Adaptation and counteradaptation to complex optical distortion

The optical distortion caused by wearing a facemask in water magnifies the angular size of objects and reduces their optical distance. However, objects generallyappear to be further than their optical distance, with the result that points in the left part of the visual field are apparently displaced to the left, and those on the right to the right. Experiments on hand-eye coordination under water showed that adaptation to one aspect of the distortion produced some counteradaptation to complementary aspects: adaptation to distance produced increased lateral distortion, and adaptation to one side of the lateral distortion produced increased distortion on the opposite side. Nevertheless, “trading” was incomplete, and some overall adaptation of the visual metric occurred.     

Adaptation to biological motion leads to a motion and a form aftereffect

Recent models have proposed a two-stage process of biological motion recognition. First, template or snapshot neurons estimate the body form. Then, motion is estimated from body form change. This predicts separate aftereffects for body form and body motion. We tested this prediction. Observers viewing leftward- or rightward-facing point-light walkers that walked forward or backward subsequently experienced oppositely directed aftereffects in stimuli ambiguous in the facing or the walking direction. These aftereffects did not originate from adaptation to the motion of the individual light points, because they occurred for limited-lifetime stimuli that restrict local motion. They also occurred when the adaptor displayed a random sequence of body postures that did not induce the walking motion percept. We thus conclude that biological motion gives rise to separate form and motion aftereffects and that body form representations are involved in biological motion perception.     

Using morphs of familiar objects to examine how shape discriminability influences view sensitivity

We investigated how the difficulty of detecting a shape change influenced the achievement of object constancy across depth rotations for object identification and categorization tasks. In three sequential matching experiments, people saw pictures of morphs between two everyday, nameable objects (e.g., bath-sink morphs, along a continuum between "bath" and "sink" end-point shapes). In each experiment, both view changes and shape changes influenced performance. Furthermore, the deleterious effects of view changes were strongest when shape discrimination was hardest. In our earlier research, using morphs of novel objects, we found a similar interaction between view sensitivity and shape sensitivity (Lawson, 2004b; Lawson & Bülthoff, 2006; Lawson, Bülthoff, & Dumbell, 2003). The present results extend these findings to familiar-object morphs. They suggest that recognition remains view-sensitive at the basic level of identification for everyday, nameable objects, and that the difficulty of shape discrimination plays a critical role in determining the degree of this view sensitivity.     

Psychoanalytic reflections on a particular form of language distortion.

A female obsessive patient communicated with her sister via a distortion of the Hebrew language, in which she masculinized the feminine gender second person pronoun and certain nouns. This treatment of words is analyzed in terms ranging from the concrete to the metaphoric uses of language. Lacan's emphasis on the meaning of the word is explored and is seen as an amplification rather than a replacement of the object relations approach to language and metaphor.     

Adaptation effects of highly familiar faces: Immediate and long lasting

A central problem of face identification is forming stable representations from entities that vary--both in a rigid and nonrigid manner--over time, under different viewing conditions, and with altering appearances. Three experiments investigated the underlying mechanism that is more flexible than has often been supposed. The experiments used highly familiar faces that were first inspected as configurally manipulated versions. When participants had to select the veridical version (known from TV/media/movies) out of a series of gradually altered versions, their selections were biased toward the previously inspected manipulated versions. This adaptation effect (face identity aftereffect, Leopold, Rhodes, Müller, & Jeffery, 2005) was demonstrated even for a delay of 24 h between inspection and test phase. Moreover, the inspection of a specific image version of a famous person not only changed the veridicality decision of the same image, but also transferred to other images of this person as well. Thus, this adaptation effect is apparently not based on simple pictorial grounds, but appears to have a rather structural basis. Importantly, as indicated by Experiment 3, the adaptation effect was not based on a simple averaging mechanism or an episodic memory effect, but on identity-specific information.     

Rapid adaptation to a prismatic distortion

Among several shape distortions caused by a wedge prism is one where a pattern of evenly spaced lines that are parallel to the prism base reaches the eye with distances seen through the base region contracted and distances seen through the apex region expanded. Rapid partial adaptation to this distortion was obtained by having subjects who wore the prism in vertical orientation move the head up and down during the exposure period. The head movements caused the distortion to shift up and down through the line pattern. When, with subjects’ heads stationary, the distortion was made to shift up and down by artificial means, rapid adaptation failed to develop. It is proposed that head movements are here needed for adaptation to develop, because the covariance between them and the shifting of the distortion serves as a signal that the distortions are not objective facts and causes the initiation of the adaptation process.     

Bias toward regular form in mental shape spaces

The distribution of figural "goodness" in 2 mental shape spaces, the space of triangles and the space of quadrilaterals, was examined. In Experiment 1, participants were asked to rate the typicality of visually presented triangles and quadrilaterals (perceptual task). In Experiment 2, participants were asked to draw triangles and quadrilaterals by hand (production task). The rated typicality of a particular shape and the probability that that shape was generated by participants were each plotted as a function of shape parameters, yielding estimates of the subjective distribution of shape goodness in shape space. Compared with neutral distributions of random shapes in the same shape spaces, these distributions showed a marked bias toward regular forms (equilateral triangles and squares). Such psychologically modal shapes apparently represent ideal forms that maximize the perceptual preference for regularity and symmetry.     

