Spotlight Of Attention Research Articles

The role of local conjunction in the integration process of shape and color

It is an open question how simple features are integrated in the attention spotlight. In this paper, we examined two opposing models for the integration process of shape and color. One is a local conjunction model in which simple features of shape and color are combined directly. The other is a whole conjunction model in which simple features of shape are integrated into the whole shape and then it is combined with color. In Experiment 1, we measured the time required to search for a target defined by a conjunction of shape and color for five subjects with changing coloring of the figures. The slope of the search function was gentler when corners of figures were colored (p < 0.01). In Experiment 2, we measured the time required to integrate shape and color of figures presented in rapid serial visual presentation (RSVP) for five subjects. The presentation time required to answer the correct combination was shorter when corners were colored (p < 0.01). These results support the local conjunction model.

Narrowing the spotlight: A visual attentional disorder in presumed alzheimer's disease

Abstract Visuo-spatial dysfunction is the initial and most disabling impairment in a small proportion of patients with progressive dementia. We report a series of investigations of two patients with probable Alzheimer's disease (AD) in which progressive visuo-spatial deficits dominated the clinical picture. Both patients exhibited substantial impairments on a visual search task and read words printed in small letters better than words printed in large letters. When stimuli were presented in which a large letter was composed of small letters (e.g. an ‘S’ composed of T's), the patients identified the small letter faster and more reliably. These and other data are consistent with the hypothesis that the patients exhibit a restriction in the capacity of the spotlight of visual attention.

Disability and work: risk assessment.

Recent parliamentary debate has brought the rights of disabled people back into the spotlight of media attention. In the workplace, the occupational health nurse (OHN) is uniquely placed to make a positive contribution to the achievement of equal opportunities for people with disabilities. The author describes a risk assessment approach to the occupational health and safety of disabled persons and their employers. Such approaches can help to ensure that the work skills of all employees are used to maximum potential.

Multiple parallel access in visual attention.

It is widely accepted that there exists a region or locus of maximal resource allocation in visual perception--sometimes referred to as the spotlight of attention. We have argued that even if there is a single locus of processing, there must be multiple loci of parallel access--several places in the visual field must be indexed at once and these indexes can be used to determine where attention is allocated. We have carried out a variety of studies to support these ideas, including experiments showing that subjects can track multiple independent moving targets in a field of identical distractors, that the enhanced ability to detect changes occurring on these targets does not accrue to nontargets nor to items lying inside the convex polygon that they form (so that a zoom-lens of attention does not fit the data). We have used a visual search paradigm to show that (serial or parallel) search can be confined to a subset of indexed items and the layout of these items is of little importance. We have also studied the phenomenon known as subitizing and have shown that subitizing occurs only when items can be preattentively individuated and in those cases location precuing has little effect, compared with when counting occurs, which suggests that subitizing may be carried out by counting active indexes rather than items in the visual field. And finally we have run studies showing that a certain motion effect that is sensitive to attention can occur at multiple precued loci. We believe that this evidence suggests that there is an early preattentive stage in vision where a small number of salient items in the visual field are indexed and thereby made readily accessible for a variety of visual tasks.

A Curse on Russia: Gorenshtein's Anti-Psalom and the Critics

ridrikh Gorenshtein was born in Kiev in 1932. His father was arrested in 1935, and died in a camp. His mother, who had unsuccessfully tried to avoid arrest herself, died shortly after being released from prison. Gorenshtein spent the war years in state-run children's homes and then was cared for by relatives. He published his first story in Iunost' in 1964, but from that year until 1989 none of his works was published in the former Soviet Union, with the exception of a number of film scripts, Solarus and A Slave of Love being the two most widely known in the West. In the late seventies, along with Aksenov, Bitov and others, Gorenshtein participated in the controversial literary almanac Metropol', which was first published in the Soviet Union in 1991. Afterward, Gorenshtein emigrated to West Berlin. Gorenshtein now says that he regrets his involvement with Metropol', not because of any personal consequences, but because he is basically opposed to the liberal humanistic ideology of the generation of the 1960s-as we will see.' Some of Gorenshtein's important works are Iskuplenie (1979) and Mesto (published in 1990, written between 1969 and 1976). A play, Spory o Dostoevskom, appeared in Teatr in 1990, and a story,Poslednee leto na Volge, in Znamia in 1992. Psalom, to which this article is mostly devoted, and which Gorenshtein has called his foundation,2 was written during 1974-75, was first published in French in 1984, in Russian by the emigre publishing house Strana i Mir in 1986, and in Oktiabr' beginning in 1991. The twenty-five year silence that Gorenshtein endured has finally ended. Gorenshtein is part of a wider phenomenon of contemporary Russian book culture: the return of the repressed. He is being published in his former homeland. In 1991 and 1992 he has leapt from obscurity to the spotlight of critical attention in the Russian press.3

