Now,Pay Attention! The Effects of Instruction on Children's Attention

We investigated the effects of instructions to “stay on task” on preschoolers' attention and cognitive performance in the face of either incomprehensible or comprehensible distraction. Three- and 4-year-olds completed problem-solving tasks while a distracting event played continuously in the background under conditions of a) no instruction, b) moderate instruction, or c) frequent instruction to “stay on task.” Under conditions where an incomprehensible distractor was present, any amount of instruction reduced looking to the distracting event. Under conditions where a comprehensible distractor was present, however, frequent instruction was the most effective in increasing looking to the task and decreasing looking to the distracting event.     

The Effects of Continuous and Intermittent Distractors on Cognitive Performance and Attention in Preschoolers

We investigated the effects of different amounts of distraction on preschoolers’ task performance and attention. Children 3.5 and 4 years of age completed problem-solving tasks in one of three conditions: no distraction, intermittent (periodic) distraction, or continuous distraction. The results revealed differential effects of the distractors at the different ages. The younger group was susceptible to any kind of distraction; task performance and attention were equally impaired during both distraction conditions. The older group was less susceptible to external distraction, with task performance and attention most impaired in the continuous distraction condition. The results are discussed in terms of the relevance of the amount of competition for attentional focus present in distractors and the development of executive functions in early childhood.     

Event‐related potential differences in children supplemented with long‐chain polyunsaturated fatty acids during infancy

Long‐chain polyunsaturated fatty acids (LCPUFA) have been shown to be necessary for early retinal and brain development, but long‐term cognitive benefits of LCPUFA in infancy have not been definitively established. The present study sought to determine whether LCPUFA supplementation during the first year of life would result in group differences in behavior and event‐related potentials (ERPs) while performing a task requiring response inhibition (Go/No‐Go) at 5.5 years of age. As newborns, 69 children were randomly assigned to infant formulas containing either no LCPUFA (control) or formula with 0.64% of total fatty acids as arachidonic acid (ARA; 20:4n6) and various concentrations of docosahexaenoic acid (DHA; 22:6n3) (0.32%, 0.64% or 0.96%) for the first 12 months of life. At 5.5 years of age, a task designed to test the ability to inhibit a prepotent response (Go/No‐Go) was administered, yielding both event‐related potentials (ERPs) and behavioral data. Behavioral measures did not differ between groups, although reaction times of supplemented children were marginally faster. Unsupplemented children had lower P2 amplitude than supplemented children to both Go and No‐Go conditions. N2 amplitude was significantly higher on No‐Go trials than Go trials, but only for supplemented children, resulting in a significant Group × Condition interaction. Topographical analysis of the ERPs revealed that the LCPUFA‐supplemented group developed a novel period of synchronous activation (microstate) involving wider anterior brain activation around 200 ms; this microstate was not present in controls. These findings suggest that LCPUFA supplementation during the first 12 months of life exerts a developmental programming effect that is manifest in brain electrophysiology. A video abstract of this article can be viewed at: https://www.youtube.com/watch?v=oM2leg4sevs .     

Knowledge of the ordinal position of list items in pigeons

Ordinal knowledge is a fundamental aspect of advanced cognition. It is self-evident that humans represent ordinal knowledge, and over the past 20 years it has become clear that nonhuman primates share this ability. In contrast, evidence that nonprimate species represent ordinal knowledge is missing from the comparative literature. To address this issue, in the present experiment we trained pigeons on three 4-item lists and then tested them with derived lists in which, relative to the training lists, the ordinal position of the items was either maintained or changed. Similar to the findings with human and nonhuman primates, our pigeons performed markedly better on the maintained lists compared to the changed lists, and displayed errors consistent with the view that they used their knowledge of ordinal position to guide responding on the derived lists. These findings demonstrate that the ability to acquire ordinal knowledge is not unique to the primate lineage. (PsycINFO Database Record (c) 2011 APA, all rights reserved).     

Foveal spatial summation in human cone mechanism

We measured at the fovea the chromatic contrast threshold for stimuli modulated along different chromatic directions in the isoluminant plane of MBDKL colour space, considering the two cardinal axes (L/M) and S/(L + M) and other intermediate non-cardinal directions. This psychophysical determination was conducted as a function of stimulus size. The test stimulus was a foveal isoluminant Gaussian patch with a raised cosinusoidal temporal profile superimposed on a neutral background. The task was performed binocularly. The increment threshold was measured for three observers by a Bayesian adaptive psychometric method (QUEST). The Ricco area of complete spatial summation was estimated from the threshold-versus-area curves. The perceptive fields are smaller for the L/M-cone opponent direction than the S/(L + M)-cone opponent. The perceptive field sizes for the stimuli in non-cardinal chromatic directions and stimuli modulated at the (L/M)-cone opponent direction present similar values. Measurements were made at two luminance levels, 5 and 40 cd m(-2), but the differences found were small. The perceptive field sizes found could be associated with LGN area.     

