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 recognition and inhibitory control in manifest and pre-manifest Huntington's disease: evidence from a new Stroop task.

Huntington's disease (HD) is a genetic neurodegenerative disorder that affects not only the motor but also the cognitive domain. In particular, cognitive symptoms such as impaired executive skills and deficits in recognizing other individuals' mental state may emerge many years before the motor symptoms. This study was aimed at testing two cognitive hypotheses suggested by previous research with a new Stroop task created for the purpose: 1) the impairment of emotion recognition in HD is moderated by the emotions' valence, and 2) inhibitory control is impaired in HD. Forty manifest and 20 pre-manifest HD patients and their age- and gender-matched controls completed both the traditional "Stroop Color and Word Test" (SCWT) and the newly created "Stroop Emotion Recognition under Word Interference Task" (SERWIT), which consist in 120 photographs of sad, calm, or happy faces with either congruent or incongruent word interference. On the SERWIT, impaired emotion recognition in manifest HD was moderated by emotion type, with deficits being larger in recognizing sadness and calmness than in recognizing happiness, but it was not moderated by stimulus congruency. On the SCWT, six different interference scores yielded as many different patterns of group effects. Overall our results corroborate the hypothesis that impaired emotion recognition in HD is moderated by the emotions' valence, but do not provide evidence for the hypothesis that inhibitory control is impaired in HD. Further research is needed to learn more about the psychological mechanisms underlying the moderating effect of emotional valence on impaired emotion recognition in HD, and to corroborate the hypothesis that the inhibitory processes involved in Stroop tasks are not impaired in HD. Looking beyond this study, the SERWIT promises to make important contributions to disentangling the cognitive and the psychomotor aspects of neurological disorders. The research was approved by the Ethics Committee of the "Istituto Leonarda Vaccari", Rome on January 24, 2018.

Effects of stimulus-related variables on mental states recognition in Huntington's disease.

BACKGROUND: Cognitive abnormalities in Huntington's Disease (HD) can involve the specific impairment of the social perspective taking as well as difficulties in recognizing others' mental state many years before the onset of motor symptoms. AIMS: At the scope of assessing how the difficulties in mental state recognition might be an HD early sign before motor symptoms appear, our study was aimed to investigate how the recognition of others' mental states in HD subjects is moderated by different stimulus related features (gender, difficulty (low, medium, high), and valence (positive, negative, neutral) of the mental states that are to be recognized). METHODS: Subjects with premanifest (n = 20) and manifest (n = 40) HD performed the revised 'Reading the Mind in the Eyes Test' and were compared with age-matched healthy controls (HC, 40 subjects per cohort). RESULTS: Our results highlight an early impairment in mental state recognition preceding manifest HD symptoms and a deterioration of these abilities with HD progression. Moreover, we found in HD premanifest subjects an impairment concerning the recognition of negative and neutral mental states, as well as of mental states with moderate recognition difficulty. Finally, we found that participant gender did not influence the performance in recognizing others' mental states, while all participants recognized mental states displayed by females more accurately than those displayed by males. CONCLUSIONS: We conclude that difficulties in the recognition of complex mental states can be considered as an early sign of HD, before evident behavioral manifestations, and peculiar features of the stimulus influence it.

Patients with moderate Alzheimer's disease engage in verbal reminiscence with the support of a computer-aided program: a pilot study.

This study focused on the assessment of a program recently developed for helping patients with moderate Alzheimer's disease engage in computer-mediated verbal reminiscence (Lancioni et al., 2014a). Sixteen participants were involved in the study. Six of them used the original program version with the computer showing a virtual partner posing questions and providing attention and guidance. The other 10 used a slightly modified program version with the computer presenting photos and videos and providing encouragements to talk as well as attention and guidance. Participants were exposed to brief program sessions individually. The results showed that 15 participants (five of those using the first version and all of those using the second version) had a clear and lasting increase in verbal engagement/reminiscence during the intervention sessions with the program. Those 15 participants had mean percentages of intervals with verbal engagement/reminiscence below 10 during baseline and between about 45 and 75 during the intervention. The results' implications and the need for new research were discussed.

Supporting self-managed leisure engagement and communication in post-coma persons with multiple disabilities.

