Ambiguous Tone Research Articles

A neuronal network model for context-dependence of pitch change perception.

Many natural stimuli have perceptual ambiguities that can be cognitively resolved by the surrounding context. In audition, preceding context can bias the perception of speech and non-speech stimuli. Here, we develop a neuronal network model that can account for how context affects the perception of pitch change between a pair of successive complex tones. We focus especially on an ambiguous comparison—listeners experience opposite percepts (either ascending or descending) for an ambiguous tone pair depending on the spectral location of preceding context tones. We developed a recurrent, firing-rate network model, which detects frequency-change-direction of successively played stimuli and successfully accounts for the context-dependent perception demonstrated in behavioral experiments. The model consists of two tonotopically organized, excitatory populations, Eup and Edown, that respond preferentially to ascending or descending stimuli in pitch, respectively. These preferences are generated by an inhibitory population that provides inhibition asymmetric in frequency to the two populations; context dependence arises from slow facilitation of inhibition. We show that contextual influence depends on the spectral distribution of preceding tones and the tuning width of inhibitory neurons. Further, we demonstrate, using phase-space analysis, how the facilitated inhibition from previous stimuli and the waning inhibition from the just-preceding tone shape the competition between the Eup and Edown populations. In sum, our model accounts for contextual influences on the pitch change perception of an ambiguous tone pair by introducing a novel decoding strategy based on direction-selective units. The model's network architecture and slow facilitating inhibition emerge as predictions of neuronal mechanisms for these perceptual dynamics. Since the model structure does not depend on the specific stimuli, we show that it generalizes to other contextual effects and stimulus types.

Neural correlates of valence generalization in an affective conditioning paradigm

In case of uncertainty, predictions that are based on prior, similar experiences guide our decision by processes of generalization. Over-generalization of negative information has been identified as an important feature of several psychopathologies, including anxiety disorders and depression, and might underlie biased interpretation of ambiguous information.Here, we investigated the neural correlates of valence generalization to ambiguous stimuli using a translational affective conditioning task during fMRI. Twenty-five healthy individuals participated in a conditioning procedure with (1) an initial acquisition phase, where participants learned the positive and negative valence of two different tones (reference tones) through their responses and subsequent feedback and (2) a test phase, where participants were presented with the previously learned reference tones and three additional tones with intermediate frequency to the learned reference tones. By recording the responses to these intermediate stimuli we were able to assess the participantś interpretation of ambiguous tones as either positive or negative.Behavioral results revealed a graded response pattern to the three intermediate tones, which was mirrored on the neural level. More specifically, parametric analyses OF BOLD responses to all five tones revealed a linear effect in bilateral anterior insula and SMA with lowest activation to the negative reference tone and highest activation to the positive negative tone. In addition, a cluster in the SMA showed a reverse-quadratic response, i.e., the strongest response for the most ambiguous tone. These findings suggest overlapping regions in the salience network that mediate valence generalization and decision-making under ambiguity, potentially underlying biased ambiguous cue interpretation.

Decision-making under risk and ambiguity in low-birth-weight pigs.

Low birth weight (LBW) in humans is a risk factor for later cognitive, behavioural and emotional problems. In pigs, LBW is associated with higher mortality, but little is known about consequences for surviving piglets. Alteration in hypothalamic-pituitary-adrenal axis function in LBW pigs suggests altered emotionality, but no behavioural indicators have been studied. Decision-making under uncertain conditions, e.g., risk or ambiguity, is susceptible to emotional influences and may provide a means of assessing long-term effects of LBW in piglets. We tested LBW (N=8) and normal-birth-weight (NBW; N=8) male pigs in two decision-making tasks. For decision-making under risk, we developed a simple two-choice probabilistic task, the Pig Gambling Task (PGT), where an 'advantageous' option offered small but frequent rewards and a 'disadvantageous' option offered large but infrequent rewards. The advantageous option offered greater overall gain. For decision-making under ambiguity, we used a Judgement Bias Task (JBT) where pigs were trained to make an active response to 'positive' and 'negative' tone cues (signalling large and small rewards, respectively). Responses to ambiguous tone cues were rated as more or less optimistic. LBW pigs chose the advantageous option more often in later blocks of the PGT, and were scored as less optimistic in the JBT, than NBW pigs. Our findings demonstrate that LBW pigs have developed different behavioural strategies with respect to decision-making. We propose that this is guided by changes in emotionality in LBW piglets, and we provide behavioural evidence of increased negative affect in LBW piglets.

