Biomedical subjects

Cesare Cornoldi

Publications and source records attributed to Cesare Cornoldi.

At least 19 recordsLinked to original sources

PubMed2007

Aging and the intrusion superiority effect in visuo-spatial working memory.

This study investigated the active component of visuo-spatial working memory (VSWM) in younger and older adults testing the hypotheses that elderly individuals have a poorer performance than younger ones and that errors in active VSWM tasks depend, at least partially, on difficulties in avoiding intrusions (i.e., avoiding already activated information). In two experiments, participants were presented with sequences of matrices on which three positions were pointed out sequentially: their task was to process all the positions but indicate only the final position of each sequence. Results showed a poorer performance in the elderly compared to the younger group and a higher number of intrusion (errors due to activated but irrelevant positions) rather than invention (errors consisting of pointing out a position never indicated by the experiementer) errors. The number of errors increased when a concurrent task was introduced (Experiment 1) and it was affected by different patterns of matrices (Experiment 2). In general, results show that elderly people have an impaired VSWM and produce a large number of errors due to inhibition failures. However, both the younger and the older adults' visuo-spatial working memory was affected by the presence of activated irrelevant information, the reduction of the available resources, and task constraints.

Adolescent↗

PubMed2006

Evidence for a double dissociation between spatial-simultaneous and spatial-sequential working memory in visuospatial (nonverbal) learning disabled children.

The paper describes the performance of three children with specific visuospatial working memory (VSWM) impairments (Study 1) and three children with visuospatial (nonverbal) learning disabilities (Study 2) assessed with a battery of working memory (WM) tests and with a number of school achievement tasks. Overall, performance on WM tests provides evidence of a double dissociation between spatial-simultaneous processes, underpinning the memorization item positioning in a spatial configuration, and spatial-sequential processes, which allow memorization of the presentation order. In both groups of children of the two studies, a selective impairment either on spatial-sequential or on spatial-simultaneous working memory tasks was observed. These data support the existence of -simultaneous and -sequential modality-dependent processes in visuospatial working memory and confirm the importance of distinguishing between different subtypes of visuospatial (nonverbal) learning-disabled children.

Child↗

PubMed2006

Why Cyclops could not compete with Ulysses: monocular vision and mental images.

The present research demonstrates that the limitations of congenitally blind people in tasks requiring the processing of mental images are specifically related to the absence of binocular vision and not to the absence of vision per se. We contrasted three different groups of participants: sighted; visually impaired, with reduced binocular vision; monocular, with a normal visual acuity although in one eye only. Visually impaired participants (i.e. blurred vision) show a pattern of performance comparable to that of the sighted. In contrast, monocular participants show a similar pattern of performance to congenitally blind individuals despite being able to see perfectly well. These results shed new light on the relationship between perception and imagery and on the characteristics of sequential and simultaneous processes in the human brain.

Adult↗

PubMed2006

Intrusion errors in visuospatial working memory performance.

This study tested the hypothesis that failure in active visuospatial working memory tasks involves a difficulty in avoiding intrusions due to information that is already activated. Two experiments are described, in which participants were required to process several series of locations on a 4 x 4 matrix and then to produce only the final location of each series. Results revealed a higher number of errors due to already activated locations (intrusions) compared with errors due to new locations (inventions). Moreover, when participants were required to pay extra attention to some irrelevant (non-final) locations by tapping on the table, intrusion errors increased. Results are discussed in terms of current models of working memory functioning.

Adolescent↗

PubMed2006

What people believe about memory.

Two representative samples of adult Norwegians (n=2000) were asked a set of general and specific questions regarding their beliefs and opinions about human memory. The results indicate that on many questions, such as time of the earliest memories, inhibiting effects of collaboration, and memory for dramatic versus ordinary events, the views of the general public concurred with current research findings, and people in general had realistic views about their own memory performance. On other questions, such as the reliability of olfactory as compared with visual and auditory memory, the memory of small children in comparison with that of adults, the likelihood of repression of adult traumatic memories, and on more general questions such as the possibility of training memory and the capacity limitations of long-term memory, a large proportion of the participants expressed views that are less supported by scientific evidence. Implications of these findings are briefly discussed.

