Artifact Categories Research Articles

Application of a new typological approach to classifying denticulate and notched tools: the study of two Mousterian lithic assemblages

Identifying tools by means of morphological attributes are widely used in lithic studies to categorize retouched artifacts from different archaeological periods. This procedure has facilitated the exchange of information between separate researchers and has improved the comparison of different assemblages. In these classifications, denticulates and notched tools have been regularly interpreted as analogues and chronologically unvaried in different and vast territories. Based on the definitions developed by Bordes, the denticulate category has become a catchall for any kind of tool bearing concavities. In this paper a new quantitative approach to the classification of denticulates and notched tools is proposed. The new methodology is based on measuring the length of notches and their distribution on the perimeter of the blank. Analyzing the lithic series of the Abric Romaní rock-shelter (Spain) and Grotta Maggiore di San Bernardino (Italy) led to the identification of 11 redundant forms: eight denticulates and three notched tools. Moreover, the application of Kuhn’s Geometric Index of Unifacial Reduction brought local manufacturing trends to light, calling into question the presumed geographical uniformity of these categories of artifacts.

Pediatric99mTc-MDP Bone SPECT with Ordered Subset Expectation Maximization Iterative Reconstruction with Isotropic 3D Resolution Recovery

To perform a preliminary evaluation of the image quality of pediatric technetium 99m ((99m)Tc) methylene diphosphonate (MDP) bone single photon emission computed tomography (SPECT) by using iterative reconstruction-ordered subset expectation maximization with three-dimensional resolution recovery (OSEM-3D)-and to assess whether any improvements with use of this technique could lead to a reduction in patient dose or a shortening in imaging time. Institutional advisory board approval was obtained for this investigation. Fifty (99m)Tc-MDP SPECT studies of the spine were evaluated (36 female and 14 male patients; mean age, 15.5 years). Each study was acquired by using a dual-detector camera, with each detector rotating 360°. By using filtered back projection (FBP) and OSEM-3D, images were reconstructed from data generated by both detectors. Likewise, OSEM-3D was used to reconstruct data from a single detector simulating half the administered radiopharmaceutical activity. Two nuclear medicine physicians, blinded to the patient data, reviewed the images for image quality in four different categories by using a four-point scale: artifacts (category 1), lesions (category 2), noise (category 3), and image sharpness (category 4). Compared with FBP, images reconstructed by using OSEM-3D with one or two detectors showed significant improvement in image quality with regard to lesion detection, noise level, and image sharpness (P < .02, .01, and .001, respectively). With OSEM-3D, no significant differences were observed when either one or two detectors were used. Improved image quality of skeletal SPECT with either a 50% reduction in radiation dose or a 50% reduction in acquisition time or combination of the two can be achieved by using OSEM-3D.

Not Growling but Smiling: New Interpretations of the Bared‐Teeth Motif in the Pre‐Columbian Caribbean

Insights into the character of social relations are rare but exciting glimpses when it comes to archaeological populations. This paper uses a multidisciplinary combination of archaeological and evolutionary biological approaches to assess the social value of the bared‐teeth motif (BTM) in pre‐Columbian iconography of the Greater Antilles. Bared teeth feature on discrete artifact categories within the material culture of many different groups in the Taino culture area after AD 1000. This BTM, usually part of facial anthropomorphic or zoomorphic decoration, is used for bodily adornments and items associated with healing and shamanic practices. It has generally been interpreted as representative of death, aggression, or the shamanic trance. However, the motif has never been examined in terms of its signal value as a positive facial expression. Studies of facial expression in human and nonhuman primates have shown that the bared‐teeth expression is used in social contexts as an unambiguous signal of nonaggres...

Arte e simbolismo xamânico na Amazônia

Os chamados ídolos de pedra amazônicos, apesar de conhecidos há mais de cem anos, constituem uma categoria de artefatos indígenas sem contexto arqueológico, histórico ou etnográfico. Este artigo apresenta uma primeira análise formal das peças conhecidas e algumas hipóteses sobre a sua função e finalidade. O estilo, os motivos simbólicos e o detalhe funcional de pares de furos idênticos em todos os exemplares sugerem que eles eram parte do instrumental usado nos rituais xamânicos de inalação do paricá e de outras substâncias alucinógenas.

