Perceptual Status Research Articles

Multisensory conflict affects body schema and reaching space

Multisensory integration plays a crucial role in building the sense of body ownership, i.e., the perceptual status of one’s body for which the body is perceived as belonging to oneself. Temporal and spatial mismatching of visual and tactile signals coming from one’s body can reduce ownership feelings towards the body and its parts, i.e., produce disownership feelings. Here, we investigated whether visuo–tactile conflict also affects the sensorimotor representation of the body in space (i.e., body schema) and the perception of the space around the body in terms of action potentiality (i.e., reaching space). In two experiments, body schema (Experiment 1) and reaching space (Experiment 2) were assessed before and after either synchronous or asynchronous visuo–tactile stimulation. Results showed that the asynchronous condition, provoking multisensory conflict, caused disownership over one’s hand and concurrently affected the body schema and the reaching space. These findings indicate that body schema and reaching space could be dynamically shaped by the multisensory regularities that build up the sense of body ownership.

Preliminary Observations of Personalized Repetitive Magnetic Stimulation (PrTMS) Guided by EEG Spectra for Concussion.

There are no FDA-approved treatments for the chronic sequelae of concussion. Repetitive magnetic transcranial stimulation (rTMS) has been explored as a therapy but outcomes have been inconsistent. To address this we developed a personalized rTMS (PrTMS) protocol involving continual rTMS stimulus frequency adjustment and progressive activation of multiple cortical sites, guided by spectral electroencephalogram (EEG)-based analyses and psychological questionnaires. We acquired pilot clinical data for 185 symptomatic brain concussion patients who underwent the PrTMS protocol over an approximate 6 week period. The PrTMS protocol used a proprietary EEG spectral frequency algorithm to define an initial stimulation frequency based on an anteriorly graded projection of the measured occipital alpha center peak, which was then used to interpolate and adjust regional stimulation frequency according to weekly EEG spectral acquisitions. PrTMS improved concussion indices and normalized the cortical alpha band center frequency and peak EEG amplitude. This potentially reflected changed neurotransmitter, cognitive, and perceptual status. PrTMS may be a promising treatment choice for patients with persistent concussion symptoms. This clinical observational study was limited in that there was no control group and a number of variables were not recorded, such as time since injury and levels of depression. While the present observations are indeed preliminary and cursory, they may suggest further prospective research on PrTMS in concussion, and exploration of the spectral EEG as a concussion biomarker, with the ultimate goals of confirmation and determining optimal PrTMS treatment parameters.

Perception needs modular stimulus-control

Perceptual processes differ from cognitive, this paper argues, in functioning to be causally controlled by proximal stimuli, and being modular, at least in a modest sense that excludes their being isotropic in Jerry Fodor's sense. This claim agrees with such theorists as Jacob Beck and Ben Phillips that a function of stimulus-control is needed for perceptual status. In support of this necessity claim, I argue, inter alia, that E.J. Green's recent architectural account misclassifies processes deploying knowledge of grammar as perceptual. Pace Beck and Phillips, however, I argue a function of stimulus-control is insufficient for perceptual as opposed to cognitive status. One consideration in favour of such insufficiency, noted but (I argue) not convincingly rebutted by these theorists, concerns perpetually grounded demonstrative thought. Two other considerations trade on the fact that a function of stimulus-control can arise not from blind nature but intentional design or social institutions, where so-functioning processes may but need not be perceptual. I offer two cases where such processes are cognitive, viz. skilful play-by-play announcing of ongoing events, and voluntary visualizing of ongoing events under the guidance of apt play-by-play announcements, dubbed announcement-driven visualizing (ADV). The cognitive status of these three diverse phenomena cannot be explained by an absence of a perception-like representational format or content (for ADV has such) or by a presence of personal-level mental states causally mediating between stimuli and outputs (for perception has such). A bettter explanation invokes, I argue, the non-modular character of the generating process.

