Skip to main content

Carlo Umilta

Followers

136

Following

69

Co-authors

66

Public Views

Robert Lickliter

Florida International University

University of Kansas

Harvard University

Canadian University of Dubai

University of California, Merced

Julian Kiverstein

Academic Medical Centre/ Universiteit van Amsterdam

Kansas State University

Shaun Gallagher

University of Memphis

Universidade Federal do Rio Grande do Sul

University of Hertfordshire

Interests

Uploads

Papers by Carlo Umilta

Memória de longo prazo modulada pela memória de curto prazo Long term memory modulated by short term memory Memoria a largo plazo modulada por la memoria a corto plazo

by Luiz G Gawryszewski, Carlo Umilta, and Erick Conde

Resumo: Quando um estímulo ocorre aleatoriamente à esquerda ou à direita, a resposta é mais rápid... more Resumo: Quando um estímulo ocorre aleatoriamente à esquerda ou à direita, a resposta é mais rápida quando estímulo e resposta estão no mesmo lado (condição compatível) do que em lados opostos (condição incompatível). Na tarefa de Simon, embora a resposta seja selecionada pela forma (ou cor) do estímulo, a posição deste influencia o Tempo de Reação Manual (TRM). O efeito Simon corresponde à diferença entre as médias dos TRMs nas duas condições (incompatível e compatível). Neste trabalho, estudamos como uma tarefa prévia de compatibilidade realizada com um dedo indicador modula o efeito Simon. Vinte e oito voluntários realizaram uma tarefa de compatibilidade seguida pela tarefa de Simon. No grupo compatível (14 voluntários), encontramos um efeito Simon de 24 ms. No incompatível (14 voluntários), ocorreu um efeito Simon inverso de -16 ms. Estes resultados mostram uma modulação da memória de longo prazo por uma tarefa envolvendo a memória de curto prazo. Palavras-chave: Controle motor. Processos motores. Tempo de reação. Percepção espacial. Lateralidade.

Perceptual conditions necessary to induce change blindness

by Sandro Bettella and Carlo Umilta

Visual Cognition, 2003

... The ``geon'' theory (Hummel & Biederman, 1992), for instance, codes real-world ... more

Simultaneous lightness contrast induced by global factors is reduced in brain damaged patients: A pilot study

by A. Lunardelli, Carlo Umilta, and antonia fumarola

Is Handedness Recognition Automatic? A Study Using a Simon-Like Paradigm

by Carlo Umilta and Alessia Tessari

Journal of Experimental …, Jan 1, 2005

The authors used a modified Simon task (J. R. Simon, 1969) to assess the automatic recognition of... more The authors used a modified Simon task (J. R. Simon, 1969) to assess the automatic recognition of handedness. Participants responded to the color of a circle in the center of the photograph of a right or a left hand, displayed in the center of the computer screen. A regular Simon effect was found for back views, whereas a reverse Simon effect was found for palm views. This pattern of results was found when the forearm was present (Experiment 2), when 1 finger at a time was rendered invisible (Experiment 3), and when the hands were connected to a body image (Experiment 4). When the hands were cut at the wrist, no effect emerged (Experiment 1). These findings suggest an automatic encoding of the relative position of the hand in relation to the body (imaginary or real) rather than the automatic encoding of handedness.

Rehabilitation of endogenous task shift processes in closed head injury patients

by Mariantonietta Mazzoldi and Carlo Umilta

Neuropsychological Rehabilitation, 2007

Automatic spatial association for luminance

by Valter Prpic, Tiziano Agostini, and Carlo Umilta

Attention, Perception, & Psychophysics, 2014

In the present study, we investigated whether luminance and the side of response execution are as... more In the present study, we investigated whether luminance and the side of response execution are associated, showing a SNARC-like effect (faster responses with the left hand for dark stimuli, and vice versa for light stimuli). A total of 30 participants were tested in two experiments. In Experiment 1, the association between space and the luminance of chromatic stimuli was directly tested (brightness discrimination). In Experiment 2, the same spatial association was tested indirectly (hue discrimination). The results showed that participants responded faster with their left hand to hues with lower luminance, and with their right hand to hues with higher luminance, in either the direct or the indirect task. The consistency of this association in both tasks demonstrates the automaticity of the SNARC-like effect for luminance.

