Similar neural and perceptual masking effects of low-power optogenetic stimulation in primate V1

Can direct stimulation of primate V1 substitute for a visual stimulus and mimic its perceptual effect? To address this question, we developed an optical-genetic toolkit to 'read' neural population responses using widefield calcium imaging, while simultaneously using optogenetics to 'write' neural responses into V1 of behaving macaques. We focused on the phenomenon of visual masking, where detection of a dim target is significantly reduced by a co-localized medium-brightness mask [1, 2]. Using our toolkit, we tested whether V1 optogenetic stimulation can recapitulate the perceptual masking effect of a visual mask. We find that, similar to a visual mask, low-power optostimulation can significantly reduce visual detection sensitivity, that a sublinear interaction between visual and optogenetic evoked V1 responses could account for this perceptual effect, and that these neural and behavioral effects are spatially selective. Our toolkit and results open the door for further exploration of perceptual substitutions by direct stimulation of sensory cortex.

Agency evaluation in motor cognition: Action’s control-effectiveness feedback and its environmental context enhances motor performance

A perceptual effect that is temporally contiguous on one’s action holds important information about one’s control over the action and its effect (“I did that”). Previous work has demonstrated the impact of such immediate action-effect on perception and motor processes. In the current study, we investigated the promoting impact of control-effectiveness feedback – an effect that is temporally contiguous on one’s action – on motor performance. In two experiments, participants performed a rapid movement towards a target location on a computer monitor and clicked on the target with their mouse key as quickly and accurately as possible. Their click response triggered a perceptual effect (a brief white flash) on the target. We manipulated control-effectiveness feedback by employing varying levels of action-effect delay in two experimental contexts - long versus short lag distributions. Such design enabled us to investigate the impact of both the recent action-effect delay and its experimental context on motor performance. The findings demonstrate that control-effectiveness feedback (e.g., temporally contiguous perceptual effect) enhances motor performance as indicated by both endpoint precision and movement speed. In addition, a substantial effect of the experimental context was observed. Namely, we found enhanced motor performance, especially after an ambiguous (intermediate) action-effect delay when it was sampled from a short compared to long lag distribution; a pattern that supports the contribution of both ‘control’ expectations and control-feedback on motor performance. We discuss findings in the context of previous work on control-effectiveness and movement control and their potential implications for clinicians and digital interface developers.

Semantic and Style Concepts in Mass Communication Content

The article examines the semantic and style concepts of the functioning of mass communication in modern conditions, determines their role and significance for the transfer of public information from the communicator to the recipient. The author, analyzing the semantics and stylistics of media texts of an outstanding communicative personality (well-known journalist E.E. Kish), (1) traces gradual changes in the author’s worldview and the associated transformation of the nominal language and style; (2) identifies creative resources strengthening the intention of a journalistic work and improving the perceptual effect in “Author” – “Audience”, (3) comments on the positions established in the theory of the press on the relationship of ideas and style in publishing and (4) gives professional lessons in figurative and logical mastery novice journalists.