THE IMPACT OF COLOUR ON STUDENTS’ PERCEPTION IN LEARNING SPACES

Color has a crucial impact on students’ perception. It encourages the learning atmosphere to be affiliated with the anticipated learning outcomes. The purpose of this study is to investigate the impacts of contextual colors on student’s perception of interior spaces and to validate previous related studies that emphasize on colors as a media to convey meanings that affect behaviors and students’ perception as well. Accordingly, the objective of this study is to determine and validate previous related studies regarding the impact of background color on student’s perception. Meanwhile the study evaluates the previous relevant models in order to validate or reject previous assumptions. The study concentrates on quantitative survey method using in depth questionnaire to determine student’s perception at UHD-University of Human Development, Sulaimani. Seven Colors from Munsell color system (yellow, green, blue, purple, white, and black, grey) are applied in the test in order to indicate the students’ perceptual status. The results show that cool colors like white, green and blue are mostly recommended for educational spaces. These colors affected positively the perception of respondents and add feeling of hope, curiosity and satisfaction to the group. In contrast dark colors (black and grey) are indicated as colors of worry and fear. The findings demonstrate that environments colors play an important effect on student’s perception. The study concluded that colors affect the behavior, performance and mood of the space users.

Monitoring Heart Rate Variability and Perceived Well-Being in Brazilian Elite Beach Volleyball Players: A Single-Tournament Pilot Study.

Nakamura, FY, Torres, VBC, da Silva, LS, Gantois, P, Andrade, AD, Ribeiro, ALB, Brasileiro-Santos, MdS, and Batista, GR. Monitoring heart rate variability and perceived well-being in Brazilian elite beach volleyball players: A single-tournament pilot study. J Strength Cond Res 36(6): 1708-1714, 2022-The aim of this study was to monitor the changes in heart rate variability (HRV) and perceptual well-being status after a beach volleyball (BV) tournament day in high-level U17 and senior players. Seventeen BV players (U17 [15-16 years]: n = 08; and senior [19-41 years]: n = 09) competing at national and/or international BV level participated in this study. Resting HRV and perceptual well-being measures were recorded across 4 moments: night 1 (prematches night), morning 1 (prematches morning), night 2 (postmatches night), and morning 2 (postmatches morning). Session rating of perceived exertion was assessed 10 minutes after each match, and accumulated match loads were used for analysis. Senior players presented higher values of natural logarithm of square root of the mean squared differences of successive RR intervals (lnRMSSD) at the 4 observation moments than U17 players (p = 0.006). Within-subjects analysis showed a larger mean difference regarding both lnRMSSD and natural logarithm SD of normal R-R intervals (lnSDNN) between night 1 vs. night 2 in U17 players (effect size = 1.11 and, 0.96, respectively) compared with senior (effect size = 0.40 and 0.32, respectively). Accumulated match loads were negatively correlated with percentage change in lnRMSSD (r = -0.54; p = 0.037). U17 players showed higher well-being variation than senior (group × time; p = 0.02). In conclusion, the lnRMSSD index was able to discriminate the U17 and senior BV players, and maintaining high vagally related HRV indices is an important response to BV training and competition.

Modulation of Body Representation Impacts on Efferent Autonomic Activity.

The afferent branch of the autonomic nervous system contributes with interoception to the multimodal sensory correlation continuously needed to update our representation of the body. To test whether the modulation of body representation would have an impact on the efferent branch of the autonomic nervous system, nonspecific skin conductance has been measured in three rubber hand illusion (RHI) experiments, controlled with asynchronous brush-stroking and incongruent fake hand position. Nonspecific skin conductance standard deviation (SCSD) computed along the whole 90 sec of stroking was found to be increased by the illusion and to correlate with all the typical measures of embodiment. Computing SCSD in shorter time windows strongly enhanced the difference between illusion and controls. The highest difference was found in the 10-55 sec window, being the 14-34 sec window as the most informative one. The higher correlations with the validated measures of embodiment (all but the proprioceptive drift) were found for time windows ranging between 35 and 65 sec. The SCSD was no longer significantly higher when the RHI was repeated twice (two trials each iteration), but it was still significantly higher in synchronous stroking even when considering only the second trial. However, after the first iteration of the RHI paradigm, the effect of the embodiment on nonspecific skin conductance response results to be attenuated, suggesting that novelty in presentation of the RHI can contribute to the effect on nonspecific skin conductance response. Results candidate SCSD as a noninvasive, cheap, easy, and objective measure of embodiment, especially sensible to onset and strength of the illusion. Alike the already known enhanced autonomic reaction to a threatening, SCSD does not interfere with the collection of other behavioral measures. Correlations and their dynamics, presence of the effect in the second presentation of the setup but relative low robustness against multiple repetition, suggest that the increased fluctuations of skin conductance caught by SCSD are not just the effect of different presented sensory stimuli but more likely a stronger arousal response to the novelty of the updated perceptual status.

