Central Processing Mechanisms Research Articles

NMDA receptor within nucleus accumbens shell regulates propofol self-administration through D1R/ERK/CREB signalling pathway.

Addictive properties of propofol have been demonstrated in both humans and animals. The nucleus accumbens (NAc) shell (NAsh) in the brain, along with the interactions between N-methyl-D-aspartate receptor (NMDAR) and the dopamine D1 receptor (D1R), as well as their downstream ERK/CREB signalling pathway in the NAc, are integral in regulating reward-seeking behaviour. Nevertheless, it remains unclear whether NMDARs and the NMDAR-D1R/ERK/CREB signalling pathway in the NAsh are involved in mediating propofol addiction. To investigate it, we conducted experiments with adult male Sprague-Dawley rats to establish a model of propofol self-administration behaviour. Subsequently, we microinjected D-AP5 (a competitive antagonist of NMDARs, 1.0-4.0μg/0.3μL/site) or vehicle into bilateral NAsh in rats that had previously self-administered propofol to examine the impact of NMDARs within the NAsh on propofol self-administration behaviour. Additionally, we examined the protein expressions of NR2A and NR2B subunits, and the D1R/ERK/CREB signalling pathways within the NAc. The results revealed that propofol administration behaviour was enhanced by D-AP5 pretreatment in NAsh, accompanied by elevated expressions of phosphorylation of NR2A (Tyr1246) and NR2B (Tyr1472) subunits. There were statistically significant increases in the expressions of D1Rs, as well as in the phosphorylated ERK1/2 (p-ERK1/2) and CREB (p-CREB). This evidence substantiates a pivotal role of NMDARs in the NAsh, with a particular emphasis on the NR2A and NR2B subunits, in mediating propofol self-administration behaviour. Furthermore, it suggests that this central reward processing mechanism may operate through the NMDAR-D1R/ERK/CREB signal transduction pathway.

Central Sensitization in Patients with Chronic Pain Secondary to Carpal Tunnel Syndrome and Determinants.

Central sensitization (CS) is commonly seen in chronic pain disorders, including neuropathic pain. However, there exist inconsistencies concerning the presence of CS in chronic pain secondary to carpal tunnel syndrome (CTS). CS and neuropathic pain manifestations in CTS remain not well established. Therefore, this study aims to investigate the CS and pain profiles in patients with CTS and to explore the potential determinants associated with CS. Patients with suspected CTS symptoms lasting 3 months or above and healthy controls were enrolled. History, physical examinations, and nerve conduction studies were employed to confirm the diagnosis and severity of median nerve dysfunction. The central sensitization inventory (CSI) was used to screen CS. Other outcomes included neuropathic pain, CTS-specific symptom severity and functions, emotion, and health-related quality of life. Between-group comparisons were conducted in terms of the CS presence. Logistic regression analysis was performed to identify determinants associated with CS. Over 60% of participants with CTS were found with clinical CS, significantly higher than that in the control group. More than 70% of the CTS participants were identified to have possible or very likely neuropathic pain components. In addition, one-fourth of CTS cases had depression or anxiety. Anxiety was associated with an increased risk of developing CS in CTS (adjusted OR=1.31, 95% CI 1.08-1.59), whereas higher self-perceived general health rating was negatively associated with the presence of CS (adjusted OR=0.92, 95% CI 0.88-0.97) in the multivariate adjusted regression model. CS is prevalent in patients with CTS. Predominant neuropathic pain characteristics were uncovered in CTS patients as well as comorbid psychological distress. Significant association was found between anxiety and CS presence. Self-perceived general health was inversely related to CS. Further research is warranted to explore the mechanisms of anxiety and central pain processing in painful entrapment neuropathy.

