Perception of object unity in young infants: The roles of motion,depth, and orientation

One hundred twenty-eight 4-month-old infants were habituated to one of several displays that depicted two rod pieces above and below a box. The effects of common motion, background texture, and orientation of the rod pieces on infants' perception of unity of the partially occluded rod were examined. Infants who viewed displays in which the rod pieces were aligned and presented in front of a textured background, subsequently looked longer at a broken rod (two rod pieces separated by a gap) than at a complete rod, implying that the infants experienced the rod pieces as connected behind the box in the first display. Infants who viewed displays with no background texture, or displays in which the rod pieces were nonaligned but relatable (i.e., connected if extended behind the occluder), looked equally at the two posthabituation displays. Infants who viewed displays containing nonrelatable rod pieces looked longer at the complete rod, implying that nonrelatable edges specify disjoint objects to 4-month-olds. A threshold model, stipulating that perception of object unity is supported by multiple visual cues, is proposed to account for these results. Veridical perception of motion of display elements, depth ordering, and edge orientation are necessary, but not individually sufficient, to support young infants' perception of object unity.     

The role of three-dimensional depth cues in infants' perception of partly occluded objects

Newborn infants were familiarized to a three dimensional display consisting of a rod which moved behind a central occluder, so that only the top and bottom of the rod were visible. The infants' eyes were 38 cm from the rod and the occluder was 15 cm in front of the rod, a separation intended to ensure that the gap between the two was detected by the infants. On subsequent test trials the infants looked longer at a complete rod than at two rod pieces, suggesting that the hidden unity, or completeness of the rod had not been perceived. In a study by Johnson and Náñez (in press), using computer. generated stimuli, 4 month olds perceived the hidden unity of a similar display presented on a VDU in the complete absence of three. dimensional depth cues. Taken together, these findings suggest that, for these displays, perception of three. dimensional depth cues is not necessary for the detection of the unity of partially hidden objects. It is suggested that age changes in early infancy in the perception of occluded objects may result either from the emergence of abilities to perceive objects from kinematic information or from the emergence of sensitivity to that information itself.     

At the root of the left–right asymmetries in spatial–numerical processing: From domestic chicks to human subjects

In this review, we discuss evidence showing that birds (Gallus gallus and Nucifraga columbiana) represent numerical magnitudes as being oriented from left to right. Subjects, trained to identify a target element (i.e. the 4th) in a series of sagittally oriented identical elements, when required to generalise on an identical series oriented spatially from left to right, correctly identified the target element “counting” from the left of the array. Moreover, chicks, when presented with sets of 5 vs. 10 or 6 vs. 9 imprinting objects, which were made to disappear one at a time behind one of two identical screens, spontaneously inspected the screen which occluded the larger set. Interestingly, chicks scored a higher percentage of correct choices when the larger of the two sets was on their right side. Similarities with the phenomenon of the spatially oriented (left to right) number line in humans are discussed. Animal models promise a fresh approach to the understanding of developmental mechanisms underlying the expression of knowledge, offering attractive arguments for doubting the uniqueness of human numerical cognition.     

Measuring the speed of newborn object recognition in controlled visual worlds

How long does it take for a newborn to recognize an object? Adults can recognize objects rapidly, but measuring object recognition speed in newborns has not previously been possible. Here we introduce an automated controlled‐rearing method for measuring the speed of newborn object recognition in controlled visual worlds. We raised newborn chicks (Gallus gallus) in strictly controlled environments that contained no objects other than a single virtual object, and then measured the speed at which the chicks could recognize that object from familiar and novel viewpoints. The chicks were able to recognize the object rapidly, at presentation rates of 125 ms per image. Further, recognition speed was equally fast whether the object was presented from familiar viewpoints or novel viewpoints (30° and 60° azimuth rotations). Thus, newborn chicks can recognize objects across novel viewpoints within a fraction of a second. These results demonstrate that newborns are capable of both rapid and invariant object recognition at the onset of vision.     

Will jurors correct for evidence interdependence in their verdicts? It depends

Throughout an investigation, pieces of evidence are likely to contaminate one another, yet at trial jurors are expected to treat pieces of evidence as if they are independent. Are jurors able to understand potential evidence contamination? The present study showed mock jurors a videotaped trial simulation. Participants were randomly assigned to hear testimony regarding one piece of evidence, two pieces of independent evidence, or two pieces of interdependent evidence. The study tested the hypothesis that jurors who hear evidence that is interdependent will be just as likely to find the defendant guilty as jurors who hear about two pieces of independent evidence. When an eyewitness's identification was the uncontaminated piece of evidence, our hypothesis was supported. However, when the confession was the uncontaminated piece of evidence, jurors seemed to understand that one piece of evidence had been influenced by another and adjusted their beliefs about the defendant's guilt accordingly. This study supports the conclusion that jurors can sometimes identify and correct for evidence contamination in their perceptions of a defendant's guilt. Implications for reform support are discussed.     

