Perceptual dimensions of infant cry signals: a semantic differential analysis

In the present study the Semantic Differential technique was used to examine perceived characteristics of infant cry sounds. 24 cries (6 each of pain, hunger, birth, and "pleasure") were rated by 39 mothers on 50 scales. A factor analysis of the scale ratings uncovered three main factors, labelled Affect, Potency, and Evaluation, respectively. 5 "factorially-pure" scales were selected to represent each factor. A hierarchical cluster analysis of the mean factor-scale ratings uncovered 3 major cry clusters which essentially represented 3 cry-type groups, hunger, pleasure, and pain/birth. A close correspondence was found between this set of clusters and another set generated independently from cry-recognition data, indicating that the semantic differential factor-scales effectively discriminated perceptually distinct cries. This procedure adequately separates the physical (acoustic) properties of signals from their listener-perceived (auditory) ones. This distinction is not possible with studies which depend upon multivariate techniques and casts doubt on their findings.     

A multidimensional scaling analysis of 16 complex sounds

The INDSCAL multidimensional scaling model was used to investigate the distinctive features involved in the perception of 16 complex nonspeech sounds. The signals differed along four physical dimensions: fundamental frequency, waveform, formant frequency, and number of formants. Scaling results indicated that subjects’ similarity ratings could be accounted for by three psychological or perceptual dimensions. A statistically reliable correspondence was observed between these perceptual dimensions and the physical characteristics of fundamental frequency, waveform, and a combination of the two formant parameters. These results were further explored with Johnson’s (1967) hierarchical clustering analysis. Large differences in featural saliency occurred in the group data with fundamental accounting for more variability than the remaining dimensions. Further analysis of individual subject data revealed large individual differences in featural saliency. These differences were related to past musical experience of the subject and to earlier findings using similar signals. It was concluded that (1) the INDSCAL model provides a useful method for the analysis of auditory perception in the nonspeech mode, and (2) featural saliency in such sounds is likely to be determined by an unspecified attentional mechanism.     

Bilingualism and the perception of professional concepts

A selected set of professional concepts was subjected to analysis through two separate multidimensional scaling techniques, the INDSCAL and TORSCA models, to evaluate the intergroup perceptual differences of four experimental groups, made up of unilingual French, unilingual English and bilingual students. The linguistic relativism thesis provided the research hypotheses on the relationship between language access and usage and concept perception. The multidimensional scaling techniques were applied to the matrix of subjects' similarity judgments on pairs of concepts, thus enabling the identification of three dimensions. The dimensions were labelled as conjunctive, relational and disjunctive, and were assumed to be related to the criteria employed by the subjects in their similarity rankings. An analysis of variance of the individual saliences on each dimension provided evidence of linguistic relativism for both the relational and disjunctive dimensions. These findings support the contention that unilingual speakers of separate languages differ from each other and from bilingual speakers in their perception of professional concepts.     

Internal representation of visual texture as the basis for the judgment of similarity

The relationship between Fourier spectra of visual textures (represented both by the actual frequency components and by the response of four hypothetical channels selectively sensitive to spatial frequency) and the perceptual appearance of the textures was investigated. Thirty textures were synthesized by combining seven spatial frequencies whose amplitudes were randomly chosen and then scaled to give an overall contrast of .9. Similarity judgments were collected using both the method of triadic comparison (two subjects, 4,060 trials each) and the method of paired comparison (six subjects, 435 trials each). The similarity judgments were subjected to MDSCAL and INDSCAL dimensions were found to be optimally oriented in terms of spatial frequency information without rotation. The seven spatial frequency components accounted for 90.6% of the variance in the 3-D INDSCAL space, while the four channels accounted for 91.8% of the variance in the first two dimensions. The data further suggest that the four channels may interact in an opponent process manner. The results support the idea that the visual internal representation of stimuli is based on spatial frequency analysis rather than feature extraction.     