Altered effective connectivity from cerebellum to motor cortex in chronic low back pain: A multivariate pattern analysis and spectral dynamic causal modeling study

To explore the central processing mechanism of pain perception in chronic low back pain (cLBP) using multi-voxel pattern analysis (MVPA) based on the static and dynamic fractional amplitude of low-frequency fluctuations (fALFF) analysis, and spectral dynamic causal modeling (spDCM). Thirty-two patients with cLBP and 29 matched healthy controls (HCs) for the first cohort and 24 patients with cLBP and 22 HCs for the validation cohort underwent resting-state fMRI scan. The alterations in static and dynamic fALFF were as classification features to distinguish patients with cLBP from HCs. The brain regions gotten from the MVPA results were used for further spDCM analysis. We found that the most discriminative brain regions that contributed to the classification were the right supplementary motor area (SMA.R), left paracentral lobule (PCL.L), and bilateral cerebellar Crus II. The spDCM results displayed decreased excitatory influence from the bilateral cerebellar Crus II to PCL.L in patients with cLBP compared with HCs. Moreover, the conversion of effective connectivity from the bilateral cerebellar Crus II to SMA.R from excitatory influence to inhibitive influence, and the effective connectivity strength exhibited partially mediated effects on Chinese Short Form Oswestry Disability Index Questionnaire (C-SFODI) scores. Our findings suggest that the cerebellum and its weakened or inhibited connections to the motor cortex may be one of the underlying feedback pathways for pain perception in cLBP, and partially mediate the degree of dysfunction.

Processing of food stimuli in anorexia nervosa: An ERP-study comparing adolescents and adults.

Anorexia nervosa (AN) is associated with altered processing of disorder-relevant stimuli. Event-related potentials (ERP) - such as the Late Positive Potential (LPP) - give information about the underlying mechanisms of central nervous stimulus processing. Patients with AN (22 adolescents, 23 adults) and healthy controls (HCs; 17 adolescents, 24 adults) were included. Neutral, low, and high calorie food-images were rated for valence and arousal; EEG activity was recorded and LPPs (early: 350-700ms; late: 800-1200ms) were extracted. Effects of patient status, age group, and stimulus category were analyzed via mixed 2×2×3-AN(C)OVAs. Patients with AN rated high calorie stimuli lower in valence and higher in arousal than HCs. Controlling for hunger, food stimuli elicited higher early LPPs than neutral ones in patients and HCs. For the late LPP, patients with AN showed larger amplitudes. Results suggest a highly automatic attentional bias towards low-calorie foods. Patients with AN seem to have more intense cognitive processing independent of stimulus material. More research is needed to validate and clarify differences between early and late LPP measures as well as the operationalization and relevance of hunger status.

Colour and melanopsin mediated responses in the murine retina.

Introduction: Intrinsically photosensitive retinal ganglion cells (ipRGCs) integrate melanopsin and rod/cone-mediated inputs to signal to the brain. Whilst originally identified as a cell type specialised for encoding ambient illumination, several lines of evidence indicate a strong association between colour discrimination and ipRGC-driven responses. Thus, cone-mediated colour opponent responses have been widely found across ipRGC target regions in the mouse brain and influence a key ipRGC-dependent function, circadian photoentrainment. Although ipRGCs exhibiting spectrally opponent responses have also been identified, the prevalence of such properties have not been systematically evaluated across the mouse retina or yet been found in ipRGC subtypes known to influence the circadian system. Indeed, there is still uncertainty around the overall prevalence of cone-dependent colour opponency across the mouse retina, given the strong retinal gradient in S and M-cone opsin (co)-expression and overlapping spectral sensitivities of most mouse opsins. Methods: To address this, we use photoreceptor isolating stimuli in multielectrode recordings from human red cone opsin knock-in mouse (Opn1mwR) retinas to systematically survey cone mediated responses and the occurrence of colour opponency across ganglion cell layer (GCL) neurons and identify ipRGCs based on spectral comparisons and/or the persistence of light responses under synaptic blockade. Results: Despite detecting robust cone-mediated responses across the retina, we find cone opponency is rare, especially outside of the central retina (overall ~3% of GCL neurons). In keeping with previous suggestions we also see some evidence of rod-cone opponency (albeit even more rare under our experimental conditions), but find no evidence for any enrichment of cone (or rod) opponent responses among functionally identified ipRGCs. Conclusion: In summary, these data suggest the widespread appearance of cone-opponency across the mouse early visual system and ipRGC-related responses may be an emergent feature of central visual processing mechanisms.