Post-coma persons affected by extensive motor impairment and lack of speech, with or without disorders of consciousness, need special support to manage leisure engagement and communication. These two studies extended research efforts aimed at assessing basic technology-aided programs to provide such support. Specifically, Study I assessed a program for promoting independent stimulation choice in four post-coma persons who combined motor and speech disabilities with disorders of consciousness (i.e., were rated between the minimally conscious state and the emergence from such state). Study II assessed a program for promoting independent television operation and basic communication in three post-coma participants who, contrary to those involved in Study I, did not have disorders of consciousness (i.e., had emerged from a minimally conscious state). The results of the studies were largely positive with substantial levels of independent stimulation choice and access for the participants of Study I and independent television operation and communication for the participants of Study II. The results were analyzed in relation to previous data in the area and in terms of their implications for daily contexts dealing with these persons.

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.

The representation of conceptual knowledge: visual, auditory, and olfactory imagery compared with semantic processing.

Two experiments comparing imaginative processing in different modalities and semantic processing were carried out to investigate the issue of whether conceptual knowledge can be represented in different format. Participants were asked to judge the similarity between visual images, auditory images, and olfactory images in the imaginative block, if two items belonged to the same category in the semantic block. Items were verbally cued in both experiments. The degree of similarity between the imaginative and semantic items was changed across experiments. Experiment 1 showed that the semantic processing was faster than the visual and the auditory imaginative processing, whereas no differentiation was possible between the semantic processing and the olfactory imaginative processing. Experiment 2 revealed that only the visual imaginative processing could be differentiated from the semantic processing in terms of accuracy. These results showed that the visual and auditory imaginative processing can be differentiated from the semantic processing, although both visual and auditory images strongly rely on semantic representations. On the contrary, no differentiation is possible within the olfactory domain. Results are discussed in the frame of the imagery debate.

Attention and P300-based BCI performance in people with amyotrophic lateral sclerosis.

The purpose of this study was to investigate the support of attentional and memory processes in controlling a P300-based brain-computer interface (BCI) in people with amyotrophic lateral sclerosis (ALS). Eight people with ALS performed two behavioral tasks: (i) a rapid serial visual presentation (RSVP) task, screening the temporal filtering capacity and the speed of the update of the attentive filter, and (ii) a change detection task, screening the memory capacity and the spatial filtering capacity. The participants were also asked to perform a P300-based BCI spelling task. By using correlation and regression analyses, we found that only the temporal filtering capacity in the RSVP task was a predictor of both the P300-based BCI accuracy and of the amplitude of the P300 elicited performing the BCI task. We concluded that the ability to keep the attentional filter active during the selection of a target influences performance in BCI control.

The relationship between 'theory of mind' and attachment-related anxiety and avoidance in Italian adolescents.

This study examined the relationship between 'theory of mind' and attachment-related anxiety and avoidance in adolescence. The "Reading the Mind in the Eyes" test and the "Experiences in Close Relationships - Relationship Structures" questionnaires were administered to 402 14-19 year-old adolescents. Contrary to expectations, anxiety but not avoidance with mother was associated with less accurate mindreading, and this effect was stronger in younger than in older adolescents. Results might be explained in terms of the inconsistency of caregiver behavior that is supposed to cause anxious strategies, and thus illustrate the need to consider not only the effects, but also the causes of different types of insecure strategies.

ViSA: a neurodynamic model for visuo-spatial working memory, attentional blink, and conscious access.

Two separate lines of study have clarified the role of selectivity in conscious access to visual information. Both involve presenting multiple targets and distracters: one simultaneously in a spatially distributed fashion, the other sequentially at a single location. To understand their findings in a unified framework, we propose a neurodynamic model for Visual Selection and Awareness (ViSA). ViSA supports the view that neural representations for conscious access and visuo-spatial working memory are globally distributed and are based on recurrent interactions between perceptual and access control processors. Its flexible global workspace mechanisms enable a unitary account of a broad range of effects: It accounts for the limited storage capacity of visuo-spatial working memory, attentional cueing, and efficient selection with multi-object displays, as well as for the attentional blink and associated sparing and masking effects. In particular, the speed of consolidation for storage in visuo-spatial working memory in ViSA is not fixed but depends adaptively on the input and recurrent signaling. Slowing down of consolidation due to weak bottom-up and recurrent input as a result of brief presentation and masking leads to the attentional blink. Thus, ViSA goes beyond earlier 2-stage and neuronal global workspace accounts of conscious processing limitations.

