The role of variation in the perception of accented speech

Phonetic variation has been considered a barrier that listeners must overcome in speech perception, but has been proved beneficial in category learning. In this paper, I show that listeners use within-speaker variation to accommodate gross categorical variation. Within the perceptual learning paradigm, listeners are exposed to p-initial words in English produced by a native speaker of French. Critically, listeners are trained on these words with either invariant or highly-variable VOTs. While a gross boundary shift is made for participants exposed to the variable VOTs, no such shift is observed after exposure to the invariant stimuli. These data suggest that increasing variation improves the mapping of perceptually mismatched stimuli.     

Coping with phonological assimilation in speech perception: evidence for early compensation

The pronunciation of the same word may vary considerably as a consequence of its context. The Dutch word tuin (English, garden) may be pronounced tuim if followed by bank (English, bench), but not if followed by stoel (English, chair). In a series of four experiments, we examined how Dutch listeners cope with this context sensitivity in their native language. A first word identification experiment showed that the perception of a word-final nasal depends on the subsequent context. Viable assimilations, but not unviable assimilations, were often confused perceptually with canonical word forms in a word identification task. Two control experiments ruled out the possibility that this effect was caused by perceptual masking or was influenced by lexical top-down effects. A passive-listening study in which electrophysiological measurements were used showed that only unviable, but not viable, phonological changes elicited a significant mismatch negativity. The results indicate that phonological assimilations are dealt with by an early prelexical mechanism.     

Individual differences in pulse brightness perception

When brightness-pulse duration relations are studied with a simultaneous brightness discrimination procedure, three classes of observers emerge (Bowen & Markell, 1980). These classes are defined by whether or not observers perceive temporal brightness enhancement (the Broca-Sulzer effect) under two asynchrony conditions for pulses to be compared: simultaneous onset and simultaneous offset. Type A observers perceive brightness enhancement for both asynchrony conditions; Type B observers perceive brightness enhancement for simultaneous offset of pulses but not for simultaneous onset; Type C observers do not generate the Broca-Sulzer effect under either asynchrony condition. Here we present supplementary measures on observers of all three types: (1) magnitude estimation of the brightness of single pulses of light of varying duration, (2) modulation sensitivity for sin~wave flicker, and (3) contrast sensitivity for moving sine-wave gratings. The magnitude estimation data differentiated the three types of observers, but flicker and motion sensitivity did not. The three classes of observers probably differ in the perceptual criteria they employ in judging the brightness of isolated pulses of light; they probably do not differ in their underlying neurophysiological responses.     

Individual differences in the perception of similarity and difference

Thematically related concepts like coffee and milk are judged to be more similar than thematically unrelated concepts like coffee and lemonade. We investigated whether thematic relations exert a small effect that occurs consistently across participants (i.e., a generalized model), or a large effect that occurs inconsistently across participants (i.e., an individualized model). We also examined whether difference judgments mirrored similarity or whether these judgments were, in fact, non-inverse. Five studies demonstrated the necessity of an individualized model for both perceived similarity and difference, and additionally provided evidence that thematic relations affect similarity more than difference. Results suggest that models of similarity and difference must be attuned to large and consistent individual variability in the weighting of thematic relations.     

Remembering talk: Individual and gender differences in reported speech

This study examined individual and group differences in the nature and frequency of reports of past speech in the autobiographical memories of young adults. A sample of 108 participants (60 females, 48 males) responded in writing to six memory prompts. They also completed the Five Factor Inventory (Costa & McCrae, 1992) and the Personal Attributes Questionnaire (Spence & Helmreich, 1978). The frequency with which participants used reported speech was correlated with agreeableness, openness, and expressivity; however, regression analyses indicated that narrators’ gender alone was the best predictor. Females used more reported speech than did males. The findings suggest that recollections of past speech are an under-appreciated yet important component of autobiographical memory.     

Individual differences in speech fusion: Methodological and theoretical explorations

Day (Note 1) constructed pairs of speech sounds such as “lanket” and “banket” from words (e.g., blanket) by omitting either the first or second consonant. When these two components were presented about the same time, one to each ear, some people appeared to fuse them, reporting they heard the word. Other people rarely fused. Moreover, if asked to report the first letter they heard, a judgment of temporal order, subjects that tended to fuse also reported what would be the first consonant of the word, even when it was not first in the pair of components. From this and other evidence, Day concluded that the perception of some individuals might be “language-bound.” We tested a strong version of the language-boundness view of fusion and were able to reject it. We also examined several other possible causes of individual differences in fusion rate. Our second experiment provides evidence that a more general failure to discriminate temporal order of even nonlinguistic material may be involved.     