Adult↗

PubMed2006

Visual experience is not necessary for efficient survey spatial cognition: evidence from blindness.

This study investigated whether the lack of visual experience affects the ability to create spatial inferential representations of the survey type. We compared the performance of persons with congenital blindness and that of blindfolded sighted persons on four survey representation-based tasks (Experiment 1). Results showed that persons with blindness performed better than blindfolded sighted controls. We repeated the same tests introducing a third group of persons with late blindness (Experiment 2). This last group performed better than blindfolded sighted participants, whereas differences between participants with late and congenital blindness were nonsignificant. The present findings are compatible with results of other studies, which found that when visual perception is lacking, skill in gathering environmental spatial information provided by nonvisual modalities may contribute to a proper spatial encoding. It is concluded that, although it cannot be asserted that total lack of visual experience incurs no cost, our findings are further evidence that visual experience is not a necessary condition for the development of spatial inferential complex representations.

Adult↗

PubMed2005

Left mediotemporal structures mediate the retrieval of episodic autobiographical mental images.

The aim of this functional magnetic resonance imaging (fMRI) study was to investigate the neuroanatomical substrates associated with the process of mental generation of specific (i.e., exemplar) and episodic autobiographical (i.e., an image of a unique life episode connected with an object) images. The fMRI paradigm in this experiment included a non-image generation baseline and two activation conditions requiring the generation of either specific or episodic autobiographical images. Image generation times and brain activation were recorded. Behavioral results showed that generating specific mental images took significantly less than generating episodic autobiographical images. Individuals generated specific images that were well distinct from the episodic autobiographical ones, semantic in nature without an episodic reference. Episodic autobiographical images did not show a significant bias towards preferential retrieval from any particular life period but were retrieved from across the entire life span. Conjunction analysis of the fMRI data showed that the two image generation conditions significantly activated a common set of neural structures, including mediofrontal areas. This shared pattern of activation might be the result of an underlying similar format and characteristics (e.g., richness in details) between the two types of images and might reflect the involvement of similar cognitive processes. Distinct patterns of significant activation were also present. Activation in the right parietal regions, cuneus, precuneus and left temporal regions was associated solely with the generation of specific images. Regions more specifically devoted to episodic memory retrieval and imagery, such as the left parahippocampal gyrus and precuneus, and the posterior cingulate cortex bilaterally, were significantly activated exclusively by the generation of episodic autobiographical images.

Adult↗

PubMed2005

Difficulties in the control of irrelevant visuospatial information in children with visuospatial learning disabilities.

This research tested the hypothesis that children's difficulties in visuospatial working memory (VSWM) may mirror difficulties found with verbal working memory tasks in other categories of children. Two experiments compared the number of correct responses and errors in groups of visuospatial learning disabled children (VSLD) and Controls who were engaged in an active task testing visuospatial working memory. Children were presented with sequences of positions on a 4x4 matrix and were subsequently asked to remember only the last position of each series. In the first Experiment, VSLD children showed greater difficulty in both recalling the last positions and avoiding the irrelevant non-final positions compared with Controls. In the second experiment children of different age groups (second-graders and fifth-graders) were also required to stress, by tapping on the table, the irrelevant positions whenever the experimenter pointed to a coloured cell. Results showed that the number of errors was greater in the VSLD children, and the pattern of errors differed with their grade. In particular, the increased activation of stressed locations produced an increase of correct responses, and a decrease of intrusion errors, except in the case of VSLD second-graders, who made a higher number of intrusions for stressed than for unstressed locations. Results confirm that children with VSLD show a specific deficit in active VSWM, and in particular, in the ability to avoid intrusion errors. In general, the control of irrelevant information appears critical for a successful use of VSWM.

Adolescent↗

PubMed2005

Updating in working memory: a comparison of good and poor comprehenders.