OBSOLETE VOCABULARY IN POETIC TEXTS BY SERGIY ZHADAN: FUNCTIONAL-SEMANTIC ASPECT

The article is devoted to the functional-semantic aspect of obsolete vocabulary, which is widely used in poetic texts of Serhiy Zhadan. The traditional approach to the classification of obsolete vocabulary is revealed, among which archaisms and historicisms are distinguished. Groups of archaisms – lexical, lexical-word-forming, lexical-phonetic, morphological, lexical-semantic are considered. It is noted that historicisms, in contrast to archaisms, have no synonymous equivalents in modern Ukrainian language. They perform proper nominative function in historical texts, reproducing facts, events and phenomena of past epochs.It was found that Serhiy Zhadan introduced outdated words, which he has organically inserted into the artistic fabric of poetic works. In poetic texts of the artist (the collections of poems “Templars”, “Antenna”, “List of ships” were taken as the source base of the study) among obsolete vocabulary lexical archaisms, lexical-phonetic and lexical-word-forming were found. The following semantic groups of archaisms: names of body parts; names of diseases; names of individuals by profession, occupation, etc.; names of military items, ammunition, concepts, etc.; names of family relations; names of numbers are distinguished.In Serhiy Zhadan’s poetic texts archaisms give the language a solemn sound, express the author’s attitude to the depicted, convey his feelings and enhance the emotionality of poetic works.Historicisms in poetic texts of the artist outnumber archaisms. The following semantic groups of historicisms are revealed in his creative works: geographical names; words that characterize the social status, place of an individual in society; names of former professions, occupations; names of extinct nations; names of historical epochs; names of household items, women’s jewelry, etc.; names of buildings or their parts; names of various scientific studies, directions, etc.A detailed analysis of Serhiy Zhadan’s poetic language made it possible to identify the main functions performed by obsolete words in poetic texts: realistic depiction of the events of certain historical epoch; strengthening of solemnity, pathos of the depicted; creation of strong perceptual effect; expression of author’s opinion, etc.Key words: archaisms, historicisms, semantic groups, stylistic means, expressive function, nominative function. Стаття присвячена функціонально-семантичному аспекту застарілої лексики, що широко вживається в поетичних текстах Сергія Жадана. Розкрито традиційний підхід до класифікації застарілої лексики, серед якої виділяють архаїзми й історизми. Розглянуто групи архаїзмів – лексичні, лексико-словотвірні, лексико-фонетичні, морфологічні, лексико-семантичні. Зауважено, що історизми на відміну від архаїзмів не мають у сучасній українській мові синонімічних відповідників. Вони виконують власне номінативну функцію в історичних текстах, відтворюючи факти, події, явища минулих епох.З’ясовано, що Сергій Жадан широко послуговується застарілими словами, які органічно вводить у художню тканину поетичного твору. У поетичних текстах митця (джерельною базою дослідження послужили збірки поезій «Тамплієри», «Антена», «Список кораблів») серед застарілої лексики виявлено лексичні архаїзми, лексико-фонетичні й лексико-словотвірні. Виділено такі семантичні групи архаїзмів: назви частин тіла; назви хвороб; назви осіб за професією, родом занять тощо; назви військових речей, амуніцій, понять тощо; назви родинних стосунків; назви чисел.У поетичних текстах Сергія Жадана архаїзми надають мові урочистого звучання, виражають авторське став-лення до зображуваного, передають його почуття, переживання, підсилюють емоційність віршованого твору.Історизми в поетичних текстах митця кількісно переважають над архаїзмами. У його творчому доробку виявлено такі семантичні групи історизмів: географічні назви; слова, що характеризують соціальний стан, місце людини в суспільстві; назви колишніх професій, роду занять; назви зниклих народів; назви історичних епох; назви предметів побуту, жіночих прикрас тощо; назви будівель, їх частин; назви різноманітних наукових учень, течій, напрямів тощо.Детальний аналіз поетичної мови Сергія Жадана дав змогу виділити основні функції, що виконують застарілі слова у віршових текстах: реалістичне зображення подій певної історичної епохи; підсилення урочистості, пафосу зображуваного; створення сильного перцептивного ефекту; увиразнення авторської думки тощо.Ключові слова: архаїзми, історизми, семантичні групи, стилістичний засіб, експресивна функція, номінативна функція.

The Lightness/Pitch Crossmodal Correspondence Modulates the Rubin Face/Vase Perception

We examine whether crossmodal correspondences (CMCs) modulate perceptual disambiguation by considering the influence of lightness/pitch congruency on the perceptual resolution of the Rubin face/vase (RFV). We randomly paired a black-and-white RFV (black faces and white vase, or vice versa) with either a high or low pitch tone and found that CMC congruency biases the dominant visual percept. The perceptual option that was CMC-congruent with the tone (white/high pitch or black/low pitch) was reported significantly more often than the perceptual option CMC-incongruent with the tone (white/low pitch or black/high pitch). However, the effect was only observed for stimuli presented for longer and not shorter durations suggesting a perceptual effect rather than a response bias, and moreover, we infer an effect on perceptual reversals rather than initial percepts. We found that the CMC congruency effect for longer-duration stimuli only occurred after prior exposure to the stimuli of several minutes, suggesting that the CMC congruency develops over time. These findings extend the observed effects of CMCs from relatively low-level feature-based effects to higher-level object-based perceptual effects (specifically, resolving ambiguity) and demonstrate that an entirely new category of crossmodal factors (CMC congruency) influence perceptual disambiguation in bistability.