Exogenous and endogenous control of attention: The effect of visual onsets and offsets

Two experiments were carried out to investigate the relation between exogenous and endogenous control of visual attention. Subjects searched for a target letter among three nontarget letters that were positioned on an imaginary circle around a fixation point. At different cue-display intervals, a centrally located arrowhead cue reliably indicated the location of the target letter. At different SOAs, a peripheral line segment near one of the letters was either abruptly switched on (Experiment 1) or abruptly switched off (Experiment 2). Presenting the central arrowhead after display onset prevents attention from being focused in advance on the critical location. In this unfocused attentional state, both onset and offset transients attracted attention. When the central arrowhead was available in advance, the focusing of attention prior to display onset precluded attention attraction to the location of the onset or offset transient. Contrary to an offset transient, an onset transient presented at the attended location disrupted performance, indicating that an onset within the spotlight of attention attracts attention. The results are reconciled by means of the zoom-lens theory of attention, suggesting that outside the focus of attention, abrupt transients are not capable of attracting attention. Since the size of the zoom lens is under voluntary control, it can be argued that transients do not fulfill the intentionality criterion of automaticity.

A Winner-Take-All Mechanism Based on Presynaptic Inhibition Feedback

A winner-take-all mechanism is a device that determines the identity and amplitude of its largest input (Feldman and Ballard 1982). Such mechanisms have been proposed for various brain functions. For example, a theory for visual velocity estimate (Grzywacz and Yuille 1989) postulates that a winner-take-all selects the strongest responding cell in the cortex's middle temporal area (MT). This theory proposes a circuitry that links the directionally selective cells in the primary visual cortex to MT cells, making them velocity selective. Generally, several velocity cells would respond, but only the winner would determine the perception. In another theory, a winner-take-all guides the spotlight of attention to the most salient image part (Koch and Ullman 1985). Also, such mechanisms improve the signal-to-noise ratios of VLSI emulations of brain functions (Lazzaro and Mead 1989). Although computer algorithms for winner-take-all mechanisms exist (Feldman and Ballard 1982; Koch and Ullman 1985), good biologically motivated models do not. A candidate for a biological mechanism is lateral (mutual) inhibition (Hartline and Ratliff 1957). In some theoretical mutual-inhibition networks, the inhibition sums linearly to the excitatory inputs and the result is passed through a threshold non linearity (Hadeler 1974). However, these networks work only if the difference between winner and losers is large (Koch and Ullman 1985). We propose an alternative network, in which the output of each element feeds back to inhibit the inputs to other elements. The action of this presynaptic inhibition is nonlinear with a possible biophysical substrate. This paper shows that the new network converges stably to a solution that both relays the winner's identity and amplitude and suppresses information on the losers with arbitrary precision. We prove these results mathematically and illustrate the effectiveness of the network and some of its variants by computer simulations.

On analog movements of visual attention.

On analog movements of visual attentionSTEVEN YANTISJohns Hopkins University, Baltimore, MarylandA great deal of evidence has accumulated over the last20 years or so suggesting that decisions concerning thecontents of a visual .scene can be enhanced with the as-sistance of advance information about the spatial locationor locations in the scene that are likely to contain task-relevant information. For example, Eriksen and his col-leagues have demonstrated that reaction time to identifya target letter in visual search is improved when a spatialcue is provided about 200 msec before the onset of thesearch display (Colegate, Hoffman, & Eriksen, 1973;Eriksen & Hoffman, 1972, 1973, 1974). Eriksen andHoffman (1972) suggested that the spatial extent of theenhancement is limited to about 1 o of visual angle (seealso Eriksen & St..lames, 1986). Posner and his col-leagues have also provided evidence that can bespatially directed in response to an appropriately timedcue. Reaction time in a dot-detection task is enhancedwhen the dot appears in an attended location and is slowedwhen it appears in an unattended location (e.g., Posner,1980; Posner, Snyder, & Davidson, 1980). Jonides (1981)demonstrated that the effectiveness of spatial cues in focus-ing varies ’with their location: Peripheral cuesapparently capture automatically, whereas cen-tral cues require effortful allocation procedures. LaBerge(1983) and Downing and Pinker (1985) showed that whensubjects focus on a restricted spatial location,reaction time to objects at unattended locations increaseswith their distance from the focus. There is also evidencethat is more efficiently applied to objects thatare physically proximal to one another (e.g., Hoffman N Kahneman & Henik, 1981; Podgorny S Posner et al., 1980).A quite natural heuristic for this body of results is thatthe application of spatial is analogous to shin-ing a on the visual field. Objects that fall underthe spotlight of attention can be identified or detectedmore rapidly than other objects. This sort of analogy hasbeen advocated by many writers (e.g., Broadbent, 1982,p. 271; Downing & Pinker, 1985; Eriksen & Hoffman,1973; Eriksen & St. James, 1986; Eriksen & Yeh, 1985;LaBerge, 1983; Posner, 1980; Posner, Cohen, & Rafal,1982, p. 188; Posner et al., 1980, p. 172; Shulman,Remington, & McLean, 1979; Tsal, 1983).1 Only a fewtheorists (e.g., Duncan, 1981) question the viability ofthe metaphor. Certainly the metaphoris held with varying degrees of concreteness and differ-