Promoting adaptive behavior in persons with acquired brain injury, extensive motor and communication disabilities, and consciousness disorders.

These two studies extended the evidence on the use of technology-based intervention packages to promote adaptive behavior in persons with acquired brain injury and multiple disabilities. Study I involved five participants in a minimally conscious state who were provided with intervention packages based on specific arrangements of optic, tilt, or pressure microswitches (linked to preferred environmental stimuli) and eyelid, toe and finger responses. Study II involved three participants who were emerging from a minimally conscious state and were provided with intervention packages based on computer presentations of stimulus options (i.e., preferred stimuli, functional caregiver's procedures, and non-preferred stimuli) and pressure microswitches to choose among them. Intervention data of Study I showed that the participants acquired relatively high levels of microswitch responding (thus engaging widely with preferred environmental stimuli) and kept that responding consistent except for one case. Intervention data of Study II showed that the participants were active in choosing among preferred stimuli and positive caregivers' procedures, but generally abstained from non-preferred stimuli. The results were discussed in terms of the successful use of fairly new/infrequent microswitch-response arrangements (Study I) and the profitable inclusion of functional caregiver's procedures among the options available to choice (Study II).

Toward functioning and usable brain-computer interfaces (BCIs): a literature review.

PURPOSE: The aim of this paper is to provide an exhaustive review of the literature about brain-computer interfaces (BCIs) that could be used with these paralysed patients. The electroencephalography (EEG) is the best candidate for the continuous use in the environment of patients' houses, due to its portability and ease of use. For this reason, the present paper will focus on this kind of BCI. Moreover, it is our aim to focus more on the patients, regarding their active role in the modulation of the brain activity. This leads to a differentiation between studies that use an active regulation and studies that use a non-active regulation. METHOD: Relevant articles in the BCIs field were selected using MEDLINE and PsycINFO. RESULTS: Research through data banks produced 980 results, which were reduced to 127 after exclusion criteria selection. These references were divided in four categories, based on the use of active or non-active regulation, and on the event related potential used. CONCLUSIONS: In most of the examined works, the focus was on the development of systems and algorithms able to recognise and classify brain events. Although this kind of research is fundamental, a user-centred point of view was rarely adopted. [Box: see text].

Microswitch technology and contingent stimulation to promote adaptive engagement in persons with minimally conscious state: a case evaluation.

This study assessed whether a post-coma woman functioning at the lower end of the minimally conscious state would (a) develop adaptive responding through the use of microswitch technology and contingent stimulation, (b) consolidate and maintain her responding over time, and (c) show evidence of response-consequences awareness (learning and discrimination). The study involved an ABABB1CB1 sequence in which the A represented baseline phases, the B and B1 intervention phases, and the C a control phase with continuous stimulation. Results indicated that the woman developed adaptive responding and consolidated it over the intervention phases of the study. The woman also showed evidence of being aware of response-consequences links. Potential implications and limitations of these findings are discussed.

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.

Multisensory integration affects visuo-spatial working memory.

In the present study, we investigate how spatial attention, driven by unisensory and multisensory cues, can bias the access of information into visuo-spatial working memory (VSWM). In a series of four experiments, we compared the effectiveness of spatially-nonpredictive visual, auditory, or audiovisual cues in capturing participants' spatial attention towards a location where to-be-remembered visual stimuli were or were not presented (cued/uncued trials, respectively). The results suggest that the effect of peripheral visual cues in biasing the access of information into VSWM depend on the size of the attentional focus, while auditory cues did not have direct effects in biasing VSWM. Finally, spatially congruent multisensory cues showed an enlarged attentional effect in VSWM as compared to unimodal visual cues, as a likely consequence of multisensory integration. This latter result sheds new light on the interplay between spatial attention and VSWM, pointing to the special role exerted by multisensory (audiovisual) cues.

Technology-assisted writing opportunities for a man emerged from a minimally conscious state and affected by extensive motor disabilities.

OBJECTIVE: To assess a computer-aided technology for assisting writing in a man who emerged from a minimally conscious state and presented with extensive motor disabilities. METHOD: The technology served to present letters, in groups, at the centre of a computer screen and display (write) the letters selected by the man (i.e. through a simplified pointing response) on the upper half of that screen. RESULTS: The results showed that the technology enabled the man to produce clear (readily readable) writing. This writing compared positively with the results obtained using a communication board containing the letters (i.e. a system already available to the man). CONCLUSION: Computer-aided technology may provide basic writing (communication) opportunities to persons emerged from a minimally conscious state and affected by extensive motor disabilities and lack of speech.

