Looking for two targets at the same time: One search or two?

A considerable amount of evidence suggests that, under conditions of high discriminability, subjects are able to process multiple elements in a visual display simultaneously when searching for a single target among distractors. Relatively little emphasis, however, has been placed on the question of whether subjects can search for and detect multiple targets simultaneously. This latter question is the focus of the present report. In two experiments, we compare performance in single-target and multiple-target detection tasks in order to investigate whether or not multiple targets can be detected simultaneously. In Experiment 1, subjects searched for one or two targets that were defined by color. In Experiment 2, subjects searched for a color and/or a letter target. When the two targets were presented in the same location (e.g., a red X when Target 1 was red and Target 2 was an X), they seemed to be detected simultaneously. Implications for object-based processing of visual information are discussed.     

Only one or two cultures?

One Culture: Essays in Science and Literature, edited by George Levine, Madison, WI: University of Wisconsin Press, 1987, 359 pages, hb $45, pb $12.95     

Visual short-term memory for two sequential arrays: One integrated representation or two separate representations?

Two dot arrays, each containing a different set of six randomly selected locations from a 5 × 5 matrix, were presented briefly and were separated by an interstimulus interval (ISI) of 0, 200, 500, or 1,500 msec. Subjects were asked to remember these locations and to report whether a probe dot matched the locations in memory. To find out whether the subjects had formed an integrated representation of the two arrays, the probe dot was accompanied by matrix elements from the first array, from the second array, or from both arrays. Memory for Array 1 was significantly impaired when the retrieval context was drawn from Array 2, and vice versa, suggesting that the two arrays were represented separately. This effect was observed only at an ISI of 500 msec or longer. We propose that as Array 1 is better consolidated, its representation becomes more separated from that of Array 2.     

Could there be exactly two things?

Many philosophers think that, necessarily, any material objects have a fusion (let’s call that doctrine “Universalism”). In this paper I point out a couple of strange consequences of Universalism and related doctrines, and suggest that they are strange enough to constitute a powerful argument against those views.     

Psychoanalysis is a two‐way street

The paper discusses psychoanalysis as a mutual exchange between the analyst and analysand. A number of questions are raised: What was Ferenczi's and the early psychoanalysts' contribution to the interpersonal relational dynamics of psychoanalytic treatment? Why did countertransference become an indispensable tool in relationship‐based psychoanalysis? Why is the transference‐countertransference dynamic seen as a special dialogue between the analyst and analysand? What was Ferenczi's paradigm shift in the trauma theory? How did he combine the object relation approach with Freud's original trauma theory? The paper illustrates through some case study vignettes the intersubjective and intrapsychic dynamic in the process of traumatization. We can look at countertransference as an indicator of the patient's basic interpersonal experiences and traumas. Finally the paper discusses countertransference in the light of attachment theory, connecting the early initiatives of inter‐relational approaches in psychoanalysis with recent research.     

One blue colour channel or two?

Contrary to the general belief that the yellow-blue mechanism has lower spatial resolution than the red-green mechanism, it has been recently claimed that both mechanisms have similar spatial sensitivity (McKeefry et al, 2001 Vision Research 41 245-255). Studying high-spatial-frequency tritanopia (a colour illusion based on spatio-chromatic interactions in human vision), we found strong evidence for the existence of two blue mechanisms-with low and high spatial-frequency resolution. If confirmed, this may resolve the apparent paradox concerning spatial resolution of the yellow-blue mechanism.     

Early and deep: two independent paradigms?

Did Winnicott replace or transform Freud's metapsychology? The author's aim is to explore more deeply the views developed in a previous paper based solely on Winnicott. Here the author draws on other studies to respond to two questions recently posed by Fulgencio concerning the meaning of the term metapsychology and the existence of a new topography in Winnicott's work. For many authors, Winnicott does not reject Freudian metapsychology and says nothing new in this field; in the field of paediatric anthropology, however, he focuses on dependence, and in the field of the living embodiment of the drives on being and self as different from ego. But Green notes the existence of a third topography, that of self/object, and also examines the vicissitudes of being by isolating the concept in Winnicott's work. For the author, however, being seems in continuity with his whole anthropological and ontological perspective; and when Winnicott introduces environmental factors of which the infant is unaware, he also introduces a heuristic distinction between early and deep: there is thus neither a rejection nor a reformulatation of the metapsychological theorization, but rather a coexistence of two paradigms.     

Are there two classes of classically-conditioned responses?

It is proposed that two response classes interact during classical conditioning: (1) a specific effect which directs responding towards or away from the CS, depending upon whether a positive or negative outcome is signaled, and (2) a general, emotional effect which interferes with responding. The interaction between these two response classes can account for the varied results obtained under CER and autoshaping procedures, and must be considered in any analysis which attempts to account for the complex nature of the conditioned response.     

Partial report: iconic store or two buffers?