Response to the article “depression, self-love, time, and the ‘right’ to suicide” by Bursztajn et al.

The paper by Bursztajn et al. is an ambitious contribution to medical, moral, and legal thinking. At the same time, its publication in this journal poses an interesting ethical question. The Principles of Medical Ethics, With Annotations Especially Applicable to Psychiatry contain a paragraph (Section 7, paragraph 3) addressed to psychiatrists who offer professional opinions about persons in the spotlight of public attention. It is considered unethical to publish such opinions “unless he/she has conducted an examination and has been granted proper authorization for such a statement.” This rule applies specifically when the psychiatrist has had no access to confidential information and everything known is a matter of public record, as is the case here. The manuscript nowhere indicates that the authors are aware of this ethical principle or that it could be invoked against the publication of their professional opinions about Elizabeth Bouvia’s purported mental incompetence in this journal. It so happens that, as an A.P.A. officer, I argued and voted against the inclusion of Section 7, paragraph 3. I continue to oppose its inclusion in our Principles of Ethics. I therefore welcome Bursztajn et al. and this journal to the ranks of those practicing ethical “civil disobedience.” However, it would have been even more encouraging to me had these authors and the editor of the journal intimated in some small way that they were familiar with the Principles of Ethics and knew what they were doing. Imagine how someone given to the kind of

Spotlight on attention

Computer scientists have always emphasized that the brain represents the ultimate in parallel computer architecture, its highly interconnected neurons performing up to billions of operations simultaneously. This parallelism is often cited as the critical advantage of the brain with respect to our serial computers still based on a von Neumann architecture, performing single operations step-by-step. The construction of new parallel computers (such as the Connection Machine 1) with thousands of simple processors and the power to solve previously intractable problems in computational vision is therefore an especially exciting event for both computer and brain scientists. Ironically, just as the new technology of powerful parallel computers begins to close the gap between machine and brain, new psychophysical, anatomical and physiological findings 2–6 suggest it might not be so wide: in certain simple but crucial tasks of early vision, the brain acts as a serial processor. These tasks are mediated by the ‘spotlight of attention’ which can scan the visual field independently of eye movements 7–10.

Employee Participation: The Pension Trustee Experience

No one today can doubt that pensions are big news. Whereas a few years ago those involved in pension matters were left to conduct their affairs away from the spotlight of public attention, in more recent times their activities have attracted substantial interest attended by official enquiries, increasing scrutiny and suggestions of regulation.

Is radiochemistry the ultimate in trace analysis?

Abstract

The City of Black Angels: Emergence of the Los Angeles Ghetto, 1890-1930

THE SPOTLIGHT of national attention on black ghettos during the past decade has led historians to study a field which had previously been largely the preserve of sociologists and economists. Several excellent studies of the formation of major areas of black urban concentration prior to the Great Depression have been written, and long-held interpretations of the causes and timing of ghetto development have been altered.' To date, however, no historian has produced a scholarly study of the origins of the community in Los Angeles which, by 1960, ranked sixth among all black urban populations in the United States. This neglect resulted partly from the fact that writers saw no substantial black population in the West prior to the 1940s and concluded that the presence of Negroes was largely a phenomenon of wartime migration. Thus Gunnar Myrdal dismissed the role of blacks in the development of the West by noting that in 1940 they constituted in all states west of the Mississippi, outside of the South, only 2.2 percent of the nation's Negro population.2 He was typical in neglecting to observe that one-fourth of this percentage resided in one county, mostly in certain sections of one city, Los Angeles, which already ranked fourteenth among the nation's cities in Negro population. It had been the largest black community

Books for Babies

INTEREST IN THE YOUNG has gradually filtered down the age scale so that now even babies come under the spotlight of serious attention. Whereas at one time children were treated as miniature adults and expected to behave as such, nowadays the character of each age group is respected and its needs are catered for. In many cases formal education from the age of two and a half replaces the free activity of the play group for the under‐fives. But parents are constantly exhorted to evoke response from their baby even earlier by dangling brightly coloured objects over his cot, filling his environment with gay pictures and selecting educational toys.

