Familiarity Ratings Research Articles

Low odor awareness predicts reduced olfactory abilities in women with depressive symptoms, but not with anxiety symptoms

BackgroundOlfactory disorders and affective symptoms are tightly related. However, the factors underlying this association are not yet understood. One candidate factor is “odor awareness”: the degree of attention individuals pays to the odors. However, the association between odor awareness and olfactory abilities in individuals with affective symptoms has not been clarified yet. MethodThe present study examined whether odor awareness may moderate (a) the relation between olfactory dysfunctions and depressive and anxiety symptoms; (b) the relation between the perceptual ratings of the odors and depressive and anxiety symptoms in a sample of healthy women (n = 214). Self-report measures of depression and anxiety were collected, whereas the Sniffin’ Stick test was employed to measure olfactory abilities. ResultsLinear regression analysis revealed that individuals with higher depressive symptoms presented lower olfactory abilities and that odor awareness was a significant moderator of the association between depressive symptoms and olfactory abilities. Anxiety symptoms were not related to any of the olfactory abilities considered, and this relationship did not change according to odor awareness. The familiarity rating of the odor was significantly predicted by odor awareness. These results were confirmed by Bayesian statistics. LimitationsThe sample was composed only of women. ConclusionsIn a healthy population of women, only the presence of depressive symptoms is related to reduced olfactory performance. Odor awareness may be implicated in the development and maintenance of olfactory dysfunction; hence it could be used as a useful target for specific treatments in clinical settings.

Perirhinal cortex automatically tracks multiple types of familiarity regardless of task-relevance

Perirhinal cortex (PrC) has long been implicated in familiarity assessment for objects and corresponding concepts. However, extant studies have focused mainly on changes in familiarity induced by recent exposure in laboratory settings. There is an increasing appreciation of other types of familiarity signals, in particular graded familiarity accumulated throughout one's lifetime. In prior work (Duke et al., 2017, Cortex, 89, 61–70), PrC has been shown to track lifetime familiarity ratings when participants make related judgements. A theoretically important characteristic of familiarity is its proposed automaticity. Support for automaticity comes from a documented impact of recent stimulus exposure on behavioral performance, and on PrC signals, under conditions in which this exposure is not task relevant. In the current fMRI study, we tested whether PrC also tracks lifetime familiarity of object concepts automatically, and whether this type of familiarity influences behavior even when it is not task relevant. During scanning, neurotypical participants (N = 30, age range 18–40, 7 males) provided animacy judgements about concrete object concepts presented at differing frequencies in an initial study phase. In a subsequent test phase, they made graded judgements of recent or lifetime familiarity. Behavioral performance showed sensitivity to lifetime familiarity even when it was not relevant for the task at hand. Across five sets of fMRI analyses, we found that PrC consistently tracked recent and lifetime familiarity of object concepts regardless of the task performed. Critically, while several other temporal-lobe regions also showed isolated familiarity effects, none of them tracked familiarity with the same consistency. These findings demonstrate that PrC automatically tracks multiple types of familiarity. They support models that assign a broad role in the representation of information about object concepts to this structure.

Development of phonologically-balanced and perceptually equivalent Singapore Mandarin word lists for word recognition test

Background Word recognition tests must be conducted in the native language of the listener to obtain valid word recognition scores. Existing Singapore Mandarin speech audiometry test materials that are disyllabic lack in sensitivity and are not phonologically balanced. Objective The purpose of this study was to address those limitations and develop a set of word lists for testing speakers of Singapore Mandarin. Methods The word lists were developed over three phases. (1) Frequently occurring words were chosen from a database consisting of subtitles from local Mandarin programmes, and subjected to familiarity rating by 50 native Singapore Mandarin speakers. (2) Phonologically balanced word lists were created and professionally recorded using words rated as familiar in phase 1. (3) Psychometric curves of words were obtained from 20 normal-hearing native speakers and word lists were analysed for perceptual equivalence. Results Sixteen phonologically balanced word lists consisting of 25 monosyllables each were created in phase 2. Eight of the 16 lists were found to be perceptually equivalent. Conclusion Word lists developed in this study addressed the limitations of existing Singapore Mandarin speech audiometry materials. The word lists need to be validated with normal-hearing and hearing-impaired Singapore Mandarin speakers before they can be used clinically.