Form follows function: Learning about function helps children learn about shape

Object functions help young children to organize new artifact categories. However, the scope of their influence is unknown. We explore whether functions highlight property dimensions that are relevant to artifact categories in general. Specifically, using a longitudinal training procedure, we assessed whether experience with functions highlights shape as important for categorization. Seventeen-month-olds were provided experience with novel categories of similarly shaped objects. In Study 1, the function group learned about the objects’ shape-based functions; a control group did not. In Study 2, 17-month-olds were trained on the same categories, but the objects’ shapes and functions were no longer causally related. Only the function group in Study 1 subsequently used shape reliably when categorizing novel objects. These results suggest that function is instrumental in establishing a ‘shape bias’ in early categorization and that it does so via conceptually based processes.

Different views about the nature of gender-related asymmetries in tasks based on biological or artefact categories.

Sex-related asymmetries in the ability to process different semantic categories have been reported both in normal subjects and in brain-damaged patients, but the nature of these asymmetries is still controversial. Some authors suggest that these differences might be due to social-role related familiarity factors, whereas others attribute them to inborn neural differences rooted in evolution. Drawing in part on this second line of thought, some authors have suggested that gender-related asymmetries might be due to differences in stimulus processing between men and women, namely, to the tendency of females to focus mainly on perceptual features and of males to focus equally on both perceptual and functional features. To test this hypothesis, we asked 53 male and 65 female undergraduate students to evaluate the relevance of a number of perceptual and functional features in the representation of various kinds of biological and artefact categories. Contrary to the hypothesis, evaluation of the weight of different sources of knowledge in representing living and artefact categories was similar in males and females.

Different Views about the Nature of Gender-Related Asymmetries in Tasks Based on Biological or Artefact Categories

Sex-related asymmetries in the ability to process different semantic categories have been reported both in normal subjects and in brain-damaged patients, but the nature of these asymmetries is still controversial. Some authors suggest that these differences might be due to social-role related familiarity factors, whereas others attribute them to inborn neural differences rooted in evolution. Drawing in part on this second line of thought, some authors have suggested that gender-related asymmetries might be due to differences in stimulus processing between men and women, namely, to the tendency of females to focus mainly on perceptual features and of males to focus equally on both perceptual and functional features. To test this hypothesis, we asked 53 male and 65 female undergraduate students to evaluate the relevance of a number of perceptual and functional features in the representation of various kinds of biological and artefact categories. Contrary to the hypothesis, evaluation of the weight of different sources of knowledge in representing living and artefact categories was similar in males and females.

Gold foil covering of the handle of an iron knife from burial 2 of the Hunnic Period cemetery at Mukhino, in the Upper Don area

The chemical composition of 7 fragments of the gold foil covering the wooden (?) handle attached to an iron knife from the burial of a noblewoman in the Upper Don area was investigated by two methods – XRF and X-ray electronic spectroscopy (XRS). All samples showed that the gold foil was produced from an Au-Ag-Cu alloy (type III), with a high degree of Ag concentration in the XRS samples. The data suggests that this is the result of the process of silver diffusion to the surface of the samples, but the reasons for this are not clear yet. The actual quality of the knife handle is low and, in comparison with other high-status objects, it cannot be included in the category of high-quality artefacts. Thus, we cannot exclude the possibility that the knife from burial 2 at Mukhino is a local copy, or an item produced in the ‘metropolis’ especially for export to the ‘barbarian’ world.

Feature integration in natural language concepts

Two experiments measured the joint influence of three key sets of semantic features on the frequency with which artifacts (Experiment 1) or plants and creatures (Experiment 2) were categorized in familiar categories. For artifacts, current function outweighed both originally intended function and current appearance. For biological kinds, appearance and behavior, an inner biological function, and appearance and behavior of offspring all had similarly strong effects on categorization. The data were analyzed to determine whether an independent cue model or an interactive model best accounted for how the effects of the three feature sets combined. Feature integration was found to be additive for artifacts but interactive for biological kinds. In keeping with this, membership in contrasting artifact categories tended to be superadditive, indicating overlapping categories, whereas for biological kinds, it was subadditive, indicating conceptual gaps between categories. It is argued that the results underline a key domain difference between artifact and biological concepts.

