Development and validation of a novel Context-Based Prospective Memory Task among neurotypical adults.

PURPOSE: To address the paucity and potential of context-based prospective memory (PM) assessment tasks suitable to Indian ethnicity, the study aimed to develop a novel context-based PM task and determine its psychometric properties among neurotypical adults. METHODS: Rendered images in 2-D were extracted from a 3-D shopping mall, where PM and ongoing tasks were embedded within them to provide participants with a semi-immersive experience. The design and scoring of the novel task were constructed in alignment with the Memory for Intentions Screening Test. Fifty neurotypical adults in and around Mangaluru were recruited. The Memory of Intentions Test (MIST) and novel context-based PM task were administered. RESULTS: The validity of the novel task was established with a Content Validity Index of 0.98. The intraclass correlation for the test-retest reliability of the novel context-based PM task was 0.92 (p<0.001) and the inter-rater reliability was 0.98 (p<0.001). The internal consistency of the six subscales was high (Cronbach's α= 0.86), and the Spearman-Brown coefficient indicated a strong split-half reliability of 0.87. Spearman's correlation showed that the trials exhibited strong connections to the dichotomic characteristics of the subscales to which they belonged. Further, McNemar's test suggested similar profiles of the participants for the MIST and novel task. CONCLUSION: The results of the present study suggest that the novel context-based PM task offers good validity and reliability measures, providing valuable insight into the mechanisms of PM, and therefore, could be ideal for inclusion in a battery of cognitive assessments.

Effect of inter-aural temporal envelope differences on inter-aural time difference thresholds for amplitude modulated noise.

PURPOSE: The inter-aural time difference (ITD) and inter-aural level difference (ILD) are important acoustic cues for horizontal localization and spatial release from masking. These cues are encoded based on inter-aural comparisons of tonotopically matched binaural inputs. Therefore, binaural coherence or the interaural spectro-temporal similarity is a pre-requisite for encoding ITD and ILD. The modulation depth of envelope is an important envelope characteristic that helps in encoding the envelope-ITD. However, inter-aural difference in modulation depth can result in reduced binaural coherence and poor representation of binaural cues as in the case with reverberation, noise and compression in cochlear implants and hearing aids. This study investigated the effect of inter-aural modulation depth difference on the ITD thresholds for an amplitude-modulated noise in normal hearing young adults. METHODS: An amplitude modulated high pass filtered noise with varying modulation depth differences was presented sequentially through headphones. In one ear, the modulation depth was retained at 90% and in the other ear it varied from 90% to 50%. The ITD thresholds for modulation frequencies of 8 Hz and 16 Hz were estimated as a function of the inter-aural modulation depth difference. RESULTS: The Friedman test findings revealed a statistically significant increase in the ITD threshold with an increase in the inter-aural modulation depth difference for 8 Hz and 16 Hz. CONCLUSION: The results indicate that the inter-aural differences in the modulation depth negatively impact ITD perception for an amplitude-modulated high pass filtered noise.

Effect of inter-aural temporal envelope differences on inter-aural time difference thresholds for amplitude modulated noise

ABSTRACT Purpose The inter-aural time difference (ITD) and inter-aural level difference (ILD) are important acoustic cues for horizontal localization and spatial release from masking. These cues are encoded based on inter-aural comparisons of tonotopically matched binaural inputs. Therefore, binaural coherence or the interaural spectro-temporal similarity is a pre-requisite for encoding ITD and ILD. The modulation depth of envelope is an important envelope characteristic that helps in encoding the envelope-ITD. However, inter-aural difference in modulation depth can result in reduced binaural coherence and poor representation of binaural cues as in the case with reverberation, noise and compression in cochlear implants and hearing aids. This study investigated the effect of inter-aural modulation depth difference on the ITD thresholds for an amplitude-modulated noise in normal hearing young adults. Methods An amplitude modulated high pass filtered noise with varying modulation depth differences was presented sequentially through headphones. In one ear, the modulation depth was retained at 90% and in the other ear it varied from 90% to 50%. The ITD thresholds for modulation frequencies of 8 Hz and 16 Hz were estimated as a function of the inter-aural modulation depth difference. Results The Friedman test findings revealed a statistically significant increase in the ITD threshold with an increase in the inter-aural modulation depth difference for 8 Hz and 16 Hz. Conclusion The results indicate that the inter-aural differences in the modulation depth negatively impact ITD perception for an amplitude-modulated high pass filtered noise.

Development and validation of a novel Context-Based Prospective Memory Task among neurotypical adults

ABSTRACT Purpose To address the paucity and potential of context-based prospective memory (PM) assessment tasks suitable to Indian ethnicity, the study aimed to develop a novel context-based PM task and determine its psychometric properties among neurotypical adults. Methods Rendered images in 2-D were extracted from a 3-D shopping mall, where PM and ongoing tasks were embedded within them to provide participants with a semi-immersive experience. The design and scoring of the novel task were constructed in alignment with the Memory for Intentions Screening Test. Fifty neurotypical adults in and around Mangaluru were recruited. The Memory of Intentions Test (MIST) and novel context-based PM task were administered. Results The validity of the novel task was established with a Content Validity Index of 0.98. The intraclass correlation for the test-retest reliability of the novel context-based PM task was 0.92 (p<0.001) and the inter-rater reliability was 0.98 (p<0.001). The internal consistency of the six subscales was high (Cronbach's α= 0.86), and the Spearman-Brown coefficient indicated a strong split-half reliability of 0.87. Spearman's correlation showed that the trials exhibited strong connections to the dichotomic characteristics of the subscales to which they belonged. Further, McNemar's test suggested similar profiles of the participants for the MIST and novel task. Conclusion The results of the present study suggest that the novel context-based PM task offers good validity and reliability measures, providing valuable insight into the mechanisms of PM, and therefore, could be ideal for inclusion in a battery of cognitive assessments.

Thinking about what he thinks of what I think: Assessing higher theory of mind abilities in Indian bilingual children between 3.0 and 8.11 years of age.

CONTEXT: The competence in theory of mind (ToM) abilities occurs in parallel with the development of language. To gain a deeper discernment about its proficiency, tasks tapping on higher-order ToM abilities have been implemented. AIMS: This study aims to explore the development of higher-order ToM abilities in bilingual Indian children between 3.0 and 8.11 years of age, to achieve an insight into the influence of language on ToM abilities. SETTINGS AND DESIGN: The current study followed a cross-sectional design along with an employment of a random convenient sampling procedure. The study was conducted in regular English medium schools with each participant individually being assessed. MATERIALS AND METHODS: The study was done on 60 Kannada-English bilingual children, with each participant being assessed using two sets of stories (English and Kannada) that were constructed based on two different central themes which were verbally narrated. The stimulus of each set consisted of questions tapping on three levels (first-second-third orders) of ToM abilities. STATISTICAL ANALYSIS: Descriptive statistics determined the mean and standard deviation of the total ToM scores (in both languages). Wilcoxon Signed-Rank and Mann-Whitney U-tests were done to determine the level of significance across and between the age groups (in both languages), respectively. RESULTS: The results revealed a significant difference across the age groups. In addition, a significant difference between the responses in English and Kannada were obtained. CONCLUSIONS: The development of metalinguistic abilities is influenced by socioenvironmental factors as well as the language maturity of the child.