Kant argued that the perceptual representations of space and time were templates for the perceived spatiotemporal ordering of objects, and common to all modalities. His idea is that these perceptual representations were specific to no modality, but prior to all—they are pre-modal, so to speak. In this paper, it is argued that active perception—purposeful interactive exploration of the environment by the senses—demands premodal representations of time and space.
This paper argues that a common form of representationalism has trouble accommodating empirical findings about visual spaceperception. Vision science tells us that the visual system systematically gives rise to different experiences of the same spatial property. This, combined with a naturalistic account of content, suggests that the same spatial property can have different veridical looks. I use this to argue that a common form of representationalism about spatial experience must be rejected. I conclude by considering alternatives to (...) this view. (shrink)
The two contrasting theoretical approaches to visual perception, the constructivist and the ecological, are briefly presented and illustrated through their analyses of space and size perception. Earlier calls for their reconciliation and unification are reviewed. Neurophysiological, neuropsychological, and psychophysical evidence for the existence of two quite distinct visual systems, the ventral and the dorsal, is presented. These two perceptual systems differ in their functions; the ventral system's central function is that of identification, while the dorsal system is (...) mainly engaged in the visual control of motor behavior. The strong parallels between the ecological approach and the functioning of the dorsal system, and between the constructivist approach and the functioning of the ventral system are noted. It is also shown that the experimental paradigms used by the proponents of these two approaches match the functions of the respective visual systems. A dual-process approach to visual perception emerges from this analysis, with the ecological-dorsal process transpiring mainly without conscious awareness, while the constructivist-ventral process is normally conscious. Some implications of this dual-process approach to visual-perceptual phenomena are presented, with emphasis on spaceperception. Key Words: constructivist; dual-process approach; ecological; size perception; spaceperception; two visual systems; visual perception theories. (shrink)
Vestibular inputs make a key contribution to the sense of one’s own spatial location. While the effects of vestibular stimulation on visuo-spatial processing in neurological patients have been extensively described, the normal contribution of vestibular inputs to spatial perception remains unclear. To address this issue, we used a line bisection task to investigate the effects of galvanic vestibular stimulation (GVS) on spatial perception, and on the transition between near and far space. Brief left-anodal and right-cathodal GVS or (...) right-anodal and left-cathodal GVS were delivered. A sham stimulation condition was also included. Participants bisected lines of different lengths at six distances from the body using a laser pointer. Consistent with previous results, our data showed an overall shift in bisection bias from left to right as viewing distance increased. This pattern suggests leftward bias in near space, and rightward bias in far space. GVS induced strong polarity dependent effects in spatial perception, broadly consistent with those previously reported in patients: left-anodal and right-cathodal GVS induced a leftward bisection bias, while right-anodal and left-cathodal GVS reversed this effect, and produced bisection bias toward the right side of the space. Interestingly, the effects of GVS were comparable in near and far space. We speculate that vestibular-induced biases in spaceperception may optimize gathering of information from different parts of the environment. (shrink)
This chapter discusses the causal requirements on perceptual success in putative cases of the perception of absence – in particular, in cases of hearing silence and seeing darkness. It is argued that the key to providing the right account of the respect in which we can perceive silence and darkness lies in providing the right account of the respect in which we can have conscious perceptual contact with intervals of time and regions of space within which objects can (...) potentially be perceived. In this account, a significant explanatory role is assigned to comparatively invariant structural features of our conscious experience of regions of space and intervals of time. The chapter discusses how the explanatory role assigned to these structural features affects our view of the causal requirements on perceptual success. (shrink)
This paper, which has both a historical and a polemical aspect, investigates the view, dominant throughout the eighteenth and nineteenth centuries, that the sense of sight is, originally, not phenomenally three-dimensional in character, and that we must come to interpret its properly two-dimensional data by reference to the sense of 'touch'. The principal argument for this claim, due to Berkeley, is examined and found wanting. The supposedly confirming findings concerning 'Molyneux subjects' are also investigated and are shown to be either (...) irrelevant or disconfirming. Recent investigations on infant and neonatal perception are discussed and are also found to be disconfirming. An innatist version of the theory is then considered and is shown to be undermined by the largely 'Gibsonian' character of early space-perception. Finally three recent arguments in favour of the theory - two from psychologists, one from a philosopher - are considered and answered. (shrink)
This paper aims to investigate the temporal content of perceptual experience. It argues that we must recognize the existence of temporal perceptions, i.e., perceptions the content of which cannot be spelled out simply by looking at what is the case at an isolated instant. Acts of apprehension can cover a succession of events. However, a subject who has such perceptions can fall short of having a concept of time. Similar arguments have been put forward to show that a subject who (...) has spatial perceptions can fall short of having a concept of space. In both cases, it is the fact that perception is from a point of view which stands in the way of it constituting an exercise of a concept of how things are objectively. However, the paper also shows that the way in which perception is perspectival takes a different form in each of the two cases. (shrink)
The papers in this volume question how perceptions of space influenced understandings of the body and its functions, illness and treatment, and the surrounding natural and built environments in relation to health in the classical and ...
