The Spatial Musical Association of Response Codes does not depend on a normal visual experience: A study with early blind individuals

Converging evidence suggests that the perception of auditory pitch exhibits a characteristic spatial organization. This pitch–space association can be demonstrated experimentally by the Spatial Musical Association of Response Codes (SMARC) effect. This is characterized by faster response times when a low-positioned key is pressed in response to a low-pitched tone, and a high-positioned key is pressed in response to a high-pitched tone. To investigate whether the development of this pitch–space association is mediated by normal visual experience, we tested a group of early blind individuals on a task that required them to discriminate the timbre of different instrument sounds with varying pitch. Results revealed a comparable pattern in the SMARC effect in both blind participants and sighted controls, suggesting that the lack of prior visual experience does not prevent the development of an association between pitch height and vertical space.     

Intuitive Heuristics Linking Perfectionism, Control, and Beliefs Regarding Body Shape in Eating Disorders

A number of correlational studies have established a clear association between perfectionism, control and beliefs regarding body shape in eating disorders (EDs). The aim of this study is to test the effectiveness of the above- mentioned associations in exploring the presence of intuitive heuristics. Intuitive heuristics can be conceived as as mental shortcuts, cognitive processes that are highly susceptible to irrational biases. Forty one non clinical female controls and 27 in-patient females with an ED diagnosis participated in an experimental task that tested whether participants would show an intuitive rather than a logically based link between perfectionism in different domains (study, work, hygiene) and a thin body shape. In the healthy female participants the occurrence of proposed link was noted in the hygiene domain only, while ED participants showed this intuitive association in all the domains explored: study, work, and hygiene. The study confirms in clinical ED sample a wider employment of heuristics associating perfectionism and thinness that is based on purely intuitive irrational reasoning.     

Hemispheric asymmetry in discriminating faces differing for featural or configural (second-order relations) aspects

The human capacity to discriminate among different faces relies on distinct parallel subprocesses, based either on the analysis of configural aspects or on the sequential analysis of the single elements of a face. A particular type of configural processing consists of considering whether two faces differ in terms of internal spacing among their features, referred to as second-order relations processing. Findings from electrophysiological, neuroimaging, and lesion studies suggest that, overall, configural processes rely more on the right hemisphere, whereas analysis of single features would involve more the left. However, results are not always consistent, and behavioral evidence for a right-hemisphere specialization in second-order relations processing is lacking. Here, we used divided visual field presentation to investigate the possible different contributions of the two hemispheres to face discrimination based on relational versus featural processing. Our data indicate a right-hemispheric specialization in relational processing of upright (but not inverted) faces. Furthermore, we provide evidence regarding the involvement of both the right and left hemispheres in the processing of faces differing for inner features, suggesting that both analytical and configural modes of processing are at play.     

Happiness takes you right: The effect of emotional stimuli on line bisection

Emotion recognition is mediated by a complex network of cortical and subcortical areas, with the two hemispheres likely being differently involved in processing positive and negative emotions. As results on valence-dependent hemispheric specialisation are quite inconsistent, we carried out three experiments with emotional stimuli with a task being sensitive to measure specific hemispheric processing. Participants were required to bisect visual lines that were delimited by emotional face flankers, or to haptically bisect rods while concurrently listening to emotional vocal expressions. We found that prolonged (but not transient) exposition to concurrent happy stimuli significantly shifted the bisection bias to the right compared to both sad and neutral stimuli, indexing a greater involvement of the left hemisphere in processing of positively connoted stimuli. No differences between sad and neutral stimuli were observed across the experiments. In sum, our data provide consistent evidence in favour of a greater involvement of the left hemisphere in processing positive emotions and suggest that (prolonged) exposure to stimuli expressing happiness significantly affects allocation of (spatial) attentional resources, regardless of the sensory (visual/auditory) modality in which the emotion is perceived and space is explored (visual/haptic).     

Crossmodal interaction between the mental number line and peripersonal haptic space representation in sighted and blind individuals

Humans tend to represent numbers in the form of a mental number line. Here we show that the mental number line can modulate the representation of peripersonal haptic space in a crossmodal fashion and that this interaction is not visually mediated. Sighted and early-blind participants were asked to haptically explore rods of different lengths and to indicate midpoints of those rods. During each trial, either a small (2) or a large (8) number was presented in the auditory modality. When no numbers were presented, participants tended to bisect the rods to the left of the actual midpoint, consistent with the notion of pseudoneglect. In both groups, this bias was significantly increased by the presentation of a small number and was significantly reduced by the presentation of a large number. Hence, spatial shifts of attention induced by number processing are not limited to visual space or embodied responses but extend to haptic peripersonal space and occur crossmodally without requiring the activation of a visuospatial representation.     