Deletion of forebrain glycine transporter 1 enhances conditioned freezing to a reliable, but not an ambiguous, cue for threat in a conditioned freezing paradigm

Enhanced expression of Pavlovian aversive conditioning but not appetitive conditioning may indicate a bias in the processing of threatening or fearful events. Mice with disruption of glycine transporter 1 (GlyT1) in forebrain neurons exhibit such a bias, but they are at the same time highly sensitive to manipulations that hinder the development of the conditioned response (CR) suggesting that the mutation may modify higher cognitive processes that extract predictive information between environmental cues. Here, we further investigated the development of fear conditioning in forebrain neuronal GlyT1 knockout mice when the predictiveness of a tone stimulus for foot-shock was rendered ambiguous by interspersing [tone→no shock] trials in-between [tone→shock] trials during acquisition. The CR to the ambiguous tone CS (conditioned stimulus) was compared with that generated by an unambiguous CS that was always followed by the shock US (unconditioned stimulus) during acquisition. We showed that rendering the CS ambiguous as described significantly attenuated the CR in the mutants, but it was not sufficient to modify the CR in the control mice. It is concluded that disruption of GlyT1 in forebrain neurons does not increase the risk of forming spurious and potentially maladaptive fear associations.

Rimbaud’s Poetic Vision as a Clue to Perception in the Later Merleau-Ponty

One of the difficulties in understanding the meaning of perception in Merleau-Ponty’s work comes from the ambiguous tone of his descriptions. Therefore, to understand it thoroughly one should question the origin of this tone and inquire about the relationship between perception and language and, more particularly, between philosophy and literature. This is what is at stake in his last courses at the Collège de France, where Merleau-Ponty envisages perception as being associated with literature and as having a special kinship to the notion of “poetic vision,” which appears in Rimbaud’s first ‘Letter from the Seer’.

Investigating the psychopharmacology of cognitive affective bias in rats using an affective tone discrimination task

Affective states are known to influence behaviour in humans resulting in cognitive affective biases, which may play an important role in the development and treatment of mood disorders. Similar biases have recently been shown in animals, including the rat, providing an opportunity to investigate these processes in non-human species. This study sought to investigate the psychopharmacology of cognitive affective bias in rats using systemic treatments with anxiolytic (diazepam) and antidepressant drugs (reboxetine or fluoxetine). Lister hooded rats were trained to discriminate two distinct tones and respond on the appropriate lever to either obtain reward (food) or avoid punishment (mild foot shock). Cognitive affective bias, following acute or chronic drug treatment, was investigated using test sessions where both reference tones and intermediate ambiguous tones were included. Rats exhibited a negative judgement bias under vehicle conditions which was not significantly attenuated by any of the acute drug treatments, diazepam (0.3, 1.0 mg/kg), reboxetine (0.3-3.0 mg/kg) or fluoxetine 0.1-1.0 mg/kg). Acute reboxetine induced a significant and dose-dependent decrease in the anticipation of reward. Chronic treatment with fluoxetine tended to reduce the negative bias observed in the rats after 1 week of treatment although no significant main effect of treatment was observed. The results from these initial psychopharmacological studies show that drug treatments can differentially affect motivation to respond to cues associated with reward versus punishment. Our data also suggest that cognitive affective bias, quantified using this method, may be sensitive to chronic but not acute antidepressant treatment.

Cyrillic Cycles:

Cyrillic Cycles:

Figures of Reading

Figures of Reading Nathan K. Hensley (bio) Garrett Stewart , Novel Violence: A Narratography of Victorian Fiction. Chicago: University of Chicago Press, 2009. Pp. 268. $45.00 cloth. If you've browsed the Internet or visited a blog at any point in the past decade, then you probably already know that reading is dead. Doomsday reports in the popular and academic presses conspire with our own daily experience, as we tweet and text (or don't), to suggest that the data-processing function called reading has morphed forever into browsing, skimming, multitasking. These shifts in everyday life have found institutional corollaries in literary studies, as older methods now feel called upon to justify their relevance in the face of new processes like data mining, information aggregating, n-gramming. "Today," says Franco Moretti with ambiguous tone, "we can replicate in a few minutes investigations that took a giant like Leo Spitzer months and years of work."1 Moretti is citing a study in Science heralding a new species of technological reading, "Culturomics"—a rival, it would appear, to his own. Such advances in literary numerology transform quality to quantity on a massive scale, reconceiving reading as data analysis, hermeneutics as information science. With just a keystroke on Google's Ngram website, anyone can graph a word's frequency in printed books since 1500—or at least those scanned by Google—test driving what even the New York Times now calls "Humanities 2.0."2 Depending on how you view it, this transformation has either [End Page 329] chipped away at what makes the humanities human or helped outfit English for a renovated world. Within the discipline, the digital turn has generated dynamic new subfields, but has also enabled critics in historical areas to rethink reading from the ground up. Led by Nicholas Dames, Caroline Levine, Alan Liu, Deidre Lynch, Mary Poovey, and Leah Price, these critics have reached beyond new historicism and cultural studies to examine our place in the history of reading and to question the metaphors that define—or should define—our engagement with text-based information. Should the reading we do be close or distant? Deep or superficial? Fast or slow? And is literature information or something, well, better? In a much-discussed 2009 special issue of Representations called "The Way We Read Now," Sharon Marcus and Steven Best catalog alternatives to the interpretive reading-for-depth they claim has become orthodox in literary studies.3 Their proposal, surface reading, combines methods that linger instead on the manifest, the tactile: from book history and autotelic formalism to Marcus's just reading,4 a theoretically elaborated version of what students sometimes call not reading too much into it. Leah Price, for her part, suggests "we do not, and need not, read books at all."5 Against such invocations of surface and speed are arrayed defenses of the deep and slow. Thus, for example, Jane Gallop has indexed the losses already suffered by fine-grained reading and called for a reinvigorated curriculum of closeness. For Gallop, intimate reading at small scales defeats preconceived notions of what a text "will probably say," short-circuiting prewired expectations. This ability to register particularity is the very justification for teaching literature in the first place—and not, as the New Critics had it, the other way around.6 In ways Best and Marcus do not, Gallop therefore makes explicit that by redrawing the boundaries of what reading is and should be, critics also (whether they like it or not) take positions on larger questions about the nature of the humanities in the contemporary marketplace of ideas. If the new austerity has made humanities an endangered species, does a shift to what has been called distant reading hasten or slow their extinction? In a universe organized according to principles of numbers-based rationality, should literary analysis become more efficient, more transparent, more informational—or less so?7 Without citing any of this, Garrett Stewart's new book intervenes into recent debates about reading by showing how the slow and deep can share space with the quick and new. Despite its own claims, Novel Violence is less an investigation into violence or an announcement of a new...

Evaluation of a novel translational task for assessing emotional biases in different species

Changes in the processing of emotional information are key features of affective disorders. Neuropsychological tests based on emotional faces or words are used to detect emotional/affective biases in humans, but these tests are not applicable to animal species. In the present study, we investigated whether a novel affective tone discrimination task (ATDT), developed to study emotion-related behaviour in rats, could also be used to quantify changes in affective states in humans. To date, the methods used in human neuropsychology have not been applicable to animal experiments. Participants completed a training session in which they learnt to discriminate specific tone frequencies and to correctly respond in order to gain emotionally valenced outcomes, to obtain rewards (money), or to avoid punishment (an aversive sound clip). During a subsequent test session, additional ambiguous probe tones were presented at frequencies intermediate between the reward and avoidance paired tones. At the end of the task, participants completed self-report questionnaires. All participants made more avoidance responses to the most ambiguous tone cues, suggesting a bias towards avoidance of punishment. Individual differences in the degrees of bias observed were correlated with anxiety measures, suggesting the task's sensitivity to differences in state anxiety within a healthy population. Further studies in clinical populations will be necessary to assess the task's sensitivity to pathological anxiety states. These data suggest that this affective tone discrimination task provides a novel method to study cognitive affective biases in different species, including humans, and offers a novel assessment to study anxiety.

Innovation Starvation

Innovation Starvation

Production and perception of lexical tones in Beijing and Taiwan Mandarin.