Neurophysiological Basis of Deep Brain Stimulation and Botulinum Neurotoxin Injection for Treating Oromandibular Dystonia.

Oromandibular dystonia (OMD) induces severe motor impairments, such as masticatory disturbances, dysphagia, and dysarthria, resulting in a serious decline in quality of life. Non-invasive brain-imaging techniques such as electroencephalography (EEG) and magnetoencephalography (MEG) are powerful approaches that can elucidate human cortical activity with high temporal resolution. Previous studies with EEG and MEG have revealed that movements in the stomatognathic system are regulated by the bilateral central cortex. Recently, in addition to the standard therapy of botulinum neurotoxin (BoNT) injection into the affected muscles, bilateral deep brain stimulation (DBS) has been applied for the treatment of OMD. However, some patients' OMD symptoms do not improve sufficiently after DBS, and they require additional BoNT therapy. In this review, we provide an overview of the unique central spatiotemporal processing mechanisms in these regions in the bilateral cortex using EEG and MEG, as they relate to the sensorimotor functions of the stomatognathic system. Increased knowledge regarding the neurophysiological underpinnings of the stomatognathic system will improve our understanding of OMD and other movement disorders, as well as aid the development of potential novel approaches such as combination treatment with BoNT injection and DBS or non-invasive cortical current stimulation therapies.

Odor mixture perception during flavor consumption in rats.

Odor mixtures can be perceived as configural (i.e., different from their components) or elemental (i.e., similar to their components). Previous work demonstrates that these perceptual modes are determined by both peripheral and central interactions among mixture components. Flavor consumption is associated with unique peripheral and central odor processing mechanisms, but how this context affects perception of odor mixtures remains unknown. Here, we used a flavor consumption task in rats to measure preferences for solutions of binary odor mixtures and their components. In contrast to previous findings using identical mixtures in other contexts, our results demonstrate that rats employ elemental mixture processing strategies in the context of consumption. We discuss potential peripheral and central mechanisms that could explain unique mixture perception during consumption. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Halo Sport Transcranial Direct Current Stimulation Improved Muscular Endurance Performance and Neuromuscular Efficiency During an Isometric Submaximal Fatiguing Elbow Flexion Task.

The present study examined the effects of transcranial direct current stimulation (tDCS) using Halo Sport on the time to exhaustion (TTE) in relation with muscle activities and corticomuscular coupling of agonist and antagonist muscles during a sustained isometric fatiguing contraction performed with the elbow flexors. Twenty healthy male college students were randomly assigned to tDCS group and control group. The two group participants performed two experimental sessions which consisted of pre-fatigue isometric maximal voluntary contraction (MVC), sustained submaximal voluntary contractions (30% maximal torque) performed to exhaustion, and post-fatigue MVC with the right elbow flexor muscles. Sham stimulation (90 s) and tDCS (20 min) were applied for control and tDCS group participants 20 min prior to the second session test, respectively. MVC strength in pre- and post-fatigue test, TTE, electroencephalogram (EEG), and electromyography (EMG) of biceps brachii (BB) and triceps brachii (TB) were recorded during the tests. It was found that tDCS using the Halo Sport device significantly increased TTE and thus improved muscular endurance performance. The improvement may be partly related to the improvement of neuromuscular efficiency as reflected by decrease of antagonistic muscle coactivation activities, which may be related to cortical originated central processing mechanism of neuromuscular activities.

