Developing a Sufficient Knowledge Base for Faces: Implicit Recognition Memory for Distinctive versus Typical Female Faces

Research on adults' face recognition abilities provides evidence for a distinctiveness effect such that distinctive faces are remembered better and more easily than typical faces. Research on this effect in the developmental literature is limited. In the current study, two experiments tested recognition memory for evidence of the distinctiveness effect. Study 1 tested infants (9- and 10-month olds) using a novelty preference paradigm. Infants were tested for immediate and delayed memory. Results indicated memory for only the most distinctive faces. Study 2 tested preschool children (3- and 4-year-olds) using an interactive story. Children were tested with an implicit (i.e. surprise) memory test. Results indicated a memory advantage for distinctive faces by three-year-old girls and four-year-old boys and girls. Contrary to traditional theories of changes in children's processing strategies, experience is also a critical factor in the development of face recognition abilities

Intergroup Dynamics in Speech Perception: Interaction Among Experience, Attitudes and Expectations

Experience, attitudes, and expectations have been identified as separate influences on speech perception and comprehension across groups. In this study, we investigate the interaction among these three variables. 58 Australia-born participants completed an online survey and a vowel categorization task. The survey examined participants’ experience with Vietnamese-accented English and their attitudes towards Asians. The vowel categorization task examined participants’ recovery of a Vietnamese-accented speaker’s intended vowels. Half of the participants were told to expect a Vietnamese accent whereas the other half were not. Results indicated that the relationship between listener expectations and group attitudes varied according to whether or not participants had experience with the Vietnamese accent. This interaction was most clearly reflected on the ‘book’ vowel. Compared to participants who did not expect a Vietnamese accent, had no experience with the Vietnamese accent, but positive attitudes towards the Vietnamese group, those who expected a Vietnamese accent showed a decrease in accuracy on ‘book’ categorization. A decrease in ‘book’ categorization accuracy was also found for those having experience with the accent but negative attitudes. In contrast, an increase in accuracy was found for those having no experience with the Vietnamese accent and negative attitudes towards the Vietnamese group, and those having experience with the accent and positive attitudes. We concluded that expectations, experience and attitudes interact in their relationship with speech perception

The Role of Words in Cognitive Tasks: What, When, and How?

The current review focuses on how exposure to linguistic input, and count nouns in particular, affect performance on various cognitive tasks, including individuation, categorization and category learning, and inductive inference. We review two theoretical accounts of effects of words. Proponents of one account argue that words have top-down effects on cognitive tasks, and, as such, function as supervisory signals. Proponents of the other account suggest that early in development, words, just like any other perceptual feature, are first and foremost part of the stimulus input and influence cognitive tasks in a bottom-up, non-supervisory fashion. We then review evidence supporting each account. We conclude that, although much research is needed, there is a large body of evidence indicating that words start out like other perceptual features and become supervisory signals in the course of development

The role of acoustic similarity and non-native categorisation in predicting non-native discrimination : Brazilian Portuguese vowels by English vs. Spanish listeners

This study tests whether Australian English (AusE) and European Spanish (ES) listeners differ in their categorisation and discrimination of Brazilian Portuguese (BP) vowels. In particular, we investigate two theoretically relevant measures of vowel category overlap (acoustic vs. perceptual categorisation) as predictors of non-native discrimination difficulty. We also investigate whether the individual listener’s own native vowel productions predict non-native vowel perception better than group averages. The results showed comparable performance for AusE and ES participants in their perception of the BP vowels. In particular, discrimination patterns were largely dependent on contrast-specific learning scenarios, which were similar across AusE and ES. We also found that acoustic similarity between individuals’ own native productions and the BP stimuli were largely consistent with the participants’ patterns of non-native categorisation. Furthermore, the results indicated that both acoustic and perceptual overlap successfully predict discrimination performance. However, accuracy in discrimination was better explained by perceptual similarity for ES listeners and by acoustic similarity for AusE listeners. Interestingly, we also found that for ES listeners, the group averages explained discrimination accuracy better than predictions based on individual production data, but that the AusE group showed no difference

Resilience of English vowel perception across regional accent variation

In two categorization experiments using phonotactically legal nonce words, we tested Australian English listeners’ perception of all vowels in their own accent as well as in four less familiar regional varieties of English which differ in how their vowel realizations diverge from Australian English: London, Yorkshire, Newcastle (UK), and New Zealand. Results of Experiment 1 indicated that amongst the vowel differences described in sociophonetic studies and attested in our stimulus materials, only a small subset caused greater perceptual difficulty for Australian listeners than for the corresponding Australian English vowels. We discuss this perceptual tolerance for vowel variation in terms of how perceptual assimilation of phonetic details into abstract vowel categories may contribute to recognizing words across variable pronunciations. Experiment 2 determined whether short-term multi-talker exposure would facilitate accent adaptation, particularly for those vowels that proved more difficult to categorize in Experiment 1. For each accent separately, participants listened to a pre-test passage in the nonce word accent but told by novel talkers before completing the same task as in Experiment 1. In contrast to previous studies showing rapid adaptation to talker-specific variation, our listeners’ subsequent vowel assimilations were largely unaffected by exposure to other talkers’ accent-specific variation

