When awareness gets in the way : reactivation aversion effects resolve the generality/specificity paradox in sensorimotor interference tasks

Interference tasks combining different distractor types usually find that between-trial adaptations (congruency sequence effects [CSEs]) do not interact with each other, suggesting that sensorimotor control is domain-specific. However, within each trial, different distractor types often do interact, suggesting that control is domain-general. The present study presents a solution to this apparent paradox. In 3 experiments, testing 130 participants in total, we (a) confirm the simultaneous presence of between-trial domain-specific (noninteracting) CSEs and within-trial “domain-general” interactions in a fully factorial hybrid prime-Simon design free of repetition or contingency confounds; (b) demonstrate that the within-trial interaction occurs with supraliminal, but not with subliminal primes; and (c) show that it is disproportionately enlarged in older adults. Our findings suggest that whereas interference (priming and Simon) effects and CSEs reflect direct sensorimotor control, the within-trial interaction does not reflect sensorimotor control but “confusion” at higher-level processing stages (reactivation aversion effect [RAE])

The role of phonology in visual word recognition: evidence from Chinese

Posters - Letter/Word Processing V: abstract no. 5024The hypothesis of bidirectional coupling of orthography and phonology predicts that phonology plays a role in visual word recognition, as observed in the effects of feedforward and feedback spelling to sound consistency on lexical decision. However, because orthography and phonology are closely related in alphabetic languages (homophones in alphabetic languages are usually orthographically similar), it is difficult to exclude an influence of orthography on phonological effects in visual word recognition. Chinese languages contain many written homophones that are orthographically dissimilar, allowing a test of the claim that phonological effects can be independent of orthographic similarity. We report a study of visual word recognition in Chinese based on a mega-analysis of lexical decision performance with 500 characters. The results from multiple regression analyses, after controlling for orthographic frequency, stroke number, and radical frequency, showed main effects of feedforward and feedback consistency, as well as interactions between these variables and phonological frequency and number of homophones. Implications of these results for resonance models of visual word recognition are discussed.postprin

Change blindness: eradication of gestalt strategies

Arrays of eight, texture-defined rectangles were used as stimuli in a one-shot change blindness (CB) task where there was a 50% chance that one rectangle would change orientation between two successive presentations separated by an interval. CB was eliminated by cueing the target rectangle in the first stimulus, reduced by cueing in the interval and unaffected by cueing in the second presentation. This supports the idea that a representation was formed that persisted through the interval before being 'overwritten' by the second presentation (Landman et al, 2003 Vision Research 43149–164]. Another possibility is that participants used some kind of grouping or Gestalt strategy. To test this we changed the spatial position of the rectangles in the second presentation by shifting them along imaginary spokes (by ±1 degree) emanating from the central fixation point. There was no significant difference seen in performance between this and the standard task [F(1,4)=2.565, p=0.185]. This may suggest two things: (i) Gestalt grouping is not used as a strategy in these tasks, and (ii) it gives further weight to the argument that objects may be stored and retrieved from a pre-attentional store during this task

Interactive effects of orthography and semantics in Chinese picture naming

Posters - Language Production/Writing: abstract no. 4035Picture-naming performance in English and Dutch is enhanced by presentation of a word that is similar in form to the picture name. However, it is unclear whether facilitation has an orthographic or a phonological locus. We investigated the loci of the facilitation effect in Cantonese Chinese speakers by manipulating—at three SOAs (2100, 0, and 1100 msec)—semantic, orthographic, and phonological similarity. We identified an effect of orthographic facilitation that was independent of and larger than phonological facilitation across all SOAs. Semantic interference was also found at SOAs of 2100 and 0 msec. Critically, an interaction of semantics and orthography was observed at an SOA of 1100 msec. This interaction suggests that independent effects of orthographic facilitation on picture naming are located either at the level of semantic processing or at the lemma level and are not due to the activation of picture name segments at the level of phonological retrieval.postprin

ARSTREAM: A Neural Network Model of Auditory Scene Analysis and Source Segregation

