Crossmodal interference on counting performance: Evidence for shared attentional resources.

During the act of counting, our perceptual system may rely on information coming from different sensory channels. However, when the information coming from different sources is discordant, such as in the case of a de-synchronization between visual stimuli to be counted and irrelevant auditory stimuli, the performance in a sequential counting task might deteriorate. Such deterioration may originate from two different mechanisms, both linked to exogenous attention attracted by auditory stimuli. Indeed, exogenous auditory triggers may infiltrate our internal "counter", interfering with the counting process, resulting in an overcount; alternatively, the exogenous auditory triggers may disrupt the internal "counter" by deviating participants' attention from the visual stimuli, resulting in an undercount. We tested these hypotheses by asking participants to count visual discs sequentially appearing on the screen while listening to task-irrelevant sounds, in systematically varied conditions: visual stimuli could be synchronized or de-synchronized with sounds; they could feature regular or irregular pacing; and their speed presentation could be fast (approx. 3/sec), moderate (approx. 2/sec), or slow (approx. 1.5/sec). Our results support the second hypothesis since participants tend to undercount visual stimuli in all harder conditions (de-synchronized, irregular, fast sequences). We discuss these results in detail, adding novel elements to the study of crossmodal interference.

Exposure to nature is associated with decreased functional connectivity within the distress network: A resting state EEG study.

Introduction: Despite the well-established evidence supporting the restorative potential of nature exposure, the neurophysiological underpinnings of the restorative cognitive/emotional effect of nature are not yet fully understood. The main purpose of the current study was to investigate the association between exposure to nature and electroencephalography (EEG) functional connectivity in the distress network. Methods: Fifty-three individuals (11 men and 42 women; mean age 21.38 ± 1.54 years) were randomly assigned to two groups: (i) a green group and (ii) a gray group. A slideshow consisting of images depicting natural and urban scenarios were, respectively, presented to the green and the gray group. Before and after the slideshow, 5 min resting state (RS) EEG recordings were performed. The exact low-resolution electromagnetic tomography (eLORETA) software was used to execute all EEG analyses. Results: Compared to the gray group, the green group showed a significant increase in positive emotions (F 1; 50 = 9.50 p = 0.003) and in the subjective experience of being full of energy and alive (F 1; 50 = 4.72 p = 0.035). Furthermore, as compared to urban pictures, the exposure to natural images was associated with a decrease of delta functional connectivity in the distress network, specifically between the left insula and left subgenual anterior cingulate cortex (T = -3.70, p = 0.023). Discussion: Our results would seem to be in accordance with previous neurophysiological studies suggesting that experiencing natural environments is associated with brain functional dynamics linked to emotional restorative processes.

Searching for a Relationship between Early Breastfeeding and Cognitive Development of Attention and Working Memory Capacity.

Previous research consistently reported that subjects that were exclusively breastfed (eBF) vs. not-exclusively breastfed (neBF) during infancy (0-6 months) showed increased scores of general intelligence measures (e.g., the intelligence quotient). However, the existent literature largely neglected whether breastfeeding also affects specific cognitive processes, such as attention and working memory (WM) capacity. We tested whether eBF vs. neBF subjects showed performance differences in relation to these two core cognitive functions. The Attention Network Test (ANT), to measure alerting, orienting, and conflict, and the Change Colour Task (CCT), to measure visuospatial WM capacity, were administered to 144 participants divided according to age (6-, 10-, and 18-year-old participants) and breastfeeding (eBF or neBF during 0-6 months of life). Importantly, the sub-groups were homogenous in terms of maternal education, a factor potentially affecting the relation between breastfeeding and cognition. While we found increased performance as a function of participants' age in both tasks, we failed to observe effects related to breastfeeding, as evidenced by Bayesian analyses. These findings highlight for the first time that the pattern of nutrition provided during early infancy does not appear to affect the development of attention and WM capacity, at least starting from the age considered in the present study.

eStroop: Implementation, Standardization, and Systematic Comparison of a New Voice-Key Version of the Traditional Stroop Task.

The Stroop effect is a well-documented phenomenon, demonstrating both interference and facilitation effects. Many versions of the Stroop task were created, according to the purposes of its applications, varying in numerous aspects. While many versions are developed to investigate the mechanisms of the effect itself, the Stroop effect is also considered a general measure of attention, inhibitory control, and executive functions. In this paper, we implement "eStroop": a new digital version based on verbal responses, measuring the main processes involved in the traditional effect. eStroop features four categories of stimuli in four different colors: (1) geometrical shapes, (2) neutral words, (3) congruent words, and (4) incongruent words. The results of the administration to 307 University students confirm the Stroop effect and offer baseline data for future research and clinical testing. Direct comparisons with other recent versions of the task are discussed, offering insights into differences and similarities between different task variables.