Mental representation of normal subjects about the sources of knowledge in different semantic categories and unique entities.

According to the "sensory-motor model of semantic knowledge," different categories of knowledge differ for the weight that different "sources of knowledge" have in their representation. Our study aimed to evaluate this model, checking if subjective evaluations given by normal subjects confirm the different weight that various sources of knowledge have in the representation of different biological and artifact categories and of unique entities, such as famous people or monuments. Results showed that the visual properties are considered as the main source of knowledge for all the living and nonliving categories (as well as for unique entities), but that the clustering of these "sources of knowledge" is different for biological and artifacts categories. Visual data are, indeed, mainly associated with other perceptual (auditory, olfactory, gustatory, and tactual) attributes in the mental representation of living beings and unique entities, whereas they are associated with action-related properties and tactile information in the case of artifacts.

Five-year-olds’ beliefs about the discreteness of category boundaries for animals and artifacts

Research on adult concepts indicates that category structure varies by domain; adults view membership in animal categories as absolute but membership in artifact categories as graded. In this study, we examined domain differences in beliefs about category boundaries among young children (5-year-olds). The results indicated that young children, like adults, were less likely to endorse graded category membership for animal than for artifact categories. These domain differences could not be attributed to domain differences in typicality. Implications for conceptual development and for models of domain specificity in adult cognition are discussed.

Artificial arterial blood pressure artifact models and an evaluation of a robust blood pressure and heart rate estimator

BackgroundWithin the intensive care unit (ICU), arterial blood pressure (ABP) is typically recorded at different (and sometimes uneven) sampling frequencies, and from different sensors, and is often corrupted by different artifacts and noise which are often non-Gaussian, nonlinear and nonstationary. Extracting robust parameters from such signals, and providing confidences in the estimates is therefore difficult and requires an adaptive filtering approach which accounts for artifact types.MethodsUsing a large ICU database, and over 6000 hours of simultaneously acquired electrocardiogram (ECG) and ABP waveforms sampled at 125 Hz from a 437 patient subset, we documented six general types of ABP artifact. We describe a new ABP signal quality index (SQI), based upon the combination of two previously reported signal quality measures weighted together. One index measures morphological normality, and the other degradation due to noise. After extracting a 6084-hour subset of clean data using our SQI, we evaluated a new robust tracking algorithm for estimating blood pressure and heart rate (HR) based upon a Kalman Filter (KF) with an update sequence modified by the KF innovation sequence and the value of the SQI. In order to do this, we have created six novel models of different categories of artifacts that we have identified in our ABP waveform data. These artifact models were then injected into clean ABP waveforms in a controlled manner. Clinical blood pressure (systolic, mean and diastolic) estimates were then made from the ABP waveforms for both clean and corrupted data. The mean absolute error for systolic, mean and diastolic blood pressure was then calculated for different levels of artifact pollution to provide estimates of expected errors given a single value of the SQI.ResultsOur artifact models demonstrate that artifact types have differing effects on systolic, diastolic and mean ABP estimates. We show that, for most artifact types, diastolic ABP estimates are less noise-sensitive than mean ABP estimates, which in turn are more robust than systolic ABP estimates. We also show that our SQI can provide error bounds for both HR and ABP estimates.ConclusionThe KF/SQI-fusion method described in this article was shown to provide an accurate estimate of blood pressure and HR derived from the ABP waveform even in the presence of high levels of persistent noise and artifact, and during extreme bradycardia and tachycardia. Differences in error between artifact types, measurement sensors and the quality of the source signal can be factored into physiological estimation using an unbiased adaptive filter, signal innovation and signal quality measures.