"Worthless female material": nursemaids and governesses in Freud's cases

The figure of the governess, central in Freud's own history, is present in most of his cases. Freud described his nursemaid as "the prime originator" of his neuroses. Well after Freud's abandonment of the seduction theory, female servants were consistently portrayed as seducing boys, while their relationship with girls consisted of identification and rivalry. The role of Freud's own surrogate mother in his life and writing is examined, and two cases, Lucy R. and Dora, are looked at through the lens of female caretaking. A review and integration of relevant literature is followed by an exploration of the perplexing adherence in Freud's writing to the reality of seduction by a governess, even after he had abandoned the seduction theory. It is argued that it is in the figure of the female maid that the "shadowy" early history of Freud's mothering experiences may actually be engaged, however indirectly and unconsciously. This figure, and Freud's powerful, problematic identification with her, is a thread that when pulled helps unravel struggles in Freud's early theoretical development around issues of female sexuality and analytic authority. Revisiting Lucy R. and Dora provides a new perspective on Freud's difficulty with maternal transferences, and restores to their original importance his "worthless" governesses, those first analysts.     

A positional coding mechanism in pigeons after learning multiple three-item lists

Pigeons were trained on three three-item lists (List 1: A₁ → B₁ → C_1; List 2: A₂ → B₂ → C_2; List 3: A₃ → B₃ → C₃). After sessions in which any one of the three lists could be presented on a trial, derived-maintained list and derived-changed list probe trials were introduced. The derived list probe trials were composed of three items, one drawn from each of the training lists. On derived-maintained probe trials, each item was in the same ordinal position it occupied during training (e.g., A₃ → B₁ → C₂). On derived-changed probe trials, items that occupied the second and third position during training were exchanged (e.g., A₂ → C₃ → B₁). The performance of subjects on derived-maintained probe trials was significantly above chance and no different to that observed on the training lists. In contrast, subjects’ performance on derived-changed probe trials was significantly below chance. To our knowledge, this is the first study that has demonstrated pigeons are able to learn and retain multiple three-item lists. In addition, subjects’ performance on the derived-maintained probe trials suggests that they acquire knowledge of each list item’s ordinal position when learning multiple lists.     

Anatomy of the episodic buffer: a voxel-based morphometry study in patients with dementia

In 2000 Baddeley proposed the existence of a new component of working memory, the episodic buffer, which should contribute to the on-line maintenance of integrated memory traces. The author assumed that this component should be critical for immediate recall of a short story that exceeds the capacity of the phonological store. Accordingly, patients with Alzheimer's dementia (AD) should suffer of a deficit of the episodic buffer when immediate recall of a short story is impossible. On the other hand, the episodic buffer should be somewhat preserved in such patients when some IR can occur (Baddeley and Wilson, 2002). We adopted this logic for a voxel-based morphometry study. We compared the distribution of grey-matter density of two such groups of AD patients with and of a group of age-matched controls. We found that both AD groups had a significant atrophy of the left mid-hippocampus; on the other hand, the anterior part of the hippocampus was significantly more atrophic in patients who were also impaired on the immediate prose recall task. Six out of ten patients with no immediate recall were spared at "central executive" tasks. Taken together our findings suggest that the left anterior hippocampus contributes to the episodic buffer of the revised working memory model. We also suggest that the episodic buffer is somewhat independent from the central executive component of working memory.     

Prior beliefs and methodological concepts in scientific reasoning

This investigation focuses on the relations between prior beliefs, methodological concepts, and college students' (N=211) scientific reasoning in different problem contexts. Participants were presented with exercises that described the method and results of experiments, and were asked to draw conclusions about the causal status of variables that violated their prior beliefs. Participants drew conclusions in both abstract (i.e. recommend a conclusion for the fictional experimenter), and personal settings (i.e. draw their own conclusions about the phenomenon). Participants' recommendations for the hypothetical experimenter were predicted by their understanding of two methodological concepts: the function of empirical evidence and experimental control. Students' personal conclusions were predicted by their prior beliefs and their appreciation of the objectivity of inquiry. Thus, even when students understand in the abstract how data should relate to scientific conclusions, prior beliefs often take precedence in their own conclusions, especially when they do not understand the issue of objectivity. Copyright © 2004 John Wiley & Sons, Ltd.     

Accessing lexical ambiguity: Effects of context and dominance

Summary The paper examines the effects of sentential context and frequency of meaning (dominance) on the lexical access of ambiguous words. Two experiments were carried out using Swinney's (1979) cross-modal paradigm. The sentential contexts were constructed in such a way as to make salient the most characteristic features of either the dominant (Experiment 1) or the secondary (Experiment 2) meaning of the ambiguous word. The claim was that if context is sufficiently constraining selective access of the congruent meaning can be obtained. Consistent with this prediction, context biasing the dominant meaning facilitated lexical decision only on target words related to the dominant meaning. When context biased the secondary meaning, both context and dominance produced a facilitation effect.The research reported here was supported by grants from the Ministero della Pubblica Istruzione (fondi 40%) and the Consiglio Nazionale delle Ricerche