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R Dell'Acqua

Publications and source records attributed to R Dell'Acqua.

9 recordsLinked to original sources
PubMed2001

Selective effect of closed-head injury on central resource allocation: evidence from dual-task performance.

Two dual-task experiments are reported bearing on the issue of slower processing time for severe chronic closed-head injury (CHI) patients compared to matched controls. In the first experiment, a classical psychological refractory period (PRP) paradigm was employed, in which two sequential stimuli, a pure tone and a colored dot, were presented at variable stimulus onset asynchronies (SOAs), each associated with a distinct task. The task on the tone required a speeded vocal response based on pitch, and the task on the colored dot required a speeded manual response based on color. In the second experiment, either one or three masked letters was presented, followed by a pure tone at variable SOAs. The task on the letters required a delayed report of the letters at the end of each trial. The task on the tone required an immediate manual response based on pitch. In both experiments, both CHI patients and matched controls reported an SOA-locked slowing of the speeded response to the second stimulus, a PRP effect. The PRP effect was more substantial for CHI patients than for matched controls, suggesting that a component of the slower processing time for CHI patients was related to a selective increase in temporal demands for central processing of the stimuli.

Acoustic Stimulation↗
PubMed2000

Naming times and standardized norms for the Italian PD/DPSS set of 266 pictures: direct comparisons with American, English, French, and Spanish published databases.

The present study provides Italian normative measures for 266 line drawings belonging to the new set of pictures developed by Lotto, Dell'Acqua, and Job (in press). The pictures have been standardized on the following measures: number of letters, number of syllables, name frequency, within-category typically, familiarity, age of acquisition, name agreement, and naming time. In addition to providing the measures, the present study focuses on indirect and direct comparisons (i.e., correlations) of the present norms with databases provided by comparable studies in Italian (in which normative data were collected with Snodgrass & Vanderwart's set of pictures; Nisi, Longoni, & Snodgrass, 2000), in British English (Barry, Morrison, & Ellis, 1997), in American English (Snodgrass & Vanderwart, 1980; Snodgrass & Yuditsky, 1996), in French (Alario & Ferrand, 1999), and in Spanish (Sanfeliu & Fernandez, 1996).

Adult↗
PubMed2000

Visual encoding of patterns is subject to dual-task interference.

Two stimuli were presented at varying stimulus onset asynchronies (SOAs), with each stimulus associated with a distinct task. The first stimulus was a tone at one of either two or three frequencies. In two conditions, the task associated with a tone was either a speeded two-alternative discrimination (2AD), or a speeded three-alternative discrimination (3AD) based on the pitch of the tone. In a third condition, subjects were told to ignore the tone. The second stimulus was a briefly exposed study matrix of red and black squares followed by a mask. After a fixed delay, the mask was replaced by a test matrix that was either the same or different from the study matrix. The task associated with the matrices was to indicate, with no speed pressure, whether the study matrix and the test matrix were the same or different. Results from each speeded AD condition showed that subject's accuracy in the matrix task decreased as the SOA between the tone and the study matrix decreased. This effect was larger for the 3AD tone task than with a 2AD tone task. In addition, within each speeded AD condition, longer RTs in the tone task were associated with lower accuracy in the matrix task. None of these effects was evident when the subjects were told to ignore the tone. These results suggest that encoding visual information can be subject to significant capacity limitations imposed by cross-modal multitasking.

Adult↗
PubMed2000

Selective influence of second target exposure duration and task-1 load effects in the attentional blink phenomenon.

The purpose of the experiments was to constrain the locus of interference in the attentional blink (AB) paradigm. Two visual stimuli, T1 and T2, were shown 300 msec apart, and each was followed by a mask. T1 was an "H," an "S," an "&," or a blank field; T2 consisted of five letters. In Task1, blank fields and & characters could be ignored, whereas Hs and Ss had to be identified and reported. Task2 was always to report as many letters as possible from T2. Task2 performance was lower when T1 had to be reported, as expected from the attentional blink phenomenon (AB). The exposure duration of T2 was also manipulated. More letters could be reported as exposure duration was increased. However, this effect was additive with manipulations of Task1 processing load that produced the AB effect. Log-linear analyses assuming that effects of T2 exposure duration and Task1 load effects occur at functionally distinct stages of processing provided satisfactory fits to the results, suggesting that none of the AB effect occurs as early as those of T2 exposure duration. The results suggest that the locus of the AB effect is later than the stage(s) of processing affected by exposure duration.

