Mixing measures: testing an assumption of the attention network test

The human attention system has been subdivided into three networks that appear to be functionally and anatomically independent: alerting, orienting, and executive control. The Attention Network Test (ANT) is a quick and easy tool that measures the efficiency of these three networks by averaging reaction time and accuracy scores across several different cue and flanker conditions. Using ANOVAs and correlation procedures, we found that (a) intranetwork correlations were surprisingly low, and (b) Cue X Flanker interactions were found within alerting, orienting, and executive control measures. Taken together, these findings highlight the interaction between the three networks and the potential difficulty in accurately measuring them with this task.     

The affective consequences of cognitive inhibition: devaluation or neutralization?

Affective evaluations of previously ignored visual stimuli are more negative than those of novel items or prior targets of attention or response. This has been taken as evidence that inhibition has negative affective consequences. But inhibition could act instead to attenuate or "neutralize" preexisting affective salience, predicting opposite effects for stimuli that were initially positive or negative in valence. We tested this hypothesis by presenting trustworthy and untrustworthy faces (Experiment 1), strongly positive and negative photographs (Experiment 2), and monetary gain- and loss-associated patterns (Experiment 3) in a Go/No-Go task and assessing subsequent affective ratings. Evaluations of prior No-Go (inhibited) stimuli were more negative than of prior Go (noninhibited) stimuli, regardless of a priori affective valence. Ratings of No-Go stimuli also became increasingly negative (vs. increasingly neutral) when preexisting salience was increased via stimulus repetition (Experiment 4). Our results suggest inhibition leads to affective devaluation, not affective neutralization.     

Revealing the invisible hand: The role of teachers in children's peer experiences

To introduce this special issue, the concept of the teacher as an “invisible hand” is presented as a metaphor to describe the potentially influential but relatively understudied contribution that educators are likely to have on children’s peer relationships and their broader interpersonal growth. Building from conceptual work distinguishing between the role of adults and peers in children’s social development, we summarize empirical support for the view that teachers are in a position to develop and guide the classroom as a society by simultaneously directing institutional expectations while also providing students with opportunities to collectively construct their own peer culture. Key social development constructs are reviewed from this lens, and the four articles and two commentaries that constitute this special issue are discussed in relation to their contributions to clarifying and extending current views of the role of teachers in school social dynamics. We conclude by considering intervention implications of this work, and we argue that teachers are the one professional in a child’s life who have the opportunity to view the whole child in relation to the social ecology in which he or she is embedded.     

Interpreting spatial terms involves simulating interactions

Recent research in spatial language has demonstrated that the interpretation of a spatial term depends not only on the geometry of the configuration of the objects being spatially related, but also on extrageometric information, including information about the objects and their interaction. Such effects could emerge from activation of general knowledge of the association between the objects; thus, they should be widely observed. In contrast, they could be more restricted, emerging only in situations in which the spatial language task positions objects in a manner that is consistent with a simulation of their interaction. In two experiments, we test each of these ideas and demonstrate that extrageometric information augments geometric information in the interpretation of spatial terms only when the situation enables the interaction.     

Cholinergic modulation of trace conditioning trained in serial compound: A developmental analysis

In four experiments the effects of serial compound conditioning on responding to a trace-conditioned CS were evaluated using a fear conditioning paradigm. The subjects were 18- and 25-day-old Sprague-Dawley rats, previously shown to exhibit little or no trace fear conditioning. Here, animals as young as 18 days of age were shown to be capable of trace conditioning between a visual CS1 and a shock US, provided the trace interval was filled with a non-target CS2 during serial conditioning trials (CS1-->CS2-->US). To explore cholinergic mechanisms involved in trace and serial conditioning, additional experiments assessed conditioned responding following pre-training administration of the muscarinic receptor antagonist scopolamine. Scopolamine produced a dose-dependent reduction in responding to the trace CS1, regardless of whether subjects were trained with standard trace (CS1-->trace interval-->US) or serial (CS1-->CS2-->US) trials. Responding to CS2 was unaffected by scopolamine. These data suggest that central cholinergic systems are functional in the young animals, but are not normally sufficiently activated by standard trace conditioning procedures. The results suggest that serial compound conditioning can promote trace conditioning in young rats, as it does in adults, perhaps by enhancing cholinergic activity during training. Implications for the late ontogenetic emergence of trace conditioning as it relates to maturation of neural pathways and their role in the potentiating effects of a gap filler are discussed.     

Gaze following: why (not) learn it?

We propose a computational model of the emergence of gaze following skills in infant-caregiver interactions. The model is based on the idea that infants learn that monitoring their caregiver's direction of gaze allows them to predict the locations of interesting objects or events in their environment (Moore & Corkum, 1994). Elaborating on this theory, we demonstrate that a specific Basic Set of structures and mechanisms is sufficient for gaze following to emerge. This Basic Set includes the infant's perceptual skills and preferences, habituation and reward-driven learning, and a structured social environment featuring a caregiver who tends to look at things the infant will find interesting. We review evidence that all elements of the Basic Set are established well before the relevant gaze following skills emerge. We evaluate the model in a series of simulations and show that it can account for typical development. We also demonstrate that plausible alterations of model parameters, motivated by findings on two different developmental disorders - autism and Williams syndrome - produce delays or deficits in the emergence of gaze following. The model makes a number of testable predictions. In addition, it opens a new perspective for theorizing about cross-species differences in gaze following.     

Audiospatial and visuospatial working memory in 6-13 year old school children

The neural processes subserving working memory, and brain structures underlying this system, continue to develop during childhood. We investigated the effects of age and gender on audiospatial and visuospatial working memory in a nonclinical sample of school-aged children using n-back tasks. The results showed that auditory and visual working memory performance improves with age, suggesting functional maturation of underlying cognitive processes and brain areas. The gender differences found in the performance of working memory tasks suggest a larger degree of immaturity in boys than girls at the age period of 6–10 yr. The differences observed between the mastering of auditory and visual working memory tasks may indicate that visual working memory reaches functional maturity earlier than the corresponding auditory system.     

Hemispheric asymmetries for global and local processing as a function of stimulus exposure duration

The experiments assess the relationship between stimulus exposure duration and hemispheric asymmetries for global and local processing. Six durations (27, 40, 53, 67, 80, and 147 ms) were tested in a selective attention task in which hierarchical letterforms were presented unilaterally to the left or right visual field. The results indicated that left hemisphere-local asymmetries were demonstrated more often than right hemisphere-global asymmetries and that asymmetries were most commonly found in the middle range of durations tested. The pattern of results emphasizes the importance of further study into those conditions under which the predicted asymmetries can be reliably demonstrated in healthy individuals.