The acoustic properties of four lexical tones between two regional varieties of Mandarin Chinese, Beijing Mandarin (Putonghua), and Taiwan Mandarin (Guoyu) were examined in terms of duration, pitch contours, and rms amplitude. Tokens included CV and V monosyllables, representing each of the four tones of Mandarin Chinese, and were produced in isolation and in sentence context by 15 adult native speakers. A different durational pattern of citation tones emerged for two dialect variety groups. In Taiwan Mandarin, it was T2>T1>T3>T4; whereas, it was T3>T2>T1>T4 in Beijing Mandarin [Deng et al. (2006)]. The durational discrepancy in isolated T3 may be related to different realization of T3 between two dialect groups. While T3 exhibited a falling-rising pitch contour in Beijing Mandarin, it was falling in Taiwan Mandarin. Such dialectal divergence in T3 contours shapes can be verified from the amplitude contours. Furthermore, pitch contours of other tones in two dialects will be compared to see if there is tonetic sound change in other Taiwan Mandarin tones. These surface acoustic variations in linguistically identical categories can result in perceptually ambiguous tones. A gating experiment was utilized to examine how native and non-native listeners adapt to speaker and dialect variability in the stimuli.

Effects of frequency disparities on trading of an ambiguous tone between two competing auditory objects

Listeners are relatively good at estimating the true content of each physical source in a sound mixture in most everyday situations. However, if there is a spectrotemporal element that logically could belong to more than one object, the correct way to group that element can be ambiguous. Many psychoacoustic experiments have implicitly assumed that when a sound mixture contains ambiguous sound elements, the ambiguous elements "trade" between competing sources, such that the elements contribute more to one object in conditions when they contribute less to others. However, few studies have directly tested whether such trading occurs. While some studies found trading, trading failed in some recent studies in which spatial cues were manipulated to alter the perceptual organization. The current study extended this work by exploring whether trading occurs for similar sound mixtures when frequency content, rather than spatial cues, was manipulated to alter grouping. Unlike when spatial cues were manipulated, results are roughly consistent with trading. Together, results suggest that the degree to which trading is obeyed depends on how stimuli are manipulated to affect object formation.

Effects of Reverberant Spatial Cues on Attention-dependent Object Formation

A recent study showed that when a sound mixture has ambiguous spectrotemporal structure, spatial cues alone are sufficient to change the balance of grouping cues and affect the perceptual organization of the auditory scene. The current study synthesizes similar stimuli in a reverberant setting to see whether the interaural decorrelation caused by reverberant energy reduces the influence of spatial cues on perceptual organization. Results suggest that reverberant spatial cues are less influential on perceptual segregation than anechoic spatial cues. In addition, results replicate an interesting finding from the earlier study, where an ambiguous tone that could logically belong to either a repeating tone sequence or a simultaneous harmonic complex can sometimes "disappear" and never be heard as part of the perceptual foreground, no matter which object a listener attends. As in the previous study, the perceived energy of the ambiguous element does not "trade" between the objects in a complex scene (i.e., the element does not necessarily contribute more to one object when it contributes less to a competing object). Results are consistent with the idea that the perceptual organization of an acoustic mixture depends on what object a listener attends.

A multilevel and cross-modal approach towards neuronal mechanisms of auditory streaming

We report first results of a multilevel, cross-modal study on the neuronal mechanisms underlying auditory sequential streaming, with the focus on the impact of visual sequences on perceptually ambiguous tone sequences which can either be perceived as two separate streams or one alternating stream. We combined two psychophysical experiments performed on humans and monkeys with two human brain imaging experiments which allow to obtain complementary information on brain activation with high spatial (fMRI) and high temporal (MEG) resolution. The same acoustic paradigm based on the pairing of tone sequences with visual stimuli was used in all human studies and, in an adapted version, in the psychophysical study on monkeys. Our multilevel approach provides experimental evidence that the pairing of auditory and visual stimuli can reliably introduce a bias towards either an integrated or a segregated perception of ambiguous sequences. Thus, comparable to an explicit instruction, this approach can be used to control the subject's perceptual organization of an ambiguous sound sequence without the need for the subject to directly report it. This finding is of particular importance for animal studies because it allows to compare electrophysiological responses of auditory cortex neurons to the same acoustic stimulus sequence eliciting either a segregated or integrated percept.