Selective recall of a subset of letters from a multiletter array declines systematically with increases in the delay of the partial report cue. The issues addressed were (a) whether such a decline is due to progressive loss of location information or to systematic loss of features and (b) whether partial report is the result of a select-then-identify or an identify-then-select process. Instructing the subjects to guess or not to guess had an effect of intra-array, displacement, and extra-array errors. Emphasizing on recall location affected both intra- and extra-array errors. The interstimulus interval manipulation had an effect on extra-array errors as well as on intra-array errors. These observations are contrary to the suggestions that intra-array errors are due to loss of location information and that extra-array errors are indicative of a joint effect on misidentification due to chance and the ratio of extra-array errors to intra-array errors. Some other results are difficult for a dual-buffer model but can readily be accounted for by the orthodox view of the iconic store.     

I. Marx's two‐fold character of labour

Ulrich Steinvorth ('Marx's Analysis of Commodity Exchange’, Inquiry, Vol. 19 [1976]) and C. J. Arthur ('Labour: Marx's Concrete Universal’, Inquiry, Vol. 21 [1978]) rely on the two‐fold character of labour in arguing that the mysteries of money and profit have been correctly interpreted by Marx. However, Marx's own arguments for his distinction between abstract and concrete labour are faulty, as is his identification of labour and material products. They also claim that the exchange of commodities and distribution of resources in capitalist society validate Marx's theory that the determination of value by labour‐time is the ‘secret’ behind capitalist crises. These claims are insufficiently justified, and provide no additional reason for accepting the two‐fold character of labour.     

Transcortical motor aphasia: One or two aphasias?

The name "transcortical motor aphasia" has been used to refer to two different types of language alterations: damage in the left supplementary motor area and Luria's dynamic aphasia. It is proposed that they represent two types of language disturbances different enough to be considered two different forms of aphasia.     

One concept or two? A reply to Raine

It is suggested that Raine's criticisms of the paper by Barbour-McMullen, Coid and Howard rest on misconceptions, particularly regarding the nature of the supposed conceptual dichotomy between “North American” and “European” concepts of psychopathy. Several points of clarification are offered. It is maintained that psychopathy is indeed a dual, rather than a unitary, concept.     

The two‐thirds power law in motion perception

If a visual motion abruptly vanishes, the vanishing point is mislocalized in the anticipated direction of the motion (cf. Freyd & Finke, 1984; Hubbard & Bharucha, 1988; Verfaillie & d'Ydewalle, 1991). Here, we replicate this effect for curvilinear motions, showing that the compatibility with human movements, as expressed by the two‐thirds power law (cf. Lacquaniti, Terzuolo, & Viviani, 1983; Viviani, 2002), specifically contribute to this anticipation error. Thus, the compatibility effect does not manifest itself solely in an overshooting of the judged vanishing position in comparison to the objective vanishing position, but also in a more accurate anticipation of the curvilinearity of the forthcoming motion. The latter effect only occurred for spatially unpredictable target motions. Spatially more predictable target motions allowed for a different kind of anticipation, which overrode the compatibility effect. The results are discussed with regard to the notion of an action‐related influence on motion perception.     

A Peircean examination of Gettier’s two cases

If we accept certain Peircean commitments, Gettier’s two cases are not cases of justified true belief because the beliefs are not true. On the Peircean view, propositions are sign substitutes, or “representamens.” In typical cases of thought about the world, propositions represent facts. In each of Gettier’s examples, we have a case in which a person S believes some proposition p, there is some fact F* such that were p to represent F* to S then p would be true, and yet p does not represent F* to S but some other fact F of which p is false. Since truth is a property of propositions with respect to their representational function, it follows that the belief is not true. Although an examination of Gettier’s two cases, this essay is not a defense of the justified true belief (JTB) analysis of knowledge, for there are objections to the JTB analysis other than Gettier’s two cases. Rather, Gettier’s two cases are of particular interest for the light they shed on the nature of truth and representation.

     

Temperature sensitivity: One subjective continuum or two?

An experiment is reported on the effect of six consecutive days of exposure to distortions of binaural time and intensity cues on the localization function for tones of 350, 1000, and 4000 Hz. Tests were conducted under “free-field” conditions. The changes in auditory spatial orientation indicate that adjustments to binaurally distorted temporal and intensive cues can occur. Reorientation does not appear to depend upon the existence of veridical auditory cues.     

Projecting two words with one machine: Presenting two different visual stimuli using just one projector without viewers’ noticing the duality

A new method, named the fMORI technique, for presenting two different visual stimuli using just one video projector without the viewers' noticing the duality is introduced along with several sample applications of this presentation method. The LCD projectors available now have three color LCD panels aligned differently in terms of their polarization, polarizing differently the green and magenta (red plus blue) components of its emitting image. Therefore, two visual stimuli either in green or in magenta projected on thesame screen canbe observed separately by subjects wearing an appropriate polarizing filter. This is a variation of the MORI technique (Mori, 2003, 2007b) but it requires only one video projector rather than two. Full-color movies cannot be presented with the fMORI technique, but it may be utilized in various research areas in which only static monochrome visual stimuli, such as words or numbers, are used.