection task a memory performance was observed that corresponds to a capacity of 3 - 4 objects. In contrast a drastic decrease of performance corresponding to a capacity of only 1 object was observed, when the task was to find a matching item among changed distractors. These results lead to the idea of a change signal, by which the empirical data can be explained. The change signal is elicited by a local mismatch between the information stored in VSTM and perceptual online information. The retrieval process is efficient, when the change signal can be used in the memory task. However, retrieval is extremely limited, when in the presence of multiple changes a less efficient strategy has to be applied. In the course of the present study, moreover, it became evident that there are various links between VWM processes and visual attention. Visual attention is probably crucial for feature binding in VWM. In retrieval the change signal probably involves mechanisms of visual attention. The present study could, therefore, contribute to a clarification of the relation between VWM and visual attention. (shrink)