Evidence for visuomotor priming effect

by Carlo Umilta and laila craighero

NeuroReport, Jan 1, 1996

Newborns' preference for goal-directed actions

by laila craighero, Francesca Simion, Irene Leo, and Carlo Umilta

Cognition, Jan 1, 2011

The central role of sensory-motor representations in cognitive functions is almost universally ac... more The central role of sensory-motor representations in cognitive functions is almost universally accepted. However, determining the link between motor execution and its sensory counterpart and when, during ontogenesis, this link originates are still under investigation. The aim of the present study is to investigate whether at birth this link is already present and 2-day-old newborns are able to discriminate between visual cues indicating goal-directed or non-goal-directed actions. Here, with a preferential looking technique, a hand grasping a ball was the observed movement and we orthogonally manipulated the three factors necessary to successfully reach the goal: a) presence of the ball, b) direction of the arm movement, and c) hand shaping. Results indicated that newborns orient more frequently and look longer at a hand shape for whole hand prehension but only when the movement is directed away from the body and toward the external world. In addition, newborns prefer the away from the body movement only when the object is present. We argue that newborns prefer a movement directed toward the external world only when it may develop into a purposeful movement because of the presence of the to-be-grasped object. Overall, our results support the existence of primitive sensory-motor associations since the first days after birth.

Action for perception: A motor-visual attentional effect.

by Carlo Umilta and laila craighero

Journal of Experimental …, Jan 1, 1999

The spatial representation of numerical and non-numerical ordered sequences: Insights from a random generation task

by Carlo Umilta, Maria Grazia Di Bono, and Marco Zorzi

The Quarterly Journal of Experimental Psychology, 2013

It is widely believed that numbers are spatially represented from left to right on the mental num... more It is widely believed that numbers are spatially represented from left to right on the mental number line. Whether this spatial format of representation is specific to numbers or is shared by non-numerical ordered sequences remains controversial. When healthy participants are asked to randomly generate digits they show a systematic small-number bias that has been interpreted in terms of &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;pseudoneglect in number space&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;. Here we used a random generation task to compare numerical and non-numerical order. Participants performed the task at three different pacing rates and with three types of stimuli (numbers, letters, and months). In addition to a small-number bias for numbers, we observed a bias towards &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;early&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; items for letters and no bias for months. The spatial biases for numbers and letters were rate independent and similar in size, but they did not correlate across participants. Moreover, letter generation was qualified by a systematic forward direction along the sequence, suggesting that the ordinal dimension was more salient for letters than for numbers in a task that did not require its explicit processing. The dissociation between numerical and non-numerical orders is consistent with electrophysiological and neuroimaging studies and suggests that they rely on at least partially different mechanisms.

Paying Attention through Eye Movements: A Computational Investigation of the Premotor Theory of Spatial Attention

by Matteo Lisi, Carlo Umilta, and Marco Zorzi

Journal of Cognitive Neuroscience

■ Growing evidence indicates that planning eye movements and orienting visuospatial attention sha... more ■ Growing evidence indicates that planning eye movements and orienting visuospatial attention share overlapping brain mechanisms. A tight link between endogenous attention and eye movements is maintained by the premotor theory, in contrast to other accounts that postulate the existence of specific attention mechanisms that modulate the activity of information processing systems. The strong assumption of equivalence between attention and eye movements, however, is challenged by demonstrations that human observers are able to keep attention on a specific location while moving the eyes elsewhere.

Why are left-right spatial codes easier to form than above-below ones?

by Carlo Umilta, Patrizio Tressoldi, and Carlo Marzi

Attention, Perception, & …, Jan 1, 1988

Previous studies have shown that spatial compatibility is stronger in the left-right than in the ... more Previous studies have shown that spatial compatibility is stronger in the left-right than in the above-below dimension. This left-right dominance cannot be attributed to a better representation ofthe effectors in left-right than in above-below locational codes or to the fact that incompatible left-right stimulus-response pairings cross the body midline, whereas incompatible above-below ones do not. proposedthat the left-right dominance should be attributed to the allocation of attention to the more difficult discrimination, which, in vision, is that concerning the left-right dimension. This attentional hypothesis was tested in the present study, in which we used the auditory modality. We reasoned that because in the auditory modality the above-below discriminations are more difficult than left-right ones, attention should be preferentially allocated to the former. Therefore, in audition an above-below dominance should replace the left-right dominance observed in vision. Experiments 1 and 2 showed a clear-cut compatibility effect in the auditory modality for both the left-right and above-below dimensions. Experiment 3 showed that spatial compatibility was still stronger for the left-right than for the above-below dimension. Since the left-right one proved to be the more discriminable dimension, this finding rules out the attentional hypothesis, at least in the version originally proposed.