The Rapid Emergence of Musical Pitch Structure in Human Cortex.

In tonal music, continuous acoustic waveforms are mapped onto discrete, hierarchically arranged, internal representations of pitch. To examine the neural dynamics underlying this transformation, we presented male and female human listeners with tones embedded within a Western tonal context while recording their cortical activity using magnetoencephalography. Machine learning classifiers were then trained to decode different tones from their underlying neural activation patterns at each peristimulus time sample, providing a dynamic measure of their dissimilarity in cortex. Comparing the time-varying dissimilarity between tones with the predictions of acoustic and perceptual models, we observed a temporal evolution in the brain's representational structure. Whereas initial dissimilarities mirrored their fundamental-frequency separation, dissimilarities beyond 200 ms reflected the perceptual status of each tone within the tonal hierarchy of Western music. These effects occurred regardless of stimulus regularities within the context or whether listeners were engaged in a task requiring explicit pitch analysis. Lastly, patterns of cortical activity that discriminated between tones became increasingly stable in time as the information coded by those patterns transitioned from low-to-high level properties. Current results reveal the dynamics with which the complex perceptual structure of Western tonal music emerges in cortex at the timescale of an individual tone.SIGNIFICANCE STATEMENT Little is understood about how the brain transforms an acoustic waveform into the complex perceptual structure of musical pitch. Applying neural decoding techniques to the cortical activity of human subjects engaged in music listening, we measured the dynamics of information processing in the brain on a moment-to-moment basis as subjects heard each tone. In the first 200 ms after onset, transient patterns of neural activity coded the fundamental frequency of tones. Subsequently, a period emerged during which more temporally stable activation patterns coded the perceptual status of each tone within the "tonal hierarchy" of Western music. Our results provide a crucial link between the complex perceptual structure of tonal music and the underlying neural dynamics from which it emerges.

Psycholinguists should resist the allure of linguistic units as perceptual units

Abstract The current study has empirical, methodological, and theoretical components. It draws heavily on two recent papers: Bowers et al. (2016) (JML, 87, 71–83) used results from selective adaptation experiments to argue that phonemes play a critical role in speech perception. Mitterer et al. (2018) (JML, 98, 77–92) responded with their own adaptation experiments to advocate instead for allophones. These studies are part of a renewed use of the selective adaptation paradigm. Empirically, the current study reports results that demonstrate that the Bowers et al. findings were artifactual. Methodologically, the renewed use of adaptation in the field is a positive development, but many recent studies suffer from a lack of knowledge of prior adaptation findings. As the use of selective adaptation grows, it will be important to draw on the considerable existing knowledge base (this literature is also relevant to the currently popular research on phonetic recalibration). Theoretically, for a half century there has been a recurring effort to demonstrate the psychological reality of various linguistic units, such as the phoneme or the allophone. The evidence is that listeners will use essentially any pattern that has been experienced often enough, not just the units that are well-suited to linguistic descriptions of language. Thus, rather than trying to identify any special perceptual status for linguistic units, psycholinguists should focus their efforts on more productive issues.