Dimensions of the perception of art: verbal scales and similarity judgements

Abstract.— An INDSCAL analysis was performed on subjects' similarity judgements of all pairs of 12 landscape paintings. Three principal INDSCAL dimensions were identified by analysing responses to 24 unidimensional rating scales derived from previous experiments. The present findings, together with those of previously published studies, suggest that three of the principal dimensions of perception of art appear to be (1) Hedonic-Representational, (2) Clarity, (3) A Dynamic factor involving activity, balance and symmetry. It is suggested that although Complexity may be an important factor influencing responses to simple stimuli, its rôle in the perception of paintings is small, and has frequently been over-emphasised.     

Multidimensional scaling of individual differences for an individual person with a hand-held calculator

An extension to the INDSCAL method of individual differences scaling was developed. The method derives measures of deviation from a “standard” observer, who is defined in terms of the INDSCAL subject weights. These weights are calculated for one individual person at a time. The method is implemented in a small hand-held calculator. The calculator is used for data acquisition, and it interacts with the user in a conversational manner through an alpha-numeric display. The present implementation of the method scales 84 judgments of pair similarity among seven objects and derives subject weights on two dimensions. The method can be extended to sets of up to 16 objects and up to six dimensions. The method is a feasible, cost-effective approach to classification of individuals on complex perceptual attributes within a single 1-h session.     

Judgment of infant cry: The roles of acoustic characteristics and sociodemographic characteristics

Adult judgments of infant cry are determined by both acoustic properties of the cry and listener sociodemographic characteristics. The main purpose of this research was to investigate how these two sources shape adult judgments of infant cry. We systematically manipulated both the acoustic properties of infant cries and contrasted listener sociodemographic characteristics. Then, we asked participants to listen to several acoustic manipulations of infant cries and to judge the level of distress the infant was expressing and the level of distress participants felt when listening. Finally, as a contrasting condition, participants estimated the age of the crying infant. Using tree‐based models, we found that judgments of the level of distress the infant was expressing as well as the level of distress listeners felt are mainly accounted for by select acoustic properties of infant cry (proportion of sound/pause, fundamental frequency, and number of utterances), whereas age estimates of a crying infant are determined mainly by listener sociodemographic characteristics (gender and parental status). Implications for understanding infant cry and its effects as well as early caregiver‐infant interactions are discussed.     

Assessment of infant cry: acoustic cry analysis and parental perception

Infant crying signals distress to potential caretakers who can alleviate the aversive conditions that gave rise to the cry. The cry signal results from coordination among several brain regions that control respiration and vocal cord vibration from which the cry sounds are produced. Previous work has shown a relationship between acoustic characteristics of the cry and diagnoses related to neurological damage, SIDS, prematurity, medical conditions, and substance exposure during pregnancy. Thus, assessment of infant cry provides a window into the neurological and medical status of the infant. Assessment of infant cry is brief and noninvasive and requires recording equipment and a standardized stimulus to elicit a pain cry. The typical protocol involves 30 seconds of crying from a single application of the stimulus. The recorded cry is submitted to an automated computer analysis system that digitizes the cry and either presents a digital spectrogram of the cry or calculates measures of cry characteristics. The most common interpretation of cry measures is based on deviations from typical cry characteristics. Another approach evaluates the pattern across cry characteristics suggesting arousal or under-arousal or difficult temperament. Infants with abnormal cries should be referred for a full neurological evaluation. The second function of crying--to elicit caretaking--involves parent perception of the infant's needs. Typically, parents are sensitive to deviations in cry characteristics, but their perception can be altered by factors in themselves (e.g., depression) or in the context (e.g., culture). The potential for cry assessment is largely untapped. Infant crying and parental response is the first language of the new dyadic relationship. Deviations in the signal and/or misunderstanding the message can compromise infant care, parental effectiveness, and undermine the budding relationship. (c) 2005 Wiley-Liss, Inc. MRDD Research Reviews 2005;11:83-93.     

