Why early tactile speech aids may have failed: no perceptual integration of tactile and auditory signals

Tactile speech aids, though extensively studied in the 1980s and 90s, never became a commercial success. A hypothesis to explain this failure might be that it is difficult to obtain true perceptual integration of a tactile signal with information from auditory speech: exploitation of tactile cues from a tactile aid might require cognitive effort and so prevent speech understanding at the high rates typical of everyday speech. To test this hypothesis, we attempted to create true perceptual integration of tactile with auditory information in what might be considered the simplest situation encountered by a hearing-impaired listener. We created an auditory continuum between the syllables BA and VA, and trained participants to associate BA to one tactile stimulus VA to another tactile stimulus. After training, we tested if auditory discrimination along the continuum between the two syllables could be biased by incongruent tactile stimulation. We found that such a bias occurred only when the tactile stimulus was above its previously measured tactile discrimination threshold. Such a pattern is compatible with the idea that the effect is due to a cognitive or decisional strategy, rather than to truly perceptual integration. We therefore ran a further study, where we created a tactile version of the McGurk effect. We extensively trained two Subjects over six days to associate four recorded auditory syllables with four corresponding apparent motion tactile patterns. In a subsequent test, we presented stimulation that was either congruent or incongruent with the learnt association, and asked Subjects to report the syllable they perceived. We found no analog to the McGurk effect. These findings strengthen our hypothesis according to which tactile aids failed because integration of tactile cues with auditory speech occurred at a cognitive or decisional level, rather than truly at a perceptual leve

Where is uphill? Exploring sex differences when reorienting on a sloped environment presented through 2-D images

One of the spatial abilities that has recently revealed a remarkable variability in performance is that of using terrain slope to reorient. Previous studies have shown a very large disadvantage for females when the slope of the floor is the only information useful for encoding a goal location. However, the source of this sex difference is still unclear. The slope of the environment provides a directional source of information that is perceived through dissociable visual and kinesthetic sensory modalities. Here we focused on the visual information, and examined whether there are sex differences in the perception of a slope presented through 2-D images with a desktop computer connected to an eye-tracking device. Participants had to identify and point to the uphill direction by looking at different orientations of two virtual, slanted environments (one indoor and one outdoor). Men were quicker and more accurate than women, indicating that the female difficulty with slope emerges at an early, unisensory, perceptual level. However, the eye-tracking data revealed no sex differences in the slope cues used, providing no support to the hypothesis of sex-specific, visual-processing strategies. Interestingly, performance correlated with a test of mental rotation, and we speculate that the disadvantage in mental rotation ability might be an important factor responsible for females’ difficulty using slope

Where is uphill? Exploring sex differences when reorienting on a sloped environment presented through 2-D images

One of the spatial abilities that has recently revealed a remarkable variability in performance is that of using terrain slope to reorient. Previous studies have shown a very large disadvantage for females when the slope of the floor is the only information useful for encoding a goal location. However, the source of this sex difference is still unclear. The slope of the environment provides a directional source of information that is perceived through dissociable visual and kinesthetic sensory modalities. Here we focused on the visual information, and examined whether there are sex differences in the perception of a slope presented through 2-D images with a desktop computer connected to an eye-tracking device. Participants had to identify and point to the uphill direction by looking at different orientations of two virtual, slanted environments (one indoor and one outdoor). Men were quicker and more accurate than women, indicating that the female difficulty with slope emerges at an early, unisensory, perceptual level. However, the eye-tracking data revealed no sex differences in the slope cues used, providing no support to the hypothesis of sex-specific, visual-processing strategies. Interestingly, performance correlated with a test of mental rotation, and we speculate that the disadvantage in mental rotation ability might be an important factor responsible for females’ difficulty using slope

Cross-cultural differences in intercultural mindreading: Evidence from a sample of Palestinian, Italian, and German adolescents

Despite the fact that the “Reading the Mind in the Eyes” Test (RMET) is now available in more than 20 languages, there are only very few cross-cultural researchers using this test, and these researchers generally focus on North American versus East Asian cultures. Considering that the RMET stimuli were selected and constructed in the United Kingdom, this research explored cross-cultural differences in intercultural mindreading with a large sample of adolescents from Palestine (PAL), Italy (ITA), and Germany (GER). In addition to significant main effects of age (younger < older) and gender (male < female), we found a significant main effect of country (PAL < ITA < GER) and a significant interaction between gender and country. Individualism was not related to mindreading in any of the three countries whereas collectivism was positively related in PAL, but not in ITA or GER, accounting only for a very small amount of the variance. Our results suggest that (a) there may be cultural ingroup effects on mindreading, (b) the known female superiority in mindreading may be moderated by cultural factors, and (c) depending on cultural factors, individualism and collectivism may be differently related to mindreading