High arousal as the source of food rejection in food neophobia

Food neophobia (FN) at moderate to high levels is very common among adult populations in all cultures and is usually defined in terms of rejection of unfamiliar foods. However, food rejection in FN is only partly related to food familiarity. Experimental and survey studies have suggested that unpleasantly high arousal may be induced by food novelty, but also be produced by foods with intense or complex flavours, that are perceived as dangerous or foreign, or that have unusual ingredients. Liking for foods with these characteristics have recently been shown to be strongly negatively associated with FN. Thus, induced high arousal may underlie food rejection in FN. Here, we collected familiarity, liking and arousal ratings, and scores on the standard Food Neophobia Scale from more than 7000 consumers in four countries – Australia, United Kingdom, Singapore, Malaysia – for a series of food names that were manipulated to produce standard and ‘high arousal’ (variant) versions of the same foods. Consistent across all four countries, arousal ratings increased, and liking decreased, with decreases in food familiarity. Variant food names were always associated with ratings of higher arousal than the standard names. The variant foods were generally less familiar than the standard foods, although this was not a necessary condition for their higher arousal ratings, suggesting that the other arousal-inducing factors (e.g., flavour intensity) also played a role. Across all foods, arousal ratings increased, and liking ratings decreased, as FN increased, but these effects were accentuated for the variant foods. The consistency of these effects across multiple countries supports a view that arousal is universally a strong determinant of liking for foods and that this underlies the rejection of foods, familiar and novel, in FN.

Ortho‐ and Retronasal stimulations with specific food odours: Hedonic and familiarity ratings are related to chemosensory pleasure scale (CPS) scores

AbstractVolatile compounds can reach olfactory epithelium though the nose (orthonasal olfaction) or the mouth (retronasal olfaction). Although differences have been found between these two pathways in terms of odour sensitivity and identification, few studies have examined ortho‐ and retronasal differences taking into consideration the three main dimensions of olfactory perception (i.e. hedonicity, intensity and familiarity). Olfactory perception, and particularly odour hedonic perception, is influenced by several factors such as sex or age. Another variability factor worth considering, especially regarding food‐related odours, is the ability to experience pleasure simulated by smell or taste, which can be measured with the Chemosensory Pleasure Scale (CPS). Thus, the aims of this study were (1) to compare odour sensory ratings in response to ortho‐ and retronasal presentation and (2) to examine the relationship between CPS scores and odour sensory ratings in ortho‐ and retronasal pathways. Participants rated ten food odours in ortho‐ and retronasal conditions using visual analogue scales and were divided into two subgroups based on the median CPS score (CPS+ and CPS− groups). Results revealed similar sensory responses to food odours between ortho‐ and retronasal pathways for the three main dimensions of olfactory perception. Interestingly, when CPS scores were considered, clear differences in odour familiarity and hedonicity were shown, particularly for the retronasal pathway (i.e. odours were perceived as more pleasant and more familiar in CPS+ group than in CPS− group). Overall, these findings suggest that differences in odour perception between ortho‐and retronasal pathways may be related to specific individual characteristics such as chemosensory hedonic capacity.

The Whole is Not Different From its Parts

Music psychology has a long history, but the question of whether brief music excerpts are representative of whole songs has been largely unaddressed. Here, we explore whether preference and familiarity ratings in response to excerpts are predictive of these ratings in response to whole songs. We asked 643 participants to judge 3,120 excerpts of varying durations taken from different sections of 260 songs from a broad range of genres and time periods in terms of preference and familiarity. We found that within the range of durations commonly used in music research, responses to excerpts are strongly predictive of whole song affect and cognition, with only minor effects of duration and location within the song. We concluded that preference and familiarity ratings in response to brief music excerpts are representative of the responses to whole songs. Even the shortest excerpt duration that is commonly used in research yields preference and familiarity ratings that are close to those for whole songs, suggesting that listeners are able to rapidly and reliably ascertain recognition as well as preference and familiarity ratings of whole songs.