Representation of two geometric features of the environment in the domestic chick (<Emphasis Type="Italic">Gallus gallus</Emphasis>)

We report experiments based on a novel test in domestic chicks (Gallus gallus), designed to examine the encoding of two different geometric features of an enclosed environment: relative lengths of the walls and amplitude of the corners. Chicks were trained to search for a food reward located in one corner of a parallelogram-shaped enclosure. Between trials, chicks were passively disoriented and the enclosure was rotated, making reorientation possible only on the basis of the internal spatial structure of the enclosure. In order to reorient, chicks could rely on two sources of information: the relative lengths of the walls of the enclosure (associated to their left-right sense order) and the angles subtended by walls at corners. Chicks learned the task choosing equally often the reinforced corner and its rotational equivalent. Results of tests carried out in novel enclosures, the shapes of which were chosen ad hoc (1) to induce reorientation based only on the ratio of walls lengths plus sense (rectangular enclosure), or (2) to induce reorientation based only on corner angles (rhombus-shaped enclosure), suggested that chicks encoded both features of the environment. In a third test, in which chicks faced a conflict between these geometric features (mirror parallelogram-shaped enclosure), reorientation seemed to depend on the salience of corner angles. These results shed light on the elements of the environmental geometry which control spatial reorientation, and broaden the knowledge on the geometric representation of space in animals.     

Piecing together numerical language: children's use of default units in early counting and quantification

When asked to ‘find three forks’, adult speakers of English use the noun ‘fork’ to identify units for counting. However, when number words (e.g. three) and quantifiers (e.g. more, every) are used with unfamiliar words (‘Give me three blickets’) noun‐specific conceptual criteria are unavailable for picking out units. This poses a problem for young children learning language, who begin to use quantifiers and number words by age 2, despite knowing a relatively small number of nouns. Without knowing how individual nouns pick out units of quantification – e.g. what counts as a blicket– how could children decide whether there are three blickets or four? Three experiments suggest that children might solve this problem by assigning ‘default units’ of quantification to number words, quantifiers, and number morphology. When shown objects that are broken into arbitrary pieces, 4‐year‐olds in Experiment 1 treated pieces as units when counting, interpreting quantifiers, and when using singular–plural morphology. Experiment 2 found that although children treat object‐hood as sufficient for quantification, it is not necessary. Also sufficient for individuation are the criteria provided by known nouns. When two nameable things were glued together (e.g. two cups), children counted the glued things as two. However, when two arbitrary pieces of an object were put together (e.g. two parts of a ball), children counted them as one, even if they had previously counted the pieces as two. Experiment 3 found that when the pieces of broken things were nameable (e.g. wheels of a bicycle), 4‐year‐olds did not include them in counts of whole objects (e.g. bicycles). We discuss the role of default units in early language acquisition, their origin in acquisition, and how children eventually acquire an adult semantics identifying units of quantification.     

THE ELUSIVENESS OF JEWISHNESS: JEWS IN VIENNESE POPULAR CULTURE AROUND 1900

The participation of Jews in Viennese popular culture in the fin-de-siècle period has to date been scarcely investigated. This essay sheds light on one aspect of the vast field of popular culture, the lively scene of Jewish Volkssänger. They formed ensembles of musicians who played Viennese songs (Wienerlieder) and performed short theatrical pieces. The central questions posed in the article concern the Jewishness of the Volkssänger: how is it expressed and can it be determined, what distinguishes Jewish from non-Jewish Volkssänger, does Jewishness play a role in the formers' performances? In order to answer these questions, several theatre pieces of various Jewish Volkssänger ensembles are examined using a new analytical tool, Jewish difference. Through its application, it is possible to show that the theatre pieces performed by the Jewish Volkssänger represented Jews without a fixed, static self-understanding. Their Jewishness was depicted as fluid, diverse, determinable only at certain moments and in specific contexts. The distinction between Jews and non-Jews was blurred. A glance at the biographies of the Jewish Volkssänger revealed that their lives were very much like those of the Jewish characters in the plays: they readily intermingled with non-Jews, and their Jewishness was only one––and an always changing––facet of their multiple identities.     

