The effects of whispers,voice-sample duration,and voice distinctiveness on criminal speaker identification

A total of 156 introductory psychology students heard a taped voice of a mock kidnapper for either 30 seconds or 8 minutes. The kidnapper had either a distinctive voice or a non-distinctive voice, and spoke either in a whisper or in a normal tone of voice. Voice identification from six-person, tape-recorded lineups was tested 2 days later. Participants who initially heard the perpetrator speak in a normal tone were tested with normal tone lineups. Participants who initially heard the perpetrator speak in a whisper were tested either with whispered lineups or normal tone lineups. Results showed that identification performance was superior with longer voice-sample durations. Voice disguise through whispering, distinctiveness of suspect's voice, and changes in tone of voice from initial hearing and lineup test significantly influenced identification performance on both suspect-present and suspect-absent lineups. Small but significant accuracy-confidence correlations were found in both suspect-present and suspect-absent lineups. Duration estimations of the length of the speaker's voice-sample were overestimated, particularly for the short 30-second voice sample.     

Effects of message, source, and context on evaluations of employee voice behavior

The article contained a production-related error. In Table 5, the four values in the rows for Study 1 Prosocial motives and Study 1 Constructive voice should have been shifted one column to the right, to the Direct and Total Performance evaluations columns. All versions of this article have been corrected.] Although employee voice behavior is expected to have important organizational benefits, research indicates that employees voicing their recommendations for organizational change may be evaluated either positively or negatively by observers. A review of the literature suggests that the perceived efficacy of voice behaviors may be a function of characteristics associated with the (a) source, (b) message, and (c) context of the voice event. In this study, we manipulated variables from each of these categories based on a model designed to predict when voice will positively or negatively impact raters' evaluations of an employee's performance. To test our model, we conducted 3 laboratory studies in which we manipulated 2 source factors (voicer expertise and trustworthiness), 2 message factors (recommending a solution and positively vs. negatively framing the message), and 2 context factors (timing of the voice event and organizational norms for speaking up vs. keeping quiet). We also examined the mediating effects of liking, prosocial motives, and perceptions that the voice behavior was constructive on the relationships between the source, message, and context factors and performance evaluations. Generally speaking, we found that at least one of the variables from each category had an effect on performance evaluations for the voicer and that most of these effects were indirect, operating through one or more of the mediators. Implications for theory and future research are discussed.     

The effect of positive emotion on infants' gaze shift

Infants often voluntarily glance at their social partner during their toy play, disengaging their gaze from a toy and selecting a caregiver as their new looking target. This study posed two research questions: Do positive emotions disengage infants' gaze from their point of fixation, and do positive emotions facilitate the selection of the caregiver as their next looking target? The rate of gaze shifts was calculated for neutral and positive emotional states during their toy play. Across all ages, infants exhibited more disengagement from their point of fixation in the positive state than in the neutral one. However, 6- and 9-month-old infants revealed no difference in selecting a caregiver or a physical object as their next looking target in the positive state, but 12-month-olds increased gazing at caregivers in the positive state. These results were discussed with regard to the role of positive emotions on the development of infants' initiating joint attention.     

The effect of affine transformation on redundancy analysis

Canonical redundancy analysis provides an estimate of the amount of shared variance between two sets of variables and provides an alternative to canonical correlation. The proof that the total redundancy is equal to the average squared multiple correlation coefficient obtained by regressing each variable in the criterion set on all variables in the predictor set is generalized to the case in which there are a larger number of criterion than predictor variables. It is then shown that the redundancy for the criterion set of variables is invariant under affine transformation of the predictor variables, but not invariant under transformation of the criterion variables.     

