1,721,141 research outputs found
Effect of spatiotopic factors on bisection of radial lines
No full textAbstract Under visual guidance normal subjects usually misbisect radial lines farther than the true midpoint (distal bias). We investigated whether this distal bias is constant across the peripersonal space or it varies by varying the distance of the stimulus from the subject. Subjects were asked to bisect radial lines presented below eye level either in the near or far peripersonal space. The results showed an increase of distal bias in the far-space. This Wnding suggests that the inXuence of spatial factors on bisection of radial lines is not constant across the peripersonal space. Distal bias increases as a function of the distance of the stimulus from the subject, according to a spatiotopic processing scheme
Utilization behavior: What is known and what has to be known
Full text linkSince the first description by Lhermitte (1983), the utilization behavior (UB) still represents an enigma for behavioral neurology and neuropsychology. Recent findings shed some light on new frameworks for interpreting this interesting phenomenon. Functional neuroanatomical basis is still unclear, although recent advances in neuroimaging techniques have contributed to a better understanding of the syndrome. An important and promising step is given by shifting researcher’s attention from frontoparietal to intrafrontal mechanisms. From a cognitive standpoint, three models have been proposed. However, a comprehensive account for the UB neurobehavioral complexity is still lacking. Aims of this paper are to briefly review the reported cases of utilization behavior (UB) and to describe the putative neurological mechanisms underlying UB. Furthermore, the cognitive models proposed to interpret UB will be summarized. For clinical purposes, features suitable for distinguishing UB from other neurobehavioral symptoms will be briefly described
Influenza esercitata da distrattori visivi sulla bisezione di linee: differenze legate all'età
No full text
Anosognosia for memory deficit in amnestic mild cognitive impairment and Alzheimer's disease
No full textAbstract Objective: to investigate patterns of anosognosia for memory deficit in subjects with amnestic mild cognitive impairment (MCI) and Alzheimer's disease (AD). Methods: the study involved twenty-five subjects with MCI, 15 with mild AD and 21 normal controls (NC). Subjective rating of memory functioning was assessed with a six-items questionnaire that was administered before and after memory testing; an informant version from caregivers gave a discrepancy score (SRD). In the Objective Judgement (OJ) task, aiming to evaluate memory-monitoring abilities, subjects were requested three times to predict their memory performance in recalling words from a list of ten. Then they had to recall the words. Prediction accuracy was computed by subtracting the predicted performance from the actual performance. Results: MCI and AD showed reduced awareness of memory difficulties at the SRD and did not change their rating of these difficulties after memory testing. At the OJ task, MCI and AD consistently overestimated their memory performances as compared with NC. The SRD and OJ measures were not correlated with some patients being impaired on only one measure. Only the OJ measure was significantly related to executive functioning. Conclusions: AD and MCI subjects show unawareness for memory deficit and significant memory-monitoring disorder. This confirms that anosognosia is an important symptom of MCI. Similarities of patterns of impaired awareness between AD and MCI supports the view of a continuum of the anosognosia phenomenon in MCI and A
Error pattern in an autistic savant calendar calculator
No full textSpecial ability in computing the day of the week from given dates was observed in a 18 years old male, L.E., suffering from autism. Neuropsychological testing revealed severe deficits in all cognitive domains and poor explicit knowledge of calendar structure. The subject scored well above the chance level on dates of the past and future decades. Error rate and response latency increased with temporal remoteness of dates. Most of errors were in indicating the weekday before or after that of date stimulus. The performance and error pattern suggest that L.E. used ‘‘encapsulated’’ computation algorithm(s) for the day of week task
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
- …