Critique of Intuition According to Scientific Empiricism

Is there intuitive knowledge? The answer to this question depends on which meaning we associate with the notoriously ambiguous term intuition. In what follows I shall first attempt to list and discuss briefly the philosophically more important meanings of intuition. Once these diverse meanings are differentiated, I shall proceed to assess the possibility and the validity especially of trans-empirical intuitive knowledge in the light of the epistemology of scientific empiricism. I realize fully that this is a typical Western point of view; and, although I have made sincere efforts to understand and to appreciate the roles assigned to in Oriental (as well as in Occidental) philosophies, my Western bias and scientism will remain all too obvious. Divide and conquer is the maxim of analytic philosophy. However, we are not splitting hairs just for the enjoyment of the exercise. We distinguish between the various uses of the word intuition (and of related terms) in order to prevent confusion. And it is not merely clarity of discourse and communication, eminently desirable though it is in itself, which we are seeking. In the present context, just as in most other contexts of philosophy, clarity and univocality are prerequisites for making sure that credit is given only where it is due. If intuition in one of its many senses designates a way of knowing, it need nort, and indeed does not, designate such a way in some of the other senses. I shall try to show that the claims made for trans-empirical are all too often supported by spurious reasons. These reasons are spurious, and in the end illegitimate, precisely because of shifts in meaning of the word intuition. These shifts are, of course, made quite unwittingly. But it has always been, and will remain, an indispensable part of the Socraticanalytic technique to focus the spotlight of attention on the ambiguity of terms and the dangers of confusion. The word intuition lends itself easily to shifts in meaning because there is a common core, at least a tenuous one, in all its connotations. If these

Europe's Classical Balance of Power: A Case History of the theory and Practice of one of the Great Concepts of European Statecraft

What was the origin of the idea of the of power? How did European leaders apply its principles in actual practice? Widespread as the term balance of power has been, and vital as its principles have been in European statecraft, nevertheless study of its theory and practice has often been neglected by historians. A more complete understanding of the concept is arrived at in Edward Vose Gulick's well-knit examination of the two questions posed above. Throughout the book, the events of history and the diplomatic struggle as played out by statesmen are related to balance-of-power theory as conceived by political scientists. Europe's Classical Balance of Power brings into the spotlight of scholarly attention an idea that has demonstrated great vitality in times gone by, that has worked behind the scenes in the conclaves of power, and that, under another name, has survived to influence twentieth-century diplomacy.

A Re-Examination of the Validity of Our Sex Psychopath Statutes in the Light of Recent Appeal Cases and Experience

Under the tradition of our Anglo-American legal and criminal system, we have in marked contrast differentiated the handling of ordinary criminals from psychotic and feeble-minded offenders. We have maintained two separate and distinct sets of procedures for these groups, employing civil methods of commitments for the latter. Originally there arose a widespread conviction that in the general, over-all field of delinquency there was a special class designated as defective delinquents who should not be sent to ordinary prisons but who should receive special handling adapted to meet their peculiar needs. And historically, society has quite early recognized that its interests might best be protected through administering medical treatment as opposed to imprisonment for insane criminal offenders. A striking aspect of this type of procedure is that the commitments are for indeterminate lengths of time. Parole or complete freedom is given only upon the reestablishment of sufficient control and mental stability. This is diametrically opposed to the mode of handling the criminal. In that case we have felt it important that a maximum period be set for sentence in accordance with the seriousness of the crime or the dangerousness of the offender. Throughout the years another exception has crept into criminal procedure in the defense of insanity, the case of the irresistible impulse. This is a radical extension of the same theory inasmuch as the offender is considered not insane. Most recently, however, still another extension of this concept has been made in affording similar treatment to sane criminal sex offenders who are found to be what has been loosely characterized as sexual psychopaths. Up to this time we have avoided granting any exception to neurotics or psychopaths on the ground that they know what they are doing and if they so desired could control their behavior. However, because the spotlight of public attention has focused in recent times on several brutal sex crimes involving children, a great clamor has arisen for the suppression and control of these atrocities. It is quite easy to under-