Bilateral comparison of occipital lobe sulci: A sulcus identifying algorithm

A procedure for automatic identification of sulci of cerebral hemispheres in magnetic resonance images is presented. The algorithm departs from information of the spatial location of a given feature (e.g., sulcal contour) in one hemisphere and automatically defines its course in the other hemisphere. The automatic tracing of sulci was successfully performed in the mesial aspect both hemispheres in 18 normal individuals. The sulcal location in the target hemisphere was first approximated by assuming an affine transformation between hemispheres, and then refined by local edge analysis. The method produced reliable results in comparing the intersulcal areas (the cuneus), sulcal length, their complexity, and the angle between the pariteooccipital and retrocalcarine fissures.     

Category-selective attention modulates unconscious processes in the middle occipital gyrus

Many studies have revealed the top-down modulation (spatial attention, attentional load, etc.) on unconscious processing. However, there is little research about how category-selective attention could modulate the unconscious processing. In the present study, using functional magnetic resonance imaging (fMRI), the results showed that category-selective attention modulated unconscious face/tool processing in the middle occipital gyrus (MOG). Interestingly, MOG effects were of opposed direction for face and tool processes. During unconscious face processing, activation in MOG decreased under the face-selective attention compared with tool-selective attention. This result was in line with the predictive coding theory. During unconscious tool processing, however, activation in MOG increased under the tool-selective attention compared with face-selective attention. The different effects might be ascribed to an interaction between top-down category-selective processes and bottom-up processes in the partial awareness level as proposed by Kouider, De Gardelle, Sackur, and Dupoux (2010). Specifically, we suppose an “excessive activation” hypothesis.     

Visual implicit memory in the left hemisphere: evidence from patients with callosotomies and right occipital lobe lesions

Identification of visually presented objects and words is facilitated by implicit memory for past visual experiences with those items. Several behavioral and neuroimaging studies suggest that this form of memory is dependent on perceptual processes localized in the right occipital lobe. We tested this claim by examining implicit memory in patients with extensive right occipital lobe lesions, using lexical-decision, mirror-reading, picture-fragment, and word-fragment-completion tests, and found that these patients exhibited normal levels of priming. We also examined implicit memory in patients with complete callosotomies, using standard and divided-visual-field word-fragment-completion procedures, and found that the isolated left hemisphere exhibited normal priming effects. The results indicate that the right occipital lobe does not play a necessary role in visual implicit memory, and that the isolated left hemisphere can support normal levels of visual priming in a variety of tasks.     

Computational exploration of metaphor comprehension processes using a semantic space model

Recent metaphor research has revealed that metaphor comprehension involves both categorization and comparison processes. This finding has triggered the following central question: Which property determines the choice between these two processes for metaphor comprehension? Three competing views have been proposed to answer this question: the conventionality view ( Bowdle & Gentner, 2005 ), aptness view ( Glucksberg & Haught, 2006b ), and interpretive diversity view ( Utsumi, 2007 ); these views, respectively, argue that vehicle conventionality, metaphor aptness, and interpretive diversity determine the choice between the categorization and comparison processes. This article attempts to answer the question regarding which views are plausible by using cognitive modeling and computer simulation based on a semantic space model. In the simulation experiment, categorization and comparison processes are modeled in a semantic space constructed by latent semantic analysis. These two models receive word vectors for the constituent words of a metaphor and compute a vector for the metaphorical meaning. The resulting vectors can be evaluated according to the degree to which they mimic the human interpretation of the same metaphor; the maximum likelihood estimation determines which of the two models better explains the human interpretation. The result of the model selection is then predicted by three metaphor properties (i.e., vehicle conventionality, aptness, and interpretive diversity) to test the three views. The simulation experiment for Japanese metaphors demonstrates that both interpretive diversity and vehicle conventionality affect the choice between the two processes. On the other hand, it is found that metaphor aptness does not affect this choice. This result can be treated as computational evidence supporting the interpretive diversity and conventionality views.     

Understanding symptoms of medical frontal lobe disorder: A clinical case study

A case of anterior communicating artery aneurysm with damage to inferior medial frontal areas (Brodmann areas 25, 32, 24-inferior) is presented. Four prominent deficits are discussed: (1) anterograde amnesia, (2) inert perseverative card sorting, (3) motor stereotypies, and (4) reduplicative paramnesia. These four deficits are discussed as negative or positive symptoms, related either to damage in inferior medial frontal (Brodmann areas 25, 32, 24-inferior) regions or release phenomena of superior medial frontal (Brodmann areas 6-medial and 24-superior) regions. It is concluded that the inferior and superior medial frontal regions act as opponent processors, with the inferior (B25, 32) area functioning to switch current mental set while the superior (B24-superior, 6-medial) region functions to maintain current mental set. Testable hypotheses about the opponent processor mechanism are suggested, as applied to neuropsychiatric disorders.     

