Some philosophers take Perky's experiments to show that perceiving can be mistaken for visualizing and so that the two sometimes match in phenomenology. On Segal’s alternative interpretation Perky’s subjects did not consciously perceive the stimuli at all. I argue that even setting this alternative aside, Perky's results do not prove what the philosophers think. She showed her subjects, not the objects they were asked to visualise, but pictures of them. What they mistook for visualizing was not perceptual consciousness of stimuli, (...) but pictorial consciousness. Once clear about the nature of the latter, we can see that Perky's results reveal nothing very surprising. (shrink)

What might a theory of mental imagery look like, and how might one begin formulating such a theory? These are the central questions addressed in the present paper. The first section outlines the general research direction taken here and provides an overview of the empirical foundations of our theory of image representation and processing. Four issues are considered in succession, and the relevant results of experiments are presented and discussed. The second section begins with a discussion of the proper form (...) for a cognitive theory, and the distinction between a theory and a model is developed. Following this, the present theory and computer simulation model are introduced. This theory specifies the nature of the internal representations (data structures) and the processes that operate on them when one generates, inspects, or transforms mental images. In the third, concluding, section we consider three very different kinds of objections to the present research program, one hinging on the possibility of experimental artifacts in the data, and the others turning on metatheoretical commitments about the form of a cognitive theory. Finally, we discuss how one ought best to evaluate theories and models of the sort developed here. (shrink)

Two experiments investigated the reality attributed to hypnotic suggestion through subtle projection of a visual image during simultaneous suggestion for a visual hallucination that resembled the projected image. In Experiment 1, high and low hypnotizable participants were administered either a hypnotic induction or wake instructions, given a suggestion to hallucinate a shape, and then the projected image was subsequently introduced. Although highs in both conditions rated the projected image more vividly than lows, highs in the hypnosis condition made comparable reality (...) ratings when the projected image was absent and present. In Experiment 2, high hypnotizable participants were administered a suggestion to see a shape on a wall. For half the participants the suggested image was projected on the wall and then removed, and for half the projection was initially absent and then introduced. Participants who had the projection absent and then present reported comparable reality and vividness ratings when the projection was absent and present. These findings indicate that elevated hypnotizability and hypnosis are associated with attributions of external reality to suggested experiences. (shrink)

It is generally accepted that there is something special about reasoning by using mental images. The question of how it is special, however, has never been satisfactorily spelled out, despite more than thirty years of research in the post-behaviorist tradition. This article considers some of the general motivation for the assumption that entertaining mental images involves inspecting a picture-like object. It sets out a distinction between phenomena attributable to the nature of mind to what is called the cognitive architecture, and (...) ones that are attributable to tacit knowledge used to simulate what would happen in a visual situation. With this distinction in mind, the paper then considers in detail the widely held assumption that in some important sense images are spatially displayed or are depictive, and that examining images uses the same mechanisms that are deployed in visual perception. I argue that the assumption of the spatial or depictive nature of images is only explanatory if taken literally, as a claim about how images are physically instantiated in the brain, and that the literal view fails for a number of empirical reasons – for example, because of the cognitive penetrability of the phenomena cited in its favor. Similarly, while it is arguably the case that imagery and vision involve some of the same mechanisms, this tells us very little about the nature of mental imagery and does not support claims about the pictorial nature of mental images. Finally, I consider whether recent neuroscience evidence clarifies the debate over the nature of mental images. I claim that when such questions as whether images are depictive or spatial are formulated more clearly, the evidence does not provide support for the picture-theory over a symbol-structure theory of mental imagery. Even if all the empirical claims were true, they do not warrant the conclusion that many people have drawn from them: that mental images are depictive or are displayed in some (possibly cortical) space. Such a conclusion is incompatible with what is known about how images function in thought. We are then left with the provisional counterintuitive conclusion that the available evidence does not support rejection of what I call the “null hypothesis”; namely, that reasoning with mental images involves the same form of representation and the same processes as that of reasoning in general, except that the content or subject matter of thoughts experienced as images includes information about how things would look. (shrink)

The method of phenomenal contrast (in perception) invokes the phenomenal character of perceptual experience as a means to discover its contents. The method implicitly takes for granted that ‘what it is like’ to have a perceptual experience e is the same as ‘what it is like’ to imagine or recall it; accordingly, in its various proposed implementations, the method treats imaginations and/or recollections as interchangeable with real experiences. The method thus always contrasts a pair of experiences, at least one of (...) which is imagined or remembered rather than occurrent. Surveying all eighteen forms of implementing the method, I argue that in all of the proposed pairings, the substitution of imagination or recollection for perceptual experience in the method, is either inconceivable or impermissible. I identify four reasons why I think imagination cannot be substituted for real experience, and three reasons why recollection cannot be substituted for real experience. If my argument works, there is no form of implementing the method that is useful for discovering the contents of experience, and thus the method is not a well‐functioning tool to study the contents of perception. (shrink)

Does phenomenal force, the distinctive phenomenology attributed to perceptual experience, really form an integral part of the latter? If not, what implications does it have for perceptual justification? In this paper, I first argue for a metacognitive account, according to which phenomenal force constitutes a separate, metacognitive state. This account opens up a previously unexplored path for challenging phenomenal conservatism or dogmatism, which has been a prominent theory of perceptual justification over the past two decades. Moreover, I investigate several alternative (...) possibilities in which phenomenal force might still be deemed as significant, but ultimately demonstrate that its epistemic role remains marginal at best. (shrink)

Philosophers and psychologists assume that mental imagery is a cognitive state, that it represents things as being a certain way. However, I argue that imagery is a conative state: it represents things as to be made a certain way. I challenge the traditional assumption by targeting an increasingly popular cognitive account that identifies mental imagery, such as inner speech, with predictions of sensory input. This predictive account faces both empirical and theoretical problems. The account not only fails to capture the (...) salience effects exhibited by mental imagery, it also cannot explain why subjects should not spend their lives minimizing prediction error by engaging in fantasy. These shortcomings highlight what I call the conative profile of imagery, which includes its salience, motivational, and performance effects. I argue that an alternative, conative view of imagery, according to which mental images are goal states, is best able to account for its conative profile. (shrink)

According to phenomenal conservatism or dogmatism, perceptual experiences can give us immediate justification for beliefs about the external world in virtue of having a distinctive kind of phenomenal character—namely phenomenal force. I present three cases to show that phenomenal force is neither pervasive among nor exclusive to perceptual experiences. The plausibility of such cases calls out for explanation. I argue that contrary to a long-held assumption, phenomenal force is a separate, non-perceptual state generated by some metacognitive mechanisms that monitor one’s (...) first-order mental processes and states. This new account advances our understanding of the nature of phenomenal force. (shrink)

6. Seeing With the Mind’s Eye 1: The Puzzle of Mental Imagery .................................................6-1 6.1 What is the puzzle about mental imagery?..............................................................................6-1 6.2 Content, form and substance of representations ......................................................................6-6 6.3 What is responsible for the pattern of results obtained in imagery studies?.................................6-8..