老龄化对F0轮廓线索在汉语言语识别去掩蔽作用的影响

动态基频(F0)轮廓有助于嘈杂环境下的言语识别,可以作为将目标语音从背景声中分离的知觉线索。本研究通过评估老年人与年轻人在言语掩蔽下聆听具有自然动态F0轮廓与对F0轮廓操作调节后的汉语语句的言语识别能力,探讨老龄化对F0轮廓线索在汉语言语识别去掩蔽作用中的影响。结果显示,在言语掩蔽下自然动态的F0轮廓比压扁或拉伸的F0轮廓更能帮助年轻人抵抗信息掩蔽识别目标言语;而老年人在言语掩蔽下却难以从动态F0轮廓线索中受益。研究结果揭示了老年人利用F0轮廓线索促进掩蔽下言语感知能力的老化特点。     

Infant auditory perception: Tonal masking

The results of an earlier study (Olsho, 1984) indicated that 5- to 8-month-old infants were relatively better at discriminating among high-frequency pitches than low. In the present study, sensory and nonsensory explanations for that effect were evaluated by examining infants' performance in a task requiring similar sensory processing but differing in the demands placed on processes such as memory. Infants' ability to resolve frequency was tested using a tonal masking paradigm, the psychophysical tuning curve. Twenty-four infants were tested at probe frequencies ranging from 500 to 4000 Hz; a group of young adults served as a comparison. Masked and unmasked thresholds were estimated using the visually reinforced head turn procedure in conjunction with an adaptive psychophysical method. Although infants' tuning curves fell below those of adults (indicating poorer performance), the widths and slopes of the infants' curves were not different from the adults'. Moreover, the difference between age groups remained constant across probe frequencies. These findings imply that by 5 months of age, the infant's ability to resolve sound frequency is similar to the adult's.     

Ensemble coding of facial identity is not refined by experience: Evidence from other-race and inverted faces

The ability to recognize identity despite within-person variability in appearance is likely a face-specific skill and shaped by experience. Ensemble coding – the automatic extraction of the average of a stimulus array – has been proposed as a mechanism underlying face learning (allowing one to recognize novel instances of a newly learned face). We investigated whether ensemble encoding, like face learning and recognition, is refined by experience by testing participants with upright own-race faces and two categories of faces with which they lacked experience: other-race faces (Experiment 1) and inverted faces (Experiment 2). Participants viewed four images of an unfamiliar identity and then were asked whether a test image of that same identity had been in the study array. Each test image was a matching exemplar (from the array), matching average (the average of the images in the array), non-matching exemplar (a novel image of the same identity), or non-matching average (an average of four different images of the same identity). Adults showed comparable ensemble coding for all three categories (i.e., reported that matching averages had been present more than non-matching averages), providing evidence that this early stage of face learning is not shaped by face-specific experience.     

眼跳的双相调节理论的行为证据

为了研究眼跳的双相调节理论是否适用于人类的视觉系统,本研究测量了人类被试对分别呈现在三种眼跳时间段（基线、眼跳抑制和眼跳增强）内的光栅的朝向辨别准确率。研究发现：相对于光栅呈现在基线时间段内,被试对呈现在抑制（或增强）时间段内的光栅的朝向辨别准确率显著地更低（或更高）（实验1）;另外,只有使用低或中等空间频率光栅作为测试刺激时,才有这种双相调节作用（实验2）。这些结果表明：人类的视觉系统在眼跳过程中存在双相调节机制,并且这种双相调节机制具有刺激选择性。     

Emotional facial expressions affect visual rule learning in 7- to 8-month-old infants

Rule learning (RL) is an implicit learning mechanism that allows infants to detect and generalize rule-like repetition-based patterns (such as ABB and ABA) from a sequence of elements. Increasing evidence shows that RL operates both in the auditory and the visual domain and is modulated by the perceptual expertise with the to-be-learned stimuli. Yet, whether infants’ ability to detect a high-order rule from a sequence of stimuli is affected by affective information remains a largely unexplored issue. Using a visual habituation paradigm, we investigated whether the presence of emotional expressions with a positive and a negative value (i.e., happiness and anger) modulates 7- to 8-month-old infants’ ability to learn a rule-like pattern from a sequence of faces of different identities. Results demonstrate that emotional facial expressions (either positive and negative) modulate infants’ visual RL mechanism, even though positive and negative facial expressions affect infants’ RL in a different manner: while anger disrupts infants’ ability to learn the rule-like pattern from a face sequence, in the presence of a happy face infants show a familiarity preference, thus maintaining their learning ability. These findings show that emotional expressions exert an influence on infants’ RL abilities, contributing to the investigation on how emotion and cognition interact in face processing during infancy.     

