The relative strengths of indirect and direct word learning

Indirect word learning lacks many of the overt social-pragmatic cues to reference available in direct word learning, yet the two result in equally robust mappings when comprehension is assessed immediately after learning. The 3 studies reported here investigated how 3-year-olds (N=96) respond to more challenging tests of the relative strengths of indirect and direct word learning. In Study 1, children's comprehension of indirectly and directly learned proper and common names was tested after a 2-day delay. Both types of learning resulted in proper name mappings that picked out an individual and in common name mappings that could be extended to another category member. In Studies 2 and 3, children's comprehension was tested after they had been provided with additional, and sometimes inconsistent, information about the scope of previously learned words. There was a hint of a difference between indirect and direct word learning. but results overall suggested that the two were equivalent.     

Pathways to violence in the children of mothers who were depressed postpartum

The impact of postnatal depression on a child's risk for violent behavior was evaluated in an urban British community sample (N=122 families). Mothers were interviewed during pregnancy, at 3 months postpartum, and when the child was 1, 4, and 11 years of age. Mothers, teachers, and children reported on violent symptoms at age 11. Structural equation modeling revealed that the child's violence was predicted by the mother's postnatal depression even when her depression during pregnancy, her later history of depression, and family characteristics were taken into account. Violence was associated with symptoms of attention-deficit/hyperactivity disorder and problems with anger management. Children were most violent if mothers had been depressed at 3 months and at least once thereafter.     

Dual prism adaptation: calibration or alignment?

Dual adaptation to different amounts or directions of prismatic displacement, or both, can be acquired and maintained with little mutual interference. Associative recalibration of the regional task- or workspace, contingent on differentiation of distinguishing sensory information, can explain such adaptation. In contrast, nonassociative realignment restores dimensional mapping among spatial representations. Methods for measuring the separate contributions of those 2 kinds of prism adaptation are identified in the present article. On the basis of a critique of dual-adaptation studies, the authors suggest that recalibration can explain the data but that the method used in those experiments confounded realignment and might have obscured the effectiveness of dual-calibration training.     

Inhibitory attentional control in patients with frontal lobe damage

The performance of a group of frontal lobe lesion and a group of frontal lobe dementia patients was compared with the performance of their respective matched normal control groups on two tests of inhibitory attentional control-the stop-signal reaction time task and a negative priming task. Both patient groups responded significantly slower than their respective normal control groups, but they showed only marginally significant selective impairments on the measures of inhibition. The data suggest that the specific inhibitory processes evaluated by these two tests are, in general, spared in patients with focal frontal lobe lesions or frontal lobe degeneration.     

Confirmatory factor analysis of the WMS-III in patients with temporal lobe epilepsy

Five competing models specifying the factor structure underlying the Wechsler Memory Scale-Third Edition (D. Wechsler, 1997b) primary subtest scores were evaluated in a sample of patients with intractable temporal lobe epilepsy (N = 254). Models specifying separate immediate and delayed constructs resulted in inadmissible parameter estimates and model specification error. There were negligible goodness-of-fit differences between a 3-factor model of working memory, auditory memory, and visual memory and a nested--more parsimonious--2-factor model of working memory and general memory. The results suggest that specifying a separate visual memory factor provides little advantage for this sample--an unexpected finding in a population with lateralized dysfunction, for which one might have predicted separate auditory and visual memory dimensions.     

Large-scale ensemble averaging of ambulatory impedance cardiograms

Impedance cardiography has been used increasingly to measure human physiological responses to emotional and mentally engaging stimuli. The validity of large-scale ensemble averaging of ambulatory impedance cardiograms was evaluated for preejection period (PEP), interbeat interval, and dZ/dt_(min) amplitude. We tested whether the average of “classical” 60-sec ensemble averages across periods with fixed activity, posture, physical load, social situation, and location could be accurately estimated from a single large-scale ensemble average spanning these entire periods. Impedance and electrocardiograms were recorded for about 24-h from 21 subjects. Recordings were scored by seven raters, using both methods for each subject. Good agreement (average intraclass correlation coefficient was .91) between both ensemble averaging methods was found for all three cardiac function measures. The results indicate that for unambiguous ambulatory impedance cardiograms, large-scale ensemble averaging is valid, which makes measuring prolonged changes in cardiac sympathetic activity by measuring ambulatory PEP feasible even in large epidemiological samples.     

Acquired ‘theory of mind'' impairments following stroke

The ability to attribute thoughts and feelings to self and others (‘theory of mind') has been hypothesised to have an innate neural basis and a dedicated cognitive mechanism. Evidence in favour of this proposal has come from autism; a brain-based developmental disorder which appears to be characterised by impaired theory of mind, despite sometimes good general reasoning skills/IQ. To date no case of specific acquired theory of mind impairment has been reported. The present study examined theory of mind in adults who had suffered right hemisphere stroke, a group known to show pragmatic and social difficulties. In one study using story materials and two using cartoons, patients' understanding of materials requiring attribution of mental states (e.g. ignorance, false belief) was significantly worse than their understanding of non-mental control materials. Data from healthy elderly subjects, and a small group of left hemisphere patients (who received the tasks in modified form), suggest that this impairment on mental state tasks is not a function of task difficulty. The findings support the notion of a dedicated cognitive system for theory of mind, and suggest a role for the healthy right hemisphere in the attribution of mental states.     

Differential effects of shared attention on perception of heading and 3-D object motion

When a person moves in a straight line through a stationary environment, the images of object surfaces move in a radial pattern away from a single point. This point, known as thefocus of expansion (FOE), corresponds to the person’s direction of motion. People judge their heading from image motion quite well in this situation. They perform most accurately when they can see the region around the FOE, which contains the most useful information for this task. Furthermore, a large moving object in the scene has no effect on observer heading judgments unless it obscures the FOE. Therefore, observers may obtain the most accurate heading judgments by focusing their attention on the region around the FOE. However, in many situations (e.g., driving), the observer must pay attention to other moving objects in the scene (e.g., cars and pedestrians) to avoid collisions. These objects may be located far from the FOE in the visual field. We tested whether people can accurately judge their heading and the three-dimensional (3-D) motion of objects while paying attention to one or the other task. The results show that differential allocation of attention affects people’s ability to judge 3-D object motion much more than it affects their ability to judge heading. This suggests that heading judgments are computed globally, whereas judgments about object motion may require more focused attention.