Browsing by Author "Prpic, Valter"
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Item Open Access Automatic spatial association for luminance(Springer, 2014-01-09) Fumarola, Antonia; Prpic, Valter; Da Pos, Osvaldo; Murgia, Mauro; Umilta, Carlo; Agostini, TizianoIn 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.Item Open Access Contrasting a Misinterpretation of the Reverse Contrast(MDPI, 2020) Agostini, Tiziano; Murgia, Mauro; Sors, Fabrizio; Prpic, Valter; Galmonte, AlessandraThe reverse contrast is a perceptual phenomenon in which the effect of the classical simultaneous lightness contrast is reversed. In classic simultaneous lightness contrast configurations, a gray surrounded by black is perceived lighter than an identical gray surrounded by white, but in the reverse contrast configurations, the perceptual outcome is the opposite: a gray surrounded by black appears darker than the same gray surrounded by white. The explanation provided for the reverse contrast (by different authors) is the belongingness of the gray targets to a more complex configuration. Different configurations show the occurrence of these phenomena; however, the factors determining this effect are not always the same. In particular, some configurations are based on both belongingness and assimilation, while one configuration is based only on belongingness. The evidence that different factors determine the reverse contrast is crucial for future research dealing with achromatic color perception and, in particular, with lightness induction phenomena.Item Open Access The contribution of early auditory and visual information to the discrimination of shot power in ball sports(Elsevier, 2017-04-05) Sors, Fabrizio; Murgia, Mauro; Santoro, Ilaria; Prpic, Valter; Galmonte, Alessandra; Agostini, TizianoObjective: It is well-established that early visual information has an important role in human ability to play ball sports, as its correct interpretation promotes accurate predictions concerning the ball motion. Other research highlights that auditory information provides relevant cues in various sport situations. The present study combines these two lines of research with the aim to investigate the contribution of early auditory and visual information to the discrimination of shot power in sport-specific situations. Design: Two experiments were run, one concerning soccer penalty kicks and the other concerning volleyball smashes. In both experiments there were three conditions: Audio, Audiovideo, and Video; a within subjects design was used, with the three conditions carried out in three different days and in a counterbalanced order among participants. Method: Participants’ task was to discriminate the power of two penalties/smashes presented in rapid sequence, on the basis of a two-alternative forced choice paradigm. Results: The results revealed that, for both penalties and smashes, response accuracy was above chance level in all the three conditions; moreover, while for the penalties no difference among the conditions was observed, for the smashes participants were more accurate in the Audio and Audiovideo conditions compared to the Video condition. As concerns the response times, for both penalties and smashes participants were faster in the Audio and Audiovideo conditions compared to the Video condition. Conclusions: Taken together, the results suggest that the discrimination of shot power was more easily performed on the basis of early auditory information than on the basis of the respective visual information.Item Open Access Do You Hear More Piano or Drum Sounds? An Auditory Version of the Solitaire Illusion(Sage, 2016-10-03) Prpic, Valter; Luccio, RiccardoThe solitaire illusion is an illusion of numerosity proposed by Frith and Frith. In the original version, an apparent number of elements was determined by the spatial arrangement of two kinds of elements (black and white marbles). In our study, an auditory version of the solitaire illusion was demonstrated. Participants were asked to judge if they perceived more drum or piano sounds. When half of the piano tones were perceived as lower in pitch than a drum sound and the other half higher, piano tones appeared to be arranged in small units, leading to numerosity underestimation. Conversely, when all piano tones were perceived to be higher in pitch than the drum sounds, they appeared to be arranged in a single large unit, leading to numerosity overestimation. Comparable to the visual version of the solitaire illusion, the clustering seems to be determined by Gestalt principles. In our auditory version, a clear reversal of the illusion (numerosity overestimation or underestimation) was observed when piano tones appeared to be arranged in a single large cluster or in several small clusters, respectively.Item Open Access Ecological sounds affect breath duration more than artificial sounds(Springer, 2015-01-31) Murgia, Mauro; Santoro, Ilaria; Tamburini, Giorgia; Prpic, Valter; Sors, Fabrizio; Galmonte, Alessandra; Agostini, TizianoPrevious research has demonstrated that auditory rhythms affect both movement and physiological functions. We hypothesized that the ecological sounds of human breathing can affect breathing more than artificial sounds of breathing, varying in tones for inspiration and expiration. To address this question, we monitored the breath duration of participants exposed to three conditions: (a) ecological sounds of breathing, (b) artificial sounds of breathing having equal