Category contingent aftereffects for faces of different races, ages and species

Exposure to faces biases perceptions of subsequently viewed faces such that normality judgments of similar faces are increased. Simultaneously inducing such an aftereffect in opposite directions for two groups of faces might indicate discrete responding of the neural populations coding for those groups. Here we show such "category contingent" aftereffects following exposure to faces differing in eye-spacing (wide versus narrow) for European versus African faces, adult versus infant faces, and human versus monkey faces. As aftereffects reflect changes in responses of neural populations that code faces, our results may then suggest that functionally distinct neural populations code faces of different ages, races and species and that the human brain potentially contains discrete representations of these categories.     

Cognitive addition and multiplication: Evidence for a single memory network

In an experiment using verification task procedures, 100 subjects responded to simple and complex problems of addition and multiplication. Identical structural parameters were found to model reaction time accurately to both addition and multiplication problems. Slope estimates for a memory network parameter did not differ significantly between simple and complex problems within an operation or between addition and multiplication problems. Both complex addition and complex multiplication problems were processed columnwise, with column sums or products being retrieved from an interrated memory network. The two types of complex problems included similar processes for carrying and for encoding of single digits, and both were self-terminated when an error in the units column was encountered. Addition and multiplication facts appear to be retrieved from a single interrelated memory network. A conceptual model for this interrelated network is discussed.     

Personality and Personal Projects: Linking Big Five and PAC Units of Analysis

This article examines the relationships between classical trait units as represented by the five-factor model (e.g., Digman, 1990) and personal action construct (PAC) units as measured by Personal Projects Analysis (Little, 1983). One hundred and forty-seven students were administered the NEO Personality Inventory (Costa & McCrae, 1985) and two components of Personal Projects methodology during their first term in university. Neuroticism and Conscientiousness were related to problematic and positive project systems, respectively, with these effects generalizing across the academic and interpersonal project domains. Extraversion and Agreeableness were also associated with positive evaluations of personal projects, particularly in the interpersonal domain. Openness was distinctively linked with project initiation and value congruency. We suggest theoretical and applied implications of using PAC methods to expand and refine the classical trait research agenda.     

Classical conditioning and retention of the infant's eyelid response: effects of age and interstimulus interval

Independent groups of 10-,20-, and 30-day-old infants were subjected to a classical eyelid conditioning procedure involving either a 500- or a 1500-msec interstimulus interval (ISI). Ten days later, all received a second conditioning session. A reliable increase in conditioned responding was observed at all ages but only by infants receiving the 1500-msec ISI. Although age was not a significant factor in any conditioning measure except final performance level, which was greater for the oldest than for the youngest group, it did influence long-term retention. A reliable memory component was observed in the Session 2 performance of infants initially trained at 20 and 30 days but not at 10 days. These data demonstrate the importance of temporal parameters in the formation of conditioned associations very early in infancy and provide evidence for the long-term behavioral consequences of those associations.     

Developmental color perception.

The purpose of this research is to extend the investigation of surface color perception to several age levels. The 108-item color perception test, originally used with young children, employs six Munsell hue matrices divided into nine combinations each of low, mid, and high chroma and low, mid, and high value across two levels of hue difficulty. The pattern of error results are the same across the age groups comprising kindergartners, fifth graders, high school sophomores, nonartist adults, and professional artists: the lower the chroma and value, the higher the error rate; the higher the chroma and value, the lower the error rate. In hues, green and red are most difficult; orange and yellow are easiest. The frequency of error is linear with respect to age: the younger the group, the higher the error. The latency data differ with respect to age: adults are slowest, followed by kindergartners and fifth graders. High school sophomores are the fastest. The remaining latency results parallel the error results: the lower the chroma and value, the longer the latency and the more difficult the hue, the longer the latency. A set of surface color perception rules are generated.     

Tutor-Pupil Relationship and Academic Progress

This study examines the characteristics of the tutor-student relationship in small tutorial groups and the degree of association between this relationship and academic success. Four factors were identified: a general factor of likeableness and factors representing equality, personal involvement, and control in the relationship. The likeableness factor was significantly related to academic success but the other factors were not.