Reversibility of single-incentive selective associations.

Rats were trained to press a lever in the presence of a tone-light compound stimulus and not to press in its absence. In each of two experiments, schedules were designed to make the compound a conditioned punisher for one group and a conditioned reinforcer for the other. In Experiment 1, one group's responding produced food in the presence of the compound but not in its absence. The other group's responding terminated the compound stimulus, and food was presented only in its absence. When tone and light were later presented separately, light controlled more responding than did tone in the former group, but tone gained substantial control in the latter. The same effects were also observed within subjects when the training schedules were switched over groups. In Experiment 2, two groups avoided shock in the presence of the compound stimulus. In the absence of the compound, one group was not shocked, and the other received both response-independent and response-produced shock. When tone and light were presented separately, the former group's responding was mainly controlled by tone, but the latter group's responding was almost exclusively controlled by light. These effects were also observed within subjects when the training schedules were switched over groups. Thus, these single-incentive selective association effects (appetitive in Experiment 1 and aversive in Experiment 2) were completely reversible. The schedules in which the compound should have been a conditioned reinforcer consistently produced visual control, and auditory control increased when the compound should have become a conditioned punisher. Currently accepted accounts of selective associations based on affinities between shock and auditory stimuli and between food and visual stimuli (i.e., stimulus-reinforcer interactions) do not adequately address these results. The contingencies of reinforcement most recently associated with the compound and with its absence, rather than the nature of the reinforcer, determined whether auditory or visual stimulus control developed.     

Ocular Movements in Reversibility of Perspective

To explore the role of acoustic factors in visual detection, this study employed 40 deaf and hearing Ss. Ss were requested to cancel all the letters “e” in a passage from Treasure Island. Results were analyzed in terms of probabilities of missing a pronounced or silent e and the e in the word “the.” Hearing and hard of hearing Ss were more likely to miss silent e's than pronounced e's. There was no significant difference between silent and pronounced e's for the profoundly deaf. Deaf and hearing Ss missed significantly more e's in “the” than pronounced or silent e's. The deaf, when compared to the hearing Ss, were more efficient in detecting pronounced and silent e's. They did not differ significantly from the hearing Ss in detecting the e in “the.”     

Filial imprinting and associative learning

Evidence is reviewed that is relevant to an interpretation of filial imprinting as a form of classical or Pavlovian conditioning. For such an interpretation it has to be assumed that the imprinting object provides both the unconditioned stimulus (UCS) and the conditioned stimulus (CS). The difficulty for an experimental approach is that CS and UCS are always presented simultaneously and cannot be manipulated independently, making it virtually impossible to test phenomena such as latent inhibition and extinction. Existing evidence is consistent with a conditioning theory of imprinting, for instance with regard to the reversibility of filial preferences. Some hitherto unexplained findings can be accounted for in terms of overshadowing and blocking. Results of an experiment are discussed in which the occurrence of blocking was explicitly tested. The findings support an associative learning interpretation of imprinting, but further experiments are needed to be able to rule cut alternative explanations.     

Causal imprinting in causal structure learning

Suppose one observes a correlation between two events, B and C, and infers that B causes C. Later one discovers that event A explains away the correlation between B and C. Normatively, one should now dismiss or weaken the belief that B causes C. Nonetheless, participants in the current study who observed a positive contingency between B and C followed by evidence that B and C were independent given A, persisted in believing that B causes C. The authors term this difficulty in revising initially learned causal structures "causal imprinting." Throughout four experiments, causal imprinting was obtained using multiple dependent measures and control conditions. A Bayesian analysis showed that causal imprinting may be normative under some conditions, but causal imprinting also occurred in the current study when it was clearly non-normative. It is suggested that causal imprinting occurs due to the influence of prior knowledge on how reasoners interpret later evidence. Consistent with this view, when participants first viewed the evidence showing that B and C are independent given A, later evidence with only B and C did not lead to the belief that B causes C.     

Reversibility of the Hindsight Bias: Manipulation of Experimental Demands

A hindsight bias is found when ratings made after outcome feedback differ from ratings made before feedback. Cognitive processes, motivational factors, and demand characteristics have all been identified as possible mediators of the effect. In the first of two experiments, providing subjects with a forewarning with or without a passage that was predicted to have caused it to be ineffective in previous research failed to reduce the bias. Subsequent instructions to produce the bias inflated the effect, whereas instructions to not produce the bias did not alter ratings. In the second experiment, experimental demands were altered by forewarning subjects about a "never-knew-that" effect. The results from Experiment 2 replicated the failure of the forewarning instructions. However, the hindsight bias was removed by instructions to produce a "never-knew-that" effect. The implications of these two experiments for research into the hindsight bias were discussed.     

Second Thoughts About Decision Reversibility: An Empirical Overview

People generally expect that having the opportunity to reverse a decision contributes to the quality of decision‐making. However, previous research has unequivocally shown that reversible decisions actually yield lower levels of post‐choice satisfaction and higher levels of regret than irreversible decisions. Only recently, research has begun to investigate the underlying processes explaining these counterintuitive and detrimental consequences of decision reversibility. In the present paper, we will review and integrate this research and distinguish a number of important cognitive and motivational consequences of decision (ir)reversibility. With this paper, we aim to inspire future research into the discrepancy between people's wish for reversibility on the one hand and their need for irreversibility on the other.     