Multiple landmarks, the encoding of environmental geometry and the spatial logics of a dual brain

A series of place learning experiments was carried out in young chicks (Gallus gallus) in order to investigate how the geometry of a landmark array and that of a walled enclosure compete when disoriented animals could rely on both of them to re-orient towards the centre of the enclosure. A square-shaped array (four wooden sticks) was placed in the middle of a square-shaped enclosure, the two structures being concentric. Chicks were trained to ground-scratch to search for food hidden in the centre of the enclosure (and the array). To check for effects of array degradation, one, two, three or all landmarks were removed during test trials. Chicks concentrated their searching activity in the central area of the enclosure, but their accuracy was inversely contingent on the number of landmarks removed; moreover, the landmarks still present within the enclosure appeared to influence the shape of the searching patterns. The reduction in the number of landmarks affected the searching strategy of chicks, suggesting that they had focussed mainly on local cues when landmarks were present within the enclosure. When all the landmarks were removed, chicks searched over a larger area, suggesting an absolute encoding of distances from the local cues and less reliance on the relationships provided by the geometry of the enclosure. Under conditions of monocular vision, chicks tended to rely on different strategies to localize the centre on the basis of the eye (and thus the hemisphere) in use, the left hemisphere attending to details of the environment and the right hemisphere attending to the global shape.This contribution is part of the special issue “Animal Logics” (Watanabe and Huber 2006).     

Stroop-like interference in chess players' imagery: An unexplored possibility to be revealed by the adapted moving-spot task

Summary A group of highly skilled chess players and two control groups of subjects (nonskilled players and nonplayers) participated in a moving-spot task (cf. Attneave & Curlee, 1983). They had to move either a spot or one of several chess pieces within an imaginary grid according to instructions given by the experimenter (the imaginary motion of the imaginary object consisted of a quasirandom sequence of steps in the direction — up, right, left, or down). The general findings were as follows: (1) chess players' error rates were lower than those in the nonplayer group; (2) in a moving-spot condition there were no significant differences in the efficiency of skilled vs. nonskilled player groups; (3) in a moving chess-piece condition, ranges of spatial errors differed for chess-player and nonplayer groups, depending on the symbolic meaning of the chess pieces in the former group; (4) in a moving chess-piece condition we also found tendencies for Stroop-like interference in the group of skilled players (e. g., bishop moving illegally up, right, etc.); (5) all groups benefitted from the use of a checkerboard instead of an 8 × 8 grid as the imaginary spatial framework within which to move a piece; (6) thepost hoc analysis showed that the two small selected subgroups of subjects comprising those who used either pure visual strategy or pure chess-annotation strategy were susceptible to some Stroop-like interference and that the set of pieces with the highest incongruity of moves (bishop, knight) yielded higher error rates than the set of pieces that had congruity of moves (king, rook). Taken together, these results seem to indicate that visuospatial tasks like Attneave and Curlee's (1983) moving-spot task are performed neither on the basis of a static picture-in-the-head type of visual image, for which it is just the same whether one or another type of piece is imaginarily moved, nor on the basis of purely symbolic or propositional operations that bear no relation to the visual-configurational and spatial-localizational representations. Imagery seems to constitute a dynamicprocess of interplay between visuospatial and verbal-propositional codes.     

Stimulus Comparison and Perceptual Learning: Further Evidence and Evaluation from an Imprinting Procedure

Two experiments used chicks to investigate the role of stimulus comparison in perceptual learning. In Experiment 1, chicks received exposure to two views of a jungle fowl, SV (side view) and BV (back view), intermixed within a session (mixed exposure), exposure to SV in one session and BV in a different session (separate exposure), or no exposure to either view. All chicks then received a heat-reinforced discrimination with SV and BV serving as discriminanda. Chicks given mixed exposure acquired the discrimination more readily than did either those given separate exposure or those given no exposure. In Experiment 2, all chicks received mixed exposure to the two stimuli. For one group the interval between presentations of the stimuli was short (short-mixed), for the other group it was long (long-mixed). Subjects in the long-mixed condition acquired the heat-reinforced discrimination more rapidly than those in the short-mixed condition. These results suggest that the intermixed nature of stimulus exposure is an important determinant of the magnitude of perceptual learning effects.     

