Development Of Attentional Processes Research Articles

Is Early Bilingual Experience Associated with Greater Fluid Intelligence in Adults?

Emerging evidence suggests that early bilingual experience constrains the development of attentional processes in infants, and that some of these early bilingual adaptations could last into adulthood. However, it is not known whether the early adaptations in the attentional domain alter more general cognitive abilities. If they do, then we would expect that bilingual adults who learned their second language early in life would score more highly across cognitive tasks than bilingual adults who learned their second language later in life. To test this hypothesis, 170 adult participants were administered a well-established (non-verbal) measure of fluid intelligence: Raven’s Advanced Progressive Matrices (RAPM). Fluid intelligence (the ability to solve novel reasoning problems, independent of acquired knowledge) is highly correlated with numerous cognitive abilities across development. Performance on the RAPM was greater in bilinguals than monolinguals, and greater in ‘early bilinguals’ (adults who learned their second language between 0–6 years) than ‘late bilinguals’ (adults who learned their second language after age 6 years). The groups did not significantly differ on a proxy of socioeconomic status. These results suggest that the difference in fluid intelligence between bilinguals and monolinguals is not a consequence of bilingualism per se, but of early adaptive processes. However, the finding may depend on how bilingualism is operationalized, and thus needs to be replicated with a larger sample and more detailed measures.

A Longitudinal Study on Attention Development in Primary School Children with and without Teacher-Reported Symptoms of ADHD.

Background: Prospective longitudinal studies are essential in characterizing cognitive trajectories, yet few of them have been reported on the development of attention processes in children. We aimed to explore attention development in normal children and children with attention deficit and hyperactivity disorder (ADHD) symptoms in a repeated measures design using the attention network test (ANT).Methods: The population sample included 2,835 children (49.6% girls) aged 7–11 years from 39 schools in Barcelona (Catalonia, Spain) who performed the ANT four times from January 2012 to March 2013. According to teacher ratings, 10.5% of the children presented ADHD symptoms. We performed multilevel mixed-effects linear regression models, adjusting for school and individual, to test the effects of age-related growth on the ANT networks: alerting, orienting and executive attention, and three measurements related to attentiveness: median of hit reaction time (HRT), hit reaction time standard error (HRT-SE) and variability.Results: We observed age-related growth in all the outcomes, except orienting. The curves were steeper at the younger groups, although for alertness the improvement was further at the oldest ages. Gender and ADHD symptoms interacted with age in executive attention, HRT and variability. Girls performed better in executive attention at young ages although boys reached females at around 10 years of age. For HRT, males showed faster HRT. However, girls had a more pronounced improvement and reached the levels of boys at age 11. Children with ADHD symptoms had significant differences in executive attention, HRT and variability compared to children without ADHD symptoms.Conclusions: We detected an ongoing development of some aspects of attention in primary school children, differentiating patterns by gender and ADHD symptoms. Our findings support the ANT for assessing attention processes in children in large epidemiological studies.

Reactivity to visual signals and the cerebellar vermis: Evidence from a rare case with rhombencephalosynapsis.

The modulatory role of the cerebellum was investigated in a case with rhombencephalosynapsis (RS), a rare dysplasia characterized by the absence of the cerebellar vermis. The visual psychophysical task involved localizing a target and ignoring a distractor appearing either before, at the same time as, or after the target. It allowed us to assess reactivity to warning signals, distraction, and reactivity to signals appearing during attentive processing. Compared with a control sample, the patient exhibited greater reactivity to warning signals and difficulties interrupting attentive processing, whereas distraction was not increased. Complementary analyses showed that these deficits did not reflect just delayed development of attentional processes. These results suggest that the cerebellum modulates responsiveness and commands attentional/exploratory flexibility in response to sensory signals.