Reference patterns and the process of normalization

by Sebastiano Bagnara and Carlo Umilta

Attention Perception & Psychophysics, 1984

Two experiments investigated the effect of reference patterns on the normalization process that i... more Two experiments investigated the effect of reference patterns on the normalization process that involves the visual code. In Experiment 1, the subjects had to classify as same or different two simultaneously presented letters. The upper letter was always in the upright position, whereas the lower letter could take six different orientations and was enclosed in a congruent triangular frame. The results for same responses showed reliable orientation-dependent effects which clearly implied an operation of normalization. In Experiment 2, the orientation of the upper letter and that of its frame varied orthogonally, whereas the lower letter was always presented within a congruent frame at six different orientations. The results showed that the normalization occurred with reference to the orientation of the upper letter, and that the congruent upper frame could speed up the comparison process only at certain orientations of the lower letter. It was concluded that the direction of normalization depends on the orientation of the upper letter, and that the effect of the frame is interpretable in terms of a display symmetry facilitation effect.

Transformation processes upon the visual code

by Sebastiano Bagnara and Carlo Umilta

Attention Perception & Psychophysics, 1982

Seven experiments investigated whether orientation-dependent latency functions for the visual cod... more Seven experiments investigated whether orientation-dependent latency functions for the visual code resemble those observed in studies of mental rotations of visual images. The subjects were required to perform "same-different" classifications of two simultaneously presented letters. The dependent variables considered were reaction time (RT) and accuracy. Experiments 1, 2, 4, 5, and 6 showed that subjects could correctly classify two different letters on the basis of the visual code without preceding transformations. Experiments 1,2, and 7 showed orientationdependent effects for "same" responses. It appeared, however, that orientation functions for the visual code were clearly different from those previously observed for visual images. In addition, the findings of Experiments 4,5, and 6 indicated that a frame that jointly rotated with the disoriented letters could eliminate the orientation-dependent effects for "same" responses. Experiment 7 showed that the results of Experiments 4, 5, and 6 must be attributed to the structural characteristics of the frame and not to a directional cue. The results of Experiment 3 seemed to demonstrate that transformations did not occur when the subjects used the phonetic code to classify the letters. Overall, the results of the seven experiments were considered to provide a demonstration of the importance of the distinction between the operations on visual images and those on the visual code.

Symmetry and similarity effects in the comparison of visual patterns

by Sebastiano Bagnara and Carlo Umilta

Attention Perception & Psychophysics, 1983

University 0/Parma, Parma, Italy Models to explain same-different RT disparity have variously emp... more University 0/Parma, Parma, Italy Models to explain same-different RT disparity have variously emphasized encoding or comparison processes. Of the latter, a dual-process holistic-analytic model that bears a similarity to a putative distinction between hemispheric processes has been proposed. Here two experiments test the models by employing simultaneous and successive matching whilevarying letter similarity, symmetry, and visual field of presentation. Same-different disparity is found regardless of delay, although it can be eliminated with appropriate similarity and symmetry manipulations. While visual field interacts with the same-different factor, it fails to do so in a manner consistent with the proposed hemispheric dichotomy. These and other results argue against encoding models of letter matching, and support a revised visual comparison model that incorporates dual processing and response criterion elements. However, the role of lateralized processes remains unclear.