The multisensory basis of the self: From body to identity to others [Formula: see text

ABSTRACTBy grounding the self in the body, experimental psychology has taken the body as the starting point for a science of the self. One fundamental dimension of the bodily self is the sense of body ownership that refers to the special perceptual status of one’s own body, the feeling that “my body” belongs to me. The primary aim of this review article is to highlight recent advances in the study of body ownership and our understanding of the underlying neurocognitive processes in three ways. I first consider how the sense of body ownership has been investigated and elucidated in the context of multisensory integration. Beyond exteroception, recent studies have considered how this exteroceptively driven sense of body ownership can be linked to the other side of embodiment, that of the unobservable, yet felt, interoceptive body, suggesting that these two sides of embodiment interact to provide a unifying bodily self. Lastly, the multisensorial understanding of the self has been shown to have implications for our understanding of social relationships, especially in the context of self–other boundaries. Taken together, these three research strands motivate a unified model of the self inspired by current predictive coding models.

Intracranial spectral amplitude dynamics of perceptual suppression in fronto-insular, occipito-temporal, and primary visual cortex.

If conscious perception requires global information integration across active distant brain networks, how does the loss of conscious perception affect neural processing in these distant networks? Pioneering studies on perceptual suppression (PS) described specific local neural network responses in primary visual cortex, thalamus and lateral prefrontal cortex of the macaque brain. Yet the neural effects of PS have rarely been studied with intracerebral recordings outside these cortices and simultaneously across distant brain areas. Here, we combined (1) a novel experimental paradigm in which we produced a similar perceptual disappearance and also re-appearance by using visual adaptation with transient contrast changes, with (2) electrophysiological observations from human intracranial electrodes sampling wide brain areas. We focused on broadband high-frequency (50–150 Hz, i.e., gamma) and low-frequency (8–24 Hz) neural activity amplitude modulations related to target visibility and invisibility. We report that low-frequency amplitude modulations reflected stimulus visibility in a larger ensemble of recording sites as compared to broadband gamma responses, across distinct brain regions including occipital, temporal and frontal cortices. Moreover, the dynamics of the broadband gamma response distinguished stimulus visibility from stimulus invisibility earlier in anterior insula and inferior frontal gyrus than in temporal regions, suggesting a possible role of fronto-insular cortices in top–down processing for conscious perception. Finally, we report that in primary visual cortex only low-frequency amplitude modulations correlated directly with perceptual status. Interestingly, in this sensory area broadband gamma was not modulated during PS but became positively modulated after 300 ms when stimuli were rendered visible again, suggesting that local networks could be ignited by top–down influences during conscious perception.

Pain and Body Awareness: Evidence from Brain-Damaged Patients with Delusional Body Ownership

A crucial aspect for the cognitive neuroscience of pain is the interplay between pain perception and body awareness. Here we report a novel neuropsychological condition in which right brain-damaged patients displayed a selective monothematic delusion of body ownership. Specifically, when both their own and the co-experimenter’s left arms were present, these patients claimed that the latter belonged to them. We reasoned that this was an ideal condition to examine whether pain perception can be “referred” to an alien arm subjectively experienced as one’s own. Seventeen patients (11 with, 6 without the delusion), and 10 healthy controls were administered a nociceptive stimulation protocol to assess pain perception. In the OWN condition, participants placed their arms on a table in front of them. In the ALIEN condition, the co-experimenter’s left (or right) arm was placed alongside the participants’ left (or right) arm, respectively. In the OWN condition, left (or right) participants’ hand dorsum were stimulated. In the ALIEN condition, left (or right) co-experimenter’s hand dorsum was stimulated. Participants had to rate the perceived pain on a 0–5 Likert scale (0 = no pain, 5 = maximal imaginable pain). Results showed that healthy controls and patients without delusion gave scores higher than zero only when their own hands were stimulated. On the contrary, patients with delusion gave scores higher than zero both when their own hands (left or right) were stimulated and when the co-experimenter’s left hand was stimulated. Our results show that in pathological conditions, a body part of another person can become so deeply embedded in one’s own somatosensory representation to effect the subjective feeling of pain. More in general, our findings are in line with a growing number of evidence emphasizing the role of the special and unique perceptual status of body ownership in giving rise to the phenomenological experience of pain.