The effect of message framing on breast self-examination attitudes, intentions, and behavior

In this study we tested the framing hypothesis that a pamphlet stressing the negative consequences of not performing breast self-examination (BSE) would be more persuasive than a pamphlet emphasizing BSE's positive consequences. College-aged female subjects were exposed to a loss-frame pamphlet, a gain-frame pamphlet, or a no-arguments pamphlet, or they received no pamphlet describing the importance of and the techniques for performing BSE. Attitudes toward BSE and intentions to perform BSE were assessed immediately after this intervention and again 4 months later. The follow-up also assessed subjects' postexperimental BSE behavior. Consistent with predictions, subjects who read a pamphlet with arguments framed in loss language manifested more positive BSE attitudes, intentions, and behaviors than did subjects in the other three conditions. The greater impact of the loss pamphlet could not be attributed to greater fear arousal, better memory for pamphlet content, greater perceived susceptibility to breast cancer, or stronger beliefs in BSE's efficacy on the part of the loss subjects. Only measures of perceived self-efficacy in performing BSE were differentially affected by the framing manipulation, with loss subjects reporting the greatest levels of self-confidence. The results are discussed in terms of prospect theory's framing postulate and a simpler negativity-bias conceptualization, and underlying mechanisms such as differential salience and vividness are considered. Clinical implications of the findings are also explored.     

The effect of support ratio on infants' perception of illusory contours

We used a preferential looking technique to investigate the effect of support ratio (a ratio of the physically specified contours to the total edge length) on the perception of Kanizsa illusory contours in infants aged 3-8 months. Previous work has shown that for adult observers the illusory-contour strength increases proportionally with the support ratio. When the support ratio was relatively high (66%), infants preferred illusory contours to non-illusory figures by 3-4 months of age (experiment 1). In contrast, only infants 7-8 months old showed this preference for illusory contours when the support ratio was reduced to 37% (experiment 3). Further, infants showed no preference for an outline version of the illusory-contour figure, which produced no illusory contours (experiment 2). This result confirms that the infants' preference reflects their perception of illusory contours. Our results show that (i) illusory-contour perception emerges at around 3-4 months of age, but (ii) that this ability is very limited until around 7-8 months of age.     

The effect of perceived message choice on persuasion

We argue that giving individuals a sense of choice over the product information they receive (i.e., message choice) can have important subsequent effects when individuals are prompted to make inferences about the company. Even when the product information that is received is exactly the same, being given a sense of choice can produce more favorable company evaluations and in turn, more favorable product judgments. The first two experiments support these hypotheses using different means of prompting company inferences: when prompted, those who had been given message choice judged the company more favorably and were more willing to purchase from that company. The third experiment illustrates when message choice effects can backfire. Specifically, when the company itself highlights the provision of message choice in the ad, and consumers are prompted to make inferences about the company, message choice can backfire because it may be perceived as a persuasion tactic rather than a sincere attempt to inform. The results support company evaluations as the mediator of message choice effects and rule out alternate accounts based on dissonance, elaboration, reactance and self-labeling explanations. These findings are important in interactive media environments where marketers have opportunities and imperatives to give consumers a sense of choice in message selection.     

Perception of vocal effort and distance from the speaker on the basis of vowel utterances

The sound pressure level of vowels reflects several nonlinguistic and linguistic factors: distance from the speaker, vocal effort, and vowel quality. Increased vocal effort also involves the emphasis of higher frequency components and increases in F0 and F1. This should allow listeners to distinguish it from decreased distance, which does not have these additional effects. It is shown that listeners succeed in doing so on the basis of single vowels if phonated, but not if whispered, and that they compensate for most of the between-vowel variation in level. The results obtained when listeners had to estimate vocal effort as well as distance suggest that an analysis of an utterance takes place at an early stage in auditory processing, before memories of episodes are stored.     