Chicks prefer to peck at insect-like elongated stimuli moving in a direction orthogonal to their longer axis

Spontaneous preferences towards possible prey have been little investigated using targets in motion. Preferences of domestic chicks (Gallus gallus) to peck at video-images of stimuli representing live insects moving along their longer body axis (i.e. “forwards”) or along the shorter body axis (i.e. “sideways”) were investigated. Chicks presented with both types of stimulus displayed a significant preference for pecking at stimuli moving sideways. This preference was already present on day 1 post-hatching, and it strengthened on day 6 for those chicks that had experienced pecking at live insects. Head angles used to fixate the stimuli prior to pecking were also analysed and were consistent (i.e. 30°–35° and 60°–65°) with those reported for fixation of non-edible targets (larger stimuli at a distance). In a first control experiment the same video-presented stimuli were used but the insect’s legs were removed to reduce flickering. In a second control experiment, paper-printed images of the whole insect were used. In both cases, the sideways direction of movement was clearly preferred. Overall, our data show that chicks have a spontaneous preference to peck at video-images resembling live insects moving along their shorter body axis. Sideways movement may constitute a crucial signal attracting chicks’ attention and enhancing predatory responses possibly because of stronger stimulation of motion detectors.     

Characterizing the information content of a newly hatched chick's first visual object representation

How does object recognition emerge in the newborn brain? To address this question, I examined the information content of the first visual object representation built by newly hatched chicks (Gallus gallus). In their first week of life, chicks were raised in controlled‐rearing chambers that contained a single virtual object rotating around a single axis. In their second week of life, I tested whether subjects had encoded information about the identity and viewpoint of the virtual object. The results showed that chicks built object representations that contained both object identity information and view‐specific information. However, there was a trade‐off between these two types of information: subjects who were more sensitive to identity information were less sensitive to view‐specific information, and vice versa. This pattern of results is predicted by iterative, hierarchically organized visual processing machinery, the machinery that supports object recognition in adult primates. More generally, this study shows that invariant object recognition is a core cognitive ability that can be operational at the onset of visual object experience.     

The Development of Invariant Object Recognition Requires Visual Experience With Temporally Smooth Objects

How do newborns learn to recognize objects? According to temporal learning models in computational neuroscience, the brain constructs object representations by extracting smoothly changing features from the environment. To date, however, it is unknown whether newborns depend on smoothly changing features to build invariant object representations. Here, we used an automated controlled‐rearing method to examine whether visual experience with smoothly changing features facilitates the development of view‐invariant object recognition in a newborn animal model—the domestic chick (Gallus gallus). When newborn chicks were reared with a virtual object that moved smoothly over time, the chicks created view‐invariant representations that were selective for object identity and tolerant to viewpoint changes. Conversely, when newborn chicks were reared with a temporally non‐smooth object, the chicks developed less selectivity for identity features and less tolerance to viewpoint changes. These results provide evidence for a “smoothness constraint” on the development of invariant object recognition and indicate that newborns leverage the temporal smoothness of natural visual environments to build abstract mental models of objects.     

Cutting the silence: initial,impulsive self-cutting in adolescence

The paper explores initial, impulsive self-cutting in adolescence and conceives of early cutting as having the most potential for a communicative function, as the adolescents themselves and those around them may be most shocked at their self-harm. The author also conceives of the symptom of early, initial cutting as an effort to ‘cut through’ an emotional and familial circumstance that has been silent, suggesting that cutting generally implies a failure in containment and symbolisation. Using Green’s (1975) discussion of the original word symbol as ‘an object cut in two, constituting a sign of recognition when those who carry it can assemble the two pieces’ (Dictionnaires Le Robert), the author demonstrates that cutting has the potential to elicit intense feelings in the analyst who can have (in Green’s terms) a homologous experience to that of the patient. This elaboration within the analyst’s feelings returns a part to the patient. The meeting of the two communications (the patient’s cutting and the elaboration in the analyst’s mind) can create a potential space between them. The paper uses clinical vignettes and extended clinical material from a 16-year-old girl to elucidate the relationship between cutting – an emotionally inarticulate state – and the development of communication, containment and symbolisation through homologous experiences in the analyst.     