temporal features as the ecological sounds, (c) no sounds (control). We found that participants’ breath duration variability was reduced in the ecological sound condition, more than in the artificial sound condition. We suggest that ecological sounds captured the timing of breathing better than artificial sounds, guiding as a consequence participants’ breathing. We interpreted our results according to the Theory of Event Coding, providing further support to its validity, and suggesting its possible extension in the domain of physiological functions which are both consciously and unconsciously controlled.Item Open Access Emotional Semantic Congruency based on stimulus driven comparative judgements(Elsevier, 2019-04-22) Fantoni, Carlo; Baldassi, Giulio; Rigutti, Sara; Prpic, Valter; Murgia, Mauro; Agostini, TizianoA common cognitive process in everyday life consists in the comparative judgements of emotions given a pair of facial expressions and the choice of the most positive/negative among them. Results from three experiments on complete-facial expressions (happy/angry) and mixed-facial expressions (neutral/happy-or-angry) pairs viewed with (Experiment 1 and 3) or without (Experiment 2) foveation and performed in conditions in which valence was either task relevant (Experiment 1 and 2) or task irrelevant (Experiment 3), show that comparative judgements of emotions are stimulus driven. Judgements' speed increased as the target absolute emotion intensity grew larger together with the average emotion of the pair, irrespective of the compatibility between the valence and the side of motor response: a semantic congruency effect in the domain of emotion. This result undermines previous interpretation of results in the context of comparative judgements based on the lateralization of emotions (e.g., SNARC-like instructional flexibility), and is fully consistent with our formalization of emotional semantic congruency: The direct Speed-Intensity Association model.Item Open Access Further Empirical Evidence on Patrick Hughes’ Reverspectives: A Pilot Study(MDPI, 2020-12-26) Galmonte, Alessandra; Murgia, Mauro; Sors, Fabrizio; Prpic, Valter; Agostini, TizianoReverspectives are paintings created by the English artist Patrick Hughes. They are 3D structures, for example, pyramids or prisms, which elicit an illusory depth perception that corresponds to the reverse of the physical depth layout. Rogers and Gyani state that “the perspective information provided by a simple grid of vertical and horizontal lines on a slanting surface can be just as powerful as the information provided by a rich, naturalistic scene”. The present experiment was aimed to further investigate this perspective reversal. Three independent variables were manipulated: (1) texture components (i.e., vertical, horizontal, and oblique lines components), (2) texture spatial arrangement (i.e., Hughes-type “perspective” grid vs. equidistant “no perspective” grid), and (3) illumination direction (i.e., homogeneous illumination, light from above, and light from below). The dependent variable was the “critical distance”, namely, the distance between an approaching observer and the stimulus at which the illusory depth perception of concavity/convexity switched to the actual perception of convexity/concavity. The results showed that a stronger illusion is elicited by: (a) a Hughes-type texture spatial arrangement; (b) a complete grid texture composition, having both vertical and horizontal, and oblique components; and (c) illumination from below, as opposed to the condition in which light is coming from above.Item Open Access The Influence of Encoding and Testing Directions on Retrieval of Spatial Information in Explored and Described Environments(Taylor and Francis, 2019) Santoro, Ilaria; Sors, Fabrizio; Mingolo, Serena; Prpic, Valter; Grassi, Michele; Agostini, Tiziano; Murgia, MauroThe verbal descriptions of an environment elicit a spatial mental model, in which the linear disposition of the described objects might be related to the properties of the description. In particular the direction from which the environment is encoded might shape the spatial mental model, as a consequence of a cultural bias in reading and writing direction. The aim of the present study was to examine the influence of the direction in which objects are encoded on the retrieval of spatial information. In two experiments we asked participants to encode an environment through either physical exploration or verbal description, that are encoding modalities which preserve the sequential presentation of spatial information. We manipulated both the encoding and testing directions of the spatial information, and tested participants by using a two-alternative forced choice task. In both experiments, the results did not reveal any significant effect, disconfirming the idea of the left-right cultural bias for western people for this type of task. The lack of effect suggests that encoding an environment through physical movement and verbal descriptions determines the development of a mental representation which is relatively independent from encoding sequential order.Item Open Access Large as being on top of the world and small as hitting the roof: A shared magnitude representation for the comparison of emotions and numbers(Springer, 2020) Baldassi, Giulio; Murgia, Mauro; Prpic, Valter; Rigutti, Sara; Domijan, Drazen; Agostini, Tiziano; Fantoni, CarloPrevious work on the direct Speed–Intensity Association (SIA) on