Evaluation Of Central Auditory Function In Migraine Patients

Abstract Background Migraine is a neurological disease associated with abnormal excitability in visual, somatosensory and motor cortex. Previous researches reported abnormalities in the auditory brainstem response (ABR) and in vestibular functions. These results are an indicator of impending auditory malfunction in Migraine and disruption of central auditory processing mechanisms. Objectives This study aimed to assess and compare central auditory processing (CAP) performance in migraine patients with and without dizziness and healthy controls. Subjects and method Sixty subjects aged between18 and 60 years divided into 3 groups; control group (twenty normal healthy subjects), study group I (twenty subject diagnosed with migraine) and study group II (twenty subjects diagnosed with vestibular migraine). They were subjected to a headache sheet, central auditory processing questionnaire and Psychophysical central auditory tests: including Arabic Speech Intelligibility In Noise (SPIN) test for adults, Arabic Dichotic digit test, Gap In Noise (GIN) test, Duration pattern test and Arabic memory tests. Results Statistically significant difference was found between the 2 study groups and control group regarding right dichotic (p = 0.004),right and left duration pattern tests (p = 0.01) with highly statistically significant difference(p < 0.001) Gap In Noise (GIN) test, left dichotic digit test, right and left speech in noise. But there was no statistically significant difference between the two study groups regarding all tests. Conclusions Patients with migraine and vestibular migraine had poor performance in all central auditory tests when compared with control this mean that migraine lead to impaired central auditory processing in adults. Also, there was no significant difference between the 2 study groups regarding central auditory test results which may support that both migraine with and without dizziness have the same pathophysiology.

THE EFFECT OF FULL AND PARTIAL MAPPING ON SOUND LOCALIZATION AND CONSONANT RECOGNITION ABILITIES IN CI USERS

Sound localization is an auditory skill that allows identification of an acoustic signal in space. It’s dependent on two mechanisms; a peripheral mechanism that includes signal comparison between right and left ears of a normal hearing person and a central processing mechanism in the brain stem pathways.Hearing loss impairs both peripheral and central mechanisms. However, people with unilateral hearing loss have some ability to localize sound, a finding that reinforces the importance of monaural spectral cues for this purpose. Monaural ability to localize sound might be especially important for patients with unilateral cochlear implants, who base their ‘acoustic picture’ on limited acoustic data.Speech is a complex acoustic signal that is rich in both spectral and temporal features. The listener makes use of whatever spectral or temporal cues are available to help decode the incoming speech signal. Multiple redundant acoustic cues can contribute to the perception of a single phonemic contrast. CI processing preserves the slowly varying temporal envelope information in the speech signal (i.e., cues related to amplitude changes over time) but provides only a coarse representation of the spectral envelope.

Illusion of SNS influence: are popular SNS influential

People influence each other in the environment of social networking sites (SNS). Some SNS have gained popularity. Practitioners and researchers assume that these popular SNS are influential. However, influence and popularity are two different concepts. This research aims to provide two clear concepts of influence and popularity as well as their relationship. Popularity is hypothesised that it is affected by elements in the surroundings (e.g. societal position of a SNS owner) of SNS based on a peripheral information processing mechanism, whereas influence is hypothesised that it is affected by core elements (e.g. quality of content on a SNS message) of SNS based on a central information processing mechanism. The results indicate that influence is solely affected by the central information processing mechanism, but popularity is affected by both central and peripheral information processing mechanisms. There is a relationship between influence and popularity but it is marginal. Therefore, it should not be assumed that popular SNS are influential and vice versa.

Organ of Corti vibration within the intact gerbil cochlea measured by volumetric optical coherence tomography and vibrometry