Assessment of Emicizumab Adherence: Psychometrics and Applications of Novel Self-Report Measure Veritas-Nexgen

Background: Patients with severe hemophilia are at risk for musculoskeletal bleeding that can result in arthropathy and disability. Prophylactic treatment of hemophilia prevents bleeding and joint damage and is recommended as the standard of care for persons with severe hemophilia. Non-adherence to a prophylactic regimen can limit treatment effectiveness and result in adverse health outcomes. Emicizumab, a self-administered subcutaneous treatment, is available for prophylactic therapy of persons with hemophilia A with inhibitors and without inhibitors. This therapy is expected to enhance treatment satisfaction and adherence in hemophilia A. Aims: We completed a pilot study on the initial development and preliminary psychometrics of a new self-report adherence scale for emicizumab titled VERITAS-NEXGEN, modeled on the VERITAS-Pro hemophilia clotting factor adherence scale. In this current study, we investigated a broader set of psychometrics supporting this novel measure of emicizumab adherence in a larger sample. We also sought to describe self-reported adherence using this measure in the larger sample of patients with hemophilia. Methods: The VERITAS-NEXGEN scale consisted of five 5-item subscales (dosing, injection, timing, planning, and bleeds) and an aggregate total score. Items were rated on a 1-9 scale (higher values indicate greater adherence), and subscale and total scores were derived as average scores of constituent items. Participants (N=69 males) with factor VIII deficiency from two hemophilia treatment centers and an active prescription for emicizumab for at least four months were then recruited to complete the scale for psychometric analysis and investigation of self-reported adherence. A subset of the participants (N=20) completed a second adherence scale within one month to provide an estimate of test-retest reliability. The adherence scale was validated against two global patient-ratings of adherence: an established 1-10 rating scale of global adherence (global adherence rating; GAR) and a new 1-10 rating scale of familiarity with treatment. Results: Using the VERITAS-NEXGEN scale, total self-reported adherence was high (average total item score of 8.3 on a 1-9 scale; 9% of patients reporting perfect mean adherence scores of 9, and 87% of patients reporting strong mean adherence scores of 7-8). Based on subscale scores, dosing and injection domains (mean scores of 8.6 and 8.7, respectively; 97% of patients reporting scores of 7 or greater) had greater adherence than the timing and planning domains (mean scores of 7.8 and 8.4, respectively; 14% and 7% of patients reporting scores under 7, respectively). Adherence related to Bleeds also was lower than dosing and injections (mean score=8.1; 14% of patients reporting scores under 7). Internal consistency values for the dosing, injection, bleeds, and total scores were excellent (alpha 0.81-0.91), while alpha values for planning (alpha=0.73) and timing (alpha=0.57) fell in a fair to moderate range. Test-retest reliability for all subscales was good (Planning, r=0.61) to excellent (all other subscales and Total r=0.72-0.83). Dosing, injection, planning, and total scores correlated significantly with global ratings of adherence and treatment familiarity. Timing scores also correlated significantly with global ratings of adherence. Conclusions: Results from this study supported the reliability and validity of subscale and total scores from this new emicizumab adherence scale and provide new insights into adherence strengths and weaknesses in a sample of patients with hemophilia. Overall, self-reported emicizumab adherence was excellent in the sample, with 86-97% of the sample reporting strong to excellent adherence depending on adherence domain. In addition to providing a rapid, easy-to-obtain estimate of patient-rated adherence in the clinical setting, this new adherence scale will allow for investigation of specific adherence domains that are most challenging for patients taking emicizumab, allowing for targeted interventions.

Odor perception of aromatherapy essential oils with different chemical types: Influence of gender and two cultural characteristics.