The effect of the model's presence and of negative evidence on infants' selective imitation

This study demonstrated selective “rational” imitation in infants in two testing conditions: in the presence or absence of the model during the response phase. In the study, 14-month-olds were more likely to imitate a tool-use behavior when a prior failed attempt emphasized the logical reason and relevance of introducing this novel means, making it cognitively transparent for the infants. Infants also learned imitatively from the cognitively opaque (yet socially communicated) modeling situation, but to a lesser degree. Furthermore, the presence of the model as a social partner during testing influenced the performance of infants in that they were more likely to imitate the novel means when the model was present during testing. These results highlight the important interaction of interpretive schemas (e.g., causality, teleological stance) and social communicative cues in action interpretation guiding imitative learning.     

Age differences in vocal emotion perception: on the role of speaker age and listener sex

Older adults have greater difficulty than younger adults perceiving vocal emotions. To better characterise this effect, we explored its relation to age differences in sensory, cognitive and emotional functioning. Additionally, we examined the role of speaker age and listener sex. Participants (N?=?163) aged 19–34 years and 60–85 years categorised neutral sentences spoken by ten younger and ten older speakers with a happy, neutral, sad, or angry voice. Acoustic analyses indicated that expressions from younger and older speakers denoted the intended emotion with similar accuracy. As expected, younger participants outperformed older participants and this effect was statistically mediated by an age-related decline in both optimism and working-memory. Additionally, age differences in emotion perception were larger for younger as compared to older speakers and a better perception of younger as compared to older speakers was greater in younger as compared to older participants. Last, a female perception benefit was less pervasive in the older than the younger group. Together, these findings suggest that the role of age for emotion perception is multi-faceted. It is linked to emotional and cognitive change, to processing biases that benefit young and own-age expressions, and to the different aptitudes of women and men.     

The effects of the presence of a face and direct eye gaze on voice identity learning

We rarely become familiar with the voice of another person in isolation but usually also have access to visual identity information, thus learning to recognize their voice and face in parallel. There are conflicting findings as to whether learning to recognize voices in audiovisual vs audio-only settings is advantageous or detrimental to learning. One prominent finding shows that the presence of a face overshadows the voice, hindering voice identity learning by capturing listeners' attention (Face Overshadowing Effect; FOE). In the current study, we tested the proposal that the effect of audiovisual training on voice identity learning is driven by attentional processes. Participants learned to recognize voices through either audio-only training (Audio-Only) or through three versions of audiovisual training, where a face was presented alongside the voices. During audiovisual training, the faces were either looking at the camera (Direct Gaze), were looking to the side (Averted Gaze) or had closed eyes (No Gaze). We found a graded effect of gaze on voice identity learning: Voice identity recognition was most accurate after audio-only training and least accurate after audiovisual training including direct gaze, constituting a FOE. While effect sizes were overall small, the magnitude of FOE was halved for the Averted and No Gaze conditions. With direct gaze being associated with increased attention capture compared to averted or no gaze, the current findings suggest that incidental attention capture at least partially underpins the FOE. We discuss these findings in light of visual dominance effects and the relative informativeness of faces vs voices for identity perception.     

The attribute selection process in pattern perception: The effect of constraint redundancy and stimulus exposure time on the classification of spatially represented Markov patterns

A transfer paradigm was used to study the effect of constraint redundancy (Rc) and stimulus exposure time (ET) on the “same-different” classifications of pairs of spatially represented Markov patterns (Vargus 7 stimuli; Evans & Mueller, 1966). In the training phase, each S classified, without feedback, pairs of Vargus 7 stimuli generated as deviations from three prototypes (i.e., most probable sequences). Each S received stimuli generated at one of three levels of Rc and exposed for one of three durations. In the test phase, all Ss classified different deviations from the same three prototypes at a single Rc level and a single ET level. Unsupervised classification performance was above chance in both training and transfer and increased slightly over trials. Significant Rc and ET effects were found. These results supported two models of attribute selection and utilization; discussions of these models and their relationships to the findings were directed toward the analysis of the “schema plus correction” hypothesis.     