Perceptual biases and metacognition and their association with anomalous self experiences in first episode psychosis

Anomalous self-experiences have been described as a prerequisite for anomalous perceptual experiences. Later, these anomalous perceptual experiences may then be metacognitively appraised as distressing, maintaining these experiences and later leading to anomalous (delusional) beliefs. This model of anomalous events may potentially be driven by perceptual biases and metacognitive deficits. This cross-sectional study explored the association between perceptual biases, metacognition and anomalous self- and perceptual experiences and delusional beliefs in First Episode Psychosis (FEP) and a matched healthy control sample. Fifty-eight individuals with FEP and seventy-two healthy controls were included in the main analysis. Increased auditory perceptual biases were significantly associated with increased state and trait anomalous self-experiences, in particular alienation from surroundings and emotional numbing. No significant associations were found between metacognitive efficiency and anomalous experiences. These findings may be consistent with the minimal self-disturbance model of schizophrenia spectrum vulnerability, particularly with the hyperreflexivity concept.     

Independent perceptual reversals for simultaneously presented ambiguous figures

In two successive experiments using the divided visual field paradigm with vertical or horizontal division, two ambiguous figures, the Rubin’s vase-face or the Necker cube, were projected to the right and left or to the upper and lower visual hemifields of 108 healthy volunteers. Stimulation time was 120 s. The main hypotheses were (a) that different percepts of the same ambiguous figure may be simultaneously experienced in the two hemifields and (b) that the type (vertical vs. horizontal) of visual field division influences the reversal frequency and the temporal interdependence of the percepts.Results from the first experiment showed that the temporal interdependence of reversals was very low for both ambiguous figures, suggesting that during part of the stimulation time the subjects could experience different percepts of the same figure (e.g. a vase in the right and face profiles in the left visual hemifields). The second experiment showed that this perceptual dissociation occurred on average during one third of the stimulation time. In both experiments the type of visual field division did not influence either frequency or temporal interdependence of the reversals. When one single ambiguous figure was presented in the centre of the screen, the number of reversals was approximately the sum of the reversals observed with two figures presented simultaneously each in one hemifield.     

Eye-closure & the retrieval of item-specific information in recognition memory

Two experiments investigated the effect of eye-closure on visual and auditory memory under conditions based on the retrieval of item-specific information. Experiment 1 investigated visual recognition memory for studied, perceptually similar and unrelated items. It was found that intermittent eye-closure increased memory for studied items and decreased memory for related items. This finding was reflected by enhanced item-specific and reduced gist memory. Experiment 2 used the Deese-Roediger-McDermott (DRM) paradigm to assess auditory recognition memory for studied, related and unrelated words that had (vs. had not) been accompanied by pictures during encoding. Pictures but not eye-closure produced a picture superiority effect by enhancing memory for studied items. False memory was reduced by pictures but not eye-closure. Methodological and theoretical considerations are discussed in relation to existing explanations of eye-closure and retrieval strategies.     

Do Positive Self-Perceptions Have a “Dark Side”? Examination of the Link between Perceptual Bias and Aggression

The hypothesis that positive self-perceptions may have a dark side was investigated in the present study by examining the relationship between positively biased self-perceptions and aggression. Ratings of actual and perceived social acceptance of third-grade (n = 278), fourth-grade (n = 260), and fifth-grade (n = 321) students were compared to form a measure of perceptual bias. Peers provided nominations for overt and relational aggression. Gender differences were found for aggression (males were more overtly and relationally aggressive than females) but not perceptual bias. African-American children held more positive perceptions of their social acceptance and were perceived by peers as more aggressive than Caucasian children. Even after controlling for the effects of gender and ethnicity, more positively biased perceptions were associated with more peer nominations for overt and relational aggression. Contrary to an optimal range of bias hypothesis, even moderately positive self-perceptions were associated with elevated levels of aggression.     

Individual differences in susceptibility to experimentally induced phantom sensations

We investigated individual differences in susceptibility to two vibration-induced phantom illusions, i.e. illusory arm extension and nose prolongation (“Pinocchio illusion”). Vibration was applied to the biceps brachii tendon of 32 healthy participants. Susceptibility to the illusions was quantified by vividness ratings and by ratings of the amount of illusory position changes of the arm and illusory shape changes of the nose. Participants also completed the Perceptual Aberration (PA) and the Need for Cognition (NFC) inventories. PA reflects the frequency of spontaneously experienced body schema alterations and NFC a person's tendency to cognitively structure experiences. PA was positively correlated with participants’ susceptibility to illusory arm extension and, exclusively for men, also to nose elongation. A high NFC was weakly associated with a high susceptibility for the Pinocchio illusion. By inference, these findings indicate a physiological basis of PA and a cognitive mediation of experimentally induced phantom sensations.