The role of cuticular pheromones in courtship conditioning of Drosophila males

Courtship conditioning is an associative learning paradigm in Drosophila melanogaster, wherein male courtship behavior is modified by experience with unreceptive, previously mated females. While the training experience with mated females involves multiple sensory and behavioral interactions, we hypothesized that female cuticular hydrocarbons function as a specific chemosensory conditioned stimulus in this learning paradigm. The effects of training with mated females were determined in courtship tests with either wild-type virgin females as courtship targets, or with target flies of different genotypes that express distinct cuticular hydrocarbon (CH) profiles. Results of tests with female targets that lacked the normal CH profile, and with male targets that expressed typically female CH profiles, indicated that components of this CH profile are both necessary and sufficient cues to elicit the effects of conditioning. Results with additional targets indicated that the female-specific 7,11-dienes, which induce naive males to court, are not essential components of the conditioned stimulus. Rather, the learned response was significantly correlated with the levels of 9-pentacosene (9-P), a compound found in both males and females of many Drosophila strains and species. Adding 9-P to target flies showed that it stimulates courting males to attempt to copulate, and confirmed its role as a component of the conditioned stimulus by demonstrating dose-dependent increases in the expression of the learned response. Thus, 9-P can contribute significantly to the conditioned suppression of male courtship toward targets that express this pheromone.     

Distorted perception of the subjective temporal distance of autobiographical events in patients with schizophrenia

Disturbances of perception of subjective time have been described in schizophrenia but have not been experimentally studied until now. We investigated how patients with schizophrenia estimate the subjective temporal distance (TD) of past personal events, i.e. how these events are perceived as subjectively close or distant in time. Twenty-five patients with schizophrenia and 25 control participants recalled 24 autobiographical memories from four different life periods. They estimated the subjective TD and rated the amount of detail of each memory. Results showed that patients with schizophrenia had a distorted perception of subjective TD. Their memories were significantly less detailed than those of controls and, unlike control participants, the amount of memory detail was not significantly correlated with subjective TD. Poor access to memory detail may account for distortions of perception of subjective time in patients with schizophrenia.     

The involuntary capture of attention by novel feature pairings: A study of voice—location integration in auditory sensory memory

Past researchers of the integration of information in memory have typically required participants to attend to and/or commit to memory the stimuli conveying distinct features, rendering difficult the examination of whether the maintenance of the feature pairings can occur involuntarily. To address this issue, the integration of voice and location information in auditory sensory memory was measured using a cross-modal oddball task, in which task-irrelevant auditory deviants are known to capture attention in an involuntary fashion. Participants categorized visual digits presented shortly after to-be-ignored sounds. These sounds consisted in the same phoneme played simultaneously in both ears but in different voices (female in one ear, male in the other). On most trials, the pairing of voice to location was constant (standard sound). On rare and unpredictable trials, the voices swapped locations (deviant sound). In line with past work on attention capture by auditory novelty, the participants were significantly slower to judge the visual digits following the deviant sound, indicating the involuntary encoding of the links between voice and location in auditory memory. These results suggest that voices and locations are integrated in memory and that this binding occurs in conditions in which participants do not intend to commit any information to memory.     

Emotional expression and vocabulary learning in adults and children

A great deal of what we know about the world has not been learned via first-hand observation but thanks to others' testimony. A crucial issue is to know which kind of cues people use to evaluate information provided by others. In this context, recent studies in adults and children underline that informants' facial expressions could play an essential role. To test the importance of the other's emotions in vocabulary learning, we used two avatars expressing happiness, anger or neutral emotions when proposing different verbal labels for an unknown object. Experiment 1 revealed that adult participants were significantly more likely than chance to choose the label suggested by the avatar displaying a happy face over the label suggested by the avatar displaying an angry face. Experiment 2 extended these results by showing that both adults and children as young as 3 years old showed this effect. These data suggest that decision making concerning newly acquired information depends on informant's expressions of emotions, a finding that is consistent with the idea that behavioural intents have facial signatures that can be used to detect another's intention to cooperate.     

视觉工作记忆负载对听觉偏差干扰效应的调控：来自不同外周提示线索的证据

采用线索提示和视听Oddball结合的实验设计, 通过四个实验探讨了外周视线索下视觉工作记忆负载对听觉偏差干扰效应的调控作用。结果表明：(1)操作外周视线索有效性为50%的条件下, 视觉工作记忆负载的增加使得原本抑制无关声音的过程失败, 因此出现了显著的听觉偏差干扰效应; (2)操作外周视线索有效性为80%的条件下, 发现有策略性的注意定向消耗了注意资源, 无视觉工作记忆负载的情况下同样出现听觉偏差干扰, 并且随着工作记忆负载增加偏差干扰效应增强。研究说明视觉工作记忆负载对听觉偏差干扰的调控是有条件性的, 当来自不同感觉通道的无关刺激与目标的加工过程存在重叠时, 视觉工作记忆负载的增加使得听觉偏差干扰效应增强而不是减弱。     

Behavioral distraction by auditory novelty is not only about novelty: The role of the distracter’s informational value

Unexpected events often distract us. In the laboratory, novel auditory stimuli have been shown to capture attention away from a focal visual task and yield specific electrophysiological responses as well as a behavioral cost to performance. Distraction is thought to follow ineluctably from the sound’s low probability of occurrence or, put more simply, its unexpected occurrence. Our study challenges this view with respect to behavioral distraction and argues that past research failed to identify the informational value of sound as a mediator of novelty distraction. We report an experiment showing that (1) behavioral novelty distraction is only observed when the sound announces the occurrence and timing of an upcoming visual target (as is the case in all past research); (2) that no such distraction is observed for deviant sounds conveying no such information; and that (3) deviant sounds can actually facilitate performance when these, but not the standards, convey information. We conclude that behavioral novelty distraction, as observed in oddball tasks, is observed in the presence of novel sounds but only when the cognitive system can take advantage of the auditory distracters to optimize performance.