Associative arithmetic with Boltzmann Machines: The role of number representations

by Suzanna Becker, Ivilin P Stoianov, Carlo Umilta, and Marco Zorzi

Artificial Neural Networks— …, Jan 1, 2002

CITATIONS 7 READS 49 4 authors: Some of the authors of this publication are also working on these... more CITATIONS 7 READS 49 4 authors: Some of the authors of this publication are also working on these related projects: Examining the impact of a complex dietary supplement on BDNF, neurogenesis, amyloid, tau and behaviour in the 3xTg-AD mouse model of Alzheimer's disease View project Evaluating and probing the basis of potential neuroprotective effects of complex dietary supplementation on a SH-SY5Y cell culture model of Alzheimer's disease pathology View project Ivilin Stoianov Aix-Marseille Université

Electrophysiological correlates of stimulus processing in change blindness

by Paolo Capotosto and Carlo Umilta

Experimental Brain Research, 2007

Change blindness-the inability to detect salient changes when a distractor event occurs simultane... more Change blindness-the inability to detect salient changes when a distractor event occurs simultaneously-has been repeatedly used to investigate the neural correlates of awareness. The fact that the N2pc, which is basically assigned to attention processing, has been observed only for detected changes in such tasks lead to the assumption that this component may also reXect awareness. In contrast to previous electrophysiological studies, we used mudsplashes (experiment 1) or a very short blank (experiment 2) to induce change blindness so that the change was not occluded. A change, regardless of its detection, elicited a reliable N2pc. Successful change detection, however, was reXected in an enhanced amplitude of the N2pc component. Thus, the N2pc cannot be taken as a direct correlate of awareness but rather as a marker for a process that is necessary but not suYcient for awareness. Taking into account the generation of the N2pc in extrastriate visual areas, this Wnding Wts nicely with the recent discussion about reentrant processing as a basis for visual awareness.

Strategie dell’ orientamento implicito dell’attenzione spaziale

by Gian Maria Galeazzi and Carlo Umilta

In this experiment, two rows of four boxes, one above and the other below the fixation point, wer... more In this experiment, two rows of four boxes, one above and the other below the fixation point, were displayed on a computer monitor. A cognitive numeric cue indicated one of the four external boxes, where the attention was to be directed. Stimuli, however, could occur in any of the eight boxes. The subject was instructed to respond to the imperative stimulus as fast as possible, regardless of its location. Four time intervals between cue and stimulus presentation (SOAs) were employed in order to disclose the route along which attention is moved. With the shortest SOA (100 msec) an indication that attention movements follow the cartesian/orthogonal axes was shown

Processing of irrelevant location information under dual-task conditions

by Carlo Umilta, Peter Wühr, and Jochen Müsseler

Psychological Research, 2006

This study deals with the problem of whether the processing of irrelevant location information in... more This study deals with the problem of whether the processing of irrelevant location information in Simon-like tasks is triggered exogenously or endogenously. In Experiment 1, the primary task required one to press, as fast as possible, a left-hand-side key or a right-hand-side key (R1) to the pitch of a tone that was presented binaurally (S1). The secondary task required identifying, without time constraints, a visual stimulus (S2) that appeared randomly to the left or right of screen center. Results showed that there was a correspondence (i.e., a cross-task Simon effect) between the location of R1 and the location of S2 when S2 was presented alone. The cross-task Simon effect became much smaller (and in-significant) when a noise stimulus was presented contralateral to S2. Experiment 2 was similar to Experiment 1, except that S2 appeared unpredictably in only one-third of the trials. Results of Experiment 2 closely replicated those of Experiment 1: the cross-task Simon effect was much greater when S2 was presented alone. Experiment 3 differed from Experiment 1 because S2 had to be processed in only one-third of the trials, in which its identity was to be reported. In the remaining two-thirds of the trials, participants could ignore S2. Results confirmed that the cross-task Simon effect was much greater when S2 was presented alone. In contrast, it did not matter whether S2 had to be processed or not.

Perceptual and attentional factors in encoding irrelevant spatial information

by Carlo Umilta, Peter Wühr, and Jochen Müsseler

Psychological Research Psychologische Forschung, 2009

Numerous studies found superior performance when the irrelevant location of a stimulus and respon... more Numerous studies found superior performance when the irrelevant location of a stimulus and response location were corresponding than when they were not corresponding (Simon eVect), suggesting that stimulus location is processed in an obligatory manner. The present study compared Simon eVects from the location of a relevant (i.e., to-be-attended) object to those from the location of an irrelevant (i.e., to-be-ignored) object. In four experiments, participants were presented with a rectangular frame and a square, with the relevant object in green or red color and the irrelevant object in gray or white color. Participants' task was to respond with a lateral keypress to the color of the relevant object, and we varied spatial correspondence between the location of the relevant or the irrelevant object and the response, respectively. Results consistently showed larger Simon eVects from the location of the relevant than from the irrelevant object, even when the irrelevant object was made very salient. These results suggest that location processing is largely conWned to relevant (i.e., attended) objects, stressing the role of attention shifts for location encoding.