Individual differences in information order effects: The importance of right-hemisphere access in belief updating

The order in which information is received alters the evaluation of causal hypotheses. Specifically, research suggests that the last piece of information oftentimes has the greatest impact on the evaluation and that the difference in subjective value between two pieces of information is an important factor influencing the magnitude of this recency effect. The present paper extends this line of work by exploring individual differences in this phenomenon via one's degree of handedness. Two hundred and five participants were given two hypothetical scenarios and related causal hypotheses accompanied by two pieces of additional information and asked to revise their belief in each hypothesis as information accumulated. Results confirmed predictions that 1) inconsistent/mixed-handers (those who use their non-dominant hand for at least some activities) show a larger effect with two pieces of inconsistent weak or strong information, and 2) neither mixed-handers nor consistent/strong-handers (those who use their dominant hand for almost all activities) show an effect with strong and weak pieces of consistent information. Mixed-handers' susceptibility to persuasive arguments and Ramachandran’s (1995; Ramachandran and Blakeslee, 1998) belief-updating theory centered around communication between the two halves of the brain and functional access to the right hemisphere are used to account for these data.     

Internal and external factors modulate food-calling in domestic hens

Two series of experiments investigated factors affecting utterance of food calls in the domestic hen, Gallus domesticus. The first series of experiments tested the effect of food preference and the hen’s internal state on the utterance of food calls. Different food types were presented first singly and then in a choice test to 20 hens, first when hens were laying, and then when they were maternal. The second series of experiments tested the effect of hunger level on the utterance of food calls in laying hens, and maternal hens with or without chicks. These two series of experiments showed that laying hens and maternal hens showed a similar marked preference for certain types of food, but laying hens very rarely emitted food calls, in contrast to maternal hens. This shows the effect of the bird’s psychophysiological state on her tendency to emit food calls. The more a maternal hen preferred a food type, the more food calls she emitted. This was observed from the beginning of a test in single-food tests as well as in choice tests. Hunger level positively affected food-call production under certain feeding conditions in maternal hens, but not in laying hens. When maternal hens were tested in the absence of their chicks, utterance of food calls was more sustained than in the presence of chicks. Received: 14 May 1998 / Accepted after revision: 11 October 1998     

Maintenance of Self-Imposed Delay of Gratification by Four Chimpanzees (Pan troglodytes) and an Orangutan (Pongo pygmaeus)

Delay maintenance, which is the continuance over time of the choice to forgo an immediate, less preferred reward for a future, more preferred reward, was examined in 4 chimpanzees (Pan troglodytes) and 1 orangutan (Pongo pygmaeus). In the 1st experiment, the apes were presented with 20 chocolate pieces that were placed, one at a time, into a bowl that was within their reach. The apes could consume the available chocolate pieces at any time during a trial, but no additional pieces would be given. The total length of time taken to place the 20 items into the bowl ranged from 60 s to 180 s. All 5 apes delayed gratification on a majority of trials until all 20 chocolate pieces were presented. Unlike in most experiments with human children using this test situation, attention by the apes to the reward was not detrimental to delay maintenance. In a 2nd experiment with the chimpanzees only, 4 foods of differing incentive value were presented in different trials in the same manner as in Experiment 1. The chimpanzees were highly successful in obtaining all food pieces, and there was no difference in performance as a function of food type.     

What It Means to Be a Man: Aging and Anxiety in Beckett's Krapp's Last Tape and That Time

One of the great writers of Twentieth-century doubt, Samuel Beckett is perhaps best known for endowing his protagonists with some of the more classic symptoms of anxiety and depression. The result is an extraordinary corpus that unfolds how the intricacies and excesses of anxiety affect the behavior of men and women involved in intimate relationships, and how that behavior is exhibited in their aging years. While this discussion of Krapp's Last Tape (1960) and That Time (1976) will explore anxiety from a specifically male point of view, the works themselves compel various responses from readers of both sexes. Both pieces also may be of interest to those concerned with the rethinking of sexual roles in intimate relationships in light of an individual's response to the physical and emotional aspects of aging.     

Imprinting, Conditioning, and Within-event Learning

Three experiments investigated whether or not the temporal relationship between the visual (V) and auditory (A) components of an imprinting stimulus influenced the acquisition of a visual preference in domestic chicks (Gallus gallus domesticus). In Experiments 1a and 1b, chicks given simultaneous presentations of V and A showed a more marked tendency to approach V than those given sequential exposure to V and A. In Experiments 2 and 3, chicks received exposure to two visual stimuli, V1 and V2. During training, presentations of V1 preceded, followed, or were separated by 30 sec from presentations of a simultaneous compound comprising V2 and A. Chicks in each condition subsequently showed an equivalent preference to approach V2 rather than V1. These results show that filial imprinting, unlike Pavlovian conditioning but like within-event learning, proceeds most readily when training involves the simultaneous presentation of stimuli.