There is indirect evidence that the mammalian cochlea in the low-frequency apical and the more commonly studied high-frequency basal regions function in fundamentally different ways. Here, we directly tested this hypothesis by measuring sound-induced vibrations of the organ of Corti (OoC) at three turns of the gerbil cochlea using volumetric optical coherence tomography vibrometry (VOCTV), an approach that permits noninvasive imaging through the bone. In the apical turn, there was little frequency selectivity, and the displacement-vs.-frequency curves had low-pass filter characteristics with a corner frequency of ~0.5-0.9 kHz. The vibratory magnitudes increased compressively with increasing stimulus intensity at all frequencies. In the middle turn, responses were similar except for a slight peak in the response at ~2.5 kHz. The gain was ~50 dB at the peak and 30-40 dB at lower frequencies. In the basal turn, responses were sharply tuned and compressively nonlinear, consistent with observations in the literature. These data demonstrated that there is a transition of the mechanical response of the OoC along the length of the cochlea such that frequency tuning is sharper in the base than in the apex. Because the responses are fundamentally different, it is not appropriate to simply frequency shift vibratory data measured at one cochlear location to predict the cochlear responses at other locations. Furthermore, this means that the number of hair cells stimulated by sound is larger for low-frequency stimuli and smaller for high-frequency stimuli for the same intensity level. Thus the mechanisms of central processing of sounds must vary with frequency. NEW & NOTEWORTHY A volumetric optical coherence tomography and vibrometry system was used to probe cochlear mechanics within the intact gerbil cochlea. We found a gradual transition of the mechanical response of the organ of Corti along the length of the cochlea such that tuning at the base is dramatically sharper than that at the apex. These data help to explain discrepancies in the literature regarding how the cochlea processes low-frequency sounds.

The role of central processing in modulation masking release

When background sound is present, hearing impaired (HI) individuals and cochlear-implant (CI) listeners typically are worse at hearing out target sound as compared to normal-hearing (NH) listeners. This perceptual deficit occurs both when the background consists of noise that fluctuates over time (“modulated”) and for stationary background noise (“unmodulated”). In addition, the difference in thresholds between tone detection in modulated and unmodulated noise, referred to as modulation masking release (MMR), is much reduced or absent in HI and CI as compared to NH. Both peripheral and central processing mechanisms contribute to MMR. We previously showed that central MMR is reduced in human CI listeners, and that sound deprivation reduces central MMR in Mongolian gerbils. Here, we began to explore the neurobiological basis of central MMR. NH gerbils were trained to hear out target tones (1 kHz) in modulated (10-Hz rectangularly gated) versus unmodulated bandlimited background noise, and chronically implanted with recording electrodes in core auditory cortex. Neural discharge was analyzed as a function of the broadband energy ratio between target and background sound to determine how different types of background sound affect neural information transmission in awake behaving gerbil. Preliminary results will be discussed in the context of how hearing loss may affect central MMR.

Does changes in mismatch negativity after tinnitus retraining therapy using tinnitus pitch as deviant stimulus, reflect subjective improvement in tinnitus handicap?

Objective: The objective of this research was to study the ability of Mismatch Negativity response parameters to assess the habituation after Tinnitus Retraining Therapy through comparing MMN parameters before and after TRT and comparing MMN in tinnitus patients to non-tinnitus patients, and correlating MMN parameters to subjective measures of tinnitus.Methodology: This research included two groups: a tinnitus group of 30 tinnitus patients who were compared with a control group that consisted of well-matched 10 normal adult subjects. All participants were subjected to full history taking, audiological examination, and MMN test. Tinnitus patients were further assessed for tinnitus severity using the Tinnitus Handicap Inventory (THI), tinnitus analyses including pitch and loudness matching, with the PMF as the deviant stimulus for the MMN test.Results: The MMN latencies were significantly shorter and the MMN amplitudes were significantly greater in the tinnitus group before TRT than the control group. The MMN amplitude after TRT has significantly decreased and the MMN latency has significantly been prolonged in both ears after TRT compared with before TRT. The MMN amplitude improvement matched the subjective improvement measured subjectively by the THI.Conclusion: Tinnitus patients showed abnormality in central auditory processing mechanisms involved in pre-attentive change detection of tinnitus-related neuronal activity. This MMN abnormality showed improvement after habituation using TRT. So, we recommend adding the MMN test in evaluating tinnitus patients objectively before and after TRT for monitoring the treatment progress, together with the usual subjective measures for assessment of the degree of tinnitus severity.

Delineation between different components of chronic pain using dimension reduction - an ASL fMRI study in hand osteoarthritis.

