Sleeper effects

Early experience preserves and refines many capabilities that emerge prenatally. Here we describe another role that it plays -- establishing the neural substrate for capabilities that emerge at a much later point in development. The evidence comes from sleeper effects: permanent deficits when early experience was absent in capabilities that normally emerge long after birth. We provide evidence of sleeper effects for three aspects of vision, based on our research with children who were deprived of early visual input by congenital cataracts: contrast sensitivity for mid and high spatial frequencies, holistic face processing, and the ability to recognize the identity of faces based on small differences in the spacing among facial features.     

Contrasting effects of repetition across tasks: Implications for understanding the nature of refractory behavior and models of semantic memory

We describe a patient (J.M.) who showed “refractory” behavior in picture—word matching tasks—that is, his performance became poorer when items were repeated. This contrasts with the facilitatory effects of repetition usually observed in normal participants. We show for the first time that there can be facilitatory effects of repetition on some tasks, even though refractory behavior is shown on the same items in other tasks. In particular, in Experiments 1 and 2, we demonstrate that J.M. showed contrasting effects of repetition across different components of the language system: There were facilitatory effects of repetition priming on lexical decision but refractory behavior on picture—word matching. In Experiments 3 and 4, we demonstrate that J.M. showed contrasting effects of repetition within the same system (semantic memory). His performance became refractory when items were repeated in picture—word matching (Experiment 3), but it was facilitated when items were repeated in superordinate categorization (Experiment 4). These contrasting patterns of facilitation and interference from repetition priming have implications for understanding the nature of refractory behavior and for constraining theoretical accounts of semantic memory.     

Dissociative effects of viewpoint and semantic priming on action and semantic decisions: evidence for dual routes to action from vision

This article reports evidence that two variables—object viewpoint and semantic priming—differentially affect action and semantic decisions to objects. Changing the viewing angle of an object, so that its graspable parts are oriented away from observers, disrupted action decisions but had little effect on semantic categorization. In contrast, semantic priming influenced semantic categorization and object naming, but not action decisions. Action priming, however, did not affect performance. These selective effects are consistent with the existence of separate semantic and direct (nonsemantic) routes to action from vision.     

Group cognition,membership change,and performance: Investigating the benefits and detriments of collective knowledge

This study analyzes the effects of group membership change on group cognition and performance to determine how groups can simultaneously leverage oldtimers’ collective knowledge and a newcomer’s expertise. Our analysis focuses specifically on the interrelated effects of the two components of a transactive memory system (TMS)—TMS structure and TMS processes—to explain the cognitive mechanisms through which membership change affects group performance. Results from a laboratory study show that groups that experience partial membership change tend to rely on the TMS structure that oldtimers developed in their original group, and that doing so is ultimately detrimental to performance because it creates inefficient TMS processes. Results from a supplemental study indicate that these TMS process inefficiencies can be avoided when oldtimers are instructed to reflect upon their collective knowledge prior to task execution. We discuss the implications for managing group cognition in organizations where membership change is prevalent.     

The effect of amplitude modulation on intelligibility of time-varying sinusoidal speech in children and adults

Although researchers are currently studying auditory object formation in adults, little is known about the development of this phenomenon in children. Amplitude modulation has been suggested as one of the characteristics of the speech signal that allows auditory grouping. In this experiment, we evaluated children (4 to 13 years of age) and adults to examine whether children's ability to use amplitude modulation (AM) in perception of time-varying sinusoidal (TVS) sentences is different from that of adults, and whether there are developmental changes. We evaluated performance on recognition of TVS sentences (unmodulated, amplitude-comodulated at 25, 50, 100, and 200 Hz, and amplitude-modulated using conflicting frequencies). Overall, the youngest children performed more poorly than did older children and adults. However, difference scores, defined as the percentage of phonemes correct in a given modulation condition minus the percentage correct for the unmodulated condition, showed no significant effects of age. Unlike the findings of previous studies (Carrell & Opie, 1992), these results support the ability of modulation with conflicting frequencies to improve intelligibility. The present study provides evidence that children and adults receive the same benefits (or decrements) from amplitude modulation.     

Observer Influences on Fathers and Mothers: An Experimental Manipulation of the Structure and Function of Parent – Infant Conversation

From studies over the past 20 years four contrasting hypotheses can be made about the nature of parent–infant communication: (1) mothers and fathers display similar skills to their infants and do not exert a differential influence on their development; (2) fathers are less sympathetic to their infants' level of development and therefore inadvertently stretch the child's development more than mothers; (3) both parents differentially socialize their sons' and daughters' early communicative skills; (4) any apparent differences between parents reflect their expectations about being observed. To examine these hypotheses together, this experiment records the communication of 10 mother–infant and 10 father–infant dyads in two conditions: when an observer was present or absent. The analysis revealed two patterns. Firstly, in keeping with most research on parent–child communication, mothers and fathers both simplified their speech to their infants in similar ways. Secondly, both the structure and function of parental communication showed differences between the two conditions and many of these differences were moderated by interactions between condition and sex of parent or child. The data thus provide more support for the first and fourth hypotheses cited above. It is suggested that analyses of parent–infant interaction should move away from simple assumptions about parental ‘influences’ upon children's development to consider the subtleties of different parental styles in different settings.     

Top-down-driven grouping overrules the central attentional bias

A central bias in spatial selection has been proposed to explain the decreasing search efficiency with increasing target eccentricity that results when distractors can occur closer to fixation than the target (J. M. Wolfe, P. O'Neill, & S. C. Bennett, 1998). The authors found evidence for such a bias using an odd-man-out variant of conjunction search. However, the bias was absent for the same displays when the identity of the odd-man-out target was known in advance. The authors propose that (a) top-down knowledge of a target feature supports grouping on this feature and (b) grouping links a peripheral target to central distractors expressing the same feature, increasing the attentional weighting afforded to the target and, consequently, facilitating its detection. The effects are independent of bottom-up priming effects occurring across trials. Thus, feature-based grouping can be driven top-down and can overrule the central bias in spatial selection.     

Automatic guidance of visual attention from verbal working memory

Previous studies have shown that visual attention can be captured by stimuli matching the contents of working memory (WM). Here, the authors assessed the nature of the representation that mediates the guidance of visual attention from WM. Observers were presented with either verbal or visual primes (to hold in memory, Experiment 1; to verbalize, Experiment 2; or merely to attend, Experiment 3) and subsequently were required to search for a target among different distractors, each embedded within a colored shape. In half of the trials, an object in the search array matched the prime, but this object never contained the target. Despite this, search was impaired relative to a neutral baseline in which the prime and search displays did not match. An interesting finding is that verbal primes were effective in generating the effects, and verbalization of visual primes elicited similar effects to those elicited when primes were held in WM. However, the effects were absent when primes were only attended. The data suggest that there is automatic encoding into WM when items are verbalized and that verbal as well as visual WM can guide visual attention.     

The IPIP–HEXACO scales: An alternative, public-domain measure of the personality constructs in the HEXACO model

Recently, Lee and Ashton (2004) described the HEXACO Personality Inventory (HEXACO-PI), a new instrument designed to assess the six dimensions observed in lexical studies of personality structure of various languages. Here, we describe the development of an alternative measure of the HEXACO factors and their facets, using the items of the International Personality Item Pool (IPIP). The scales of the resulting IPIP–HEXACO inventory showed satisfactory psychometric properties, as assessed by internal-consistency reliability, convergent and discriminant correlations with the original HEXACO-PI scales, and factor structure. We discuss the potential usefulness of the new IPIP–HEXACO inventory and its strengths and limitations.