Object-centred orienting of attention

Abstract

In the present study two experiments are reported in which the subjects were presented on a computer screen with a two-dimensional line drawing that is perceived as a three-dimensionalobject (i.e. a cube). The cube could be seen as stationary, as rotating about the y-axis (Experiment 1A), or as rotating about the x-axis (Experiment 1B). The subject's attention was directed by a visual precue to a vertex of the cube. As the cube rotated, the precued location moved in viewer-centred co-ordinatesm, but the local feature of the cube that had been precued (i.e. a given vertex) did not move in object-centred co-ordinates. The imperative stimulus was presented at the precued location (valid trials) or at an uncued location (invalid trials). Precued and uncued locations were determined in object-centred coordinates. The subjects were required to signal detection of the imperative stimulus by pressing the space bar on the computer keyboard. There were also control conditions in which the procedure was identical, but the cube was not visible. When the cube was visible, valid trials were faster than invalid trials, regardless of whether it was seen as stationary or rotating. It was concluded that the subjects could allocate spatial attention in object-centred co-ordinates. There wer also indications that responses for invalid trials were faster when the imperative stimulus was presented on the same face as the precue than when it was presented on the opposite face.     

Hemispheric prevalence in acoustical attention

Two experiments were conducted in which monaural clicks were presented to the right or left ear preceded by biaural verbal (Experiment 1) and musical (Experiment 2) warnings. After the “neutral” warnings, the clicks could be presented to the right or left ear equally often (50%); after the warnings which directed the attention to the left or right ear, the clicks could be presented to either the “expected” (67%) or to the “unexpected” (33%) ear. In Experiment 1 there was a cost effect for the “unexpected” ear and reaction times were significantly faster when the clicks were presented to the right ear. In Experiment 2, the musical warnings brought about a cost effect while no significant ear advantage was observed.     

Delirium and isolated angiitis of the central nervous system: a case report and review

Central nervous system (CNS) vasculitis is a rare entity, especially when it occurs in isolation; it is seen more commonly as part of a multisystem vasculitis. Common presenting symptoms include persistent headache, encephalopathy, and multifocal signs. We discuss the case of a 68-year-old female who presented twice in 1 month with confusion and choreaform movements. Extensive workup was negative for a connective tissue disease or other conditions in the differential, including neurosarcoidosis, Creutzfeldt-Jakob disease, and neurosyphilis. The only significant findings were elevated erythrocyte sedimentation rate, inflammatory signs in the CNS, and diffuse slowing of the electroencephalogram. A presumptive diagnosis of isolated angiitis of the central nervous system (IACNS) was made and the patient was successfully treated with steroids. She recovered fully with no residual symptoms. The diagnosis of IACNS is often difficult given there are no definitive laboratory investigations or pathognomonic presentation. However, a series of signs, symptoms, and laboratory findings have been proposed that are helpful in making the diagnosis. To our knowledge, IACNS presenting primarily with delirium has not been previously reported in the literature. The diagnosis of IACNS is purely speculative for this case, as the gold standard for diagnosis, a leptomeningeal cortical biopsy, was not performed.     

Psychometric properties of the Reynolds Child Depression Scale in community and clinical samples

The factor structure of the Reynolds Child Depression Scale (RCDS; Reynolds, 1989), analyzed by confirmatory factor analysis and the scale's psychometric characteristics in a sample of 315 participants (140 boys and 175 girls) and a clinical sample of 62 participants (37 boys and 25 girls) between 10 and 12 years old, are presented. Two models are tested with confirmatory factor analysis: a one-factor model and a five-factor model. Both models show a good fit, but the one-factor model was chosen because it is the most parsimonious. The reliability coefficient ranged from .87 (at test) to .89 (at retest) in the community sample, and was .90 in the clinical sample (at test). Test-retest reliability was .66 in the community sample. Concurrent validity with other self-reports that measure depressive symptomatology was high, both in the community sample (.76) and the clinical sample (.71). There were no significant sex differences but there were differences due to age (school grade).     

Fear of The Mind. The Annihilating Power of the Gaze

The concern for the annihilating power of the gaze is not part of the Freudian discourse, but represents one of the most valuable contributions of phenomenology to psychoanalysis. When clear boundaries between the self and the others are not yet established, the gaze is experienced as a disembodied force that radiates from the eyes and can dangerously penetrate into the mind. In this regard, the body or parts of it can be used as a shelter. If the external body is not sufficiently cathected, its sheltering function is also decreased, to the point that the body is experienced as transparent, and the most intimate feelings and thoughts become dangerously available to the others. In primitive societies this situation is experienced as the danger of losing the soul. The unconscious fantasy of obstructing the sight can be used to neutralize the annihilating power of the gaze by introducing an artificial barrier between the minds. In dreams and in other expressions of the unconscious, the black color might hint at such an artificial barrier. What is then blackened are moments of the meeting of the mind that cannot be introjected. Blind spots in the perception of the mind of the other as well as in the perception of the self are a specific consequence of this kind of defense.     

Grammatical category-specific deficits in bilingual aphasia

We report the naming performance of an early and highly proficient Spanish-Catalan bilingual (JPG) suffering from Primary Progressive Aphasia (PPA). JPG's performance revealed a grammatical category-specific deficit, with worse performance in naming verbs than nouns. This dissociation was present in oral and written naming and in his two languages, and it seems to stem from damage to, at least, the lexical level. Despite the fact that JPG's performance was qualitatively very similar across languages, his second language seemed to be more affected than his first language. These results indicate that the cortical organization of the two languages of highly proficient bilinguals follow similar organizational principles, one of this principles being grammatical class.     

Dopaminergic modulation of prospective memory in Parkinson's disease

Growing interest is present in literature on the study of prospective memory functioning in Parkinson's disease (PD). Current data indicate that prospective memory may be impaired in PD and a relationship with general executive dysfunctioning has been suggested. However, although the dopamine dependency of cognitive dysfunction in PD has been widely investigated, poor is known on the dopaminergic modulation of PM. In the present study we explored the effect of acute administration of levodopa on the performance of a PD sample (n=20) in a time-based prospective memory task. PD patients were evaluated in the morning after a 12-hour therapy wash-out in two experimental conditions: i) after levodopa assumption ("on"); ii) without drug administration ("off"). The experimental task required to execute three uncorrelated actions after 10' for three consecutive trials. Distinct scores for the spontaneous recall of the intention to perform the actions (prospective component) and for the correct execution of the actions (retrospective component) have been computed. Results showed that in the "off" condition PD patients were selectively impaired on the prospective component of the task. However, L-dopa administration significantly improved PD patients' performance actually restoring the prospective memory deficit. These results support a critical role of dopaminergic modulation in prospective memory processes in PD patients, possibly through the replacement of dopamine levels in fronto-striatal pathways.     

Right—left prevalence effect with horizontal and vertical effectors

We investigated the right-left prevalence effect in spatial compatibility tasks by assessing subjects’ performance on a two-dimensional task in which both the horizontal and vertical spatial dimensions were task relevant. Two experiments were performed, in which stimulus-response mappings were one-dimensional (Experiment 1) and two-dimensional (Experiment 2). The subjects responded by using either horizontal or vertical effectors to stimuli appearing in four possible locations. With the one-dimensional mapping, the spatial compatibility effect was present only in the dimension relevant to the mapping. With the two-dimensional mapping, the horizontal compatibility effect was always present, whereas the vertical compatibility effect was present only when vertical effectors were used. This pattern of results indicates that horizontal coding takes place with either horizontal or vertical effectors, whereas vertical coding takes place only when vertical effectors are used.