BackgroundTraditional psychometric measures aimed at characterizing the pain experience often show considerable overlap, due to interlinked affective and modulatory processes under central nervous system control. Neuroimaging studies have been employed to investigate this complexity of pain processing, in an attempt to provide a quantifiable, adjunctive description of pain perception. In this exploratory study, we examine psychometric and neuroimaging data from 38 patients with painful osteoarthritis of the carpometacarpal joint. We had two aims: first, to utilize principal component analysis (PCA) as a dimension reduction strategy across multiple self‐reported endpoints of pain, cognitive and affective functioning; second, to investigate the relationship between identified dimensions and regional cerebral blood flow (rCBF) as an indirect measure of brain activity underpinning their ongoing pain experiences.MethodsPsychometric data were collected using validated questionnaires. Quantitative estimates of rCBF were acquired using pseudo‐continuous arterial spin‐labelled functional magnetic resonance imaging.ResultsTwo principal components were identified that accounted for 73% of data variance; one related to pain scores and a second to psychological traits. Voxel‐wise multiple regression analysis revealed a significant negative association between the ‘pain score’ component and rCBF to a right temporal lobe cluster, including the amygdala and the parahippocampal cortex.ConclusionWe suggest this association may represent a coping mechanism that aims to reduce fear‐related pain‐anxiety. Further investigation of central brain processing mechanisms in osteoarthritis‐related pain may offer insights into more effective therapeutic strategies.SignificanceThis study demonstrates that dimension reduction using PCA allows insight into pain perception and its affective components in relation to brain activation patterns in patients with painful hand osteoarthritis.

Influence of working memory on stimulus generalization in anomia treatment: A pilot study

Abstract Neuropsychological testing of distinct cognitive domains holds promise as a prognostic indicator of aphasia therapy success; however, it is unclear the degree to which cognitive assessments may also predict generalization abilities. The present study aimed to assess the relationship between working memory skills and stimulus generalization from a visual picture-naming treatment to an auditory definition-naming task. Seven individuals with aphasia completed verbal and nonverbal assessments of working memory prior to participating in a cued picture-naming treatment for anomia. After treatment ended, stimulus generalization percentages were calculated for definition naming for the same items that were trained using picture naming. Scores on two nonverbal working memory measures, the backward spatial span and the 1-back, and one verbal working memory assessment, the picture span, were positively correlated with generalization percentage. These results provide preliminary evidence of the relationship between working memory and stimulus generalization. When comparing performance across working memory measures, the spatial span and the picture span were highly correlated in this sample. We propose that despite the verbal and nonverbal distinction, these tasks may have tapped into working memory similarly by relying on a shared central processing mechanism.

Consumer responses to sport organizations’ corporate social responsibility initiatives: A focus on moral emotions

Purpose Sport has become a popular platform for corporate social responsibility (CSR) campaigns. Growing numbers of athletes, teams, and organizations are engaging in CSR campaigns to promote awareness and behaviors to support CSR campaigns addressing pressing social issues (e.g., disease prevention, health promotion, etc.). However, much of the previous work has focused on whether such initiatives benefit the organization, but not the community. The present paper provides theoretical explanations on the psychological mechanism that can demonstrate how consumers respond to CSR campaigns initiated by a sport organization Method In particular, existing literatures in moral psychology and CSR have been reviewed to identify an explanatory mechanism that promote prosocial behavior among sport consumers Results The present paper posits that moral emotion is a central processing mechanism explaining the link between CSR and socially responsible behaviors in consumers. The paper also provides a theoretical account to explain how moral emotions are evoked in the CSR context and how they can prompt prosocial behaviors Conclusion This paper adds to the literature by answering the call for the need to understand underlying mechanisms linking CSR with positive social outcomes (cf. Aguinis & Glavas, 2012).