A developmental examination of the conceptual structure of animal, artifact, and human social categories across two cultural contexts

Previous research indicates that the ontological status that adults attribute to categories varies systematically by domain. For example, adults view distinctions between different animal species as natural and objective, but view distinctions between different kinds of furniture as more conventionalized and subjective. The present work ( N = 435; ages 5–18) examined the effects of domain, age, and cultural context on beliefs about the naturalness vs. conventionality of categories. Results demonstrate that young children, like adults, view animal categories as natural kinds, but artifact categories as more conventionalized. For human social categories (gender and race), beliefs about naturalness and conventionality were predicted by interactions between cultural context and age. Implications for the origins of social categories and theories of conceptual development will be discussed.

Change and Continuity, Practice and Memory: Native American Persistence in Colonial New England

The archaeological study of Native Americans during colonial periods in North America has centered largely on assessing the nature of cultural change and continuity through material culture. Although a valuable approach, it has been hindered by focusing too much on the dichotomies of change and continuity, rather than on their interrelationship, by relying on uncritical cultural categories of artifacts and by not recognizing the role of practice and memory in identity and cultural persistence. Ongoing archaeological research on the Eastern Pequot reservation in Connecticut, which was created in 1683 and has been inhabited continuously since then by Eastern Pequot community members, permits a different view of the nature of change and continuity. Three reservation sites spanning the period between ca. 1740 and 1840 accentuate the scale and temporality of social memory and the relationships between practice and materiality. Although the reservation sites show change when compared to the "precontact baseline," they show remarkable continuity during the reservation period. The resulting interpretation provides not only more grounded and appropriately scaled renderings of past cultural practices but also critical engagements with analytical categories that carry significant political weight well outside of archaeological circles.

A developmental dissociation between category and function judgments about novel artifacts

Two studies investigated the relative importance of information about intended design and current use on judgments about the function (Experiment 1) or category (Experiment 2) of novel artifacts in preschool children and adults. Adults assigned function and name on the basis of information about design across all conditions, while children’s decisions about function dissociated from decisions about category. Function judgments (in both 4 and 6-year-olds) were neutral between design and current use, both when the current use was idiosyncratic (e.g. performed by just one agent) and conventional (performed by many people; Experiment 1). By contrast, where category judgments were required for the very same objects (Experiment 2), children named according to design intentions – but only if the alternate function was idiosyncratic. Judging function and assigning category are thus cognitive tasks that draw on different information across development, a fact that should be captured by theories of developing artifact concept structure.

Le matériel funéraire déposé dans les tombes de la culture de Nagada (Haute-Égypte, IVe millénaire)

The Naqadian culture represents the late phase of Neolithic in Egypt. With its important funeral dimension, this culture has left numerous necropolises, where burials often come with rich equipments. During this period, an increase of the number of graves is observed, along with a clear enhancement of social differentiation between individuals. Ceramics represents the category of artefacts mostly represented in funeral context. Food offerings, figurines, objects connected to ornaments or hunting can also be found, as well as imported objects and the first evidence of writing. Comparing these artefacts and those known in the Naqadian dwelling sites shows is difficult, mostly because of the lack of knowledge about the last. Nonetheless, as almost all the known objects of the funeral context are also met in environmental context. Starting from Nagada II, the social hierarchical organization seems to reflect the political evolution of society : the growth in wealth of certain graves compared to the others, but also by the distribution in necropolises of the elites or poorer individuals graves. The promotion from local leader to city or provincial kinglet, and finally, to Pharaoh, can be followed in the Naqadian graves.

Noise-tolerant electrocardiogram beat classification based on higher order statistics of subband components

This paper presents a noise-tolerant electrocardiogram (ECG) beat classification method based on higher order statistics (HOS) of subband components. Five levels of discrete wavelet transform (DWT) were applied to decompose the signal into six subband components. Higher order statistics proceeded to calculate four sets of HOS features from the three midband components, which together with three RR interval-related features constructed the primary feature set. A feature selection algorithm based on correlation coefficient and Fisher discriminality was then exploited to eliminate redundant features from the primary feature set. A feedforward backpropagation neural network (FFBNN) was employed as the classifier. Two sample selection strategies and four categories of noise artifacts were utilized to justify the capacity of the method. More than 97.5% discrimination rate was achieved, no matter which of the two sampling selection strategies was used. By using the feature selection method, the feature dimension can be readily reduced from 30 to 18 with negligible decrease in accuracy. Compared with other method in the literature, the proposed method improves the sensitivities of most beat types, resulting in an elevated average accuracy. The proposed method is tolerant to environmental noises; as high as 91% accuracies were retained even when contaminated with serious noises, 10 dB signal-to-noise ration (SNR), of different kinds. The results demonstrate the effectiveness and noise-tolerant capacities of the proposed method in ECG beat classification.