On Forgetting: Thomas Nast, the Middle Class, and the Visual Culture of the Draft Riots

In September of 1863, Thomas Nast produced a seemingly bucolic scene of children at play, The Attack on the “Home Guard,” for the lithographic firm of Currier and Ives (Figure 1). Organized around a strange confrontation, in which a dog bites at the pant leg of a little boy in a military uniform as another, nonuniformed boy stabs at the dog with a bayonettipped rifle, the print diverges from sentimental 19th-century envisionings of middle-class domestic life by including an act of violence in the normally sanctified space of the home. Not surprisingly, the unusual content and ambiguous tone of The Attack on the “Home Guard” has puzzled historians of visual culture. When read in the context of contemporaneous popular illustration, however, the elusive meaning of Nast's lithograph begins to take shape.

Neuromagnetic Correlates of Streaming in Human Auditory Cortex

The brain is constantly faced with the challenge of organizing acoustic input from multiple sound sources into meaningful auditory objects or perceptual streams. The present study examines the neural bases of auditory stream formation using neuromagnetic and behavioral measures. The stimuli were sequences of alternating pure tones, which can be perceived as either one or two streams. In the first experiment, physical stimulus parameters were varied between values that promoted the perceptual grouping of the tone sequence into one coherent stream and values that promoted its segregation into two streams. In the second experiment, an ambiguous tone sequence produced a bistable percept that switched spontaneously between one- and two-stream percepts. The first experiment demonstrated a strong correlation between listeners' perception and long-latency (>60 ms) activity that likely arises in nonprimary auditory cortex. The second demonstrated a covariation between this activity and listeners' perception in the absence of physical stimulus changes. Overall, the results indicate a tight coupling between auditory cortical activity and streaming perception, suggesting that an explicit representation of auditory streams may be maintained within nonprimary auditory areas.

Spontaneous classification of complex tones at high and ultrasonic frequencies in the bat, Megaderma lyra.

Megaderma lyra, a bat species using harmonically structured calls for echolocation, exploits the spectral content of its echoes for texture discrimination. It is the aim of the present study to test according to which sensory qualities harmonic complex tones are spontaneously classified by this bat. The applied experimental paradigm is especially adapted to the preference of M. lyra to use absolute pitch cues. Three animals were trained in a 2-AFC procedure to classify three-component stimuli as low or high, with all their harmonics below or above a pure tone reference of 33 kHz, respectively. Later, the original tones were interspersed with "incomplete" test stimuli, with their fundamentals (and lower harmonics) missing. These were ambiguous in that their possible virtual, i.e., collective pitches were below the reference whereas their pure tone pitches were above it. Bat 1 classified 22 of 23 test stimuli with missing fundamentals between 5.3 and 28.3 kHz according to their collective pitches, whereas bat 2 judged all presented ambiguous tones on the basis of their pure tone pitches. Bat 3 failed the pitch control criterion which is why in this case results cannot be interpreted unequivocally. The implications of these findings are discussed with respect to the bats' behavioral context, as well as to psychoacoustical models of the formation of the pitch of complex tones.

Restructuring of production and workers' health: a case study

We performed a case study on a company focusing on the form of management and the shop floor workers, in order to identify the possible effects of participant work strategies on workers' health. Data on the company included its history, type of management, and organization of both production and the work process. Data on shop floor workers included age, schooling, perceptions of work, family life, recreation, and self-reported disease history. We concluded that the characteristics of the management model adopted by the company originated from ideas imported from Japan, including flexibilization of production, outsourcing, performance of multiple tasks, and participation in the work process. Workers referred to participation in the work process in an ambiguous tone. Some reported positive effects, like greater freedom and respect, with positive effects on life both inside and outside the workplace. For part of the group studied, the characteristics of the work organization model practiced in the company had negative effects on health, leading them to complain of insomnia, nervousness, work-related dreams, and headaches.

Figures of Female Militancy in Medieval France

This plaintive voice, lamenting men's loss of military prestige, sounds the alarm over the figure of women fighting during the high Middle Ages. On one level, it heralds the classic world-upsidedown syndrome, teasing its thirteenth-century French public with an image of social disorder.2 On another, it fields the idea of women in a martial setting, bespeaking a thorny issue touching families and communities across medieval Europe. Not only are such formulations rare, but they are made doubly difficult to interpret because of their ambiguous tone. Is this vision of the topsy-turvy conceived in jest? Or does it signal a controversy