Memória de longo prazo modulada pela memória de curto prazo Long term memory modulated by short term memory Memoria a largo plazo modulada por la memoria a corto plazo

by Luiz G Gawryszewski, Carlo Umilta, and Erick Conde

Resumo: Quando um estímulo ocorre aleatoriamente à esquerda ou à direita, a resposta é mais rápid... more Resumo: Quando um estímulo ocorre aleatoriamente à esquerda ou à direita, a resposta é mais rápida quando estímulo e resposta estão no mesmo lado (condição compatível) do que em lados opostos (condição incompatível). Na tarefa de Simon, embora a resposta seja selecionada pela forma (ou cor) do estímulo, a posição deste influencia o Tempo de Reação Manual (TRM). O efeito Simon corresponde à diferença entre as médias dos TRMs nas duas condições (incompatível e compatível). Neste trabalho, estudamos como uma tarefa prévia de compatibilidade realizada com um dedo indicador modula o efeito Simon. Vinte e oito voluntários realizaram uma tarefa de compatibilidade seguida pela tarefa de Simon. No grupo compatível (14 voluntários), encontramos um efeito Simon de 24 ms. No incompatível (14 voluntários), ocorreu um efeito Simon inverso de -16 ms. Estes resultados mostram uma modulação da memória de longo prazo por uma tarefa envolvendo a memória de curto prazo. Palavras-chave: Controle motor. Processos motores. Tempo de reação. Percepção espacial. Lateralidade.

Perceptual conditions necessary to induce change blindness

by Sandro Bettella and Carlo Umilta

Visual Cognition, 2003

... The ``geon'' theory (Hummel & Biederman, 1992), for instance, codes real-world ... more

Simultaneous lightness contrast induced by global factors is reduced in brain damaged patients: A pilot study

by A. Lunardelli, Carlo Umilta, and antonia fumarola

Is Handedness Recognition Automatic? A Study Using a Simon-Like Paradigm

by Carlo Umilta and Alessia Tessari

Journal of Experimental …, Jan 1, 2005

The authors used a modified Simon task (J. R. Simon, 1969) to assess the automatic recognition of... more The authors used a modified Simon task (J. R. Simon, 1969) to assess the automatic recognition of handedness. Participants responded to the color of a circle in the center of the photograph of a right or a left hand, displayed in the center of the computer screen. A regular Simon effect was found for back views, whereas a reverse Simon effect was found for palm views. This pattern of results was found when the forearm was present (Experiment 2), when 1 finger at a time was rendered invisible (Experiment 3), and when the hands were connected to a body image (Experiment 4). When the hands were cut at the wrist, no effect emerged (Experiment 1). These findings suggest an automatic encoding of the relative position of the hand in relation to the body (imaginary or real) rather than the automatic encoding of handedness.

Rehabilitation of endogenous task shift processes in closed head injury patients

by Mariantonietta Mazzoldi and Carlo Umilta

Neuropsychological Rehabilitation, 2007

Automatic spatial association for luminance

by Valter Prpic, Tiziano Agostini, and Carlo Umilta

Attention, Perception, & Psychophysics, 2014

In the present study, we investigated whether luminance and the side of response execution are as... more In the present study, we investigated whether luminance and the side of response execution are associated, showing a SNARC-like effect (faster responses with the left hand for dark stimuli, and vice versa for light stimuli). A total of 30 participants were tested in two experiments. In Experiment 1, the association between space and the luminance of chromatic stimuli was directly tested (brightness discrimination). In Experiment 2, the same spatial association was tested indirectly (hue discrimination). The results showed that participants responded faster with their left hand to hues with lower luminance, and with their right hand to hues with higher luminance, in either the direct or the indirect task. The consistency of this association in both tasks demonstrates the automaticity of the SNARC-like effect for luminance.