What's in a face: Individual differences in face perception

White and black females judged the similarity of all pairs of white and black male faces. An individual difference multidimensional scaling analysis of the similarity judgments indicated that most of the dimensions underlying the perceptions of male faces involved affective (honest, tense, attractive) characteristics rather than simple physical features (eye width, mouth height). The major physical dimension was face shape (long vs. wide). The dimensions were similar for black and white subjects. An individual difference hypothesis that we pay attention to those characteristics that we possess was partially confirmed.     

Individual differences in athletes' perception of expressive body movements

ObjectivesUnderstanding others' actions depends on the observer's individual characteristics and sensorimotor experience. Motor performance domains, such as sports and the performing arts, provide optimal situations to investigate the determinants of action perception. We investigated athletes' perceptual identification of expression intensity in body movements.DesignA within-subjects design was used.MethodParticipants watched point-light displays (1000 ms long) depicting expressive and inexpressive dance movements. The task was to identify the dancer's intended expression intensity.ResultsThe results indicate that expressive body movements can be reliably identified, with judgement accuracy correlating with self-report empathy indices, intuitive/deliberate decision-making preferences, and indices of sports training. Only years of sports training could predict perceptual identification accuracy.ConclusionsWe discuss the findings in relation to motor and cognitive–emotional contributions to action simulation. The potential of cross-domain transfer of motor expertise for boosting perceptual judgements and a hierarchical role of factors eliciting action simulation are also outlined.     

Individual differences in risk perception versus risk taking: handedness and interhemispheric interaction

Research indicates that right-hemisphere mechanisms are specifically sensitive to and averse to risk. Research also indicates that mixed degree of handedness is associated with increased access to right hemisphere processing. Accordingly, it was predicted that mixed-handers would exhibit greater risk aversion. Participants were presented with various risky activities and were asked to rate (i) the perceived risk, (ii) the perceived benefit, and (iii) their likelihood to engage in each activity. No handedness differences were found for any of these ratings. Regression analyses, however, indicated that the likelihood to engage in risky activities was predicted primarily by the perceived risks in mixed-handers and by the perceived benefits in strong-handers.     

Individual differences in sensory integration predict differences in time perception and individual levels of schizotypy

To interact functionally with our environment, our perception must locate events in time, including discerning whether sensory events are simultaneous. The Temporal Binding Window (TBW; the time window within which two stimuli tend to be integrated into one event) has been shown to relate to individual differences in perception, including schizotypy, but the relationship with subjective estimates of duration is unclear. We compare individual TBWs with individual differences in the filled duration illusion, exploiting differences in perception between empty and filled durations (the latter typically being perceived as longer). Schizotypy has been related to both these measures and is included to explore a potential link between these tasks and enduring perceptual differences. Results suggest that individuals with a narrower TBW make longer estimates for empty durations and demonstrate less variability in both conditions. Exploratory analysis of schizotypy data suggests a relationship with the TBW but is inconclusive regarding time perception.     

Individual differences in susceptibility to the effects of speech on reading comprehension

Individuals with high working memory capacity (WMC) are less distracted by task‐irrelevant speech than others. The mechanism behind this relationship, however, is not well understood, and it has only been found in a few paradigms. We used a Number updating task to measure WMC and two suppression mechanisms (immediate and delayed), and tested how they were associated with individual differences in susceptibility to the effects of speech on reading comprehension. The results revealed a negative relationship between WMC and susceptibility to speech distraction. Of the two suppression mechanisms, only immediate suppression was associated with speech distraction, suggesting that susceptibility to distraction is determined by the ability to immediately suppress the irrelevant speech. Furthermore, the relationship between WMC and speech distraction was mediated by the immediate suppression mechanism. The implications of these results and possible explanations of similar results found in other paradigms are discussed. Copyright © 2009 John Wiley & Sons, Ltd.     

Individual differences in spatial frequency processing in scene perception: the influence of autism-related traits

Previous research suggested that coarse (High Spatial Frequency or HSF) and fine (Low Spatial Frequency or LSF) spatial information are flexibly used at different stages of processing during scene recognition in daily life. We tried to replicate and extend these findings by presenting non-social real-life scenes either as a normal picture, solely defined by LSF or HSF information, or using hybrid images consisting of overlaid LSF and HSF scene information. These were used as (in)congruent prime stimuli, modulating the rapid detection of a normal target picture in a 2-Alternative Forced Choice (2-AFC) categorization task (manmade versus natural). Our results indicated that coarse spatial information was more effective with shorter prime presentation times and fine spatial information required a longer prime presentation to influence participant performance. Interestingly, higher scores on the Autism-Spectrum Quotient questionnaire modified the impact of HSF prime information on target identification and influenced performance when ambiguous hybrid prime information preceded the categorization task.     