Dimensions in the perception of architecture:I. Identification and interpretation of dimensions of similarity

Pairwise similarity-dissimilarity ratings of 20 slides of buildings representing major architectural styles were subjected to an INDSCAL analysis. Four major similarity dimensions were identified. Subsequently, the stimuli were rated on two batteries of scales: (1) collative and affective ratings, and (2) stylistic and technical ratings. Canonical correlations and redundancy indices revealed close relations between the multidimensional stimulus locations and the scale and factor spaces. The findings of the three experiments suggest that the four principal dimensions in the perception of architecture appear to be (1)Clarity, (2)Hedonic Tone/Arousal, (3) Uncertainty, and (4) Familiarity.     

Dimensions in the perception of architecture: III. Multidimensional preference scaling

Ten subjects were presented with all possible pairs of 20 slides of buildings representing major architectural styles. On seeing each pair, the subject stated which one of the two was preferred and then, on a 7-point scale, by how much it was preferred. Subjects demonstrated considerable agreement in the number of choices for the buildings, but not in degree of preference judgements. The choice data were subjected to an MDPREF analysis, and the degree of preference data to an INDSCAL analysis. In both cases two-dimensional solutions were most appropriate. The locations of the buildings in the two preference spaces were highly similar. They also resemble two of the dimensions important i similarity judgements of the same stimuli. Relations between the preference dimensions and previously obtained verbal and non-verbal responses to the stimuli were discussed. the underlying variables of the preferences responses were suggested to be related to Hedonic Tone/Arousal and Familiarity.     

Perceptual dimensions of tactile surface texture: A multidimensional scaling analysis

The purpose of this study was to examine the subjective dimensionality of tactile surface texture perception. Seventeen tactile stimuli, such as wood, sandpaper, and velvet, were moved across the index finger of the subject, who sorted them into categories on the basis of perceived similarity. Multidimensional scaling (MDS) techniques were then used to position the stimuli in a perceptual space on the basis of combined data of 20 subjects. A three-dimensional space was judged to give a satisfactory representation of the data. Subjects’ ratings of each stimulus on five scales representing putative dimensions of perceived surface texture were then fitted by regression analysis into the MDS space. Roughness-smoothness and hardness-softness were found to be robust and orthogonal dimensions; the third dimension did not correspond closely with any of the rating scales used, but post hoc inspection of the data suggested that it may reflect the compressional elasticity (“springiness”) of the surface.     

The signal functions of early infant crying

In this article I evaluate recent attempts to illuminate the human infant cry from an evolutionary perspective. Infants are born into an uncertain parenting environment, which can range from indulgent care of offspring to infanticide. Infant cries are in large part adaptations that maintain proximity to and elicit care from caregivers. Although there is not strong evidence for acoustically distinct cry types, infant cries may function as a graded signal. During pain-induced autonomic nervous system arousal, for example, neural input to the vocal cords increases cry pitch. Caregivers may use this acoustic information, together with other cues, to guide caregiving behavior. Serious pathology, on the other hand, results in chronically and severely abnormal cry acoustics. Such abnormal crying may be a proximate cause of adaptive infant maltreatment, in circumstances in which parents cut their losses and reduce or withdraw investment from infants with low survival chances. An increase in the amount of crying during the first few months of life is a human universal, and excessive crying, or colic, represents the upper end of this normal increase. Potential signal functions of excessive crying include manipulation of parents to acquire additional resources, honest signaling of need, and honest signaling of vigor. Current evidence does not strongly support any one of these hypotheses, but the evidence is most consistent with the hypothesis that excessive early infant crying is a signal of vigor that evolved to reduce the risk of a reduction or withdrawal of parental care.     

Adults’ implicit associations to infant positive and negative acoustic cues: Moderation by empathy and gender

In this study a novel auditory version of the Single Category Implicit Association Test (SC-IAT-A) was developed to investigate (a) the valence of adults’ associations to infant cries and laughs, (b) moderation of implicit associations by gender and empathy, and (c) the robustness of implicit associations controlling for auditory sensitivity. Eighty adults (50% females) were administered two SC-IAT-As, the Empathy Quotient, and the Weinstein Noise Sensitivity Scale. Adults showed positive implicit associations to infant laugh and negative ones to infant cry; only the implicit associations with the infant laugh were negatively related to empathy scores, and no gender differences were observed. Finally, implicit associations to infant cry were affected by noise sensitivity. The SC-IAT-A is useful to evaluate the valence of implicit reactions to infant auditory cues and could provide fresh insights into understanding processes that regulate the quality of adult–infant relationships.     