In this research, we examined the relation between reading comprehension and success in a working memory updating task. We tested the hypotheses that poor comprehenders' deficiencies are associated with a specific difficulty in the working memory updating process, particularly in controlling for information that is no longer relevant. In the first experiment, groups of poor and good comprehenders, ages 8-11 years, were administered a working memory updating task. In the second experiment a year later, a subgroup of participants involved in the first experiment was tested with a different updating task. In both experiments, poor comprehenders had less accurate recall performance and made more intrusion errors than did good comprehenders. Moreover, distinguishing intrusion errors on the basis of their permanence in memory, we found that poor comprehenders were more likely to intrude items that were maintained longer in memory than were good comprehenders. This type of error predicted reading comprehension abilities better than did working memory recall. This suggests that the relation between reading comprehension and working memory is mediated by the ability to control for irrelevant information.

Child↗

PubMed2005

Different neuronal pathways support the generation of general and specific mental images.

The aim of this functional magnetic resonance imaging (fMRI) study was to investigate the neural correlates associated with the generation of general (i.e., prototypical) and specific (i.e., exemplar) visual mental images from concrete nouns. The fMRI paradigm included a non-imagery baseline, and two activation conditions requiring the generation of either general or specific images. Image generation times and brain activation were recorded. Analysis of the behavioral results showed that generating general images took less than the specific ones. The comparison of each activation condition with the baseline showed significant increase in brain activation in left frontal areas in both kinds of images, with the additional involvement of the posterior cingulate cortex during the generation of specific images. When the two activation conditions were contrasted with each other and masked for their respective comparison with baseline, significant activation was found in right frontal areas for general mental images, whereas a significant increase in activation in the left superior frontal region and the right thalamus was detected during the generation of specific mental images. These findings suggest that general and specific mental images are generated with the support of two different neural pathways. The generation of general images seems to involve brain areas associated with the formation of global gestalt-like images (areas in the right hemisphere), while the generation of specific mental images appears to require additional support from areas involved in the retrieval of visual details (i.e., the right thalamus).

Adult↗

PubMed2004

Spatial memory and integration processes in congenital blindness.

The paper tests the hypothesis that difficulties met by the blind in spatial processing are due to the simultaneous treatment of independent spatial representations. Results showed that lack of vision does not impede the ability to process and transform mental images; however, blind people are significantly poorer in the recall of more than a single spatial pattern at a time than in the recall of the corresponding material integrated into a single pattern. It is concluded that the simultaneous maintenance of different spatial information is affected by congenital blindness, while cognitive processes that may involve sequential manipulation are not.

Adolescent↗

PubMed2004

What happens to information to be suppressed in working-memory tasks? Short and long term effects.

The study explored, from an individual differences point of view, what happens to information to be suppressed in a working-memory task at short and long term. In particular, it was examined whether control mechanisms of irrelevant information in working memory imply their complete elimination from working memory or just the modulation of their activation. To this end, we compared the fate of irrelevant information in groups of subjects with high and low reading comprehension (Experiments 1 and 2) and subjects with high and low working memory (Experiments 1, 2, 3, and 4). All the experiments presented a working-memory task devised by De Beni, Palladino, Pazzaglia, and Cornoldi (1998), which required participants to process lists of words, to tap when a word from a particular category was presented, and then to recall only the last items in each list. Results confirmed that participants with high reading comprehension also have higher working memory and make less intrusion errors due to irrelevant items that have to be processed but then discarded. Furthermore, it was found that participants with low working memory have slightly better implicit (Experiment 1) and explicit memory (Experiments 3 and 4) of highly activated irrelevant information. Nevertheless, in a long-term recognition test, participants with high and low reading comprehension/working memory presented a similar pattern of memory for different types of irrelevant information (Experiment 2), whereas in a short-term memory recognition test, low-span participants presented a facilitation effect in the time required for the recognition of highly activated irrelevant information (Experiment 4). It was concluded that efficient working-memory performance is related to the temporary reduction of activation of irrelevant information but does not imply its elimination from memory.

Adult↗

PubMed2004

Verbal and visuospatial working memory deficits in children with Down syndrome.