comparative judgment tasks involved spatially distributed responses over spatially distributed stimuli with high motivational significance like facial expressions of emotions. This raises the possibility that the inferred stimulus-driven regulation of lateralized motor reactivity described by SIA, which was against the one expected on the basis of a valence-specific lateral bias, was entirely due to attentional capture from motivational significance (beyond numerical cognition). In order to establish the relevance of numerical cognition on the regulation of attentional capture we ran two complementary experiments. These involved the same direct comparison task on stimulus pairs that were fully comparable in terms of their analog representation of intensity but with different representational domain and motivational significance: symbolic magnitudes with low motivational significance in experiment 1 vs. emotions with rather high motivational significance in experiment 2. The results reveal a general SIA and point to a general mechanism regulating comparative judgments. This is based on the way spatial attention is captured toward locations that contain the stimulus which is closest in term of relative intensity to the extremal values of the series, regardless from its representational domain being it symbolic or emotionalItem Open Access Linear representation of pitch height in the SMARC effect(Psychological topics, 2018) Prpic, Valter; Domijan, DrazenThe Spatial-Musical Association of Response Codes (SMARC) effect consists in faster and more accurate responses to low (vs. high) pitched tones when they are executed in the bottom/left (vs. top/right) space. This phenomenon has many similarities with the Spatial-Numerical Association of Response Codes (SNARC) effect which, however, has been more extensively investigated and theoretically debated. The first theoretical account of the SNARC effect suggests the existence of a direct mapping between the position of a number on a mental number line and the external space of response execution. Conversely, following accounts claim that numbers are automatically categorized in two opposing categories (e.g., small vs. large) and then associated to response alternatives (left vs. right). A modified task, consisting in unimanual close/far responses relative to a reference key, has been employed to disentangle between the opposite theoretical accounts of the SNARC effect. However, this modified task has never been applied to pitch height and currently there are no specific theoretical accounts for the SMARC effect. The aim of this study is to fill this gap of knowledge. Contrary to what has been found for numbers, our data are more in line with the “direct mapping” account and suggests a linear representation of pitch height. Our data suggest that SNARC and SMARC effects might have different origins and might require different theoretical accounts.Item Open Access Loudness, but not shot power, influences simple reaction times to soccer penalty sounds(Drustvo psihologa Srbije, 2018) Sors, Fabrizio; Prpic, Valter; Santoro, Ilaria; Galmonte, Alessandra; Agostini, Tiziano; Murgia, MauroObjective: The aim of the present study was to investigate how ecological sport sounds (i.e., foot-ball impacts of soccer penalty kicks) affect simple reaction times. Design: Three within-subjects, simple reaction time experiments were carried out; they differed among each other for the manipulations performed on the stimuli. Method: In Experiment 1, the loudness of the stimuli was manipulated; instead, in Experiment 2 and 3 shot power was manipulated, using as stimuli impacts of shots with different speeds. Results: The results highlighted an inverse relation between stimuli loudness and reaction times; instead, the natural differences among shots with different power were not sufficient to influence reaction times. Conclusions: Sounds associated to different shot power seem to differ in parameters which are not actually relevant for simple reaction times. Future studies should further investigate on similar issues, better clarifying whether the properties of ecological sounds can naturally influence reaction times.Item Open Access Magnitude and Order are Both Relevant in SNARC and SNARC-like Effects: A Commentary on Casasanto and Pitt (2019)(Wiley, 2021-07-02) Prpic, Valter; Mingolo, Serena; Agostini, Tiziano; Murgia, MauroIn a recent paper by Casasanto and Pitt (2019), the authors addressed a debate regarding the role of order and magnitude in SNARC and SNARC-like effects. Their position is that all these effects can be explained by order, while magnitude could only account for a subset of evidence. Although we agree that order can probably explain the majority of these effects, in this commentary we argue that magnitude is still relevant, since there is evidence that cannot be explained based on ordinality alone. We argue that SNARC-like effects can occur for magnitudes not clearly characterized by overlearned ordinality and that magnitude can prevail on order, when the two are pitted against each other. Finally, we propose that different interpretations of the role of order and magnitude depend on the interaction of stimulus properties and task demands.Item Metadata only Modality and Perceptual-Motor Experience Influence the Detection of Temporal Deviations in Tap Dance Sequences(Frontiers, 2017-08-02) Murgia, Mauro; Prpic, Valter; O, Jenny; McCullagh, Penny; Santoro, Ilaria; Galmonte, Alessandra; Agostini, TizianoAccurate