Olfactory perception, and especially affective responses of odors, is highly flexible, but some mechanisms involved in this flexibility remain to be elucidated. This study investigated the odor perceptions of several essential oils used in aromatherapy with emotion regulation functions among college students. The influences of people's characteristics including gender, hometown region, and fragrance usage habit on odor perception were further discussed. Odor perception of nine essential oils, which can be divided into the ester-alcohol type (e.g., lavender oil) and terpene type (e.g., lemon oil) were evaluated under three odor concentrations. The results indicated that chemical type, but not concentration, significantly influenced the odor perception and there was no interaction between the two factors in this study. The arousal and emotional perception scores of odors with terpene-type oil were significantly higher than odors with ester-alcohol type. In terms of people's characteristics, participants from the southern Yangtze river gave a higher familiarity rating to almost all of these odors. The habits of fragrance usage also significantly influenced some of the odors' subjective intensity and emotional perception ratings. However, there were no significant gender differences in most of the odor perceptions. In addition, familiarity and pleasantness were positively correlated, and emotional perception and subjective intensity also showed a weak correlation. These results suggested that users' cultural characteristics could be considered to be important factors that affect the essential oil's odor perception in aromatherapy.

Identification Accuracy of Safety-Relevant Environmental Sounds in Adult Cochlear Implant Users.

Examine cochlear implant (CI) users' ability to identify safety-relevant environmental sounds, imperative for safety, independence, and personal well-being. Twenty-one experienced adult CI users completed an Environmental Sound Identification (ESI) test consisting of 42 common environmental sounds, 28 of which were relevant to personal safety, along with 14 control sounds. Prior to sound identification, participants were shown sound names and asked to rate the familiarity and, separately, relevance to safety of each corresponding sound on a 1-5 scale. Overall ESI accuracy was 57% correct for the safety-relevant sounds and 55% correct for control sounds. Participants rated safety-relevant sounds as more important to safety and more familiar than the non-safety sounds. ESI accuracy significantly correlated with familiarity ratings. The present findings suggest mediocre ESI accuracy in postlingual adult CI users for safety-relevant and other environmental sounds. Deficits in the identification of these sounds may put CI listeners at increased risk of accidents or injuries and may require a specific rehabilitation program to improve CI outcomes. 4 Laryngoscope, 133:2388-2393, 2023.

Mania associated olfactory dysfunction: A comparison between bipolar subjects in mania and remission

ObjectivesThe aim of this study was to assess the olfactory functions of patients with bipolar disorder in manic phase and to compare them to those of bipolar subjects in remission and healthy controls. MethodsWe recruited 96 participants divided in 3 groups: bipolar mania (MB), euthymic bipolar in remission (EB) and healthy controls (HC). All participants underwent an assessment of their olfactory functions using the Sniffin’ sticks threshold and identification tests. Odors' pleasantness, intensity, familiarity and emotion were assessed. All participants were screened for the presence of psychiatric disorder through the MINI questionnaire. Clinical evaluation explored dimensions of mania, depression, anxiety respectively through YMRS, MADRS and STAI scales. Anhedonia was explored through the Chapman physical and social anhedonia questionnaire. ResultsPatients in mania had deficits in identifying positive smells compared to bipolar subjects in remission and to healthy controls (MB < EB < HC; p < 0.001). Hedonic (MB < EB = HC; p < 0.001) and emotional (MB < EB = HC; p < 0.001) ratings of positive smells were lower in patients in manic phase compared to remitted subjects or controls. Mania was associated to higher emotion rating of negative smells compared to remitted subjects and controls (MB > EB = HC; p < 0.001). There was no difference between the 3 groups in the ratings of intensity and familiarity of smells, as well as in the olfactory threshold testing. The 3 groups showed no difference in the identification of negative smells. ConclusionsPatients in manic episodes showed deficits in identifying positive odors. They evaluated these smells as less pleasant and less emotional compared to remitted bipolar subjects and healthy controls. These olfactory dysfunctions may constitute potential indicators of manic state. The persistence of olfactory dysfunction in remission phase (deficit in the olfactory identification of positive odors compared to healthy controls) may constitute a potential trait indicator of bipolarity.

