Chicks' responses to familiar stimuli in unfamiliar environments

The aim of the present experiments was to find out how imprinted chicks respond to familiar figures in unfamiliar settings. Experiment I showed that chicks individually imprinted with a coloured stationary disc did not readily approach it when later confronted with it in a larger pen—a confirmation of an earlier finding. Experiment II showed a similar disruptive effect when the chicks were individually presented with a stationary object (a ball) in a pen differing in colour from the original one. Experiment III, however, in which chicks were imprinted to a moving ball, showed unattenuated imprinting when testing took place in a strange environment. It was concluded that the disruptive effect of neophobia can be overcome when a high degree of figure salience ensures powerful imprinting.     

A Study of Blocking and Overshadowing in Filial Imprinting

The occurrence of blocking and overshadowing in filial imprinting was investigated in junglefowl chicks (Gallus gallus spadiceus). When subjects were exposed to a novel object in the presence of a familiar one, imprinting on the novel object was impaired in one of two experimental groups (Experiment 1). When subjects were exposed to two objects from the beginning, imprinting on each object was impaired (Experiment 2). These results suggest that phenomena resembling blocking and overshadowing in conditioning may occur in imprinting. The fact that overshadowing was much more prevalent and convincing than blocking is discussed by referring to processes involved in the formation of internal representations. It is suggested that processes connecting these representations to the executive system of filial behaviour may follow the rules of associative learning.     

Effects of imprinting and isolation on aggressive responses in chicks

The importance of isolation and imprinting as separate factors influencing early aggressive responses in chicks (Gallus gallus) was studied in two separate experiments. In addition the effect of the presence or absence of the imprinting stimulus in the test situation was examined in Experiment 1. Neither imprinting per se, nor the presence of the imprinting stimulus significantly affected aggressiveness. Rearing conditions (isolation vs social rearing) did, however, influence aggressive responses. Isolated chicks were significantly more aggressive than socially reared buds. The adaptedness of selective aggression in socially (naturally) reared chicks, as well as the indiscriminant aggressiveness caused by social deprivation is discussed.     

Isolation-induced aggression in newly hatched ducklings.

Newly hatched Khaki Campbell ducklings (Anas platyrhynchos domesticus) were initially housed in pairs and subsequently transferred to isolated housing conditions. Subjects living with another bird displayed filial behavior and little aggression upon encountering another duckling in a test arena. In contrast, ducklings housed in isolation exhibited aggressive pecking in addition to filial behavior when another duckling was subsequently encountered. In Experiment 2, ducklings were housed with an imprinting object (i.e., an object that elicits attachment behavior), but they were otherwise isolated from other birds. These subjects displayed little aggression when they were subsequently reunited with a conspecific, indicating that the aggression-precluding effects of social housing are not limited to the particular social stimulus with which the ducklings are housed. In Experiment 3, ducklings were again housed with an imprinting object, but this time the object was behind glass, thereby precluding tactile contact with it. Since these birds also exhibited little aggression when reunited with a conspecific, it is apparent that visual stimulation from an imprinting object is sufficient in itself to preclude subsequent aggression. These findings suggest that stimulation that elicits attachment behavior is the critical factor mediating isolation-induced aggression.     

Nature reversed: Diminishing intensity of the maternal call affects approach behaviour of chicks

Skinner (1974) suggested that ducklings could be taught to move away from an imprinting object provided the natural consequences of approach behaviour was reversed. We constructed an apparatus in which approach behaviour toward an audio-visual stimulus caused reduced amplitude of a maternal call, whereas movement away caused an increase in amplitude. Chicks (Experiment 1) trained in this apparatus approached the training stimulus, but to a lesser degree than chicks exposed to calls of constant amplitude. Highly active experimental chicks kept a larger distance to the stimulus than passive chicks. Thus the reversal of the natural consequences of approaching influenced filial behaviour. However, a training period of three hours did not influence approach behaviour in the direction predicted by Skinner (1974). A second group of chicks (Experiment 2) which could increase the call amplitude by moving in one direction without being able to localize the sound source was more influenced by the amplitude gradient than Experiment I-chicks.     

A developmental-genetic analysis of aggressive behavior in mice: IV. Genotype-environment interaction

To assess the extent of plasticity in behavioral development after directional selection for aggressive behavior, male mice were reared and tested in selected social rearing and testing conditions. After four generations of selective breeding, the lines differed in all attack measures when tested in a dyadic assessment following isolation rearing. Line-specific effects of isolation vs. group rearing were demonstrated, and longitudinal studies showed the ontogenetic pattern of difference between lines to be substantially changed by conditions of rearing and testing. The social-interactional processes that might produce the developmental genotype-environment interaction were investigated. Line-specific interaction patterns within long-established sibling groups predicted aggressive behavior in cross-situational dyadic assessments. Group rearing attenuated most line differences in aggressive measures, but the high-aggressive line was more likely than the low-aggressive line to persist in attacking over consecutive days of observation. Cross-fostering in early development did not significantly change adult aggressive behavior. Some implications of a developmental-genetic approach to the study of social interactions are discussed.     