Hungry for colours? Attentional bias for food crucially depends on perceptual information.

Attentional bias has been consistently investigated with both threatening and rewarding stimuli, such as food. Several studies demonstrated the presence of an attentional bias for high-calorie food cues compared to neutral (non-food) cues. Authors have interpreted this effect in the context of top-down processes (e.g. the food draws attention thanks to the experience we have with it). The aim of the present study is to test whether perceptual features (bottom-up processes) can modulate the attentional bias effect of food stimuli. Using a dot-probe task, we investigated the relevance of colours in the occurrence of the attentional bias. We compared two different categories of naturalistic food images (high-calorie versus low-calorie) both coloured (Exp. 1) and greyscale (Exp. 2). While we found the occurrence of the attentional bias with high-calorie food coloured images, we did not obtain any significant differences with greyscale images. In Experiments 3 and 4, we compared greyscale office items images, respectively, with greyscale high-calorie food images (Exp. 3) and greyscale low-calorie food images (Exp. 4). In both these last experiments, we did not find any attentional bias. Thus, taken together, our results show that colours convey crucial identity information that could orient our attention. We interpret these results as linked to the relevance of visual appearance in our experience of food.

That does not sound right: Sounds affect visual ERPs during a piano sight-reading task.

Prolonged musical training induces important audio-visuo-motor plastic processes. However, little is known about how the musicians' brain resolves multimodal conflicts while preparing for musical action. We run an electroencephalographic (EEG) investigation on how visual processing for action (score reading) is affected by preceding task-irrelevant piano sounds, usually associated to the same or to a different action. Presentation of an incongruent sound, 100 msec before a musical score with one single note, reduces Event-Related Potentials (ERPs) associated to score reading (N170) localised in the right temporo-parietal junction, as well as ERPs associated to conflict strength (N2) localised in the anterior cingulate cortex, superior and inferior right frontal cortex. These results suggest that listening to task-irrelevant auditory action effects (musical notes) interferes with both higher-order visual and frontal conflict monitoring processes. We conclude that, in the musicians' brain, the automatic translation of musical sounds into motor plans, spread its effects to visually specific processing as well as strategic and amodal action monitoring mechanisms.

Are crossmodal correspondences relative or absolute? Sequential effects on speeded classification.

Crossmodal correspondences have often been demonstrated using congruency effects between pairs of stimuli in different sensory modalities that vary along separate dimensions. To date, however, it is still unclear the extent to which these correspondences are relative versus absolute in nature: that is, whether they result from pre-defined values that rigidly link the two dimensions or rather result from flexible values related to the previous occurrence of the crossmodal stimuli. Here, we investigated this issue in a speeded classification task featuring the correspondence between auditory pitch and visual size (e.g., congruent correspondence between high pitch/small disc and low pitch/large disc). Participants classified the size of the visual stimuli (large vs. small) while hearing concurrent high- or low-pitched task-irrelevant sounds. On some trials, visual stimuli were paired instead with "intermediate" pitch, that could be interpreted differently according to the auditory stimulus on the preceding trial (i.e., as "lower" following the presentation of a high pitch tone, but as "higher" following the presentation of a low pitch tone). Performance on sequence-congruent trials (e.g., when a small disc paired with the intermediate-pitched tone was preceded by a low pitch tone) was compared to sequence-incongruent trials (e.g., when a small disc paired with the intermediate-pitch tone was by a high-pitched tone). The results revealed faster classification responses on sequence-congruent than on sequence-incongruent trials. This demonstrates that the effect of the pitch/size correspondence is relative in nature, and subjected to trial-by-trial interpretation of the stimulus pair.

Did I see your hand moving? The effect of movement-related information on the Corsi block tapping task.

The Corsi Block Tapping Task is a widespread test used to assess spatial working memory. Previous research hypothesized that the discrepancy found in some cases between the traditional and the digital (touchscreen) version of the Corsi block tapping task may be due to a direct motor resonance between the experimenter's and the participant's hand movements. However, we hypothesize that this discrepancy might be due to extra movement-related information included in the traditional version, lacking in the digital one. We investigated the effects of such task-irrelevant information using eCorsi, a touchscreen version of the task. In Experiment 1, we manipulate timing in sequence presentation, creating three conditions. In the Congruent condition, the inter-stimulus intervals reflected the physical distance in which the stimuli were spatially placed: The longer the spatial distance, the longer the temporal interval. In the Incongruent condition the timing changed randomly. Finally, in the Isochronous condition every stimulus appeared after a fixed interval, independently from its spatial position. The results showed a performance enhancement in the Congruent condition, suggesting an incidental spatio-temporal binding. In Experiment 2, we added straight lines between each location in the sequences: In the Trajectories condition participants saw trajectories from one spatial position to the other during sequence presentation, while a condition without such trajectories served as control. Results showed better performances in the Trajectories condition. We suggest that the timing and trajectories information play a significant role in the discrepancies found between the traditional and the touchscreen version of the Corsi Block Tapping Task, without the necessity of explanations involving direct motor resonance (e.g. seeing an actual hand moving) as a causal factor.

