Hemispheric differences in the effects of context on vowel perception

Listeners perceive speech sounds relative to context. Contextual influences might differ over hemispheres if different types of auditory processing are lateralized. Hemispheric differences in contextual influences on vowel perception were investigated by presenting speech targets and both speech and non-speech contexts to listeners’ right or left ears (contexts and targets either to the same or to opposite ears). Listeners performed a discrimination task. Vowel perception was influenced by acoustic properties of the context signals. The strength of this influence depended on laterality of target presentation, and on the speech/non-speech status of the context signal. We conclude that contrastive contextual influences on vowel perception are stronger when targets are processed predominately by the right hemisphere. In the left hemisphere, contrastive effects are smaller and largely restricted to speech contexts.     

The cortical organization of lexical knowledge: a dual lexicon model of spoken language processing

Current accounts of spoken language assume the existence of a lexicon where wordforms are stored and interact during spoken language perception, understanding and production. Despite the theoretical importance of the wordform lexicon, the exact localization and function of the lexicon in the broader context of language use is not well understood. This review draws on evidence from aphasia, functional imaging, neuroanatomy, laboratory phonology and behavioral results to argue for the existence of parallel lexica that facilitate different processes in the dorsal and ventral speech pathways. The dorsal lexicon, localized in the inferior parietal region including the supramarginal gyrus, serves as an interface between phonetic and articulatory representations. The ventral lexicon, localized in the posterior superior temporal sulcus and middle temporal gyrus, serves as an interface between phonetic and semantic representations. In addition to their interface roles, the two lexica contribute to the robustness of speech processing.     

Performance on auditory and visual temporal information processing is related to psychometric intelligence

The present study investigated the relationship between psychometric intelligence and temporal resolution power (TRP) as simultaneously assessed by auditory and visual psychophysical timing tasks. In addition, three different theoretical models of the functional relationship between TRP and psychometric intelligence as assessed by means of the Adaptive Matrices Test (AMT) were developed. To test the validity of these models, structural equation modeling was applied. Empirical data supported a hierarchical model that assumed auditory and visual modality-specific temporal processing at a first level and amodal temporal processing at a second level. This second-order latent variable was substantially correlated with psychometric intelligence. Therefore, the relationship between psychometric intelligence and psychophysical timing performance can be explained best by a hierarchical model of temporal information processing.     

One hand, two objects: emergence of affordance in contexts

Studies on affordances typically focus on single objects. We investigated whether affordances are modulated by the context, defined by the relation between two objects and a hand. Participants were presented with pictures displaying two manipulable objects linked by a functional (knife-butter), a spatial (knife-coffee mug), or by no relation. They responded by pressing a key whether the objects were related or not. To determine if observing other's actions and understanding their goals would facilitate judgments, a hand was: (a) displayed near the objects; (b) grasping an object to use it; (c) grasping an object to manipulate/move it; (d) no hand was displayed. RTs were faster when objects were functionally rather than spatially related. Manipulation postures were the slowest in the functional context and functional postures were inhibited in the spatial context, probably due to mismatch between the inferred goal and the context. The absence of this interaction with foot responses instead of hands in Experiment 2 suggests that effects are due to motor simulation rather than to associations between context and hand-postures.     

A rational analysis of the acquisition of multisensory representations

How do people learn multisensory, or amodal, representations, and what consequences do these representations have for perceptual performance? We address this question by performing a rational analysis of the problem of learning multisensory representations. This analysis makes use of a Bayesian nonparametric model that acquires latent multisensory features that optimally explain the unisensory features arising in individual sensory modalities. The model qualitatively accounts for several important aspects of multisensory perception: (a) it integrates information from multiple sensory sources in such a way that it leads to superior performances in, for example, categorization tasks; (b) its performances suggest that multisensory training leads to better learning than unisensory training, even when testing is conducted in unisensory conditions; (c) its multisensory representations are modality invariant; and (d) it predicts ‘‘missing” sensory representations in modalities when the input to those modalities is absent. Our rational analysis indicates that all of these aspects emerge as part of the optimal solution to the problem of learning to represent complex multisensory environments.     

Online recognition of music is influenced by relative and absolute pitch information

Three experiments explored online recognition in a nonspeech domain, using a novel experimental paradigm. Adults learned to associate abstract shapes with particular melodies, and at test they identified a played melody's associated shape. To implicitly measure recognition, visual fixations to the associated shape versus a distractor shape were measured as the melody played. Degree of similarity between associated melodies was varied to assess what types of pitch information adults use in recognition. Fixation and error data suggest that adults naturally recognize music, like language, incrementally, computing matches to representations before melody offset, despite the fact that music, unlike language, provides no pressure to execute recognition rapidly. Further, adults use both absolute and relative pitch information in recognition. The implicit nature of the dependent measure should permit use with a range of populations to evaluate postulated developmental and evolutionary changes in pitch encoding.     

Color charts, esthetics, and subjective randomness

Color charts, or grids of evenly spaced multicolored dots or squares, appear in the work of modern artists and designers. Often the artist/designer distributes the many colors in a way that could be described as "random," that is, without an obvious pattern. We conduct a statistical analysis of 125 "random-looking" art and design color charts and show that they differ significantly from truly random color charts in the average distance between adjacent colors. We argue that this attribute generalizes results in subjective randomness in a black/white setting and gives further evidence supporting a connection between subjective randomness and what is esthetically pleasing.     

Liking and identifying emotionally expressive music: age and gender differences

Adults and children 5, 8, and 11 years of age listened to short excerpts of unfamiliar music that sounded happy, scary, peaceful, or sad. Listeners initially rated how much they liked each excerpt. They subsequently made a forced-choice judgment about the emotion that each excerpt conveyed. Identification accuracy was higher for young girls than for young boys, but both genders reached adult-like levels by age 11. High-arousal emotions (happiness and fear) were better identified than low-arousal emotions (peacefulness and sadness), and this advantage was exaggerated among younger children. Whereas children of all ages preferred excerpts depicting high-arousal emotions, adults favored excerpts depicting positive emotions (happiness and peacefulness). A preference for positive emotions over negative emotions was also evident among females of all ages. As identification accuracy improved, liking for positively valenced music increased among 5- and 8-year-olds but decreased among 11-year-olds.     

Happy to See Me,Aren’t You,Sally? Signal Detection Analysis of Emotion Detection in Briefly Presented Male and Female Faces

Using signal detection methods, possible effects of emotion type (happy, angry), gender of the stimulus face, and gender of the participant on the detection and response bias of emotion in briefly presented faces were investigated. Fifty-seven participants (28 men, 29 women) viewed 90 briefly presented faces (30 happy, 30 angry, and 30 neutral, each with 15 male and 15 female faces) answering yes if the face was perceived as emotional and no if it was not perceived as emotional. Sensitivity [d', z(hit rate) minus z(false alarm rate)] and response bias (β, likelihood ratio of "signal plus noise" vs. "noise") were measured for each face combination for each presentation time (6.25, 12.50, 18.75, 25.00, 31.25 ms). The d' values were higher for happy than for angry faces and higher for angry-male than for angry-female faces, and there were no effects of gender-of-participant. Results also suggest a greater tendency for participants to judge happy-female faces as emotional, as shown by lower β values for these faces as compared to the other emotion-gender combinations. This happy-female response bias suggests, at least, a partial explanation to happy-superiority effects in studies where performance is only measured as percent correct responses, and, in general, that women are expected to be happy.