Detecting a familiar person behind the surgical mask: recognition without identification among masked versus sunglasses-covered faces

Previous research has shown that even when famous people’s identities cannot be discerned from faces that have been filtered with monochromatic noise, these unidentifiable famous faces still tend to receive higher familiarity ratings than similarly filtered non-famous faces. Experiment 1 investigated whether a similar face recognition without identification effect would occur among faces whose identification was hindered through the wearing of a surgical mask. Among a mixture of famous and non-famous faces wearing surgical masks and hoods, participants rated how familiar each person seemed then attempted to identify the person. Though surgical masks significantly impaired identification of the famous faces, unidentified masked famous faces received higher familiarity ratings on average than the non-famous masked faces, suggesting that a sense of familiarity could still occur even when identification was impaired by the mask. Experiment 2 compared faces covered by surgical masks with faces covered by sunglasses. Though sunglasses impaired face identification more than surgical masks, the magnitude of the face recognition without identification effect was the same in both cases. This pattern suggests that holistic face processing is not a requirement for the sense of familiarity with a face, and that different facial feature types can contribute.

What does the processing of chunks by learners of Chinese tell us? An acceptability judgment investigation

Abstract Chunks are multi-word sequences that constitute an important component of the mental lexicon. In second language (L2) acquisition, chunking is essential for attaining fluency and idiomaticity. In the present study, in order to examine whether chunks provide a processing advantage over non-chunks for L2 learners at different levels of proficiency, three groups (beginner, intermediate, and advanced) English-speaking learners of Chinese participated in an online acceptability judgment task and a familiarity rating task. Our results revealed that the participants in all three groups processed chunks faster and with fewer errors than they did non-chunks. It was also found that the observed processing advantage of chunks could not be explained by a familiarity effect alone, thus suggesting that L2 learners across the board store chunks as holistic units. The implications of chunk instruction in relation to input frequency and variability in L2 settings are also discussed.

Learning words without trying: Daily second language podcasts support word-form learning in adults.

Spoken language contains overlapping patterns across different levels, from syllables to words to phrases. The discovery of these structures may be partially supported by statistical learning (SL), the unguided, automatic extraction of regularities from the environment through passive exposure. SL supports word learning in artificial language experiments, but few studies have examined whether it scales up to support natural language learning in adult second language learners. Here, adult English speakers (n = 70) listened to daily podcasts in either Italian or English for 2 weeks while going about their normal routines. To measure word knowledge, participants provided familiarity ratings of Italian words and nonwords both before and after the listening period. Critically, compared with English controls, Italian listeners significantly improved in their ability to discriminate Italian words and nonwords. These results suggest that unguided exposure to natural, foreign language speech supports the extraction of relevant word features and the development of nascent word forms. At a theoretical level, these findings indicate that SL may effectively scale up to support real-world language acquisition. These results also have important practical implications, suggesting that adult learners may be able to acquire relevant speech patterns and initial word forms simply by listening to the language. This form of learning can occur without explicit effort, formal instruction or focused study.

Stimuli in 3 Acts: A normative study on action-statements, action videos and object photos

The study of action observation and imagery, separately and combined, is expanding in diverse research areas (e.g., sports psychology, neurosciences), making clear the need for action-related stimuli (i.e., action statements, videos, and pictures). Although several databases of object and action pictures are available, norms on action videos are scarce. In this study, we validated a set of 60 object-related everyday actions in three different formats: action-statements, and corresponding dynamic (action videos) and static (object photos) stimuli. In Study 1, ratings of imageability, image agreement, action familiarity, action frequency, and action valence were collected from 161 participants. In Study 2, a different sample of 115 participants rated object familiarity, object valence, and object-action prototypicality. Most actions were rated as easy to imagine, familiar, and neutral or positive in valence. However, there was variation in the frequency with which participants perform these actions on a daily basis. High agreement between participants' mental image and action videos was also found, showing that the videos depict a conventional way of performing the actions. Objects were considered familiar and positive in valence. High ratings on object-action prototypicality indicate that the actions correspond to prototypical actions for most objects. 3ActStimuli is a comprehensive set of stimuli that can be useful in several research areas, allowing the combined study of action observation and imagery.