temporal information processing is critically important in many motor activities within disciplines such as dance, music, and sport. However, it is still unclear how temporal information related to biological motion is processed by expert and non-expert performers. It is well-known that the auditory modality dominates the visual modality in processing temporal information of simple stimuli, and that experts outperform non-experts in biological motion perception. In the present study, we combined these two areas of research; we investigated how experts and non-experts detected temporal deviations in tap dance sequences, in the auditory modality compared to the visual modality. We found that temporal deviations were better detected in the auditory modality compared to the visual modality, and by experts compared to non-experts. However, post hoc analyses indicated that these effects were mainly due to performances obtained by experts in the auditory modality. The results suggest that the experience advantage is not equally distributed across the modalities, and that tap dance experience enhances the effectiveness of the auditory modality but not the visual modality when processing temporal information. The present results and their potential implications are discussed in both temporal information processing and biological motion perception frameworks.Item Open Access Octave Bias in Pitch Perception: The Influence of Pitch Height on Pitch Class Identification(Sage, 2016-05-31) Prpic, Valter; Murgia, Mauro; De Tommaso, Matteo; Boschetti, Giulia; Galmonte, Alessandra; Agostini, TizianoPitch height and pitch class are different, but strictly related, percepts of music tones. To investigate the influence of pitch height in a pitch class identification task, we systematically analyzed the errors—in terms of direction and amount—committed by a group of musicians. The aim of our study was to verify the existence of constant errors in the identification of pitch classes across consecutive octaves. Stimuli were single piano tones from the C major scale executed in two consecutive octaves. Participants showed different response patterns in the two octaves. The direction of errors revealed a constant tendency to underestimate pitch classes in the lowest octave and to overestimate pitch classes in the highest octave. Thus, pitch height showed to influence pitch class identification. We called this bias ‘‘pitch class polarization’’, since the same pitch class was judged to be respectively lower and higher, depending on relatively low or high pitch height.Item Open Access Panic disorder patients and healthy people differently identify their own heart frequency through sound(Drustvo psihologa Srbije, 2015) Santoro, Ilaria; Murgia, Mauro; Tamburini, Giorgia; Prpic, Valter; Sors, Fabrizio; Galmonte, Alessandra; Agostini, TizianoThe ability to detect the perceptual cues related to cardiac activity is an important aspect related to the onset and maintenance of some psychopathological disorders, such as panic disorder. We tested two groups – panic disorder (PD) patients and healthy participants – in order to examine the ability to estimate participants’ own heart frequency. We used an auditory identification task, based on the administration of auditory tracks representative of ecological sounds of heartbeat. Results showed that all healthy participants underestimated their own heart frequency, whereas the majority of PD patients overestimated it. This different response tendency could influence the development of psychopathologies such as panic disorder. These outcomes suggest the possible development of training for PD patients based on the use of auditory stimulation.Item Open Access Perceiving Musical Note Values Causes Spatial Shift of Attention in Musicians(MDPI, 2017-06-07) Prpic, ValterThe Spatial-Numerical Association of Response Codes (SNARC) suggests the existence of an association between number magnitude and response position, with faster left-key responses to small numbers and faster right-key responses to large numbers. The attentional SNARC effect (Att-SNARC) suggests that perceiving numbers can also affect the allocation of spatial attention, causing a leftward (vs. rightward) target detection advantage after perceiving small (vs. large) numbers. Considering previous findings that revealed similar spatial association effects for both numbers and musical note values (i.e., the relative duration of notes), the aim of this study is to investigate whether presenting note values instead of numbers causes a spatial shift of attention in musicians. The results show an advantage in detecting a leftward (vs. rightward) target after perceiving small (vs. large) musical note values. The fact that musical note values cause a spatial shift of attention strongly suggests that musicians process numbers and note values in a similar manner.Item Open Access Perceptual belongingness determines the direction of lightness induction depending on grouping stability and intentionality(Elsevier, 2016-05-30) Murgia, Mauro; Prpic, Valter; Santoro, Ilaria; Sors, Fabrizio; Agostini, Tiziano; Galmonte, AlessandraContrast and assimilation are two opposite perceptual phenomena deriving from the relationships among perceptual elements in a visual field. In contrast, perceptual differences are enhanced; while, in assimilation, they are decreased. Indeed, if contrast or assimilation occurs depends on various factors. Interestingly, Gestalt