Symmetry perception in the blind

Bilateral mirror symmetry, especially vertical symmetry, is a powerful phenomenon in spatial organization of visual shapes. However, the causes of vertical symmetry salience in visual perception are not completely clear. Here we investigated whether the perceptual salience of vertical symmetry depends on visual experience by testing a group of congenitally blind individuals in a memory task in which either horizontal or vertical symmetry was used as an incidental feature. Both blind and sighted subjects remembered more accurately configurations that were symmetrical compared to those that were not. Critically, whereas sighted subjects displayed a higher level of facilitation by vertical than horizontal symmetry, no such difference was found in the blind. This suggests that the perceptual salience of the vertical dimension is visually based.     

Gender differences in memory for object and word locations

It has been hypothesized that gender differences in visuo-spatial working memory (VSWM) are larger in tasks requiring active elaboration of the material. In the present study we explored this issue by using an object relocation task, with both verbal and visual stimuli. The involvement of active processes was manipulated through the type of transformation required on the stimulus and through the introduction of different kinds of interference. In the three experiments reported, participants were shown either words or cartoon object icons in different locations and had to relocate them in either the same format or in the opposite one (object icons could be transformed into words and vice versa). Males outperformed females in the most demanding conditions, in which object icons and words were presented together in the encoding phase, and both had to be transformed in the recall phase; or when more demanding interferences were used. Our data suggest that the retention strategy was similar for the two groups and that the gender effect is related to a selective female difficulty associated with the increase in active VSWM processing. These findings further support the hypothesized distinction between the passive and active components of VSWM and illustrate the role that this distinction might play in accounting for individual differences.     

Processing abstract language modulates motor system activity

Embodiment theory proposes that neural systems for perception and action are also engaged during language comprehension. Previous neuroimaging and neurophysiological studies have only been able to demonstrate modulation of action systems during comprehension of concrete language. We provide neurophysiological evidence for modulation of motor system activity during the comprehension of both concrete and abstract language. In Experiment 1, when the described direction of object transfer or information transfer (e.g., away from the reader to another) matched the literal direction of a hand movement used to make a response, speed of responding was faster than when the two directions mismatched (an action-sentence compatibility effect). In Experiment 2, we used single-pulse transcranial magnetic stimulation to study changes in the corticospinal motor pathways to hand muscles while reading the same sentences. Relative to sentences that do not describe transfer, there is greater modulation of activity in the hand muscles when reading sentences describing transfer of both concrete objects and abstract information. These findings are discussed in relation to the human mirror neuron system.     

The neural basis of mirror symmetry detection: a review

The human visual system is extremely sensitive to the presence of bilateral (mirror) symmetry. In this review, I summarise the results of recent work investigating the neural basis of mirror symmetry detection, focusing in particular on brain stimulation evidence. Overall, available findings converge in pointing to the lateral occipital (LO) complex, especially in the right hemisphere, as a key region causally involved in symmetry detection. Interestingly, they also suggest that another region in the right extrastriate visual cortex, the occipital face area (OFA), is causally implied in symmetry detection, posing an interesting connection at the neural level between visual cortex responses to faces and to symmetry. Finally, this review also considers evidence on haptic symmetry detection in sighted and early blind individuals that points to LO as a multi-modal symmetry-sensitive region, and suggests that symmetry is a salient perceptual feature mediated by LO even when any visual experience is missing.     

Methodological evolution and clinical application of C.G. Jung's Word Association Experiment: a follow-up study

We became interested in the clinical application of the Word Association Experiment (AE) when we decided to use Jung's theory of complexes in the psycho-diagnostic evaluation and treatment of patients applying to our Psychotherapy Out-patients Unit (Psychiatric Clinic, Milan University). In psychopathological situations, complexes with a particularly high emotional charge become autonomous and disturbing, inhibiting the ego's functions. The representations and affective states corresponding to these complexes become dominant, conditioning the expression of symptoms and the subject's relational modes. In this experimental study we started out from the basic theory that our psycho-therapeutic work should lead to a progressive change in the patient's initial complex set up. Jung's Word Association Experiment allows us to identify those words which indicate and stimulate a specific activation of the complexes for each subject via specific markers of complexes. We therefore decided to determine whether AE, administered during the first phase of clinical-diagnostic evaluation and after one year of treatment, revealed any changes occurring in the patients' set up of complexes.