Individual differences in children’s private speech: The role of imaginary companions

Relations between children’s imaginary companion status and their engagement in private speech during free play were investigated in a socially diverse sample of 5-year-olds (N = 148). Controlling for socioeconomic status, receptive verbal ability, total number of utterances, and duration of observation, there was a main effect of imaginary companion status on type of private speech. Children who had imaginary companions were more likely to engage in covert private speech compared with their peers who did not have imaginary companions. These results suggest that the private speech of children with imaginary companions is more internalized than that of their peers who do not have imaginary companions and that social engagement with imaginary beings may fulfill a similar role to social engagement with real-life partners in the developmental progression of private speech.     

Individual differences in the perception of bodily sensations: The role of trait anxiety and coping style

Thirty young women participated in an experiment in which heart rate, blood pressure, respiration rate, skin conductance level and palmar sweat index were monitored at rest and during the administration of mental arithmetic, mirror drawing and cold pressor tasks. The accuracy of perception of somatic states was estimated by calculating within-subject correlations between four bodily sensations (racing heart, high blood pressure, shortness of breath and sweaty hands) and corresponding physiological parameters, assessed on eight occasions during the experiment. The accuracy of heart rate perception was highest, with a mean correlation between actual heart rate and ratings of racing heart of 0.76 and 66% of participants showing significant within-subject effects. The mean accuracy was 0.55 for systolic blood pressure, 0.48 for respiration rate, 0.47 for skin conductance level, and 0.64 for palmar sweat index. Accurate perception across physiological parameters did not cluster within individuals, and was not dependent on the range either of physiological changes or sensation ratings. Trait anxiety was not significantly associated with accuracy of somatic perception. Subjects with high trait anxiety reported larger increases in shortness of breath during tasks than did low anxious subjects, but this was not reflected in objective physiological measures. Information-seeking coping style, indexed by the monitoring scale of the Miller Behavioral Style Scale, was related to the accuracy of perception of skin conductance level and heart rate. The use of within-subject correlational strategies for assessing individual differences in perception of bodily states is discussed.     

Individual differences in children's private speech: Consistency across tasks, timepoints, and contexts

Children often talk themselves through their activities. They produce private speech (PS), which is internalized to form inner speech (silent verbal thought). Twenty-five 8-10-year-olds completed four tasks in a laboratory context (Tower of London, digit span, and two measures of spatial IQ). PS production was recorded. Eleven months later, the same participants completed the Tower of London and academic numeracy tasks, again in a laboratory context, as well as numeracy tasks in a classroom context. Rates of PS production and its level of internalization showed large positive correlations across time, tasks, and contexts. The results are interpreted in terms of the psychometric properties of PS production and are taken as evidence for the development of a domain-general system for verbal self-regulation in childhood.     

Individual differences in depression,induced mood,and perception of emotionally toned words

The associative network theory of emotion and memory, outlined by Bower (1981), predicts that depressed mood leads to biases which favour the perception of mood-congruent information. In this study, a lexical decision task was used to assess the effects of degree of depression and induced elation and depression on lexical decision times for positive and negative words. Subsequently, subjects were given a recall test for the words presented during the lexical decision task. The results partially offered support for perceptual bias. The data showed that in non-depressed and elation-induced subjects, decision times were differentially affected by hedonic tone. Words of positive nature were responded to significantly faster than were negative words. In mildly depressed and depression-induced, decision times were similar for both types of words (positive and negative). These findings are discussed in relation to the associative network model and a growing amount of empirical research on human emotion and cognition.     

Functional anatomy of speech perception and speech production: psycholinguistic implications

This paper presents evidence for a new model of the functional anatomy of speech/language (Hickok & Poeppel, 2000) which has, at its core, three central claims: (1) Neural systems supporting the perception of sublexical aspects of speech are essentially bilaterally organized in posterior superior temporal lobe regions; (2) neural systems supporting the production of phonemic aspects of speech comprise a network of predominately left hemisphere systems which includes not only frontal regions, but also superior temporal lobe regions; and (3) the neural systems supporting speech perception and production partially overlap in left superior temporal lobe. This model, which postulates nonidentical but partially overlapping systems involved in the perception and production of speech, explains why psycho- and neurolinguistic evidence is mixed regarding the question of whether input and output phonological systems involve a common network or distinct networks.     

Coping with stress in the australian job network: Gender differences

The authors attempted to identify (a) the coping strategies used by employment service case managers in Queensland, Australia, and (b) the strategies that could be beneficial in reducing the relatively high burnout levels that have been observed in this population. Significant gender differences in coping styles were found, and an association between burnout and escape‐avoidance behavior was identified for both female and male respondents.