Test of the effect of attention on judged length of a line

Studies to assess experimentally whether attention affects the judged length of a line have produced discordant results. This paper reports the results of a test designed to avoid factors that were not controlled in previous studies. Stimuli were either two vertical lines or two horizontal lines of equal physical length presented briefly on opposite sides of a fixation cross. Subjects were asked to direct their attention to one line when the arm of the cross pointing to the line changed in luminance. This arm was used either as a precue or as a postcue. Subjects judged lines to be longer when a precue preceded the line than when a postcue followed the line.     

Effects of partial occlusion on perceived surface segregation

Tests are reported of the possibility that local information from contour junctions and from corners of intersecting surfaces is used for perceived surface segregation. Stimuli were two intersecting squares with small disks occluding different parts of the squares. The perceived segregation of the squares from one another decreased as the amount of occlusion of parts of the squares increased. This segregation was less when disks occluded parts of contours than when disks occluded parts entirely inside the squares. Occlusion of parts of contours reduced segregation independently of whether contour junctions or corners were visible or invisible, both where the intersecting surfaces were transparent squares and when they were outlined squares. The present findings show that local information from contour junctions or from corners is not used for surface segregation, and confirm that this segregation is determined by global processes of grouping of areas and of extrapolation of contours.     

Brain activation and the phonological loop: the impact of rehearsal

Brain activation studies offer valuable techniques for exploring human cognition to complement behavioral measures and several studies report a wide range of neuroanatomical networks activated during verbal immediate memory. Behavioral investigations have shown use of multiple cognitive strategies across and within individuals, although aggregate data appear to reflect a common cognitive function. Variation in cognitive strategies could result in aggregate activation patterns that are relatively widespread and difficult to interpret. Imaging data (fMRI) from six participants instructed to use subvocal rehearsal showed significant left hemisphere activation in the inferior parietal gyrus and inferior and middle frontal gyri, a pattern of activation more clearly focused than in previous brain activation studies of immediate verbal serial ordered recall. Our results should be relatively free of the influence of other mental operations, and emphasise the importance of considering which cognitive strategies might give rise to focused or to diverse patterns of brain activation.     

The differentiation hypothesis and the Flynn effect

Many studies have shown that IQs have been increasing over the last half century. These increases have come to be known as "the Flynn effect". The "Flynn effect" represents a difference on ability-level between groups of the same age but different cohort. The ability-level differentiation hypothesis represents a difference on the relevance of cognitive factors between groups of high and low ability. Hence, it should be possible to imitate the ability-level differentiation effect by comparing groups of the same age but different cohort. The indifferentiation hypothesis represents no differences on the relevance of cognitive abilities in all age groups within the same cohort. The aim of the present study is to test the relationships between these phenomena. For this purpose we analyzed the American standardisation samples of the WISC, WISC-R and WISC-III. Results support the link between the Flynn effect and the differentiation hypothesis. Also, reported evidence replicate previous findings supporting the indifferentiation hypothesis. Implications for the assessment of the intelligence are discussed.     

Sex differences in righting from supine to prone in rats (Rattus norvegicus): a masculinized skeletomusculature is not required

Previous research has shown that sex differences exist in the composition of lateral movements (E. F. Field, I. Q. Whishaw, & S. M. Pellis, 1996, 1997a, 1997b; see also records 1996-06132-009, 1997-05322-015, and 1997-04722-005). An unresolved question is whether sex differences are present in other movements, such as rotation around the longitudinal axis, and whether this difference is dependent on a feminine or masculine skeletomusculature. Female rats (Rattus norvegicus) first rotate their forequarters and then their hindquarters in the same direction. Male rats exhibit rotation of the hindquarters counter to the direction of forequarter rotation. Males with the testicular feminized mutation, who have a feminized skeletomusculature and masculinized central nervous system, are similar to male controls. This study provides evidence that sex differences in movement integration are not restricted to the lateral plane, are not solely due to sex differences in skeletomusculature, and thus are likely mediated by the central nervous system.     