Revealing perceptual structure through input variation: cross-accent categorization of vowels in five accents of English

This paper characterizes the perceptual structure of vowel systems in five regional accents of English, from Australia (A), New Zealand (Z), London (L), Yorkshire (Y), and Newcastle upon Tyne (N), on the basis of “whole system” vowel categorization experiments. We established patterns of within-accent vowel confusions, and then explored cross-accent perception, assessing how listeners from one accent background categorize vowels from another. Our experimental task required mapping continuous phonetic dimensions to perceptual categories in the absence of phonotactic and lexical cues to vowel identity and socio-indexical information about the talker. Our results show that, without these sources of information, there is uncertainty in vowel categorization, even for native accent vowels, and that this degree of uncertainty increases for unfamiliar accents. The patterns of cross-accent perception largely reflect the accent-specific perceptual structure of the listener, as opposed to adaptations to the stimulus accents. This finding contrasts with the type of active talker adaptation found with tasks offering lexical information about vowel identity and indexical information about the talker

Social group membership before treatment for substance dependence predicts early identification and engagement with treatment communities

Social relationships play a major role in recovery from substance dependence. To date, greater attention has been paid to the role of important individuals in a person’s life and their contribution to recovery following treatment. This study is the first to examine both individual and wider group-based social connections in the lead up to residential treatment for substance misuse in a therapeutic community (TC), and their influence both on a person’s readiness to engage with the treatment community and with a recovery pathway. Participants were 307 adults interviewed early in treatment about their individual- and group-based social relationships prior to treatment entry, their social identification with the TC, as ‘a user’ and a person ‘in recovery’, their current recovery capital and quality of life. Correlational analysis showed that only pre-treatment group-based, and not individual, relationships, were significantly associated with developing social identification with the TC early in treatment. Moreover, results of hierarchical regression analyses indicated that identification with the TC was best predicted by the extent to which people saw themselves as being in recovery. Finally, mediation analysis indicated that TC identification was the mechanism through which social group memberships prior to treatment commencement protected quality of life in the early phases of treatment. These findings highlight the protective role that group memberships play in building early identification with the TC and supporting well-being in a critical period of transitioning to treatment

Challenges of diabetes prevention in the real world : results and lessons from the Melbourne diabetes prevention study

OBJECTIVE: To assess effectiveness and implementability of the public health programme Life! Taking action on diabetes in Australian people at risk of developing type 2 diabetes. RESEARCH DESIGN AND METHODS: Melbourne Diabetes Prevention Study (MDPS) was a unique study assessing effectiveness of Life! that used a randomized controlled trial design. Intervention participants with AUSDRISK score ≥15 received 1 individual and 5 structured 90 min group sessions. Controls received usual care. Outcome measures were obtained for all participants at baseline and 12 months and, additionally, for intervention participants at 3 months. Per protocol set (PPS) and intention to treat (ITT) analyses were performed. RESULTS: PPS analyses were considered more informative from our study. In PPS analyses, intervention participants significantly improved in weight (-1.13 kg, p=0.016), waist circumference (-1.35 cm, p=0.044), systolic (-5.2 mm Hg, p=0.028) and diastolic blood pressure (-3.2 mm Hg, p=0.030) compared with controls. Based on observed weight change, estimated risk of developing diabetes reduced by 9.6% in the intervention and increased by 3.3% in control participants. Absolute 5-year cardiovascular disease (CVD) risk reduced significantly for intervention participants by 0.97 percentage points from 9.35% (10.4% relative risk reduction). In control participants, the risk increased by 0.11 percentage points (1.3% relative risk increase). The net effect for the change in CVD risk was -1.08 percentage points of absolute risk (p=0.013). CONCLUSIONS: MDPS effectively reduced the risk of diabetes and CVD, but the intervention effect on weight and waist reduction was modest due to the challenges in recruiting high-risk individuals and the abbreviated intervention

Optical measurement of cell membrane tension

Using a novel noncontact technique based on optical interferometry, we quantify the nanoscale thermal fluctuations of red blood cells (RBCs) and giant unilamellar vesicles (GUVs). The measurements reveal a nonvanishing tension coefficient for RBCs, which increases as cells transition from a discocytic shape to a spherical shape. The tension coefficient measured for GUVs is, however, a factor of 4-24 smaller. By contrast, the bending moduli for cells and vesicles have similar values. This is consistent with the cytoskeleton confinement model, in which the cytoskeleton inhibits membrane fluctuations [Gov et al., Phys. Rev. Lett. 90, 228101, (2003)