“Red-Green” or “Brown-Green” Dichromats? The Accuracy of Dichromat Basic Color Terms Metacognition Supports Denomination Change

Two experiments compared “Red-Green” (R-G) dichromats’ empirical and metacognized capacities to discriminate basic color categories (BCCs) and to use the corresponding basic color terms (BCTs). A first experiment used a 102-related-colors set for a pointing task to identify all the stimuli that could be named with each BCT by each R-G dichromat type (8 protanopes and 9 deuteranopes). In a second experiment, a group of R-G dichromats (15 protanopes and 16 deuteranopes) estimated their difficulty discriminating BCCs-BCTs in a verbal task. The strong coincidences between the results derived from the pointing and the verbal tasks indicated that R-G dichromats have very accurate metacognition about their capacities (they only had considerable difficulty discriminating 13 out of the total of 55 possible BCT pairs) and limitations (Brown-Green and Blue-Purple pairs were rated especially difficult to differentiate) in the use of BCTs. Multidimensional scaling (MDS) solutions derived from both tasks were very similar: BCTs in R-G dichromats were properly represented in 2D MDS solutions that clearly show one chromatic dimension and one achromatic dimension. Important concordances were found between protanopes and deuteranopes. None of these dichromats showed substantial difficulty discriminating the Red-Green pair. So, to name them “R-G” dichromats is misleading considering their empirical capacities and their metacognition. Further reasons to propose the use of the alternative denomination “Brown-Green” dichromats are also discussed. We found some relevant differences between the “Brown-Green” dichromats’ empirical and self-reported difficulties using BCTs. Their metacognition can be considered a “caricature” of their practical difficulties. This caricature omits some difficulties including their problems differentiating “white” and “black” from other BCTs, while they overestimate their limitations in differentiating the most difficult pairs (Brown-Green and Blue-Purple). Individual differences scaling (INDSCAL) analyses indicated that the metacognition regarding the use of BCTs in “Brown-Green” dichromats, especially deuteranopes, is driven slightly more by the chromatic dimension and driven slightly less by the achromatic dimension, than their practical use of BCTs. We discuss the relevance of our results in the framework of the debate between the linguistic relativity hypothesis (LRH) and the universal evolution (UE) theories.

High-throughput powder diffraction V: the use of Raman spectroscopy with and without X-ray powder diffraction data

In high-throughput crystallography it is possible to accumulate large numbers of powder diffraction patterns on a series of related compounds, often polymorphs, salts or co-crystals. In previous papers [Gilmore, Barr & Paisley (2004).J. Appl. Cryst.37, 231–242; Barr, Dong & Gilmore (2004).J. Appl. Cryst.37, 243–252] it has been shown how such data can be analysed by generating an (n×n) correlation matrix,ρ, by correlatingnfull powder diffraction patterns, point by point. Theρmatrix is used as a source of dendrograms and metric multidimensional plots in three or more dimensions which classify the patterns into sets related by similarity. In this paper, it is shown how Raman spectroscopy data can be used by themselves or as an adjunct to powder diffraction data by combining the two techniques using the individual differences scaling method (INDSCAL) of Carroll & Chang [Psychometria, (1970),35, 283–319]. The method is very robust, and can be extended to other forms of spectroscopy. It is available as an option in the commercialPolySNAP3computer program.

Perceptual Scaling of Simultaneous Wind Instrument Timbres

Timbral similarities among wind instrument duos were studied. Flute, oboe, E♭ alto saxophone, B♭ clarinet, and B♭ trumpet instrumentalists performed in all possible duo pairings (dyads). Source material included B♭4 unisons, unison melody, major thirds, and harmonized melody. Nonunison combinations had each instrument of the pair as the soprano, creating a total of six contexts. Music major and nonmusic major subjects rated the similarity of all possible pairs of dyads in each of the six contexts. Classical multidimensional scaling (MDS) was performed; contexts were treated as " subjects" in an individual differences scaling (INDSCAL) analysis of composite data. The resulting spaces had two stable, interpretable dimensions. From verbal attribute rating experiments ( Kendall & Carterette, in preparation, a), these were identified as " nasal" vs. " not nasal," and " rich" vs. " brilliant." A third dimension was interpreted as "simple" vs. "complex."Extrema in the space were associated with three of the five instruments: Trumpet (brilliant), saxophone (rich), and oboe ( nasal). Data that were amalgamated over contexts and plotted in two dimensions yielded a circumplicial configuration. Implications for orchestration are discussed and a theoretical model of timbre combinations and groupings is presented.

A Sindscal Analysis of Perceptual Features for Consonants Produced by Esophageal and Tracheoesophageal Talkers

This study was concerned with the perceptual responses of normal-hearing listeners to consonants produced by esophageal and tracheoesophageal (TE) talkers and a single talker who was proficient in both of these alaryngeal speech modes. The listeners' perceptual responses were analyzed using Symmetric Individual Differences Scaling (SINDSCAL) to determine whether distinctive feature differences existed between these two methods of alaryngeal speech. This a posteriori analysis revealed that primary features retrieved for both speech methods included sibilant, affricate, dental, nasal, and sonorant. Although greater perceptual weightings were observed for TE speech, these productive/perceptual features were weighted similarly for both speech methods. Some secondary group-specific feature differences were also observed, but these features did not contribute substantially to the total amount of variance accounted for in the analysis. Thus, the SINDSCAL results showed that the groups did not use different feature systems. These results are discussed in regard to the unique alaryngeal speech production methods employed by esophageal and TE talkers and the relative limitations of the alaryngeal (esophageal) voicing source they use. General clinical implications of the data are discussed.