A Behavioral Approach to Treatment and Assessment of People with Disorders of Consciousness: The Response-contingent Stimulation Strategy

Response-contingent stimulation is a behavioral strategy used to improve the situation of patients with disorders of consciousness. Such strategy involves the presentation of brief periods (e.g., 10 to 15 s) of stimulation considered preferred by the patients, contingent on (immediately after) the emission of specific patients' responses. The aim is to help the patients learn the link between their responding and the preferred stimulation and thus learn to use their responding to access the stimulation in a self-determined/independent manner. Achieving these goals is considered important for the patients' recovery process and thus the response-contingent stimulation strategy that promotes such an achievement can be considered a valuable treatment approach. The same strategy combined with the use of periods of non-contingent stimulation (i.e., stimulation delivered independent of responding) may also serve as an assessment supplement with patients with apparent unresponsive wakefulness. The patients' increase in responding during the response-contingent stimulation and decline in responding during the non-contingent stimulation could be taken as a sign of discrimination between conditions, and possibly a sign of awareness of the immediate environmental situation, compatible with a diagnosis of minimally conscious state. This paper analyzes a number of studies aimed at using the response-contingent stimulation as a treatment strategy and a number of studies aimed at combining response-contingent stimulation with non-contingent stimulation for treatment and assessment purposes. The results of the studies are discussed in terms of the effectiveness, accessibility and affordability of the strategy. The need for new research (i.e., replication studies) is also pointed out

Emotion based attentional priority for storage in visual short-term memory

A plethora of research demonstrates that the processing of emotional faces is prioritised over non-emotive stimuli when cognitive resources are limited (this is known as ‘emotional superiority’). However, there is debate as to whether competition for processing resources results in emotional superiority per se, or more specifically, threat superiority. Therefore, to investigate prioritisation of emotional stimuli for storage in visual short-term memory (VSTM), we devised an original VSTM report procedure using schematic (angry, happy, neutral) faces in which processing competition was manipulated. In Experiment 1, display exposure time was manipulated to create competition between stimuli. Participants (n = 20) had to recall a probed stimulus from a set size of four under high (150 ms array exposure duration) and low (400 ms array exposure duration) perceptual processing competition. For the high competition condition (i.e. 150 ms exposure), results revealed an emotional superiority effect per se. In Experiment 2 (n = 20), we increased competition by manipulating set size (three versus five stimuli), whilst maintaining a constrained array exposure duration of 150 ms. Here, for the five-stimulus set size (i.e. maximal competition) only threat superiority emerged. These findings demonstrate attentional prioritisation for storage in VSTM for emotional faces. We argue that task demands modulated the availability of processing resources and consequently the relative magnitude of the emotional/threat superiority effect, with only threatening stimuli prioritised for storage in VSTM under more demanding processing conditions. Our results are discussed in light of models and theories of visual selection, and not only combine the two strands of research (i.e. visual selection and emotion), but highlight a critical factor in the processing of emotional stimuli is availability of processing resources, which is further constrained by task demands

Effects of Aversive Stimuli on Prospective Memory. An Event-Related fMRI Study

Prospective memory (PM) describes the ability to execute a previously planned action at the appropriate point in time. Although behavioral studies clearly showed that prospective memory performance is affected by the emotional significance attributed to the intended action, no study so far investigated the brain mechanisms subserving the modulatory effect of emotional salience on PM performance. The general aim of the present study was to explore brain regions involved in prospective memory processes when PM cues are associated with emotional stimuli. In particular, based on the hypothesised critical role of the prefrontal cortex in prospective memory in the presence of emotionally salient stimuli, we expected a stronger involvement of aPFC when the retrieval and execution of the intended action is cued by an aversive stimulus. To this aim BOLD responses of PM trials cued by aversive facial expressions were compared to PM trials cued by neutral facial expressions. Whole brain analysis showed that PM task cued by aversive stimuli is differentially associated with activity in the right lateral prefrontal area (BA 10) and in the left caudate nucleus. Moreover a temporal shift between the response of the caudate nucleus that preceded that of aPFC was observed. These findings suggest that the caudate nucleus might provide an early analysis of the affective properties of the stimuli, whereas the anterior lateral prefrontal cortex (BA10) would be involved in a slower and more deliberative analysis to guide goal-directed behaviour