Evidence for visuomotor priming effect

by Carlo Umilta and laila craighero

NeuroReport, Jan 1, 1996

Newborns' preference for goal-directed actions

by laila craighero, Francesca Simion, Irene Leo, and Carlo Umilta

Cognition, Jan 1, 2011

The central role of sensory-motor representations in cognitive functions is almost universally ac... more The central role of sensory-motor representations in cognitive functions is almost universally accepted. However, determining the link between motor execution and its sensory counterpart and when, during ontogenesis, this link originates are still under investigation. The aim of the present study is to investigate whether at birth this link is already present and 2-day-old newborns are able to discriminate between visual cues indicating goal-directed or non-goal-directed actions. Here, with a preferential looking technique, a hand grasping a ball was the observed movement and we orthogonally manipulated the three factors necessary to successfully reach the goal: a) presence of the ball, b) direction of the arm movement, and c) hand shaping. Results indicated that newborns orient more frequently and look longer at a hand shape for whole hand prehension but only when the movement is directed away from the body and toward the external world. In addition, newborns prefer the away from the body movement only when the object is present. We argue that newborns prefer a movement directed toward the external world only when it may develop into a purposeful movement because of the presence of the to-be-grasped object. Overall, our results support the existence of primitive sensory-motor associations since the first days after birth.

Action for perception: A motor-visual attentional effect.

by Carlo Umilta and laila craighero

Journal of Experimental …, Jan 1, 1999

The spatial representation of numerical and non-numerical ordered sequences: Insights from a random generation task

by Carlo Umilta, Maria Grazia Di Bono, and Marco Zorzi

The Quarterly Journal of Experimental Psychology, 2013

It is widely believed that numbers are spatially represented from left to right on the mental num... more It is widely believed that numbers are spatially represented from left to right on the mental number line. Whether this spatial format of representation is specific to numbers or is shared by non-numerical ordered sequences remains controversial. When healthy participants are asked to randomly generate digits they show a systematic small-number bias that has been interpreted in terms of &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;pseudoneglect in number space&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;. Here we used a random generation task to compare numerical and non-numerical order. Participants performed the task at three different pacing rates and with three types of stimuli (numbers, letters, and months). In addition to a small-number bias for numbers, we observed a bias towards &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;early&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; items for letters and no bias for months. The spatial biases for numbers and letters were rate independent and similar in size, but they did not correlate across participants. Moreover, letter generation was qualified by a systematic forward direction along the sequence, suggesting that the ordinal dimension was more salient for letters than for numbers in a task that did not require its explicit processing. The dissociation between numerical and non-numerical orders is consistent with electrophysiological and neuroimaging studies and suggests that they rely on at least partially different mechanisms.

Paying Attention through Eye Movements: A Computational Investigation of the Premotor Theory of Spatial Attention

by Matteo Lisi, Carlo Umilta, and Marco Zorzi

Journal of Cognitive Neuroscience

■ Growing evidence indicates that planning eye movements and orienting visuospatial attention sha... more ■ Growing evidence indicates that planning eye movements and orienting visuospatial attention share overlapping brain mechanisms. A tight link between endogenous attention and eye movements is maintained by the premotor theory, in contrast to other accounts that postulate the existence of specific attention mechanisms that modulate the activity of information processing systems. The strong assumption of equivalence between attention and eye movements, however, is challenged by demonstrations that human observers are able to keep attention on a specific location while moving the eyes elsewhere.

Why are left-right spatial codes easier to form than above-below ones?

by Carlo Umilta, Patrizio Tressoldi, and Carlo Marzi

Attention, Perception, & …, Jan 1, 1988

Previous studies have shown that spatial compatibility is stronger in the left-right than in the ... more Previous studies have shown that spatial compatibility is stronger in the left-right than in the above-below dimension. This left-right dominance cannot be attributed to a better representation ofthe effectors in left-right than in above-below locational codes or to the fact that incompatible left-right stimulus-response pairings cross the body midline, whereas incompatible above-below ones do not. proposedthat the left-right dominance should be attributed to the allocation of attention to the more difficult discrimination, which, in vision, is that concerning the left-right dimension. This attentional hypothesis was tested in the present study, in which we used the auditory modality. We reasoned that because in the auditory modality the above-below discriminations are more difficult than left-right ones, attention should be preferentially allocated to the former. Therefore, in audition an above-below dominance should replace the left-right dominance observed in vision. Experiments 1 and 2 showed a clear-cut compatibility effect in the auditory modality for both the left-right and above-below dimensions. Experiment 3 showed that spatial compatibility was still stronger for the left-right than for the above-below dimension. Since the left-right one proved to be the more discriminable dimension, this finding rules out the attentional hypothesis, at least in the version originally proposed.