Development of three-dimensional form perception

In three experiments with infants and one with adults we explored the generality, limitations, and informational bases of early form perception. In the infant studies we used a habituation-of-looking-time procedure and the method of Kellman (1984), in which responses to three-dimensional (3-D) form were isolated by habituating 16-week-old subjects to a single object in two different axes of rotation in depth, and testing afterward for dishabituation to the same object and to a different object in a novel axis of rotation. In Experiment 1, continuous optical transformations given by moving 16-week-old observers around a stationary 3-D object specified 3-D form to infants. In Experiment 2 we found no evidence of 3-D form perception from multiple, stationary, binocular views of objects by 16- and 24-week-olds. Experiment 3A indicated that perspective transformations of the bounding contours of an object, apart from surface information, can specify form at 16 weeks. Experiment 3B provided a methodological check, showing that adult subjects could neither perceive 3-D forms from the static views of the objects in Experiment 3A nor match views of either object across different rotations by proximal stimulus similarities. The results identify continuous perspective transformations, given by object or observer movement, as the informational bases of early 3-D form perception. Detecting form in stationary views appears to be a later developmental acquisition.     

Effects of Rate of Reinforcement and Rate of Change on Choice Behaviour in Transition

In two experiments with pigeons, a single variable-interval schedule assigned reinforcers to two response keys on a percentage basis. The percentage of reinforcers assigned to each key was changed every few sessions, and subjects' choice responses were recorded before and after each change. In Experiment 1, the overall rate of reinforcement was varied across conditions. The pigeons' choice responses adapted more quickly to a change in the reinforcement percentages when the overall reinforcement rates were higher, but acquisition rates varied by only about a factor of 3, whereas reinforcement rates were varied by about a factor of 9. In Experiment 2, the reinforcement percentages changed about every 8 sessions in Phases 1 and 3, but every 1 or 2 sessions in Phase 2. Pigeons' choice responses adapted to a change in reinforcement percentages more quickly in Phase 2 than in Phases 1 and 3. The results from both experiments pose difficulties for several prominent models of transitional choice behaviour. The results suggest that each successive reinforcer has more impact on a subject's subsequent choice behaviour when the overall rate of reinforcement is lower and when the reinforcement contingencies have changed frequently in the recent past.     

Absence of compensation and reasoning-like processes in the perception of orientation in depth

When errors are present in the perceived depth between the parts of a physically stationary object, the object appears to rotate as the head is moved laterally (Gogel, 1980). This illusory rotation has been attributed either to compensation (Wallach, 1985, 1987) or to inferential-like processes (Rock, 1983). Alternatively, the perceived distances of and directions to the parts of the object are sufficient to explain the illusory perceived orientations and perceived rotations of the stimulus. This was examined in three experiments. In Experiment 1, a perceived illusory orientation of a stimulus object extended in depth was produced by misleading binocular disparity and was measured at two different lateral positions of the head under two conditions. In the static condition, the head was stationary at different times at each of the two measurement positions of the head. In the dynamic condition, continuous motion of the head occurred between these two positions. In Experiment 2, static and dynamic conditions of illusory stimulus orientation were observed with the head stationary. In Experiment 3, a perspective illusion instead of binocular disparity produced the errors in perceived depth. In no experiment did the perceived orientation of the object differ for the static and dynamic conditions. In the absence of head motion, neither compensatory nor inferential-like processes were available. It is concluded that these processes are not needed to explain either illusory or nonillusory perceptions of the orientation or rotation of stimuli viewed with a laterally moving head.     

Absence of compensation and reasoning-like processes in the perception of orientation in depth.

When errors are present in the perceived depth between the parts of a physically stationary object, the object appears to rotate as the head is moved laterally (Gogel, 1980). This illusory rotation has been attributed either to compensation (Wallach, 1985, 1987) or to inferential-like processes (Rock, 1983). Alternatively, the perceived distances of and directions to the parts of the object are sufficient to explain the illusory perceived orientations and perceived rotations of the stimulus. This was examined in three experiments. In Experiment 1, a perceived illusory orientation of a stimulus object extended in depth was produced by misleading binocular disparity and was measured at two different lateral positions of the head under two conditions. In the static condition, the head was stationary at different times at each of the two measurement positions of the head. In the dynamic condition, continuous motion of the head occurred between these two positions. In Experiment 2, static and dynamic conditions of illusory stimulus orientation were observed with the head stationary. In Experiment 3, a perspective illusion instead of binocular disparity produced the errors in perceived depth. In no experiment did the perceived orientation of the object differ for the static and dynamic conditions. In the absence of head motion, neither compensatory nor inferential-like processes were available. It is concluded that these processes are not needed to explain either illusory or nonillusory perceptions of the orientation or rotation of stimuli viewed with a laterally moving head.     

