Biomedical subjects

Mary Hegarty

Publications and source records attributed to Mary Hegarty.

6 recordsLinked to original sources

PubMed2006

Modulation of neural activity by angle of rotation during imagined spatial transformations.

Imagined spatial transformations of objects (e.g., mental rotation) and the self (e.g., perspective taking) are psychologically dissociable. In mental rotation, the viewer transforms the location or orientation of an object relative to stable egocentric and environmental reference frames. In imagined shifts of perspective, the viewer's egocentric reference frame is transformed with respect to stable objects and environment. Using fMRI, we showed that during mental transformations of objects the right superior parietal cortex exhibited a positive linear relationship between hemodynamic response and degrees of rotation. By contrast, during imagined transformations of the self, the same regions exhibited a negative linear trend. We interpret this finding in terms of the role of parietal cortex in coding the locations of objects in relation to the body.

Adult↗

PubMed2005

When static media promote active learning: annotated illustrations versus narrated animations in multimedia instruction.

In 4 experiments, students received a lesson consisting of computer-based animation and narration or a lesson consisting of paper-based static diagrams and text. The lessons used the same words and graphics in the paper-based and computer-based versions to explain the process of lightning formation (Experiment 1), how a toilet tank works (Experiment 2), how ocean waves work (Experiment 3), and how a car's braking system works (Experiment 4). On subsequent retention and transfer tests, the paper group performed significantly better than the computer group on 4 of 8 comparisons, and there was no significant difference on the rest. These results support the static media hypothesis, in which static illustrations with printed text reduce extraneous processing and promote germane processing as compared with narrated animations.

Adolescent↗

PubMed2004

Spatial ability, experience, and skill in laparoscopic surgery.

BACKGROUND: Previous research showing correlations between spatial ability and surgical skills has used participants in relatively early stages of training. Research in skill acquisition has shown that the role of cognitive abilities can diminish as skills become increasingly automatic. In this study, we explored the role of spatial ability in laparoscopic surgical skills in two groups, one experienced and the other relatively inexperienced. METHODS: Subjects were recruited from two videoscopic courses: an advanced course for experienced surgeons and a laparoscopic urological surgery course attended by participants with relatively little laparoscopic experience. Three measures were obtained: spatial abilities, videoscopic experience, and operative skills. RESULTS: A significant correlation (r = 0.393) was found between spatial ability and skills in the lower experience group but not among the experienced surgeons (r = 0.020). CONCLUSIONS: The results are consistent with the prediction that the importance of spatial ability in performance of laparoscopic skills should diminish with experience.

Clinical Competence↗

PubMed2004

Mechanical reasoning by mental simulation.

Recent studies have provided evidence for mental simulation as a strategy in mechanical reasoning. This type of reasoning can be dissociated from reasoning based on descriptive knowledge in that it depends on different abilities and memory stores, is expressed more easily in gesture than in language, exhibits analog properties, and can result in correct inferences in situations where people do not have correct descriptive knowledge. Although it is frequently accompanied by imagery, mental simulation is not a process of inspecting a holistic visual image in the 'mind's eye'. Mental simulations are constructed piecemeal, include representations of non-visible properties and can be used in conjunction with non-imagery processes, such as task decomposition and rule-based reasoning.

Humans↗

PubMed2002

Orientation specificity and spatial updating of memories for layouts.

This article examines the degree to which knowledge about the body's orientation affects transformations in spatial memory and whether memories are accessed with a preferred orientation. Participants learned large paths from a single viewpoint and were later asked to make judgments of relative directions from imagined positions on the path. Experiments 1 and 2 contribute to the emerging consensus that memories for large layouts are orientation specific, suggesting that prior findings to the contrary may not have fully accounted for latencies. Experiments 2 and 3 show that knowledge of one's orientation can create a preferred direction in spatial memory that is different from the learned orientation. Results further suggest that spatial updating may not be as automatic as previously thought.

Adult↗

PubMed2001

How are visuospatial working memory, executive functioning, and spatial abilities related? A latent-variable analysis.

This study examined the relationships among visuospatial working memory (WM) executive functioning, and spatial abilities. One hundred sixty-seven participants performed visuospatial short-term memory (STM) and WM span tasks, executive functioning tasks, and a set of paper-and-pencil tests of spatial abilities that load on 3 correlated but distinguishable factors (Spatial Visualization, Spatial Relations, and Perceptual Speed). Confirmatory factor analysis results indicated that, in the visuospatial domain, processing-and-storage WM tasks and storage-oriented STM tasks equally implicate executive functioning and are not clearly distinguishable. These results provide a contrast with existing evidence from the verbal domain and support the proposal that the visuospatial sketchpad may be closely tied to the central executive. Further, structural equation modeling results supported the prediction that, whereas they all implicate some degree of visuospatial storage, the 3 spatial ability factors differ in the degree of executive involvement (highest for Spatial Visualization and lowest for Perceptual Speed). Such results highlight the usefulness of a WM perspective in characterizing the nature of cognitive abilities and, more generally, human intelligence.

Cognition↗