Infant cry as a graded signal: Experimental modifications of durations of pauses and expiratory sounds alter mothers' perceptions

The purpose of this study was to examine experimentally the effects of the temporal structure of infant crying on mothers' perceptions. Eighteen mothers of young infants rated variations of a 10-sec cry in which durations of all expiratory sounds and pauses were digitally lengthened and shortened by 50%. Results showed a general monotonic effect in which cries with increasingly shorter pauses were perceived to be more arousing, aversive, informative, and rough. Similarly, cries with short expirations were perceived to be more rhythmic and rough than cries with long expirations. The strength of the monotonic effect for pause duration on ratings of urgency interacted with the duration of expiratory sounds such that the combination of short pauses and short expirations created the greatest perceived urgency. This study replicates and extends previous findings which show that gradations in acoustic features of crying are associated with gradations in the intensity of adults' perceptions.     

Similarity and preference judgments of musical stimuli

Two experiments were performed comparing similarity (technical-structural) and preference personal-affective) judgments of jazz improvizations (Experiment 1) and of classical, pop-rock, and jazz music (Experiment 2). A multidimensional scaling paradigm (INDSCAL) was used for pairwise comparisons of the 12 musical pieces in each experiment. Each 2 minute piece was subdivided into 10 second segments in order to reduce fatigue or boredom and provide better sampling across comparison trials. In general, similarity dimensions reflected greater agreement among the subjects that did preference dimensions and were hierarchically ordered. The dominant dimensions for both similarity and preference judgments of jazz improvizations were: Tempo, Dominant Instrument (Horns-guitar), and Articulation. The dominant dimensions for similarity judgments involving all three genres were: Classical-Contemporary, Jazz-Rock, and Tempo. The dominant dimensions for preference judments were: Rock-Classical, Jazz-Classical, and Tempo. In general, the preference judgments of musically sophisticated subjects were less constrained by salient dimensions.     

The Cognative Structure of Role Norms in Taiwan

This study explores the implicit cognitive structure of role norms in Taiwan. Subjects were asked to make direct pair-wise similarity judgments of 28 role relationships in terms of the way the actor role should treat the object role (e.g., father to son vs. son to father). INDSCAL and cluster analyses were used to delineate the implicit cognitive structure underlying the similarity judgments. INDSCAL showed that Taiwanese implicitly use two dimensions, closeness–distance and dominance–submission, to construct role norms. The first dimension showed that the norm for nuclear family relationships is to love and care for each other. The second dimension revealed that the norm for status-differential relationships such as father–son or supervisor–subordinate is to behave in accordance with one's status. Cluster analysis indicated four major clusters of role relationships, of which the hierarchical family cluster was the most prominent. Taiwanese adults and college students have similar cognitive structures and use relational models to construct their system of role norms. These relational models include complementarity, communality sharing, authority ranking, and equality matching. The implications of these findings for Confucian ethics and theories of Chinese social behavior are discussed.     

Dimensions of Picture Identification Test need associations

To find a simple and more general structure for need association matrices obtained from Picture Identification Test (PIT) results, PIT need association matrices of eight college student groups were analyzed by INDSCAL, a multidimensional scaling technique. A common three dimensional structure was found. Based on the scale locations of the 22 needs, the dimensions were labeled the Combative, the Personal, and the Competitive dimensions. The INDSCAL model was used as a target for six other comparison groups including male and female English college students, male addicts and controls, and male delinquents and controls. There was enough similarity between the dimensional structure of the need associations of the comparison and target groups to assume that all groups shared the same basic structure of need associations. There were enough differences, however, to suggest that personality characteristics of groups may be related to deviations in the associative structure of their motivation systems. Applications of the techniques to clinical and personality evaluations of groups and individuals were discussed.