Uniformity of Imaging Spectrometry Data Products

The increasing quantity and sophistication of imaging spectroscopy applications have led to a higher demand on the quality of Earth observation data products. In particular, it is desired that data products be as consistent as possible (i.e., ideally uniform) in both spectral and spatial dimensions. Yet, data acquired from real (e.g., pushbroom) imaging spectrometers are adversely affected by various categories of artifacts and aberrations including as follows: singular and linear (e.g., bad pixels and missing lines), area (e.g., optical aberrations), and stability and degradation defects. Typically, the consumer of such data products is not aware of the magnitude of such inherent data uncertainties even as more uncertainty is introduced during higher level processing for any particular application. In this paper, it is shown that the impact of imaging spectrometry data product imperfections in currently available data products has an inherent uncertainty of 10%, even though worst case scenarios were excluded, state-of-the-art corrections were applied, and radiometric calibration uncertainties were excluded. Thereafter, it is demonstrated how this error can be reduced (<5%) with appropriate available technology (onboard, scene, and laboratory calibration) and assimilation procedures during the preprocessing of the data. As a result, more accurate, i.e., uniform, imaging spectrometry data can be delivered to the user community. Hence, the term uniformity of imaging spectrometry data products is defined for enabling the quantitative means to assess the quality of imaging spectrometry data. It is argued that such rigor is necessary for calculating the error propagation of respective higher level processing results and products.

Effects of age, gender, and education on semantic fluency for living and artifact categories

Background: Evidence exists that many individuals with neurological damage exhibit a “category effect”, typically naming more artifact than living items. However, there is a paucity of research exploring the existence of a category effect with neurologically intact individuals. The investigations performed to date have focused on a limited number of categories, and most authors have not controlled for possible age, gender, and/or education‐related effects among groups. Aims: The purpose of this study was to explore the effects of age, gender, and education on semantic fluency for four living and four artifact categories. Methods & Procedures: A total of 60 individuals recruited from four groups participated in the study: younger males, younger females, older males, and older females. Each group of 15 individuals was matched for years of education. Participants were asked to name as many items as possible in four living categories: birds, four‐footed animals, fruits, and vegetables as well as four artifact categories: tools, kitchen utensils, furniture, and clothing. Outcomes & Results: There was no significant difference between living and artifact domains. With regard to specific categories, females named significantly more fruit and furniture items, while males named more tools. Younger females with fewer than 16 years of education named the most fruits, and participants with at least 16 years of education had an advantage for clothing. Older males and younger females named more four‐footed animals than did their gender‐matched peers. Conclusions: In contrast to previous reports, this investigation failed to identify naming differences between living and artifact domains, which might partly be related to dissimilar task demands (i.e., semantic fluency versus confrontation naming). However, several gender‐based differences observed for specific categories were consistent with previous research. Moreover, the use of a broader range of categories exposed additional differences in naming performance.

A Mutually Facilitative Relationship Between Learning Names and Learning Concepts in Preschool Children: The Case of Artifacts

Two studies investigated the relationship between learning names and learning concepts in preschool children. More specifically, we focused on the relationship between learning the names and learning the intended functions of artifacts, given that the intended function of an artifact is generally thought to constitute core conceptual information about an artifact's category. We asked whether learning the intended function of a novel artifact facilitates retention of its name and whether learning the name of a novel artifact prompts the search for information about its intended function. In Experiment 1, 3- and 4-year-old children better retained the names of novel artifacts when the intended functions of these artifacts were revealed. The comparison condition involved providing perceptually relevant and conceptually irrelevant information about the objects. In Experiment 2, 4-year-old children who were provided with the names of novel artifacts were more likely to seek out information about the objects' functions than children provided with conceptually irrelevant information about the artifacts. Together, the studies demonstrate the intimate and mutually facilitative relationship between names and concepts in young children.