特征变化的连续性影响客体连续表征的维持

本研究采用客体回溯范式考察了特征变化的连续性对维持客体连续表征的作用。实验1和实验2分别探索了形状维度上的变化方式（不变、渐变、突变）和亮度维度上的变化方式（不变、渐变、随机变化）对客体预览利化效应的影响。在特征连续条件下（不变或渐变）,两个实验都获得了客体预览利化效应。而在特征不连续变化条件下（突变或随机变化）,该效应消失。这些结果说明特征变化的连续性同样影响客体连续表征的维持。     

Visual long-term memory and change blindness: Different effects of pre- and post-change information on one-shot change detection using meaningless geometric objects

To clarify the relationship between visual long-term memory (VLTM) and online visual processing, we investigated whether and how VLTM involuntarily affects the performance of a one-shot change detection task using images consisting of six meaningless geometric objects. In the study phase, participants observed pre-change (Experiment 1), post-change (Experiment 2), or both pre- and post-change (Experiment 3) images appearing in the subsequent change detection phase. In the change detection phase, one object always changed between pre- and post-change images and participants reported which object was changed. Results showed that VLTM of pre-change images enhanced the performance of change detection, while that of post-change images decreased accuracy. Prior exposure to both pre- and post-change images did not influence performance. These results indicate that pre-change information plays an important role in change detection, and that information in VLTM related to the current task does not always have a positive effect on performance.     

Passive tactile feedback facilitates mental rotation of handheld objects

Mental rotation of objects improves when passive tactile information for the rotating object accompanies the imagined rotation (Wraga, Creem, & Proffitt, 2000). We examined this phenomenon further using a within-subjects paradigm involving handheld objects. In Experiment 1, participants imagined rotating an unseen object placed on their upturned palms. The participants were faster at mental rotation when the object was rotated on their palm than when the object remained stationary. Experiment 2 tested whether the performance advantage would endure when the participants received tactile information for only the start- and endpoints of the rotation event. This manipulation did not improve performance, relative to a stationary control. Experiment 3 revealed that ambiguous tactile information, continuous with the rotation event but independent of object shape, actually degraded performance, relative to a stationary control. In Experiment 4, we found that continuous tactile rotation discrepant from imagined object movement also hindered performance, as compared with continuous tactile information aligned with imagined object movement. The findings suggest a tight coupling between tactile information specifying continuous object rotation and the corresponding internal representation of the rotating object.     

Paradoxes of Falsification

This paper deals with the concept of falsification in hypothesis testing research. A theoretical analysis of assumptions about falsifying behaviour and hypothesis-falsifying observations is presented, with two experimental studies. Both the theoretical analysis and the experimental results point to a number of paradoxes underlying the normative principle of falsification in cognitive psychology. First, subjects experience the falsificatory testing strategy as an impossible strategy to conduct. Obtaining falsifying results is a consequence of the quality of the hypothesis rather than of specific testing behaviour (Experiment 1 and Experiment 2). Second, under some conditions falsifying results impede rather than facilitate discovery (Experiment 2). Confirmatory testing and falsificatory testing, which have been the crucial concepts in the study of hypothesis-testing behaviour, may actually be questionable approaches to testing behaviour. The theoretical analysis is related to the standard analyses of Popper (1963) and Klayman and Ha (1987). The empirical results are discussed in relation to previous studies on falsificatory testing behaviour.     

The role of detection and recollection of change in list discrimination

In two experiments, we examined the importance of the detection and recollection of change for list discrimination. Two lists of pairs were presented, with the right-hand member being changed between lists for some pairs. Participants in Experiment 1 were instructed to explicitly indicate when they detected a change between pairs during the presentation of List 2, whereas participants in Experiment 2 were not instructed to do so. At the time of test, participants in both experiments were presented with a pair and asked whether it had been presented in List 2. Next, recollection of change was measured by asking whether the right-hand member of the pair was changed between the lists. The results from Experiment 1 revealed high correspondence between the detection of change during the presentation of List 2 and the recollection of change at the time of test. Consequently, change recollection at test can serve as a measure of earlier change detection, in combination with access to memory for change at the time of test. In both experiments, as compared to control conditions, proactive facilitation in list discrimination was observed when change was recollected, whereas proactive interference was observed when change was not recollected. These results were interpreted as showing that recursive reminding—bringing a List 1 pair to mind during the presentation of its changed List 2 pair—embeds memory for the earlier event into memory for the later event, and doing so preserves information about list membership.     