Pupillometry in auditory multistability

In multistability, a constant stimulus induces alternating perceptual interpretations. For many forms of visual multistability, the transition from one interpretation to another (“perceptual switch”) is accompanied by a dilation of the pupil. Here we ask whether the same holds for auditory multistability, specifically auditory streaming. Two tones were played in alternation, yielding four distinct interpretations: the tones can be perceived as one integrated percept (single sound source), or as segregated with either tone or both tones in the foreground. We found that the pupil dilates significantly around the time a perceptual switch is reported (“multistable condition”). When participants instead responded to actual stimulus changes that closely mimicked the multistable perceptual experience (“replay condition”), the pupil dilated more around such responses than in multistability. This still held when data were corrected for the pupil response to the stimulus change as such. Hence, active responses to an exogeneous stimulus change trigger a stronger or temporally more confined pupil dilation than responses to an endogenous perceptual switch. In another condition, participants randomly pressed the buttons used for reporting multistability. In Study 1, this “random condition” failed to sufficiently mimic the temporal pattern of multistability. By adapting the instructions, in Study 2 we obtained a response pattern more similar to the multistable condition. In this case, the pupil dilated significantly around the random button presses. Albeit numerically smaller, this pupil response was not significantly different from the multistable condition. While there are several possible explanations–related, e.g., to the decision to respond–this underlines the difficulty to isolate a purely perceptual effect in multistability. Our data extend previous findings from visual to auditory multistability. They highlight methodological challenges in interpreting such data and suggest possible approaches to meet them, including a novel stimulus to simulate the experience of perceptual switches in auditory streaming.

Similar neural and perceptual masking effects of low-power optogenetic stimulation in primate V1

Can direct stimulation of primate V1 substitute for a visual stimulus and mimic its perceptual effect? To address this question, we developed an optical-genetic toolkit to “read” neural population responses using widefield calcium imaging, while simultaneously using optogenetics to “write” neural responses into V1 of behaving macaques. We focused on the phenomenon of visual masking, where detection of a dim target is significantly reduced by a co-localized medium-brightness pedestal. Using our toolkit, we tested whether V1 optogenetic stimulation can recapitulate the perceptual masking effect of a visual pedestal. We find that, similar to a visual pedestal, low-power optostimulation can significantly reduce visual detection sensitivity, that a sublinear interaction between visual and optogenetic evoked V1 responses could account for this perceptual effect, and that these neural and behavioral effects are spatially selective. Our toolkit and results open the door for further exploration of perceptual substitutions by direct stimulation of sensory cortex.

Auditory Rate Perception Displays a Positive Serial Dependence

We investigated perceived timing in auditory rate perception using a reproduction task. The study aimed to test (a) whether central tendency occurs in rate perception, as shown for interval timing, and (b) whether rate is perceived independently on each trial or shows a serial dependence, as shown for other perceptual attributes. Participants were well able to indicate perceived rate as reproduced and presented rates were linearly related with a slope that approached unity, although tapping significantly overestimated presented rates. While the slopes approached unity, they were significantly less than 1, indicating a central tendency in which reproduced rates tended towards the mean of the presented range. We tested for serial dependency by seeing if current trial rate reproductions depended on the preceding rate. In two conditions, a positive dependence was observed. A third condition in which participants withheld responses on every second trial produced a negative dependency. These results suggest separate components of serial dependence linked to stimulus and response: Withholding responses reveals a negative perceptual effect, whereas making responses adds a stronger positive effect that is postperceptual and makes the combined effect positive. Together, these data show that auditory rate perception exhibits both central tendency and serial dependence effects.