Reference patterns and the process of normalization

by Sebastiano Bagnara and Carlo Umilta

Attention Perception & Psychophysics, 1984

Two experiments investigated the effect of reference patterns on the normalization process that i... more Two experiments investigated the effect of reference patterns on the normalization process that involves the visual code. In Experiment 1, the subjects had to classify as same or different two simultaneously presented letters. The upper letter was always in the upright position, whereas the lower letter could take six different orientations and was enclosed in a congruent triangular frame. The results for same responses showed reliable orientation-dependent effects which clearly implied an operation of normalization. In Experiment 2, the orientation of the upper letter and that of its frame varied orthogonally, whereas the lower letter was always presented within a congruent frame at six different orientations. The results showed that the normalization occurred with reference to the orientation of the upper letter, and that the congruent upper frame could speed up the comparison process only at certain orientations of the lower letter. It was concluded that the direction of normalization depends on the orientation of the upper letter, and that the effect of the frame is interpretable in terms of a display symmetry facilitation effect.

Transformation processes upon the visual code

by Sebastiano Bagnara and Carlo Umilta

Attention Perception & Psychophysics, 1982

Seven experiments investigated whether orientation-dependent latency functions for the visual cod... more Seven experiments investigated whether orientation-dependent latency functions for the visual code resemble those observed in studies of mental rotations of visual images. The subjects were required to perform "same-different" classifications of two simultaneously presented letters. The dependent variables considered were reaction time (RT) and accuracy. Experiments 1, 2, 4, 5, and 6 showed that subjects could correctly classify two different letters on the basis of the visual code without preceding transformations. Experiments 1,2, and 7 showed orientationdependent effects for "same" responses. It appeared, however, that orientation functions for the visual code were clearly different from those previously observed for visual images. In addition, the findings of Experiments 4,5, and 6 indicated that a frame that jointly rotated with the disoriented letters could eliminate the orientation-dependent effects for "same" responses. Experiment 7 showed that the results of Experiments 4, 5, and 6 must be attributed to the structural characteristics of the frame and not to a directional cue. The results of Experiment 3 seemed to demonstrate that transformations did not occur when the subjects used the phonetic code to classify the letters. Overall, the results of the seven experiments were considered to provide a demonstration of the importance of the distinction between the operations on visual images and those on the visual code.

Symmetry and similarity effects in the comparison of visual patterns

by Sebastiano Bagnara and Carlo Umilta

Attention Perception & Psychophysics, 1983

University 0/Parma, Parma, Italy Models to explain same-different RT disparity have variously emp... more University 0/Parma, Parma, Italy Models to explain same-different RT disparity have variously emphasized encoding or comparison processes. Of the latter, a dual-process holistic-analytic model that bears a similarity to a putative distinction between hemispheric processes has been proposed. Here two experiments test the models by employing simultaneous and successive matching whilevarying letter similarity, symmetry, and visual field of presentation. Same-different disparity is found regardless of delay, although it can be eliminated with appropriate similarity and symmetry manipulations. While visual field interacts with the same-different factor, it fails to do so in a manner consistent with the proposed hemispheric dichotomy. These and other results argue against encoding models of letter matching, and support a revised visual comparison model that incorporates dual processing and response criterion elements. However, the role of lateralized processes remains unclear.

Associative arithmetic with Boltzmann Machines: The role of number representations

by Suzanna Becker, Ivilin P Stoianov, Carlo Umilta, and Marco Zorzi

Artificial Neural Networks— …, Jan 1, 2002

CITATIONS 7 READS 49 4 authors: Some of the authors of this publication are also working on these... more CITATIONS 7 READS 49 4 authors: Some of the authors of this publication are also working on these related projects: Examining the impact of a complex dietary supplement on BDNF, neurogenesis, amyloid, tau and behaviour in the 3xTg-AD mouse model of Alzheimer's disease View project Evaluating and probing the basis of potential neuroprotective effects of complex dietary supplementation on a SH-SY5Y cell culture model of Alzheimer's disease pathology View project Ivilin Stoianov Aix-Marseille Université

