Recognizing people seen in events via dynamic "mug shots"

This study examined effects of an event and dynamic mug shots on facial recognition. Witnesses saw either a film of a liquor store holdup staged by six perpetrators, slides of the same targets, or freeze-framed views from the filmed event. Slides of different facial views of targets among 12 foils, or dynamic 180 degrees mug shots of the same men, or multiple static views were administered 24 hr later in yes-no recognition tests. Recognition (d') was poorer for the same men seen in the event than in slides, but better for dynamic than for static mug shots. Nondynamic event characteristics were responsible for poor recognition of people seen in events, whereas dynamic aspects of facial transformations, not multiple views, seemed responsible for the superiority of dynamic mug shots. The implications of these results for issues of ecological validity of traditional face recognition methodology and for static feature models vs. dynamic transformation models of face recognition are discussed.     

Behavioral contrast in fixed-interval components: effects of extinction-component duration.

Seven albino rats were exposed to a multiple schedule of reinforcement in which the two components (fixed interval and extinction) alternated such that a presentation of the extinction component followed each fixed-interval reinforcement. In baseline sessions, the duration of the extinction component was constant and always one-third of the fixed-interval value. Probe sessions contained a probe segment in which the duration of the extinction component was increased; the response rate in fixed-interval components during the probe segment was compared with the response rate in the segments preceding and following the probe. The effect of increasing the duration of the extinction component was studied under three values of fixed interval: 30 s, 120 s, and 18 s, in three successive conditions. Response rate within fixed intervals was a direct function of duration of the extinction component. Pausing at the beginning of the fixed interval decreased as extinction duration increased. These effects were larger and more consistent for the shorter fixed-interval values (18 s and 30 s). These results indicate a functional relation between relative component duration and responding. For the component providing more frequent reinforcement, this could be stated as an inverse relationship between relative component duration and response rate. This relation is similar to findings regarding the ratio of trial and intertrial duration in Pavlovian conditioning procedures, and suggests that behavioral contrast may be related to Pavlovian contingencies underlying the multiple schedule.     

Maps between some different kinds of contraction function: The finite case

In some recent papers, the authors and Peter Gärdenfors have defined and studied two different kinds of formal operation, conceived as possible representations of the intuitive process of contracting a theory to eliminate a proposition. These are partial meet contraction (including as limiting cases full meet contraction and maxichoice contraction) and safe contraction. It is known, via the representation theorem for the former, that every safe contraction operation over a theory is a partial meet contraction over that theory. The purpose of the present paper is to study the relationship more finely, by seeking an explicit map between the component orderings involved in each of the two kinds of contraction. It is shown that at least in the finite case a suitable map exists, with the consequence that the relational, transitively relational, and antisymmetrically relational partial meet contraction functions form identifiable subclasses of the safe contraction functions, over any theory finite modulo logical equivalence. In the process of constructing the map, as the composition of four simple transformations, mediating notions of bottom and top contraction are introduced. The study of the infinite case remains open.     

On the relation between indistinguishability of identical particles and (anti)symmetry of the wave function in quantum mechanics

Two different concepts of distinguishability are often mixed up in attempts to derive in quantum mechanics the (anti)symmetry of the wave function from indistinguishability of identical particles. Some of these attempts are analyzed and shown to be defective. It is argued that, although identical particles should be considered as observationally indistinguishable in (anti)symmetric states, they may be considered to be conceptually distinguishable. These two notions of (in)distinguishability have quite different physical origins, the former one being related to observations while the latter has to do with the preparation of the system.     

Emotions as social relationships

While emotions are usually treated as internal states, it is possible to view them as social relationships. From this perspective, the different emotions are not primarily understood in terms of facial expression, physiological pattern, hedonic tone, or level of arousal, but as different transformations of the relationship between person and other. To demonstrate the value of this approach, judgments of the similarity between different emotions were submitted to multidimensional scaling. It is shown that the resulting dimensions describe different aspects of the relation between self and other. These dimensions provide us with a taxonomy of emotions that makes some important distinctions between closely related emotions and leads to some interesting predictions about personality differences.The authors would like to thank David Stevens for his assistance with the statistical analysis, Eric de Rivera for drafting the three-dimensional figures, and James D. Laird and Shula Sommers for their helpful commentary.     

Substance P facilitation of memory: effects in an appetitively motivated learning task

Food deprived, heterogeneous strain (HS/IBG) mice were trained on two different discrimination tasks for food reinforcement. In one experiment animals were trained to make spatial discriminations in a T maze. Immediately after training they were given subcutaneous injections of either substance P (1 ng/g) or vehicle. Twenty-four hours later the animals were given reversal training in the same maze. The results showed that substance P-treated animals took significantly longer to acquire the reversal habit than did control mice. In a second experiment, animals were trained to make visual discriminations in a T maze. Immediately after reaching acquisition criterion animals were injected with either substance P (1 ng/g) or vehicle. Different groups of mice were retrained on the same task either 1, 2, 3, or 7 days after original learning. Savings scores were calculated and, at every interval, substance P-treated mice retained the task better than control animals. One interpretation of these data is that substance P-treated mice remembered the original task significantly better than vehicle-injected control animals.     

Bilinguals in a monolingual and a bilingual speech mode: The effect on lexical access

The time course of lexical access in fluent Portuguese-English bilinguals and in English speaking monolinguals was examined during the on-line processing of spoken sentences using the phoneme-triggered lexical decision task (Blank, 1980). The bilinguals were tested in two distinct speech modes: a monolingual, English or Portuguese, speech mode, and a bilingual, code-switching, speech mode. Although the bilingual’s lexical decision response times to word targets in the monolingual speech modes were identical to those of the monolingual subjects, their response times to code-switched word targets in the bilingual mode were significantly slower. In addition, the bilinguals took longer to detect nonwords in both the monolingual and bilingual modes. These results confirm that bilinguals cannot totally deactivate their other language when in a monolingual speech mode. It is hypothesized that bilinguals search both lexicons when confronted with nonwords, even when in a totally monolingual mode, and that they search the base-language lexicon before the other lexicon when in a bilingual, code-switching, speech mode.     

Michel de Certeau's keys of political discernment in May 1968: The theological-spiritual assumptions that informed his tools of analysis

This article seeks to identify the theoretical tools that supported Michel de Certeau's political discernment during the crisis of May 1968 in France. De Certeau's ability to elucidate the novelty and complexity of this event is linked to the intertwining of his experiences as a historian, traveller (voyageur), and Christian (specifically a Jesuit). De Certeau's articulation of a 'theology of difference' allowed him to construct the intellectual and spiritual tools that enabled a lucid discernment of May 1968. Through this theology, derived from negative theology, de Certeau made the experience of faith operative at a moment of cultural crisis. The article also analyses possibilities involved in the ‘rupture’, that is, the fracture that is implied in modernity; in the notion of an event that highlights the deficiency of language, its incapacity to establish ‘a truthful communication’ in society; and the recognition of the poetic dimension of speech, which is capable of interweaving speech and action. The May 1968 event invites these elements mutually to redefine themselves.