Our conscious minds exist in the Universe, therefore they should be identified with physical states that are subject to physical laws. In classical theories of mind, the mental states are identified with brain states that satisfy the deterministic laws of classical mechanics. This approach, however, leads to insurmountable paradoxes such as epiphenomenal minds and illusionary free will. Alternatively, one may identify mental states with quantum states realized within the brain and try to resolve the above paradoxes using the standard Hilbert (...) space formalism of quantum mechanics. In this essay, we first show that identification of mind states with quantum states within the brain is biologically feasible, and then elaborating on the mathematical proofs of two quantum mechanical no-go theorems, we explain why quantum theory might have profound implications for the scientific understanding of one's mental states, self identity, beliefs and free will. (shrink)

The ArgumentThis essay addresses the historiographical question of how to study scientific instruments and the connections between them without rigidly determining the boundaries of the object under historical scrutiny beforehand. To do this, I will explore an episode in the early history of the tachistoscope — defined, among other things, as an instrument for the brief exposure of visual stimuli in experimental psychology. After looking at the tachistoscope described by physiologist Volkmann in 1859, I will turn to the gravity chronometer, (...) constructed by Cattell at Wundt's Leipzig institute of psychology in the 1880s. Taking Wittgenstein's notion of family resemblances as a methodological suggestion to travel from one member to another to find out just how members relate to one another, I will investigate part of the family to which both the tachistoscope and the gravity chronometer turn out to belong. A detailed analysis of these instruments, using both historical sources and historical accounts of psychological instruments, may demonstrate that the instrument is not a standard package that, if well applied, will simply secure good results. Each package needs to be assembled again and again; the particular package that is assembled may differ on different occasions. Thus an alternative is developed to an understanding of instruments as univocally functioning material means. (shrink)

This paper provides a detailed account of the origins of the Psycho logical Review in 1894, of the policies and practices of its editors (James Mark Baldwin and James McKeen Cattell) during its first decade, and of the public and private disagreements that led them to dissolve their collaboration in 1904. In doing so, it sheds light on the significant roles played by specialized scientific journals in the development of specific scientific specialities, and illustrates the value for historical exploration of (...) (what anthropologists call) a 'thick description' of (what historians call) 'the fine texture of the past'. It argues that personal factors such as luck and character and temperament often have a greater impact on the way in which science actually evolves than do intellectual interests and concerns, and concludes with an analysis of the overwhelming signifi cance of this episode on the later careers of both Baldwin and Cattell. (shrink)

The journal Mind is now a wholly philosophical journal. At the time of its founding, in 1876, however, its mission was rather different in character. Its aim was to discover whether scientific psychology was a truly viable enterprise and, if so, what its boundaries with philosophy, with other scientific disciplines, and with the earlier generation of discredited attempts at `scientific' studies of the mind (e.g. phrenology, mesmerism) might be. Although at first Mind published mostly philosophical pieces and literature reviews, by (...) the mid-1880s it was publishing primary experimental research, mostly by American psychologists who as yet had few outlets of their own. For a time it was the leading journal of experimental psychology in the English-speaking world. As the international competition among scientific and scholarly journals intensified in the 1890s, however, Mind started to lose its share of experimental contributions, and with the editorial takeover of the journal of George Stout in 1892, the journal soon became one dedicated purely to philosophy. (shrink)

In order to assess the unique reading processes in Arabic, given its unique orthographic nature of natural inherent variations of inter letter spacing, the current study examined the extent and influence of connectedness disparity during single word recognition using the optimal viewing position paradigm. The initial word viewing position was systematically manipulated by shifting words horizontally relative to an imposed initial viewing position. Variations in recognition and processing time were measured as a function of initial viewing position. Fully connected/unconnected Arabic (...) words were used. It was found that OVP effects occurred during the processing of isolated Arabic words. In Arabic, the OVP may be in the center of the word. No OVP was found in three-letter words; for four- and five-letter words, the OVP effect appeared as a U-shaped curve with a minimum towards the second and third letters. Thus, the OVP effects generalize across structurally different alphabetic scripts. (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)