Influence of musical expertise on segmental and tonal processing in Mandarin Chinese.

A same-different task was used to test the hypothesis that musical expertise improves the discrimination of tonal and segmental (consonant, vowel) variations in a tone language, Mandarin Chinese. Two four-word sequences (prime and target) were presented to French musicians and nonmusicians unfamiliar with Mandarin, and event-related brain potentials were recorded. Musicians detected both tonal and segmental variations more accurately than nonmusicians. Moreover, tonal variations were associated with higher error rate than segmental variations and elicited an increased N2/N3 component that developed 100 msec earlier in musicians than in nonmusicians. Finally, musicians also showed enhanced P3b components to both tonal and segmental variations. These results clearly show that musical expertise influenced the perceptual processing as well as the categorization of linguistic contrasts in a foreign language. They show positive music-to-language transfer effects and open new perspectives for the learning of tone languages.

An overview of intervention options for promoting adaptive behavior of persons with acquired brain injury and minimally conscious state.

This paper presents an overview of the studies directed at helping post-coma persons with minimally conscious state improve their adaptive behavior. Twenty-one studies were identified for the 2000-2010 period (i.e., a period in which an intense debate has occurred about diagnostic, rehabilitative, prognostic, and ethical issues concerning people with severe acquired brain injury). Three of the 21 studies involved transcortical magnetic or deep brain stimulation. Six studies focused on the provision of multisensory stimulation or music therapy. The remaining 12 studies involved the use of response-related (contingent) stimulation and assistive technology. The outcomes of the studies, which were generally reported as positive, were discussed in terms of (a) the size (quantitative relevance) of the changes obtained, (b) the credibility/reliability of the changes, in light of the methodological conditions of the studies, and (c) the level of engagement and interaction involvement of the participants. Relevant issues for future research were also examined.

Perceptual preferences in depth stratification of transparent layers: Photometric and non-photometric factors.

In three experiments, using a two-alternative forced-choice task, we obtained depth judgments of displays containing transparent regions. The regions varied in lightness, size, and animation. Observers nearly always strongly preferred one certain depth ordering among the regions, even though their lightness conditions were expected to give rise to ambiguity among possible orderings. This expectation was based on the contrast polarity model, which expects ambiguity in the absence of contrast polarity reversal. The expectation was founded also on a stronger condition based on the transmittance anchoring principle, which gives preference to the largest lightness contrast between regions. In the absence of contrast polarity reversal and in conditions of balanced regional contrast, preferences were shown to depend on additional conditions of contrast between two respective regions and their overlap. Depth ordering judgment seems to be based on a critical decision threshold, independently of the coordinate system used to specify lightness. We also investigated the role of non-photometric factors such as motion and relative size, and concluded that these variables can modulate depth ordering judgments in transparency.

Neural correlates of focused attention and cognitive monitoring in meditation.

Meditation refers to a family of complex emotional and attentional regulatory practices, which can be classified into two main styles - focused attention (FA) and open monitoring (OM) - involving different attentional, cognitive monitoring and awareness processes. In a functional magnetic resonance study we originally characterized and contrasted FA and OM meditation forms within the same experiment, by an integrated FA-OM design. Theravada Buddhist monks, expert in both FA and OM meditation forms, and lay novices with 10 days of meditation practice, participated in the experiment. Our evidence suggests that expert meditators control cognitive engagement in conscious processing of sensory-related, thought and emotion contents, by massive self-regulation of fronto-parietal and insular areas in the left hemisphere, in a meditation state-dependent fashion. We also found that anterior cingulate and dorsolateral prefrontal cortices play antagonist roles in the executive control of the attention setting in meditation tasks. Our findings resolve the controversy between the hypothesis that meditative states are associated to transient hypofrontality or deactivation of executive brain areas, and evidence about the activation of executive brain areas in meditation. Finally, our study suggests that a functional reorganization of brain activity patterns for focused attention and cognitive monitoring takes place with mental practice, and that meditation-related neuroplasticity is crucially associated to a functional reorganization of activity patterns in prefrontal cortex and in the insula.