Gesture production and text structure

In the present pilot study, we examined the relationship between gesture and verbal production. Subjects were asked to read a story and then to narrate what they remembered. We analyzed verbal production according to Kintsch's procedure and obtained a list of hierarchically organized propositions that represented the meaning of subject's narration. Propositions were subdivided into High- and Low-level propositions. Further, we analyzed gesture production by identifying hand or arm movement that accompanied subject's narration. Each gesture was associated with the word simultaneously produced, and then with the proposition to which the word belonged. Analysis showed subjects were more likely to produce gestures in association with High- rather than with Low-level propositions. High-level propositions may elicit the production of gestures which, in turn, mark the importance of verbal meaning conveyed simultaneously.     

Age-related Differences in the Production of Textual Descriptions

Narratives produced by 69 healthy Italian adults were analyzed for age-related changes of microlinguistic, macrolinguistic and informative aspects. The participants were divided into five age groups (20-24, 25-39, 40-59, 60-74, 75-84). One single-picture stimulus and two cartoon sequences were used to elicit three stories per subject. Age-related differences were found with respect to semantic paraphasias, paragrammatisms, syntactic complexity, degree of both local and global coherence, local coherence errors (like ambiguous referencing), and in the level of informativeness conveyed by the stories. The results showed some null effects of age, some effects with a sharp drop in performance in the oldest group, and several effects suggesting a gradual decrease in performance across age groups. No age differences were found with respect to phonological selection and noun-verb ratio. In the proportion of details vs. main themes, the results indicated a possibly better story construction ability in the middle aged (40-59) and young elderly (60-74) groups compared to the younger or the oldest group. Story-type (single picture vs. picture sequence) had a significant influence on some macrolinguistic and informativeness measures.     

Concurrent performance of two memory tasks: evidence for domain-specific working memory systems

Previous studies of dual-task coordination in working memory have shown a lack of dual-task interference when a verbal memory task is combined with concurrent perceptuomotor tracking. Two experiments are reported in which participants were required to perform pairwise combinations of (1) a verbal memory task, a visual memory task, and perceptuomotor tracking (Experiment 1), and (2) pairwise combinations of the two memory tasks and articulatory suppression (Experiment 2). Tracking resulted in no disruption of the verbal memory preload over and above the impact of a delay in recall and showed only minimal disruption of the retention of the visual memory load. Performing an ongoing verbal memory task had virtually no impact on retention of a visual memory preload or vice versa, indicating that performing two demanding memory tasks results in little mutual interference. Experiment 2 also showed minimal disruption when the two memory tasks were combined, although verbal memory (but not visual memory) was clearly disrupted by articulatory suppression interpolated between presentation and recall. These data suggest that a multiple-component working memory model provides a better account for performance in concurrent immediate memory tasks than do theories that assume a single processing and storage system or a limited-capacity attentional system coupled with activated memory traces.     

Mental models in deductive reasoning

We report research investigating the role of mental models in deduction. The first study deals with conjunctive inferences (from one conjunction and two conditional premises) and disjunctive inferences (from one disjunction and the same two conditionals). The second study examines reasoning from multiple conditionals such as: If e then b; If a then b; If b then c; What follows between a and c? The third study addresses reasoning from different sorts of conditional assertions, including conditionals based on if then, only if, and unless. The paper also presents research on figural effects in syllogistic reasoning, on the effects of structure and believability in reasoning from double conditionals, and on reasoning from factual, counterfactual, and semifactual conditionals. The findings of these studies support the model theory, pose some difficulties for rule theories, and show the influence on reasoning of the linguistic structure and the semantic content of problems.     

The Distress of Citizen-Children with Detained and Deported Parents

In immigration enforcement, many undocumented immigrants with children are often detained and deported. But it is their US-born citizen-children that have been overlooked in immigration debates and enforcement policies and practices. Citizen-children are at risk for negative psychological outcomes when families are fractured and destabilized by arrest, detention, and deportation. The children risk being torn from their parents and, often, their undocumented siblings. To add to the small but growing empirical base on the effects of living under the threat of deportation and actual deportation of parents, we compared the psychological status of three groups of citizen-children: (1) a group living in Mexico with their deported parents; (2) a group in the US with parents affected by detention or deportation; and (3) a comparison group of citizen-children whose undocumented parents were not affected by detention or deportation. We compared children on self-report and parent-report measures of behavioral adjustment, depression, anxiety, and self-concept. Across the three groups we found elevated levels of distress, and differences between children who had experienced a parent’s detention or deportation and those who had not. We discuss findings in the context of children’s clinical needs, future research, and implications for immigration enforcement policy and practices.