Associative retrieval processes in the human medial temporal lobe: hippocampal retrieval success and CA1 mismatch detection

Hippocampal subfields CA(3) and CA(1) are hypothesized to differentially support the generation of associative predictions and the detection of associative mismatches, respectively. Using high-resolution functional MRI, we examined hippocampal subfield activation during associative retrieval and during subsequent comparisons of memory to matching or mismatching decision probes. Activity in the dentate gyrus/CA(2/3), CA(1), and other medial temporal lobe subregions tracked associative retrieval success, whereas activity in CA(1) and the perirhinal cortex tracked the presence of associative mismatches. These data support the hypothesis that CA(1) acts as a "comparator," detecting when memory for the past and sensory input in the present diverge.     

Left occipital lobectomy and the preangular anatomy of reading

Two patients had alexias after left occipital lobectomies. Case 1 was a 55-year-old man with a glioblastoma. At 4 months after surgery he could read slowly, but reading was neither efficient nor pleasant. Case 2 was a 19-year-old male who had a more restricted, medial occipital lobectomy for an encapsulated mesenchymal chondrosarcoma. The tumor did not invade brain initially, and the patient recovered efficient reading after 15 months. It is postulated that Case 2 was able to recover efficient reading because he still had a field of left ventrolateral occipitotemporal cortex connected to homologous cortex on the right.     

The nonverbal manifestations of cognitive processes in clinical listening

Nonverbal behaviors were observed during communicative sequences in videotaped clinical interviews. The interviews were conducted by two groups of physicians-in-training with contrasting cognitive profiles as determined by well-known laboratory tasks prior to the interviews. In each phase of the communicative sequences, significant differences emerged between the two groups for various types of nonverbal behaviors. Differences also emerged between the two groups of interviewers in their questioning patterns and in the nature of the narrative elicited from their interlocutors. A correlational analysis revealed consistent patterns of behaviors across phases of the communicative sequences. The findings provide additional evidence for the intimate connection between nonverbal behavior and cognitive activity and point to nonverbal behaviors as objective measures of the processes underlying clinical listening.     

A challenging intervention with maternal anxiety: Babies requiring surgical correction of a congenital anomaly after missed prenatal diagnosis

The objective of this study is to assess the impact on maternal anxiety of a short‐term intervention in a particularly stressful situation, such as a surgical anomaly diagnosed only at birth after repeated negative prenatal ultrasounds. The patients were 30 mothers of babies requiring surgical correction of a congenital anomaly who were randomly assigned to an intervention (N = 16) or control (N = 14) group. The intervention group received standard care plus short‐term intervention that included weekly meetings with the psychologist and weekly team meetings. The control group received only standard care available on the Neonatal Surgery Unit. The main outcome measure was maternal anxiety levels, assessed at birth and on discharge with the Spielberger State–Trait Anxiety Inventory (STAI–S). Statistical comparisons were made, and no significant differences were found at birth in the STAI–S scores of the two groups. At discharge, the intervention group exhibited a much lower STAI–S score than the group without short‐term intervention. The authors concluded that psychological counseling for parents of newborn babies has been shown to be helpful. However, the impact of such assistance was shown to be particularly beneficial for parents facing the emotional stress of their children requiring unexpected surgical corrections of congenital anomalies at birth. Therefore, the presence of a psychologist, as part of the standard care of newborns requiring surgical correction, is recommended. ©2003 Michigan Association for Infant Mental Health.     

老龄化社会中ICU的困境面面观

高龄、且长期罹患多种疾病的患者,病情一旦进展到必须接受有创机械通气的阶段,则康复机会极小,生存质量极差,不应划入急性可逆性范畴;而应转入社区医疗,加强现代健康观、死亡观教育,提供多种解决方案,不必一概纳入全方位支持监护系统,更不应常规给予有创机械通气、CRRT、亚低温治疗、肠内及肠外营养作为长期替代治疗。     

老龄化社会中ICU的困境面面观

高龄、且长期罹患多种疾病的患者,病情一旦进展到必须接受有创机械通气的阶段,则康复机会极小,生存质量极差,不应划入急性可逆性范畴;而应转入社区医疗,加强现代健康观、死亡观教育,提供多种解决方案,不必一概纳入全方位支持监护系统,更不应常规给予有创机械通气、CRRT、亚低温治疗、肠内及肠外营养作为长期替代治疗.