Sleep Fosters Odor Recognition in Children with Attention Deficit Hyperactivity Disorder but Not in Typically Developing Children.

Prior experience represents a prerequisite for memory consolidation across various memory systems. In the context of olfaction, sleep was found to enhance the consolidation of odors in adults but not in typically developing children (TDC), likely due to differences in pre-experience. Interestingly, unmedicated children with attention deficit hyperactivity disorder (ADHD), a neurodevelopmental condition related to dopamine dysfunction, showed lower perceptive thresholds for odors, potentially allowing for more odor experience compared to TDC. We investigated sleep-associated odor memory consolidation in ADHD. Twenty-eight children with ADHD and thirty age-matched TDC participated in an incidental odor recognition task. For the sleep groups (ADHD: n = 14, TDC: n = 15), the encoding of 10 target odorants took place in the evening, and the retention of odorants was tested with 10 target odorants and 10 distractor odorants the next morning. In the wake groups (ADHD: n = 14, TDC: n = 15), the time schedule was reversed. Odor memory consolidation was superior in the ADHD sleep group compared to the TDC sleep and the ADHD wake groups. Intensity and familiarity ratings during encoding were substantially higher in ADHD compared to TDC. Sleep-associated odor memory consolidation in ADHD is superior to TDC. Abundant pre-experience due to lower perceptive thresholds is suggested as a possible explanation. Olfaction might serve as a biomarker in ADHD.

Decomposing the Effects of Familiarity with Music Cues on Stride Length and Variability in Persons with Parkinson's Disease: On the Role of Covariates.

This study aimed to determine the role of cognitive and affective responses to music cues in modulating the effects of familiarity with music on stride length and stride-to-stride variability in people with Parkinson’s disease (PD). Using multilevel modeling, people with PD’s spatiotemporal gait parameters and self-reported ratings of familiarity, enjoyment, cognitive and physical demand, beats salience of music cues after each walking trial, as well as music reward, were analyzed. Our findings indicate that (1) condition-varying perceived enjoyment and beat salience are positively associated with increased stride length; (2) participants with a greater music reward for mood regulation and emotion evocation show greater stride length changes compared with those with less music reward; (3) condition-varying perceived enjoyment is positively associated with decreases in stride-to-stride variability; and (4) participants with lower cognitive demand of walking with music cues and higher beat salience show lower stride-to-stride variability compared with those with higher cognitive demand and lower beat salience. These results provide behavioral evidence of independent and interactive influences of cognitive and affective responses to music cues on spatiotemporal gait parameters in people with PD.

Detecting valence from unidentified images: A link between familiarity and positivity in recognition without identification.

Research using the Recognition Without Identification paradigm (Cleary & Greene, 2000, Journal of Experimental Psychology: Learning, Memory, and Cognition, 26[4], 1063–1069; Peynircioǧlu, 1990, Journal of Memory and Language, 29, 493–500) has found that participants can discriminate between old and new stimuli even when the stimuli are obscured to a degree that they are unidentifiable. This methodology has been adapted in the past by using heavily obscured threatening and nonthreatening images and asking participants to try to identify each image followed by a familiarity rating of the image. Past results showed that threatening images that were not able to be identified were rated as more familiar than nonthreatening images that were not able to be identified (Cleary et al., 2013, Memory & Cognition, 41, 989–999). The current study used a similar methodology to explore the possibility that a sense of familiarity can serve to guide our attention toward potential threats in the environment. However, contrary to earlier results, we found that positive images were rated as more familiar than negative images. This pattern was found with both identified and unidentified images and was replicated across five experiments. The current findings are consistent with the view that feelings of positivity and familiarity are closely linked (e.g., de Vries et al., 2010, Psychological Science, 21[3], 321–328; Garcia-Marques et al., 2004, Personality and Social Psychology Bulletin, 30, 585–593; Monin, 2003, Journal of Personality and Social Psychology, 85[6], 1035–1048).