The effect of anxiety,reinforcement, and intelligence on the learning of a difficult task

The effects of anxiety, reinforcement, and intelligence were studied on the learning of a difficult task (paired associates with 1% association values) in 252 subjects studying in class IX in Chandigarh schools (mean age, 14.7 years). A 2 × 3 × 3 factorial design was used with two anxiety groups (high and low), three reinforcement conditions (praise, reproof, and praise + reproof), and three levels of intelligence (high, middle, and low). In general, the results were in line with the Sarasonian theoretical framework that anxiety shows its debilitating effects under certain conditions, but not all. At upper levels of intelligence, neither anxiety nor reinforcement was found significant. At lower levels of intelligence, anxiety was found to interfere with learning under all the reinforcement conditions. It was found further that the most affected group was the middle intelligencehigh anxiety group. This group performed better under praise than under praise + reproof and reproof alone.     

The N400 effect in children: relationships with comprehension, vocabulary and decoding

Using event-related potentials (ERPs), we investigated the N400 (an ERP component that occurs in response to meaningful stimuli) in children aged 8-10 years old and examined relationships between the N400 and individual differences in listening comprehension, word recognition and non-word decoding. Moreover, we tested the claim that the N400 effect provides a valuable indicator of behavioural vocabulary knowledge. Eighteen children were presented with picture-word pairs that were either ‘congruent’ (the picture depicted the spoken word) or ‘incongruent’ (they were unrelated). Three peaks were observed in the ERP waveform triggered to the onset of the picture-word stimuli: an N100 in fronto-central channels, an N200 in central-parietal channels and an N400 in frontal, central and parietal channels. In contrast to the N100 peak, the N200 and N400 peaks were sensitive to semantic incongruency with greater peak amplitudes for incongruent than congruent conditions. The incongruency effects for each peak correlated positively with listening comprehension but when the peak amplitudes were averaged across congruent/incongruent conditions they correlated positively with non-word decoding. These findings provide neurophysiological support for the position that sensitivity to semantic context (reflected in the N400 effect) is crucial for comprehension whereas phonological decoding skill relates to more general processing differences reflected in the ERP waveform. There were no correlations between ERP and behavioural measures of expressive or receptive vocabulary knowledge for the same items, suggesting that the N400 effect may not be a reliable estimate of vocabulary knowledge in children aged 8-10 years.     

The effects of prompting,fading, and differential reinforcement on vocal mands in non‐verbal preschool children with autism spectrum disorders

There are few procedures to teach non‐vocal children vocal mands. This study evaluated the effects of prompting, fading, and differential reinforcement on eye contact, pointing, vocal approximations, independent requests and immature mands in three children with Autism Spectrum Disorders who in baseline emitted almost no independent vocal mands. This procedure resulted in a large and socially valid increase in independent vocal mands, other appropriate responses and near elimination of immature mands. Copyright © 2010 John Wiley & Sons, Ltd.     

The effect of signaled reinforcement on rats' fixed-interval responding

Four experiments examined the effect on rats' response rate of presenting a brief (500 ms) stimulus simultaneously with the delivery of food on fixed-interval (FI) schedules. In Experiment 1, reinforcement signals that were spatially diffuse (both tones and lights) elevated rates of responding, but responding was attenuated by localized visual stimuli. The remaining experiments examined the signal-induced potentiation of responding. In Experiment 2, a tone reinforcement signal potentiated response rates on an FI schedule, but attenuated response rates on a variable-interval (VI) schedule. This difference was obtained even though the overall rate of responding was equated on the two schedules before the introduction of the signal. Signal-induced potentiation of responding occurred over a range of FI values employed in Experiment 3. In Experiment 4, presenting a reinforcement signal when high local rates of response had occurred immediately before reinforcement resulted in potentiated rates of responding on an FI schedule. The opposite effect on response rate occurred when the reinforcement signal followed only low local rates of response. These results indicate that a variety of factors influence the effects of a reinforcement signal. They imply, however, that the local rate of response at the time of reinforcement is a key factor in establishing the nature of the signaling effect.