The hypothesis that deficits of children with Down syndrome on working memory tasks are more evident the higher the control required and for verbal than visuospatial tasks was tested. Two groups of children, one with Down syndrome, who ranged in age from 7 to 18, and a control group were assessed with batteries of verbal and visuospatial working memory tests requiring different levels of control. On tasks requiring low control, children with Down syndrome showed impairment of verbal but not visuospatial working memory tasks. As the requirement for control increased, they showed greater impairment on both tasks. Children with Down syndrome were comparatively better in visuospatial than verbal tasks. Implications of these results for working memory models and the role of working memory in intelligence were discussed.

Adolescent↗

PubMed2003

Visual but not spatial working memory deficit in children with spina bifida.

Twenty children with spina bifida and twenty controls were assessed on a battery of visuospatial working memory tests. Children with spina bifida performed as well as the control group in the visuospatial test and in the forward and backward versions of the Corsi test, but were impaired in the 'House Visual Span.' This test, designed in our lab, provides specific information regarding visual ability to discriminate between pictorial targets and lures, and requires specific visual processing of stimuli. These results are discussed in terms of working memory models and are viewed as supporting the distinction between the visual and spatial components of working memory.

Adolescent↗

PubMed2003

Arithmetic difficulties in children with visuospatial learning disability (VLD).

Eighteen children with visuospatial learning disability (VLD) were compared to normal control children on a series of numerical and calculation tasks. Oral and written (dictated) calculation was assessed and operations differed not only in terms of the type of number processing requirements but also in terms of their visuospatial demand. The aim was to disentangle errors due to visuospatial processing failure from those deriving from incorrect knowledge of calculation procedures. Results showed that all children had relatively good knowledge of numerical facts and there was no statistical difference between the groups. No group difference was found in the overall performance in oral calculation, but a significant difference was present when the children were required to complete the operations in writing, with the VLD group achieving poorer performance than the controls. Furthermore, VLD children had greater difficulties when operations required borrowing or carrying; this was particularly problematic in subtractions. The results indicate that VLD children do not have a generalised problem with calculation per se or number manipulation in general. Rather their problems concern dealing with some processes that govern calculation especially those loading on visuospatial abilities.

Analysis of Variance↗

PubMed2002

Remembering changes: repetition effects in face recollection.

Two experiments examined effects of repetition and change on states of awareness in face recognition. Participants studied repeatedly presented photographs of faces, with the second presentation following either immediately after the first presentation (massed repetition) or following six intervening items (spaced repetition). To manipulate perceptual change, each repeated face was either identical or a mirror image of the first presentation. Subsequently, when recognising a face, participants indicated whether they consciously recollected its prior occurrence ("remembering") or recognised it on the basis of familiarity ("knowing"). Changes in appearance between repeated faces enhanced remember, but not know, responses, and these effects were accentuated for spaced, rather than massed, repetition. These findings suggest that distinctiveness of encoding supports the phenomenological experience of conscious remembering.

Adult↗

PubMed2002

Aging and effect of predictability on reality monitoring.

This study compared the direction of source confusions and the effect of predictability on reality monitoring for internally generated information and externally derived information in younger (mean age 19-25) and older (mean age 70-85) adults. Participants were invited to listen to the conclusions of simple stories or to generate and imagine them. Conclusions could be either highly predictable (Experiment 1) or unpredictable (Experiment 2). The change in predictability produced changes in the direction of source confusions only in older adults. When a story ended in a predictable way, older adults attributed to imagination conclusions that were actually perceived, whereas the pattern of confusions tended to reverse with unpredictable stories.

Adult↗

PubMed1988

Imagery limitations in totally congenitally blind subjects.

Research on totally blind subjects performing tasks that involve visual imagery has often shown that they do not behave differently from matched sighted subjects, even when their blindness is congenital. If visual imagery is based on visual perception, such tasks may not required visual imagery. In the present article visual images are considered as representations maintaining some properties of visible objects and constructed on the basis of information from various sources. Owing to the absence of visual experience, the limitations of such representations are explored in a series of experiments requiring memorization of single nouns, pairs of nouns, or triplets of nouns associated with a cue noun. Recall by blind subjects was impaired when multiple interactive images (with noun pairs and triplets) are formed. The poorer recall of blind subjects reflected also loss of order information. Recall was better for both groups with locative noun cues and high-imagery targets.

Adolescent↗