scientists explained both phenomena as the result of perceptual belongingness, giving rise to an intriguing paradox. Benary suggested that belongingness determines contrast; conversely, Fuchs suggested that it determines assimilation. This paradox can be related both to the grouping stability (stable/multi-stable) and to the grouping intentionality (intentional/non-intentional). In the present work we ran four experiments to test whether the contrast/assimilation outcomes depend on the above-mentioned variables. We found that, intentionality and multi-stability elicit assimilation; while, non-intentionality and stability elicit contrast.Item Open Access Separate Mechanisms for Magnitude and Order Processing in the Spatial-Numerical Association of Response Codes (SNARC) Effect: The Strange Case of Musical Note Values(American Psychological Association, 2016) Prpic, Valter; Fumarola, Antonia; De Tommaso, Matteo; Luccio, Riccardo; Murgia, Mauro; Agostini, TizianoThe SNARC effect is considered an evidence of the association between numbers and space, with faster left key-press responses to small numbers and faster right key-press responses to large numbers. We examined whether visually presented note values produce a SNARC-like effect. Differently from numbers, note values are represented as a decreasing left-to-right progression, allowing us to disambiguate the contribution of order and magnitude in determining the direction of the effect. Musicians with formal education performed a note value comparison in Experiment 1 (direct task), a line orientation judgment in Experiment 2 (indirect task), and a detection task in Experiment 3 (indirect task). When note values were task relevant (direct task), participants responded faster to large note values with the left key-press, and vice versa. Conversely, when note values were task irrelevant (indirect tasks), the direction of this association was reversed. This evidence suggests the existence of separate mechanisms underlying the SNARC effect. Namely, an Order-Related Mechanism (ORM) and a Magnitude-Related Mechanism (MRM), that are revealed by different task demands. Indeed, according to a new model we proposed, ordinal and magnitude related information seem to be preferentially involved in direct and indirect tasks, respectively.Item Metadata only A serious game to explore human foraging in a 3D environment(PLOS, 2019-07-25) Prpic, Valter; Kniestedt, Isabelle; Camilleri, Elizabeth; Maureira, Marcello Gomez; Kristjansson, Arni; Thornton, Ian M.Traditional search tasks have taught us much about vision and attention. Recently, several groups have begun to use multiple-target search to explore more complex and temporally extended “foraging” behaviour. Many of these new foraging tasks, however, maintain the simplified 2D displays and response demands associated with traditional, single-target visual search. In this respect, they may fail to capture important aspects of real-world search or foraging behaviour. In the current paper, we present a serious game for mobile platforms in which human participants play the role of an animal foraging for food in a simulated 3D environment. Game settings can be adjusted, so that, for example, custom target and distractor items can be uploaded, and task parameters, such as the number of target categories or target/distractor ratio are all easy to modify. We demonstrate how the app can be used to address specific research questions by conducting two human foraging experiments. Our results indicate that in this 3D environment, a standard feature/conjunction manipulation does not lead to a reduction in foraging runs, as it is known to do in simple, 2D foraging tasks. Differences in foraging behaviour are discussed in terms of environment structure, task demands and attentional constraints.Item Open Access Slow and fast beat sequences are represented differently through space(Springer, 2019) De Tommaso, Matteo; Prpic, ValterThe Spatial-Numerical Association of Response Codes (SNARC) suggests the existence of an association between number magnitude and response position, with faster left-hand responses to small numbers and faster right-hand responses to large numbers. Recent studies have revealed similar spatial association effects for non-numerical magnitudes, such as temporal durations and musical stimuli. In the present study we investigated whether a spatial association effect exists between music tempo, expressed in beats per minutes (bpm), and response position. In particular, we were interested whether this effect is consistent through different bpm ranges. We asked participants to judge whether a target beat sequence was faster or slower than a reference sequence. Three groups of participants judged beat sequences from three different bpm ranges, a wide range (40, 80, 160, 200 bpm) and two narrowed ranges (“slow” tempo, 40, 56, 88, 104 bpm; “fast” tempo 133, 150, 184, 201 bpm). Results showed a clear SNARC-like effect for music tempo only in the narrowed “fast” tempo range, with faster left-hand responses to 133 and 150 bpm and faster right-hand responses to 184 and 201 bpm. Conversely, a similar association did not emerge in the wide nor in the narrowed "slow" tempo ranges. This evidence suggests that music tempo is spatially represented as other continuous quantities, but its representation might be narrowed to a particular range of tempi. Moreover, music tempo and temporal duration might be represented across space with an opposite direction.