The Association among Difficulties in Emotion Regulation, Hostility, and Empathy in a Sample of Young Italian Adults.

The aim of the present study was to assess the role of empathy in mediating the association between difficulties in emotion regulation and hostility. Three hundred and sixty young Italian adults (220 women and 140 men) were enrolled in the study. Psychopathological assessments included the Difficulties in Emotion Regulation Scale (DERS), the Interpersonal Reactivity Index and the Buss-Durkee Hostility Inventory (BDHI). Perspective taking (PT) and Personal distress (PD) are significantly associated with both DERS total score and BDHI total score. A mediational model analyzing the direct and indirect effects of DERS on BDHI through the mediating role of PT and PD showed that the relation between DERS and BDHI was partially mediated by PT total score (b = 0.16; se = 0.01; p = 0.02). Taken together our findings support the possibility that PT skills could play a crucial role in inhibiting hostility behaviors.

Cross-modal and intra-modal binding between identity and location in spatial working memory: The identity of objects does not help recalling their locations.

In this study we tested incidental feature-to-location binding in a spatial task, both in unimodal and cross-modal conditions. In Experiment 1 we administered a computerised version of the Corsi Block-Tapping Task (CBTT) in three different conditions: the first one analogous to the original CBTT test; the second one in which locations were associated with unfamiliar images; the third one in which locations were associated with non-verbal sounds. Results showed no effect on performance by the addition of identity information. In Experiment 2, locations on the screen were associated with pitched sounds in two different conditions: one in which different pitches were randomly associated with locations and the other in which pitches were assigned to match the vertical position of the CBTT squares congruently with their frequencies. In Experiment 2 we found marginal evidence of a pitch facilitation effect in the spatial memory task. We ran a third experiment to test the same conditions of Experiment 2 with a within-subject design. Results of Experiment 3 did not confirm the pitch-location facilitation effect. We concluded that the identity of objects does not affect recalling their locations. We discuss our results within the framework of the debate about the mechanisms of "what" and "where" feature binding in working memory.

eCorsi: implementation and testing of the Corsi block-tapping task for digital tablets.

The Corsi block-tapping task is a widely used test to assess visuo-spatial working memory. The test is traditionally administered using nine square blocks positioned on a wooden board, but numerous digital versions have been developed. In this study, we tested one-hundred and seven participants divided into two age groups (18-30 and over 50) in forward, backward and supraspan-forward conditions with eCorsi, a tablet version of the Corsi task. Compared to the traditional physical board, eCorsi has several advantages, including: simple installation, set-up, and use; considerably increased accuracy in presentation timing, automatic measures of span and reaction times, in both the forward and backward response modalities. Results showed that average span and error rates were essentially analogous to the ones obtained in the main standardization studies, which have used the original physical version of the Corsi test. Furthermore, timing results provide new indications about the mechanisms underlying spatial sequence processing, suggesting that the subject's response is not planned during sequence presentation, but between the end of the presentation and the beginning of the response.

Modifications of EEG power spectra in mesial temporal lobe during n-back tasks of increasing difficulty. A sLORETA study.

The n-back task is widely used to investigate the neural basis of Working Memory (WM) processes. The principal aim of this study was to explore and compare the EEG power spectra during two n-back tests with different levels of difficulty (1-back vs. 3-back). Fourteen healthy subjects were enrolled (seven men and seven women, mean age 31.21 ± 7.05 years, range: 23-48). EEG was recorded while performing the N-back test, by means of 19 surface electrodes referred to joint mastoids. EEG analysis were conducted by means of the standardized Low Resolution brain Electric Tomography (sLORETA) software. The statistical comparison between EEG power spectra in the two conditions was performed using paired t-statistics on the coherence values after Fisher's z transformation available in the LORETA program package. The frequency bands considered were: delta (0.5-4 Hz); theta (4.5-7.5 Hz); alpha (8-12.5 Hz); beta (13-30 Hz); gamma (30.5-100 Hz). Significant changes occurred in the delta band: in the 3-back condition an increased delta power was localized in a brain region corresponding to the Brodmann Area (BA) 28 in the left posterior entorhinal cortex (T = 3.112; p < 0.05) and in the BA 35 in the left perirhinal cortex in the parahippocampal gyrus (T = 2.876; p < 0.05). No significant differences were observed in the right hemisphere and in the alpha, theta, beta, and gamma frequency bands. Our results indicate that the most prominent modification induced by the increased complexity of the task occur in the mesial left temporal lobe structures.