Meditation practice can lead to what have been referred to as 'altered states of consciousness'. One of the phenomenological characteristics of these states is a joint alteration in the sense of time, space and body. Here, we set out to study the unique experiences of alteration in the sense of time and space by collaborating with a select group of 12 long-term Mindfulness meditation practitioners in a neurophenomenological setup, utilizing first-person data to guide the neural analyses. We hypothesized (...) that the underlying neural activity accompanying alterations in the sense of time and space would be related to alterations in bodily processing. The participants were asked to volitionally bring about distinct states of 'Timelessness' (outside time) and 'Spacelessness' (outside space) while their brain activity was recorded by MEG. In order to rule out the involvement of attention, memory or imagination, we used control states of 'Then' (past) and 'There' (another place). MEG sensors evidencing alterations in power values were identified, and the brain regions underlying these changes were estimated via spatial filtering (beamforming). Particularly, we searched for similar neural activity hypothesized to underlie both the state of 'Timelessness' and 'Spacelessness'. The results were mostly confined to the theta band, and showed that: 1) the 'Then' / 'There' overlap yielded activity in regions related to autobiographic memory and imagery (right posterior parietal lobule, right precentral / middle frontal gyrus, bilateral precuneus); 2) 'Timelessness' / 'Spacelessness' conditions overlapped in a different network, related to alterations in the sense of the body (posterior cingulate, right temporoparietal junction, cerebellum); and 3) phenomenologically-guided neural analyses enabled us to dissociate different levels of alterations in the sense of the body. This study illustrates the utility of employing experienced contemplative practitioners within a neurophenomen. (shrink)
We need to reconsider and reconceive the path that will take us from innate perceptual saliencies to basic (and perhaps other) colour language. There is a space between the perceptual and the linguistic levels that needs to be filled by an account of the rules that people use to generate relatively stable reference classes in a social context.
Current views of the parietal cortex have difficulty accommodating the human inferior parietal lobe (IPL) within a simple dorsal versus ventral stream dichotomy. In humans, lesions of the right IPL often lead to syndromes such as hemispatial neglect that are seemingly in accord with the proposal that this region has a crucial role in spatial processing. However, recent imaging and lesion studies have revealed that inferior parietal regions have non-spatial functions, such as in sustaining attention, detecting salient events embedded in (...) a sequence of events and controlling attention over time. Here, we review these findings and show that spatial processes and the visual guidance of action are only part of the repertoire of parietal functions. Although sub-regions in the human superior parietal lobe and intraparietal sulcus contribute to vision-for-action and spatial functions, more inferior parietal regions have distinctly non-spatial attributes that are neither conventionally 'dorsal' nor conventionally 'ventral' in nature. (shrink)
Barnett Newman professed that a beholder's encounter with his paintings was like meeting another person for the first time. He believed the experience produced the conditions for apprehending an ethical relationship that would entail both the individual's achievement of his or her own understanding of “self” and his or her acknowledgment of another individual. But it would be their mutual recognition of separateness as the condition of possibility for communication — for sharing worlds — that would ground the ethical relationship (...) between them. Not just interested in matters of theory, the artist was also specific about the modes of spatial experience that he intended his canvases to inaugurate for a beholder. A detailed phenomenological account of how, in particular cases, the perceptual effects of Newman's paintings are created, both technically and artistically, helps to develop the implications, for his ethics of relationship, of what he called his “sense of space.” This article focuses on major paintings (particularly Vir Heroicus Sublimis and The Wild) in order to ground an interpretation of the perceptual effects of Newman's works. (shrink)
Intentionalism is the view that the phenomenal character of a conscious experience is wholly determined by, or even reducible to, its representational content. In this essay I put forward a version of intentionalism that allows (though does not require) the reduction of phenomenal character to representational content. Unlike other reductionist theories, however, it does not require the acceptance of phenomenal externalism (the view that phenomenal character does not supervene on the internal state of the subject). According the view offered here, (...) phenomenal characters essentially represent subject-environment relations that are relevant to the possibilities for causal interaction between the subject and the environment; relations of the kind that J. J. Gibson dubbed affordances. I argue for this view chiefly through an examination of spatial perception, though other cases are also considered. The view assumes that a phenomenal character has an essential functional role; though it need not be assumed that a functional role is sufficient for a phenomenal character. (shrink)