The Many Faces of Commitment: Facet-Level Links to Performance in Military Contexts

Over the past two decades, considerable progress has been achieved in an effort to better identify and understand the various types of organizational commitment, the foci toward which such committed bonds are directed, and the myriad outcomes associated with these bonds. This research adds to and extends such work within a military context. Specifically, we explore relations among various forms (e.g., affective, normative, and continuance) of both team- and military-focused commitment and several supervisory-rated performance criteria. Across the different criteria, team-focused commitment tended to be a stronger predictor of performance than military-oriented commitment did. However, military-oriented commitment was inversely related to supervisory ratings of soldiers' negative behaviors. We discuss the psychological mechanisms that likely drive these findings, the implications of this work, and several potentially fruitful next steps within this research domain.     

Refining the visual-cortical hypothesis in category learning

Participants produce steep typicality gradients and large prototype-enhancement effects in dot-distortion category tasks, showing that in these tasks to-be-categorized items are compared to a prototypical representation that is the central tendency of the participant’s exemplar experience. These prototype-abstraction processes have been ascribed to low-level mechanisms in primary visual cortex. Here we asked whether higher-level mechanisms in visual cortex can also sometimes support prototype abstraction. To do so, we compared dot-distortion performance when the stimuli were size constant (allowing some low-level repetition-familiarity to develop for similar shapes) or size variable (defeating repetition-familiarity effects). If prototype formation is only mediated by low-level mechanisms, stimulus-size variability should lessen prototype effects and flatten typicality gradients. Yet prototype effects and typicality gradients were the same under both conditions, whether participants learned the categories explicitly or implicitly and whether they received trial-by-trial reinforcement during transfer tests. These results broaden out the visual-cortical hypothesis because low-level visual areas, featuring retinotopic perceptual representations, would not support robust category learning or prototype-enhancement effects in an environment of pronounced variability in stimulus size. Therefore, higher-level cortical mechanisms evidently can also support prototype formation during categorization.     

Temporal dynamics of generalization and representational distortion

Individuals generalize differently depending on the extent of their past experiences and what they learn from them. For instance, the peak of generalization can shift from a familiar stimulus to novel ones when the familiar stimulus has been repeatedly discriminated from another, similar stimulus. We examined how the amount of experience students had in discriminating complex sounds impacted their later generalization. As training increased, participants improved at distinguishing sounds, but their tendency to respond to certain novel sounds increased. With additional training, however, this shift dissipated. The results suggest that shifts in generalization may correspond to transitional states of perceptual learning and that learning-related changes in perceptual sensitivities involve more than just incremental increases in feature selectivity.     

Differential Reinforcement in Simple Discrimination Learning in 10- to 20-Month-Old Toddlers

The Psychological Record - The present study examined two procedures for teaching simple discrimination to six toddlers aged 10- to 20-months. A pair of toys was displayed in the windows of an...     

Language Shift and the Inclusion of Indigenous Populations in Large-Scale Assessment Programs

Indicators of academic achievement for bilingual students can be inaccurate due to linguistic heterogeneity. For indigenous populations, language shift (the gradual replacement of one language by another) is a factor that can increase this heterogeneity and poses an additional challenge for valid testing. We investigated whether and how indigenous populations can be validly included in a large-scale assessment program. We gave Mexican preschool Mayan students aged 5 to 6 years the same set of mathematics items in three versions: (1) original in Spanish, (2) Mayan translation, and (3) content equivalent, developed from scratch in Mayan. Also, we collected information on the students’ and the teachers’ use of Spanish and Mayan, and on the communities’ support of the two languages. Students performed poorly on the three versions. Generalizability theory-based analyses revealed considerable performance inconsistency across items and language versions and low generalizability and dependability coefficients. This performance instability appears to stem from a dwindling support of the Mayan language in Mayan schools and communities. Fair, valid assessment of indigenous populations in either their languages or their countries’ dominant languages appears to be difficult to accomplish with current testing models and policies.     

Age-of-acquisition effects in delayed picture-naming tasks

We report two experiments that explored the linguistic locus of age-of-acquisition effects in picture naming by using a delayed naming task that involved only a low proportion of trials (25 %) while, for the large majority of the trials (75 %), participants performed another task—that is, the prevalent task. The prevalent tasks were semantic categorization in Experiment 1a and grammatical-gender decision in Experiments 1b and 2. In Experiment 1a, in which participants were biased to retrieve semantic information in order to perform the semantic categorization task, delayed naming times were affected by age of acquisition, reflecting a postsemantic locus of the effect. In Experiments 1b and 2, in which participants were biased to retrieve lexical information in order to perform the grammatical gender decision task, there was also an age-of-acquisition effect. These results suggest that part of the age-of-acquisition effect in picture naming occurs at the level at which the phonological properties of words are retrieved.