Electrophysiological correlates of stimulus processing in change blindness

by Paolo Capotosto and Carlo Umilta

Experimental Brain Research, 2007

Change blindness-the inability to detect salient changes when a distractor event occurs simultane... more Change blindness-the inability to detect salient changes when a distractor event occurs simultaneously-has been repeatedly used to investigate the neural correlates of awareness. The fact that the N2pc, which is basically assigned to attention processing, has been observed only for detected changes in such tasks lead to the assumption that this component may also reXect awareness. In contrast to previous electrophysiological studies, we used mudsplashes (experiment 1) or a very short blank (experiment 2) to induce change blindness so that the change was not occluded. A change, regardless of its detection, elicited a reliable N2pc. Successful change detection, however, was reXected in an enhanced amplitude of the N2pc component. Thus, the N2pc cannot be taken as a direct correlate of awareness but rather as a marker for a process that is necessary but not suYcient for awareness. Taking into account the generation of the N2pc in extrastriate visual areas, this Wnding Wts nicely with the recent discussion about reentrant processing as a basis for visual awareness.

Strategie dell’ orientamento implicito dell’attenzione spaziale

by Gian Maria Galeazzi and Carlo Umilta

In this experiment, two rows of four boxes, one above and the other below the fixation point, wer... more In this experiment, two rows of four boxes, one above and the other below the fixation point, were displayed on a computer monitor. A cognitive numeric cue indicated one of the four external boxes, where the attention was to be directed. Stimuli, however, could occur in any of the eight boxes. The subject was instructed to respond to the imperative stimulus as fast as possible, regardless of its location. Four time intervals between cue and stimulus presentation (SOAs) were employed in order to disclose the route along which attention is moved. With the shortest SOA (100 msec) an indication that attention movements follow the cartesian/orthogonal axes was shown

Processing of irrelevant location information under dual-task conditions

by Carlo Umilta, Peter Wühr, and Jochen Müsseler

Psychological Research, 2006

This study deals with the problem of whether the processing of irrelevant location information in... more This study deals with the problem of whether the processing of irrelevant location information in Simon-like tasks is triggered exogenously or endogenously. In Experiment 1, the primary task required one to press, as fast as possible, a left-hand-side key or a right-hand-side key (R1) to the pitch of a tone that was presented binaurally (S1). The secondary task required identifying, without time constraints, a visual stimulus (S2) that appeared randomly to the left or right of screen center. Results showed that there was a correspondence (i.e., a cross-task Simon effect) between the location of R1 and the location of S2 when S2 was presented alone. The cross-task Simon effect became much smaller (and in-significant) when a noise stimulus was presented contralateral to S2. Experiment 2 was similar to Experiment 1, except that S2 appeared unpredictably in only one-third of the trials. Results of Experiment 2 closely replicated those of Experiment 1: the cross-task Simon effect was much greater when S2 was presented alone. Experiment 3 differed from Experiment 1 because S2 had to be processed in only one-third of the trials, in which its identity was to be reported. In the remaining two-thirds of the trials, participants could ignore S2. Results confirmed that the cross-task Simon effect was much greater when S2 was presented alone. In contrast, it did not matter whether S2 had to be processed or not.

Perceptual and attentional factors in encoding irrelevant spatial information

by Carlo Umilta, Peter Wühr, and Jochen Müsseler

Psychological Research Psychologische Forschung, 2009

Numerous studies found superior performance when the irrelevant location of a stimulus and respon... more Numerous studies found superior performance when the irrelevant location of a stimulus and response location were corresponding than when they were not corresponding (Simon eVect), suggesting that stimulus location is processed in an obligatory manner. The present study compared Simon eVects from the location of a relevant (i.e., to-be-attended) object to those from the location of an irrelevant (i.e., to-be-ignored) object. In four experiments, participants were presented with a rectangular frame and a square, with the relevant object in green or red color and the irrelevant object in gray or white color. Participants' task was to respond with a lateral keypress to the color of the relevant object, and we varied spatial correspondence between the location of the relevant or the irrelevant object and the response, respectively. Results consistently showed larger Simon eVects from the location of the relevant than from the irrelevant object, even when the irrelevant object was made very salient. These results suggest that location processing is largely conWned to relevant (i.e., attended) objects, stressing the role of attention shifts for location encoding.