Impaired cued delayed alternation behavior in adult rat offspring following exposure to 2,3,7,8-tetrachlorodibenzo- p-dioxin on gestation day 15

This investigation used random ratio (RR) and cued delayed alternation procedures to examine the operant behavior of adult male and female rats following prenatal 2,3,7,8-tetrachlorodibenzo- p-dioxin (TCDD). Offspring were exposed to a single maternal dose of 0.0, 0.06, 0.18 or 0.54 μg/kg po of TCDD on gestation day (GD) 15. For RR, adult subjects were trained to respond on one lever in a two-lever chamber for food reinforcement. The response requirement was increased across sessions. Male offspring responded at higher rates than females regardless of RR value and prenatal exposure history. For delayed alternation, animals were required to alternate responses on both apparatus levers and to inhibit responding during randomly interpolated delay intervals. The performance of male and female offspring exposed to 0.18-μg/kg TCDD was significantly less accurate and this group committed more errors by responding during the delay intervals than the other exposure groups. A similar trend was observed in the 0.54-μg/kg group. Overall, response accuracy during the delayed alternation procedure was inversely related to delay length and tended to improve with experience. Interpretations of these outcomes include the possibility that TCDD interfered with the development of attentional processes, impaired response inhibition or promoted response perseveration despite the presence of cues, indicating changes in reinforcement contingencies.

Visual filtering and covert orienting in persons with Down syndrome

A forced-choice reaction time (RT) task was used to examine the efficiency of visual filtering (the inhibition of processing of irrelevant stimuli) and covert orienting (shifts of visual attention independent of eye movement) components of attention in persons with Down syndrome ( n = 20) and children of average intelligence ( n = 20) matched for mental age (MA) (average MA = approximately 5.4 years). Conditions varied with regard to presence or absence of distractors, and the validity (valid, invalid, or neutral) of location cues. Contrary to expectations, persons with Down syndrome and MA-matched children of average intelligence at approximately age 5 showed similar patterns of performance on a task that required filtering distracting stimuli and searching for relevant information in the visual field. Both groups responded more efficiently to a target preceded by a valid cue as compared to a target preceded by an invalid or neutral cue. In addition, performance was more efficient with a target that was presented without irrelevant information as compared to one that was flanked on either side by extraneous, nontarget information and therefore necessitated filtering for efficient performance. These two findings indicate that: (1) disengaging from the location of an incorrect cue, and then searching for, locating, and responding to a target requires more time and attention than simply locating and responding to a target that has been validly cued; and (2) processing and responding to a target flanked by extraneous information entails filtering, and therefore requires more time and resources than simply responding to a target without distractors. In general, the development of visual reflexive, covert orienting, and filtering are intact in persons with Down syndrome relative to their level of functioning at an MA level of approximately 5 years, a period that is critical in the development of attentional processes.

Working memory: A developmental study of phonological recoding

A cross-sectional study using children aged 3 to 7 years and a cross-sequential study using children aged between 5 and 8 years showed that the development of phonological recoding in working memory was more complex than the simple dichotomous picture portrayed in the current literature. It appears that initially children use no strategy in recall, which is proposed to represent the level of automatic activation of representations in long-term memory and the storage capacity of the central executive. This is followed by a period in which a visual strategy prevails, followed by a period of dual visual-verbal coding before the adult-like strategy of verbal coding finally emerges. The results are discussed in terms of three working memory models (Baddeley, 1990; Engle, 1996; Logie, 1996) where strategy use is seen as the development of attentional processes and phonological recoding as the development of inhibitory mechanisms in the central executive to suppress the habitual response set of visual coding.

Parallel and serial attentional processes: A developmental ERP study

We studied the development of attentional processes in parallel and serial visual search tasks. Event‐related potentials (ERPs) were recorded for children (n = 40, age = 7–12 years) from 25 electrodes. Pop‐out paradigms were used in the 2 parallel processing tasks; the standard stimuli were small blue rectangles. In the color parallel task the pop‐out stimuli were small red rectangles. In the size task the targets were large blue squares. In the serial task the targets were a conjunction of features from the parallel tasks (i.e., large red squares). RTs varied with age and task. There were decreases in P3 latency with age, task, and an Age × Task interaction due to slower age‐related changes in the size compared to the color task. The data suggest that developmental changes in visual selective attention are tied more closely to the features of the target stimuli than to the parallel‐serial distinction, results consistent with the guided search model of attention.