Emotional conflict in a model modulates nociceptive processing in an onlooker: a laser-evoked potentials study

Observing models displaying facial expressions of pain elicits neural activity in onlookers' neural structures involved in first-hand experience of pain and in monitoring conflicting information. We investigated whether the purported conflict between the pain and its emotional expression in a model modulates cortical responses elicited by nociceptive laser stimuli in an onlooker. Seeing happy facial expressions, incongruent with the perceptual status attributed to the model, determined a significant reduction in the laser-evoked N2 potential. One of the main sources of this response is the anterior cingulate cortex, an area involved in pain perception, empathy for pain and conflict detection. A pre-activation of the anterior cingulate cortex due to the detection of the emotional conflict may, therefore, be responsible for the reduction of nociceptive-related response in the same brain area. Thus, top-down variables, like the appraisal of the others' emotional status, modulate onlookers' nociceptive-related neural activity.

Corrections to: Which image is in awareness during binocular rivalry? Reading perceptual status from eye movements

Corrections to: Which image is in awareness during binocular rivalry? Reading perceptual status from eye movements

Which image is in awareness during binocular rivalry? Reading perceptual status from eye movements

Binocular rivalry is a useful psychophysical tool to investigate neural correlates of visual consciousness because the alternation between awareness of the left and right eye images occurs without any accompanying change in visual input. The conventional experiments on binocular rivalry require participants to voluntarily report their perceptual state. Obtaining reliable reports from non-human primates about their subjective visual experience, however, requires long-term training, which has made electrophysiological experiments on binocular rivalry quite difficult. Here, we developed a new binocular rivalry stimulus that consists of two different object images that are phase-shifted to move in opposite directions from each other: One eye receives leftward motion while the other eye receives rightward motion, although both eyes' images are perceived to remain at the same position. Experiments on adult human participants showed that eye movements (optokinetic nystagmus, OKN) are involuntarily evoked during the observation of our stimulus. We also found that the evoked OKN can serve as a cue for accurate estimation about which object image was dominant during rivalry, since OKN follows the motion associated with the image in awareness at a given time. This novel visual presentation technique enables us to effectively explore the neural correlates of visual awareness using animal models.

Allophony and Contrast in Speech Perception

The present study examines the perceptual status of allophones to examine the interaction of the phonological knowledge and speech perception. With the use of Korean bilabial stops, phonemic, allophonic and two types of low-level phonetic pairs were generated, and their perception by Korean listeners was examined. Through a categorial AXB discrimination and similarity rating tasks, it was shown that phonemes are fully discriminated, while other categories are less. However, there were significant differences in similarity ratings between the tokens for an allophone pair and two identical tokens, suggesting that allophones are also discriminated by natives. Furthermore, perceptual discrimination of phonological and phonetic categories was shown to be influenced by lexicality and partly by episodic information such as token frequency. The relevance of the results to exemplar models is discussed.

Phonological Representations Are Unconsciously Used when Processing Complex, Non-Speech Signals

Neuroimaging studies of speech processing increasingly rely on artificial speech-like sounds whose perceptual status as speech or non-speech is assigned by simple subjective judgments; brain activation patterns are interpreted according to these status assignments. The naïve perceptual status of one such stimulus, spectrally-rotated speech (not consciously perceived as speech by naïve subjects), was evaluated in discrimination and forced identification experiments. Discrimination of variation in spectrally-rotated syllables in one group of naïve subjects was strongly related to the pattern of similarities in phonological identification of the same stimuli provided by a second, independent group of naïve subjects, suggesting either that (1) naïve rotated syllable perception involves phonetic-like processing, or (2) that perception is solely based on physical acoustic similarity, and similar sounds are provided with similar phonetic identities. Analysis of acoustic (Euclidean distances of center frequency values of formants) and phonetic similarities in the perception of the vowel portions of the rotated syllables revealed that discrimination was significantly and independently influenced by both acoustic and phonological information. We conclude that simple subjective assessments of artificial speech-like sounds can be misleading, as perception of such sounds may initially and unconsciously utilize speech-like, phonological processing.