Adult↗
PubMed1999

Unconscious semantic priming from pictures.

Three experiments examined the effects of unconsciously presented picture primes on semantic categorization and naming responses to both word and picture targets. Picture naming and word categorization responses to targets were faster and more accurate when the picture primes belonged to the same semantic category as the targets, so called priming effect. No priming was found when subjects performed a word reading task. When priming was evident, no difference was found between responses to targets that were nominally identical to primes (e.g. the picture of a lion followed by either the word LION or the picture of a lion) compared with nominally different targets from the same semantic category as the primes (e.g. the picture of an ELEPHANT followed by either the word LION or the picture of a lion). Responding did not differ significantly from chance when subjects were asked to categorize the primes as natural objects vs. artifacts or as meaningful vs. meaningless objects in three distinct forced-choice unspeeded tasks.

Adult↗
PubMed1998

The demonstration of short-term consolidation.

In a dual-task paradigm, a visual display (T1) containing characters (letters or symbols) was presented first, followed by an auditory signal (T2) at various stimulus-onset asynchronies (SOAs). A speeded response to T2 was required. When the information in T1 had to be recalled later, response times to T2 (RT2) were elevated at short SOAs and decreased as SOA was increased. The effects on RT2 were larger when there were more items to be remembered. We interpreted the results as evidence that encoding information into short-term memory (STM) involves a distinct process, which we call short-term consolidation (STC). The results suggested that STC has limited capacity and that it requires central processing mechanisms. Additional evidence suggested that no memory for T1 was formed in STM when STC was not engaged.

Adult↗
PubMed1989

In vivo and in vitro HeNe laser effects on phagocyte functions.

The goal of this work was to evaluate the effect of helium-neon (HeNe) laser irradiation on immunocompetent cells. We used the in vivo skin window method and in vitro granulocyte function tests. The study of cellular migration showed a marked decrease in vitro and in vivo in a dose-independent manner. Superoxide release was not modified by laser irradiation. The granulocyte's aggregation, when using PHA and PMA, presented a reduction that was statistically very significant, not as a subordinate dose. An increase of the release of ATP was demonstrated only at 4 joules and precedes granulocyte aggregation. When using Ca2+ ionophore A23187 as stimulus, laser irradiation at 1, 2 or 4J did not show any modification of granulocyte aggregation. The monoclonal antibody 60.1, which identifies a membrane antigen fundamental for aggregation and chemotaxis, is expressed in normal amounts on granulocyte membranes both before and after irradiation with a HeNe laser. In fact, Laser irradiation preferentially attacks the area of the cellular centrosome that determines a modification of cellular morphology. The electron microscope and immunofluorescence study with a monoclonal antibody have pointed out a disorganization of the microtubules. The alteration of some of the granulocyte functions is correlated to the damage in the centrioles. The granulocyte mitochondrial system and surface membrane remain intact, and this explains the normal production and release of free radicals. Further experiments are necessary to evaluate the clinical application of lasers in various diseases with immunophagocytic pathogenesis.

Adenosine Triphosphate↗
PubMed1985

Skin involvement in hemopathies: specific cutaneous manifestations of acute nonlymphoid leukemias and non-Hodgkin lymphomas.

The course of a hemopathy may be characterized by the appearance of cutaneous lesions. In such cases a correct histological investigation is needed, especially when the lesions have an aspecific appearance. It is important, therefore, to recognize the cases characterized by cutaneous involvement of typical systemic disease cells. Lymphomas and leukemias are the hemopathies which more frequently present specific and nonspecific cutaneous manifestations (with an approximate incidence of 3-40 and 6-50%, respectively). In the period 1977-1983 we examined 337 patients affected with acute nonlymphoblastic leukemia and 243 patients affected with non-Hodgkin lymphoma, in order to verify the incidence of specific cutaneous manifestations.

Acute Disease↗