The effect of lexical coverage on L2 learners’ reading comprehension of narrative and expository genres

Understanding the relationship between lexical coverage (i.e., the number of words known in a text) and second language (L2) reading comprehension is pivotal to L2 instruction as it helps teachers set sensible vocabulary learning goals and select suitable reading materials. This study examined the unique contribution of 7 lexical coverage figures (i.e., 90%, 95%, 96%, 97%, 98%, 99%, and 100%) to the comprehension of narrative and expository texts read by Chinese EFL undergraduate students (N = 234). Participants completed the Vocabulary Size Test, a L2 reading ability test, a background knowledge test, reading comprehension tests, and topic familiarity ratings. Results of hierarchical regression analyses showed that after accounting for L2 vocabulary size and L2 reading ability, lexical coverage remained a steady, though weak, predictor of narrative and expository comprehension scores. No indication of a lexical threshold for reading comprehension was found. Instead, lexical coverage was found to be a stronger predictor of expository comprehension scores than narrative. While findings suggested 98% lexical coverage was reasonable for satisfactory comprehension of L2 narrative texts, 100% lexical coverage may be needed for satisfactory comprehension of L2 expository texts without the support of background knowledge. Pedagogical implications were discussed in relation to the findings.

A neural measure of the degree of face familiarity

Recognizing a face as familiar is essential in our everyday life. However, ‘familiarity’ covers a wide range – from people we see every day to those we barely know. Although face recognition is studied extensively, little is known about how the degree of familiarity affects neural face processing, despite the critical social importance of this dimension. Here we report the results of a multivariate cross-classification EEG experiment, where we study the temporal representational dynamics of the degree of familiarity. Participants viewed highly variable face images of 20 identities. Importantly, we measured face familiarity using subjective familiarity ratings in addition to testing explicit knowledge and reaction times in a face matching task. A machine learning algorithm, trained to discriminate familiar and unfamiliar faces from a separate study, was used to predict the degree of face familiarity from the pattern of the EEG data. We found that the neural representations of the degree of familiarity emerge between 400 - 600 msec post-stimulus onset for famous persons. The correlation between decoding performance and behavioral familiarity was more reliable, occurred earlier and lasted longer when personally familiar and viewers' own faces were included in the analysis. Our findings provide new insights into how the brain represents faces with various degrees of familiarity and show that the degree of familiarity can be decoded reliably from the EEG at a relatively late time window. These results support the idea that representations of familiar faces form part of a general neural signature of the familiarity component of recognition memory processes.

Longitudinal changes in auditory and reward systems following receptive music-based intervention in older adults

Listening to pleasurable music is known to engage the brain’s reward system. This has motivated many cognitive-behavioral interventions for healthy aging, but little is known about the effects of music-based intervention (MBI) on activity and connectivity of the brain’s auditory and reward systems. Here we show preliminary evidence that brain network connectivity can change after receptive MBI in cognitively unimpaired older adults. Using a combination of whole-brain regression, seed-based connectivity analysis, and representational similarity analysis (RSA), we examined fMRI responses during music listening in older adults before and after an 8-week personalized MBI. Participants rated self-selected and researcher-selected musical excerpts on liking and familiarity. Parametric effects of liking, familiarity, and selection showed simultaneous activation in auditory, reward, and default mode network (DMN) areas. Functional connectivity within and between auditory and reward networks was modulated by participant liking and familiarity ratings. RSA showed significant representations of selection and novelty at both time-points, and an increase in striatal representation of musical stimuli following intervention. An exploratory seed-based connectivity analysis comparing pre- and post-intervention showed significant increase in functional connectivity between auditory regions and medial prefrontal cortex (mPFC). Taken together, results show how regular music listening can provide an auditory channel towards the mPFC, thus offering a potential neural mechanism for MBI supporting healthy aging.