Perceptual biases for rhythm: The Mismatch Negativity latency indexes the privileged status of binary vs non-binary interval ratios

Objective Rhythm perception appears to be non-linear as human subjects are better at discriminating, categorizing and reproducing rhythms containing binary vs non-binary (e.a. 1:2 vs 1:3) as well as metrical vs non-metrical (e.a. 1:2 vs 1:2.5) interval ratios. This study examined the representation of binary and non-binary interval ratios within the sensory memory, thus yielding a truly sensory, pre-motor, attention-independent neural representation of rhythmical intervals. Methods Five interval ratios, one binary, flanked by four non-binary ones, were compared on the basis of the MMN they evoked when contrasted against a common standard interval. Results For all five intervals, the larger the contrast was, the larger the MMN amplitude was. The binary interval evoked a significantly much shorter (by at least 23 ms) MMN latency than the other intervals, whereas no latency difference was observed between the four non-binary intervals. Conclusions These results show that the privileged perceptual status of binary rhythmical intervals is already present in the sensory representations found in echoic memory at an early, automatic, pre-perceptual and pre-motor level. Significance MMN latency can be used to study rhythm perception at a truly sensory level, without any contribution from the motor system.

Neural Signatures of Body Ownership: A Sensory Network for Bodily Self-Consciousness

Body ownership refers to the special perceptual status of one's own body, which makes bodily sensations seem unique to oneself. We studied the neural correlates of body ownership by controlling whether an external object was accepted as part of the body or not. In the rubber hand illusion (RHI), correlated visuotactile stimulation causes a fake hand to be perceived as part of one's own body. In the present study, we distinguished between the causes (i.e., multisensory stimulation) and the effect (i.e., the feeling of ownership) of the RHI. Participants watched a right or a left rubber hand being touched either synchronously or asynchronously with respect to their own unseen right hand. A quantifiable correlate of the RHI is a shift in the perceived position of the subject's hand toward the rubber hand. We used positron emission tomography to identify brain areas whose activity correlated with this proprioceptive measure of body ownership. Body ownership was related to activity in the right posterior insula and the right frontal operculum. Conversely, when the rubber hand was not attributed to the self, activity was observed in the contralateral parietal cortex, particularly the somatosensory cortex. These structures form a network that plays a fundamental role in linking current sensory stimuli to one's own body and thus also in self-consciousness.

Microsaccades Counteract Visual Fading during Fixation

Our eyes move continually, even while we fixate our gaze on an object. If fixational eye movements are counteracted, our perception of stationary objects fades completely, due to neural adaptation. Some studies have suggested that fixational microsaccades refresh retinal images, thereby preventing adaptation and fading. However, other studies disagree, and so the role of microsaccades remains unclear. Here, we correlate visibility during fixation to the occurrence of microsaccades. We asked subjects to indicate when Troxler fading of a peripheral target occurs, while simultaneously recording their eye movements with high precision. We found that before a fading period, the probability, rate, and magnitude of microsaccades decreased. Before transitions toward visibility, the probability, rate, and magnitude of microsaccades increased. These results reveal a direct link between suppression of microsaccades and fading and suggest a causal relationship between microsaccade production and target visibility during fixation.

Preference patterns in infant vowel perception

Infants show directional asymmetries in vowel discrimination tasks that reveal an underlying perceptual bias favoring more peripheral vowels. Polka and Bohn (2003) propose that this bias is language independent and plays an important role in the development of vowel perception. In the present study we measured infant listening preferences for vowels to assess whether a perceptual bias favoring peripheral vowels can be measured more directly. Monolingual (French and English) and bilingual infants completed a listening preference task using multiple natural tokens of German /dut/ and /dyt/ produced by a male talker. In previous work, discrimination of this vowel pair by German-learning and by English-learning infants revealed a robust directional asymmetry in which /u/ acts as a perceptual anchor; specifically, infants had difficulty detecting a change from /u/ to /y/, whereas a change from /y/ to /u/ was readily detected. Preliminary results from preference tests with these stimuli show that most infants between 3 and 5 months of age also listen longer to /u/ than to /y/. Preference data obtained from older infants and with other vowel pairs will also be reported to further test the claim that peripheral vowels have a privileged perceptual status in infant perception.