Mutual transfer between visual and auditory temporal interval learning supports a central clock in temporal processing

Temporal perceptual learning shows specificity to the visual or auditory modality, or asymmetric partial transfer from auditory to visual, but not vice versa. These findings are interpreted as evidence for distributed, rather than central, temporal processing (Ivry & Schlerf, 2008). For visual perceptual learning, location and orientation specificity can be eliminated with double training, indicating that learning specificity may not be used to infer the mechanisms of perceptual learning (e.g., Xiao et al., 2008). Here we investigated whether double training can eliminate the modality specificity in temporal learning. We first replicated asymmetric partial transfer results between auditory and visual learning of a temporal-interval discrimination (TID) task with standard training. The standard interval was marked by a pair of auditory beeps or visual gratings at 100-ms. The subjects practiced either the auditory or the visual TID task for 5 sessions. Visual TID learning had no impact on auditory TID performance (p=0.65), while auditory TID learning improved visual TID performance (p=0.005), although not as much as direction visual TID learning (p=0.028). However, complete learning transfer was evident with double-training. When visual TID learning was paired with an auditory frequency discrimination task at the same 100-ms interval, auditory TID performance was improved similarly to direct auditory training (p=0.051), indicating complete cross-modal learning transfer. Similarly, when auditory TID learning was paired with a visual contrast discrimination task at the same 100-ms interval, visual TID performance was improved equally as direct visual training (p=0.95), again indicating complete cross-modal learning transfer. In both cases we found no significant impact of practicing auditory frequency discrimination or visual contrast discrimination alone on TID performance. Our results suggest mutual and nearly complete learning transfer of TID learning between visual and auditory modalities, which are consistent with a central temporal processing mechanism shared by different modalities.

THE INTERNATIONAL LAW ON THE PROTECTION OF CULTURAL HERITAGE

We present a comprehensive analysis of the concept of cultural heritage and the institutionalisation of its protection by the international law in various historical contexts of involved states, i.e., during peace, conflict, social and/or political crisis. Furthermore, we discuss the human dimension of the protection of cultural heritage at an international level under the public international law. In particular, we first investigate whether states remain central actors at national and international level as far as the protection of cultural property within their territory is concerned. Subsequently, we examine the limitations imposed on the action range of a state due to primary and secondary legislation of international organizations where the state participates. Apart from this form of external pressure on the state jurisdiction, we also examine whether the action range of a state is further limited by the action of individuals and groups. Furthermore, we discuss on the potential role of international human rights law in such situations, the interdependence between the protection of individuals and cultural goods as well as whether the individual is transformed into an active actor of international law. Our analysis clearly suggests that international organizations play a catalytic role in cultural protection at an international level, with UNESCO holding a leading position. UNESCO forms a central processing mechanism for international protection standards and seems to be the main forum for monitoring compliance of states with international protection standards. However, an issue that certainly deserves further investigation is whether UNESCO can be actually efficient in the absence of ratification mechanisms regarding cultural protection. Our approach and methodology involves thorough analysis of concepts, review of historical developments in international law regarding the protection of cultural heritage, review of the activities of international organizations as well as the description of the existing legal framework. Results of our study suggest that the issue of cultural heritage protection is multidimensional and involves not only states but also individuals who are holders of rights and obligations regarding cultural heritage protection. In addition, our results clearly imply that there is still room for improvement in the continuously evolving international law towards the establishment of a more satisfactory framework for the protection of cultural heritage.

The bioinspiring potential of weakly electric fish

Electric fish are privileged animals for bio-inspiring man-built autonomous systems since they have a multimodal sense that allows underwater navigation, object classification and intraspecific communication. Although there are taxon dependent variations adapted to different environments, this multimodal system can be schematically described as having four main components: active electroreception, passive electroreception, lateral line sense and, proprioception. Amongst these sensory modalities, proprioception and electroreception show ‘active’ systems that extrct information carried by self generated forms of energy. This ensemble of four sensory modalities is present in African mormyriformes and American gymnotiformes. The convergent evolution of similar imaging, peripheral encoding, and central processing mechanisms suggests that these mechanisms may be the most suitable for dealing with electric images in the context of the other and self generated actions. This review deals with the way in which biological organisms address three of the problems that are faced when designing a bioinspired electroreceptive agent: (a) body shape, material and mobility, (b) peripheral encoding of electric images, and (c) early processing of electrosensory signals. Taking into account biological solutions I propose that the new generation of underwater agents should have electroreceptive arms, use complex peripheral sensors for encoding the images and cerebellum like architecture for image feature extraction and implementing sensory-motor transformations.