The effects of spatial frequency overlap on face recognition

The effects of spatial frequency overlap between pairs of low-pass versus high-pass images on face recognition and matching were examined in 6 experiments. Overlap was defined as the range of spatial frequencies shared by a pair of filtered images. This factor was manipulated by processing image pairs with high-pass/low-pass filter pairs whose 50% cutoff points varied in their separation from one another. The effects of the center frequency of filter pairs were also investigated. In general, performance improved with greater overlap and higher center frequency. In control conditions, the image pairs were processed with identical filters and thus had complete overlap. Even severely filtered low-pass or high-pass images in these conditions produced superior performance. These results suggest that face recognition is more strongly affected by spatial frequency overlap than by the frequency content of the images.     

Face recognition is affected by similarity in spatial frequency range to a greater degree than within-category object recognition

Previous studies have suggested that face identification is more sensitive to variations in spatial frequency content than object recognition, but none have compared how sensitive the 2 processes are to variations in spatial frequency overlap (SFO). The authors tested face and object matching accuracy under varying SFO conditions. Their results showed that object recognition was more robust to SFO variations than face recognition and that the vulnerability of faces was not due to reliance on configural processing. They suggest that variations in sensitivity to SFO help explain the vulnerability of face recognition to changes in image format and the lack of a middle-frequency advantage in object recognition.     

Activity of common marmosets (Callithrix jacchus) in limited spaces: hand movement characteristics

The increasing popularity of marmoset monkeys (Callithrix jacchus) in anatomical, behavioral, and electrophysiological studies has called for a detailed analysis of their natural behavior within limited spaces. In the present study, the authors analyzed hand movements during horizontal and vertical progressions in a cylinder. The trajectory of each hand covered the entire cylinder floor during horizontal progressions and the entire cylinder wall during vertical progressions. Different marmosets have different patterns of hand movement. The average maximum angle of hand movements for all marmosets during horizontal and vertical progressions oscillates, although the average over time is constant and similar for both hands, whereas head movements during horizontal progressions become smaller with successive progressions. Another observed difference between rats and monkeys was in the size of head and hand movements at the beginning of each experimental session. During the 1st horizontal progression, all marmosets moved their heads to a greater extent than their hands. This sequential head and hand movement is referred as bistable behavior. The bistable pattern of motor behavior, which was also observed in successive progressions, may be derived from an inherent fear of predators or exploratory interest of a novel environment.     

What personal selling and sales management recommendations from developed markets are relevant in emerging markets?

As emerging markets continue to grow, research on personal selling and sales management in these settings is coming to the fore, as this special issue of Journal of Personal Selling and Sales Management attests. With an in-depth review of extant research, this contribution addresses three key research questions. First, are there differences between established/recommended theories or styles or paradigms for effective personal selling and sales management in developed markets and emerging markets? The survey suggests there are. Second, are culture variables, traditionally used in extant research, sufficient to differentiate between developed and emerging markets? The presented analysis suggests that culture must be combined with economic variables to establish clear contexts that reflect developed and emerging markets. Third, what classification framework can serve to examine personal selling and sales management strategies in terms of their applicability in both developed and emerging markets? This article derives such a classification framework by organizing extant sales research into categories where either small differences in research findings between developed and emerging markets are expected, or where large differences in research findings are expected. Propositions for the category of selling process and technique are derived. Overall, these findings suggest the need for substantial research that examines the differences between developed and emerging markets, because of the vast implications for theory, research, and practice.     

Comment: Starting to Solve the Method Puzzle in Salesperson Self-Report Evaluations

In a recent Journal of Personal Selling & Sales Management paper, Jaramillo, Carrillat, and Locander (JCL) further extended our understanding of the errors of salesperson self-report evaluations when compared to managerial evaluations. Our paper provides contrary evidence on three major conclusions drawn in this study. First, we question the assertion by JCL that the correlation between self-report and objective measures of performance is consistently low. Second, we question JCL’s claim that the correlation between managerial evaluations and objective measures of performance is consistently high. Third, we question the key finding of JCL that self-report measures of salesperson performance are less accurate than managerial evaluations. We provide an alternative perspective to these issues by highlighting past research on performance measurement. Moreover, we reanalyze data from a previously published study to examine the issues raised by JCL. Our expectation is that this comment will serve as an impetus for further research in this area.     

Negative,zero and positive stiffness in extended Eshelby plates

Structures under loading can show positive and negative stiffness (during buckling) with zero stiffness just being one point of transition. Material structures with extended zero stiffness regimes have also been reported. Using the example of an extended Eshelby plate with a positive and negative edge dislocation, we show the existence of finite regimes of positive, zero and negative stiffness in a single system. Given that stable states/configurations of negative stiffness cannot exist in an isolated system; we show the existence of metastable states of negative stiffness along with unstable states of positive stiffness. The system also exhibits one point of unstable equilibrium.     

Switching behaviour as a function of number of options: How much is too much for consumer choice decisions?

The number of alternatives for consumers in almost all purchase situations is increasing at an extremely rapid pace. Although more choices may have many benefits to the consumers, recent studies on choice overload have found that choosing from large alternatives may lead to negative consequences. Majority of the choice overload research has compared only two groups of small versus large assortment size. In extant literature, there is no clarity as to what are small and large assortment sizes. Assortment size used as small in one study has been used as large in some other studies. Small assortment size varied from 2 to 60 choices and large assortment size from 3 to 300 choices in past studies, and the presence of choice overload has been reported at completely different levels of assortment sizes. This study has used an array of six choice sets from 6 to 36 options as compared to just two groups of small versus large assortment. Switching likelihood of consumers was used to capture the choice overload effect in this study. The probability of consumers switching their earlier choice was plotted as a function of number of options using binary logistic regression. Results showed that probability of switching was almost a linearly increasing function of assortment size from 6 to 36 options. The graph of predicted probabilities from 2 to 300 options showed a sharp increase in switching behaviour initially and subsequent flattening of the curve when options became very large.