The properties of object representations constructed during visual search in natural scenes

To investigate properties of object representations constructed during a visual search task, we manipulated the proportion of trials/task within a block: In a search-frequent block, 80% of trials were search tasks; remaining trials presented a memory task; in a memory-frequent block, this proportion was reversed. In the search task, participants searched for a toy car (Experiments 1 and 2) or a T-shape object (Experiment 3). In the memory task, participants had to memorize objects in a scene. Memory performance was worse in the search-frequent block than in the memory-frequent block in Experiments 1 and 3, but not in Experiment 2 (token change in Experiment 1; type change in Experiments 2 and 3). Experiment 4 demonstrated that lower performance in the search-frequent block was not due to eye-movement behaviour. Results suggest that object representations constructed during visual search are different from those constructed during memorization and they are modulated by type of target.     

Search behaviour of cats (Felis catus) in an invisible displacement test: cognition and experience

An invisible displacement test was administered to cats in order to test the hypothesis that search behaviour in this species is influenced by their limited capacity for object permanence as well as by their previous experience with the environment. Experiment 1 compared three groups of cats in a five-choice hiding task in which the hiding places could be discriminated by their spatial positions. Two groups received a visible displacement training before the invisible displacement test and one group did not. Experiment 2 compared two groups of trained subjects in the same task, but the hiding places could be discriminated by spatial and visual cues. The results confirmed that cats are unable to solve problems with invisible displacements. The visible displacement training improved their performance, but was not sufficient to make them succeed. Experience with the hiding potential of the covers also gives more persistence to search behaviour. Finally, the distribution of search attempts is not determined by the proximity to the target and is influenced only partially by the subjects' previous experience. Like Stage 5 infants, cats rely mainly on their immediate perception. They search for an object in the last location they have seen it disappear or under the nearest cover from this location.     

Achieving incremental semantic interpretation through contextual representation.

While much work has been done investigating the role of context in the incremental processing of syntactic indeterminacies, relatively little is known about online semantic interpretation. The experiments in this article made use of the eye-tracking paradigm with spoken language and visual contexts in order to examine how, and when listeners make use of contextually-defined contrast in interpreting simple prenominal adjectives. Experiment 1 focused on intersective adjectives. Experiment 1A provided further evidence that intersective adjectives are processed incrementally. Experiment 1B compared response times to follow instructions such as 'Pick up the blue comb' under conditions where there were two blue objects (e.g. a blue pen and a blue comb), but only one of these objects had a contrasting member in the display. Responses were faster to objects with a contrasting member, establishing that the listeners initially assume a contrastive interpretation for intersective adjectives. Experiments 2 and 3 focused on vague scalar adjectives examining the time course with which listeners establish contrast for scalar adjectives such as tall using information provided by the head noun (e.g. glass) and information provided by the visual context. Use of head-based information was examined by manipulating the typicality of the target object (e.g. whether it was a good or poor example of a tall glass. Use of context-dependent contrast was examined by either having only a single glass in the display (the no contrast condition) or a contrasting object (e.g. a smaller glass). The pattern of results indicated that listeners interpreted the scalar adjective incrementally taking into account context-specific contrast prior to encountering the head. Moreover, the presence of a contrasting object, sharply reduced, and in some conditions completely eliminated, typicality effects. The results suggest a language processing system in which semantic interpretation, as well as syntactic processing, is conducted incrementally, with early integration of contextual information.     

On the role of object representations in substitution masking

Three experiments were conducted to investigate the role of object representations in object substitution masking (OSM). OSM occurs when a very sparse mask is presented simultaneously with a target stimulus and the target offsets first, leaving the mask to linger in the display for some time. Results confirm earlier claims that there is an isolatable object-level component to OSM and indicate that a target can be protected from OSM if, prior to offsetting, it can be represented as a distinct object from the mask. When the mask was presented as sliding past the target (Experiment 1), as jiggling independently of the target (Experiment 2), or in a different color from the target (Experiment 3), OSM was reduced or eliminated. This suggests that OSM reflects basic updating processes that allow the perception of continuity of object identity over change.     

The role of color in visual search in real-world scenes: evidence from contextual cuing

Because the importance of color in visual tasks such as object identification and scene memory has been debated, we sought to determine whether color is used to guide visual search in contextual cuing with real-world scenes. In Experiment 1, participants searched for targets in repeated scenes that were shown in one of three conditions: natural colors, unnatural colors that remained consistent across repetitions, and unnatural colors that changed on every repetition. We found that the pattern of learning was the same in all three conditions. In Experiment 2, we did a transfer test in which the repeating scenes were shown in consistent colors that suddenly changed on the last block of the experiment. The color change had no effect on search times, relative to a condition in which the colors did not change. In Experiments 3 and 4, we replicated Experiments 1 and 2, using scenes from a color-diagnostic category of scenes, and obtained similar results. We conclude that color is not used to guide visual search in real-world contextual cuing, a finding that constrains the role of color in scene identification and recognition processes.