Brief flight to a familiar enclosure in response to a conditional stimulus in rats

The authors observed brief, directed movement to a familiar enclosure in rats to determine whether this behavior is part of a rat's defensive repertoire when exposed to a conditional-fear stimulus. In Experiment 1, upon exposure to the compound conditional-fear stimulus of tone and light, only rats that received paired presentations of the conditional stimuli and shock fled into a small, familiar enclosure where they then froze. Rats that had received unpaired presentations did not enter the enclosure in significant amounts when later tested. In Experiment 2, the authors observed rats' freezing and use of either a familiar or an unfamiliar enclosure when tested with a conditional-fear stimulus. Rats tested with a familiar enclosure entered it more quickly than did rats without prior exposure to the enclosure. Freezing was greatest when both training and testing environments were similar with respect to access to the enclosure. The results of these 2 experiments support the idea that brief, directed flight in rats is a component of the postencounter stage of predatory imminence (M. S. Fanselow & L. S. Lester, 1988) and is compatible with freezing.     

The comprehension of familiar and less familiar idioms

The relationship between idiom familiarity and idiom comprehension was investigated. Familiar and less familiar idioms were presented in three types of sentences. The sentences were biased toward the idiom's literal meaning, biased toward the idiom's idiomatic meaning, or unbiased toward either meaning. Reading times for sentences containing less familiar idioms were longer than for sentences containing familiar idioms, but there was no significant main effect for sentence type. The familiarity by sentence type interaction was significant. In literal sentences, less familiar idioms required more reading time than familiar idioms. In idiomatic sentences, less familiar idioms required more reading time than familiar idioms. The results are interpreted as being consistent with the idiomatic processing model, which proposes that processing of an idiom's idiomatic meaning precedes processing of its literal meaning.     

The effects of environmental change on chicks' responses to a familiar stimulus

The purpose of the present experiments was to explore chicks' proximity seeking behaviour in relation to imprinting objects in unfamiliar settings. Experiment I showed that chicks, which were individually imprinted on a stationary imprinting object, displayed reduced proximity seeking behaviour when tested in a pen smaller than the rearing pen. This finding confirmed earlier work on the effects of changed pen size. Experiment II used continuous and intermittent noise rearing and testing conditions, in all possible combinations, and a stationary imprinting object. Increased proximity seeking was found in conditions where the auditory environment was changed from rearing to testing, a result apparently opposite to that obtained in earlier work. It is suggested that the effect of environmental change on proximity seeking may vary with the modality in which change occurs and the salience of the imprinting object.     

Failure of familiar size to determine a metric for visually perceived distance

The use of knowledge of the familiar sizes of objects in determining the apparent distances of those objects is known as the familiar size cue to distance. If effective, this cue might be one of the factors responsible for supplying the metric (scalar) characteristics of perceptions of spatial extent within a visual display in which other information concerning scalar extents has been reduced to a minimum. Two groups of observers were presented with realistic objects of the same angular, but different assumed, sizes presented in such a cue-restricted display. Perceptions of size and distance within the display did not differ significantly as a function of the type of object initially presented. This result was consistent with the notion that scalar perceptions under these conditions probably are determined by a factor known as the specific distance tendency, rather than by the experiential factor of familiar size.     

Recognizing familiar objects by hand and foot: Haptic shape perception generalizes to inputs from unusual locations and untrained body parts

The limits of generalization of our 3-D shape recognition system to identifying objects by touch was investigated by testing exploration at unusual locations and using untrained effectors. In Experiments 1 and 2, people found identification by hand of real objects, plastic 3-D models of objects, and raised line drawings placed in front of themselves no easier than when exploration was behind their back. Experiment 3 compared one-handed, two-handed, one-footed, and two-footed haptic object recognition of familiar objects. Recognition by foot was slower (7 vs. 13 s) and much less accurate (9 % vs. 47 % errors) than recognition by either one or both hands. Nevertheless, item difficulty was similar across hand and foot exploration, and there was a strong correlation between an individual’s hand and foot performance. Furthermore, foot recognition was better with the largest 20 of the 80 items (32 % errors), suggesting that physical limitations hampered exploration by foot. Thus, object recognition by hand generalized efficiently across the spatial location of stimuli, while object recognition by foot seemed surprisingly good given that no prior training was provided. Active touch (haptics) thus efficiently extracts 3-D shape information and accesses stored representations of familiar objects from novel modes of input.     

Canine responses to familiar and unfamiliar humans

Dogs were observed during controlled approaches by their owners and by strangers. Significant differences between the dogs' responses to their owners and their responses to strangers were found. These results supported the popular belief that dogs respond differently to different persons, and not merely to different situations in which persons are usually encountered.     

Adaptation to context

Argument theorists often stress the idea of adaptation to context as an alternative to seeing argument as linked propositions. But adaptation is not a clear idea. It is in fact a complicated puzzle. Though many aspects of this puzzle are obscure, one clear conclusion is that the question-answer pair is not a good way to conceptualize adaptation to situation.     

Commitment to a developing preference and predecisional distortion of information

People tend to distort their evaluation of decision-relevant information in favor of the currently preferred alternative. We test whether this predecisional distortion of information is amplified by increased commitment to that current preference. We manipulated commitment, without changing the preferred option’s content, by requiring participants to indicate their preference either by circling or by darkening a sizable box (cf. feature-positive effect). Experiment 1 revealed that the effort to darken substantially increased predecisional distortion. Experiment 2 ruled out elaboration as an explanation for the effect of darkening. Experiment 3 showed that, among participants who attributed the darkening effort to an external source, predecisional distortion decreased when the source was believed to summon effort. These findings suggest that the developing commitment to a tentatively preferred alternative is one driver of predecisional distortion.     

Learning of lists of properties related to familiar objects

Four groups of Ss simultaneously learn six-word lists that indicate common objects' properties. Words of each list may either all correspond to the same object (highest homogeneity level), or, inversely, correspond to six different objects (highest heterogeneity level), with two intermediate situations in between.The homogeneity of lists has a main effect upon learning. It is hypothesized that the object corresponding to the words of a list is used, when it is detected, as a federator for this words, and thus facilitates their recall. It is concluded there is a certain similarity between word lists corresponding to several properties of an object and taxonomic lists.