Reversibility of the other-race effect in face recognition during childhood

Early experience with faces of a given racial type facilitates visual recognition for this type of face relative to others. To assess whether this so-called other-race effect can be reversed by subsequent experience with new types of faces, we tested adults of Korean origin who were adopted by European Caucasian families when they were between the ages of 3 to 9. The adoptees performed a face recognition task with photographs of Caucasian and Asian faces. They performed exactly like a control group of French participants, identifying the Caucasian faces better than the Asiatic ones. In contrast, a control group of Koreans showed the reverse pattern. This result indicates that the face recognition system remains plastic enough during childhood to reverse the other-race effect.     

Long-term potential for imprinting in ducks and chickens

In the first of five experiments, three of four adult ducks who had been reared in visual isolation gradually developed strong approach responses towards a moving panel of colored lights. Experiment 2 provided evidence that the ducks' approach response reflected the same sort of social attachment that is typically formed to moving objects by newly hatched ducklings. Experiment 3 revealed that the fourth duck would not approach the moving stimulus even after additional exposure to it, but would approach a conspecific after group housing had been enforced for seven days. In Experiment 4, none of five adult chickens who had been reared in visual isolation developed approach responses towards the moving stimulus, even though in Experiment 5, newly hatched chicks approached the stimulus quite readily. Taken together, these findings (a) indicate that ducks retain the ability to form filial-type attachments to novel objects throughout their lives, and (b) offer preliminary evidence that chickens do not retain this ability into adulthood.     

Persistence of acquired behavioral control in the context of imprinting

Newly hatched Khaki Campbell ducklings (Anas platyrhynchos domesticus) were exposed to a moving object that immediately suppressed distress vocalizations occurring in a novel environment. The static visual and auditory features of this object acquired the ability to suppress distress vocalizations after eight 20-min sessions of exposure to the object in motion. The acquired suppressive properties of these features were found to persist throughout thirty 20-min sessions given over 10 days. During these sessions, the ducklings were continually exposed to the static features in the absence of visual movement. In a second experiment, the ability of these features in the absence of visual movement. In a second experiment, the ability of these features to serve as reinforcement for a pecking response was shown to persist for up to 56 hr. In one duckling, presentations of the static visual features did not maintain pecking behavior. However, it was shown that pecking responses could be re-instated in this duckling by introducing novel stimuli to the environment.     

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.     

海洛因依赖者抑制控制功能的损伤机制及其可逆性

抑制控制障碍是海洛因依赖者认知功能受损的核心问题, 是影响复吸的关键因素。大量研究证实了海洛因依赖者抑制控制功能的受损, 并且发现长期药物滥用者额叶、前扣带回皮层、中脑腹侧被盖区、伏隔核、脑岛等相关脑区活动存在异常。以往研究表明海洛因依赖者抑制控制功能受损是一种持久性的、不可逆的脑损伤, 但最近一些研究却提供了毒品戒断者抑制控制功能生物性恢复的证据。未来的研究应该更加关注多重冲突条件下海洛因依赖者抑制控制功能的研究, 并且在戒毒实践中根据海洛因戒断者自身特点进行区分性治疗。     

Sexual imprinting on facial traits of opposite-sex parents in humans

Positive sexual imprinting is a process by which individuals use the phenotype of their opposite-sex parent as a template for acquiring mates. Recent studies in humans have concluded that an imprinting-like mechanism influences human mate choice in facial traits. However, some of the previous studies have had methodological problems or flaws which might have invalidated or led to an overgeneralization of the original interpretation of their results. In this study, 70 heterosexual adults were used to test if their partners resembled facially their opposite-sex parent as the sexual imprinting hypothesis predicts. Judges assessed the subjective facial similarity between each participant's partner and their parent. We found that there was no perceived facial similarity between women's partners and their fathers. However, men tended to pair more often with women that were perceived as resembling the men's own mothers. In contrast to previous studies, the quality of the relationship between participants and their parents did not predict the level of facial resemblance between the participant's spouse and their parent.     

Merleau-Ponty and the Advent of Meaning: From Consummate Reciprocity to Ambiguous Reversibility

The three themes of perception, expression, and history proved to be significant and consistent concerns of Merleau-Ponty from his earliest to his latest writings. In turn, Merleau-Ponty was concerned to discover and show how meaning emerged within the context of each of these themes. My main goal in this essay will be to trace ways that Merleau-Ponty conceived of this emergence, and to how his conceptions underwent increasing sophistication from his earlier to later writings. In section I, I show how a kind of perceptual meaning arises out of an exchange between subject and object, perceived and perceived, and the visible and invisible. In section II, I show how expressive meaning arises out of an exchange between the spoken and speaking word, and the synchronic and diachronic registers of language. In these sections, I also point out that what starts roughly as binary dialogue (characterized by consummate reciprocity) between these matrices of meaning evolves into a more ambiguous interplay (characterized by such later ontological notions as invisibility, reversibility, and the flesh). In section III, I show how meaning arises in history out of an ambiguous interplay between past and present, ideas and institutions, the collective and individual, and the pre-determined and the free; and I suggest ways Merleau-Ponty might have integrated earlier scattered thoughts about meaning's emergence in history with his later ontology, had his work in these directions not been cut short.