Multiple sound sources often contain harmonics that overlap and may be degraded by environmental noise. The auditory system is capable of teasing apart these sources into distinct mental objects, or streams. Such an "auditory scene analysis" enables the brain to solve the cocktail party problem. A neural network model of auditory scene analysis, called the AIRSTREAM model, is presented to propose how the brain accomplishes this feat. The model clarifies how the frequency components that correspond to a give acoustic source may be coherently grouped together into distinct streams based on pitch and spatial cues. The model also clarifies how multiple streams may be distinguishes and seperated by the brain. Streams are formed as spectral-pitch resonances that emerge through feedback interactions between frequency-specific spectral representaion of a sound source and its pitch. First, the model transforms a sound into a spatial pattern of frequency-specific activation across a spectral stream layer. The sound has multiple parallel representations at this layer. A sound's spectral representation activates a bottom-up filter that is sensitive to harmonics of the sound's pitch. The filter activates a pitch category which, in turn, activate a top-down expectation that allows one voice or instrument to be tracked through a noisy multiple source environment. Spectral components are suppressed if they do not match harmonics of the top-down expectation that is read-out by the selected pitch, thereby allowing another stream to capture these components, as in the "old-plus-new-heuristic" of Bregman. Multiple simultaneously occuring spectral-pitch resonances can hereby emerge. These resonance and matching mechanisms are specialized versions of Adaptive Resonance Theory, or ART, which clarifies how pitch representations can self-organize durin learning of harmonic bottom-up filters and top-down expectations. The model also clarifies how spatial location cues can help to disambiguate two sources with similar spectral cures. Data are simulated from psychophysical grouping experiments, such as how a tone sweeping upwards in frequency creates a bounce percept by grouping with a downward sweeping tone due to proximity in frequency, even if noise replaces the tones at their interection point. Illusory auditory percepts are also simulated, such as the auditory continuity illusion of a tone continuing through a noise burst even if the tone is not present during the noise, and the scale illusion of Deutsch whereby downward and upward scales presented alternately to the two ears are regrouped based on frequency proximity, leading to a bounce percept. Since related sorts of resonances have been used to quantitatively simulate psychophysical data about speech perception, the model strengthens the hypothesis the ART-like mechanisms are used at multiple levels of the auditory system. Proposals for developing the model to explain more complex streaming data are also provided.Air Force Office of Scientific Research (F49620-01-1-0397, F49620-92-J-0225); Office of Naval Research (N00014-01-1-0624); Advanced Research Projects Agency (N00014-92-J-4015); British Petroleum (89A-1204); National Science Foundation (IRI-90-00530); American Society of Engineering Educatio

Emotion word processing: evidence from electrophysiology, eye movements and decision making

A degree of confusion currently exists regarding how the emotionality of a textual stimulus influences its processing. Despite a wealth of research recently being conducted in the area, heterogeneity of stimuli used and methodologies utilized prevented general conclusion from being confidently drawn. This thesis aimed to clarify understanding of cognitive processes associated with emotional textual stimuli by employing well controlled stimuli in a range of simple but innovative paradigms. Emotion words used in this thesis were defined by their valence and arousal ratings. The questions asked here concerned early stages of processing of emotional words, the attention capturing properties of such words, any spill-over effects which would impact the processing of neutral text presented subsequently to the emotional material, and the effect of emotional words on higher cognitive processes such as attitude formation. The first experiment (Chapter 2) manipulated the emotionality of words (positive, negative, neutral) and their frequency (HF – high frequency, LF – low frequency) while ERPs were recorded. An emotion x frequency interaction was found, with emotional LF words responded to fastest, but only positive LF words responded to fastest. Negative HF words were also associated with a large N1 component. Chapter 3 investigated the attention-capturing properties of positive and negative words presented above and below a central fixation cross. The only significant effects appeared when a positive word was presented in the top condition, and a negative word in the bottom condition. Here saccade latencies were longer and there were a fewer number of errors made. Chapter 4 reports an eye tracking study which examined the effect of target words’ emotion (positive, negative, neutral) and their frequency (HF, LF). The pattern of results, produced in a variety of fixation time measurements such as first fixation duration and single fixation duration, was similar to those reported in Chapter 2. The existence of any spill-over effect of emotion onto subsequently presented neutral text was examined in a number of ways. Chapter 5 describes priming with emotional primes and neutral targets but no effect of emotion was found. Chapter 6 employed the same design as Chapter 4 but presented positive, negative or neutral sentences in the middle of neutral paragraphs. It was found that the positive sentences were read fastest, but the neutral sentences following the negative sentences were read faster than those following neutral sentences. Chapters 7 and 8 employed a version of the Velten mood-induction tool to examine the effect of mood when reading emotional text. Chapter 7 was a replication of Chapter 4 with 4 participant groups: positive, negative and neutral mood. While the neutral group showed similar results to those produced in Chapter 4, the positive group only fixated on the positive HF words faster, the negative group showed a frequency effect within each emotional word type, but within HF words positive words were viewed for less time than neutral words. Chapter 8 had participants read 4 product reviews and then afterwards rate each of the products on a set of semantic differentials. This was a 3 (mood: positive, negative, neutral) x 2 (message type: positive negative) x 2 (word type: positive negative). There was no effect of mood but positive messages were read quicker when they contained positive words and negative messages were read quicker when they contained negative words. Participants were asked to recommend each product to individuals in either a prevention in a promotion focus. When the focus was prevention there were additive effects of message and word type, but when the focus was positive there was an interaction, with the positive message conveyed using negative words being rated highest. The same pattern also emerged in the series of semantic differentials. Possible mechanisms to account for these findings are discussed, including many incarnations of McGinnies’s (1949) perceptual defense theory. Future studies should possibly aim to combine the current knowledge with motivational, goal-orientated models such as Higgins’s (1998) theory of regulatory focus

ARSTREAM: A Neural Network Model of Auditory Scene Analysis and Source Segregation

Multiple sound sources often contain harmonics that overlap and may be degraded by environmental noise. The auditory system is capable of teasing apart these sources into distinct mental objects, or streams. Such an "auditory scene analysis" enables the brain to solve the cocktail party problem. A neural network model of auditory scene analysis, called the AIRSTREAM model, is presented to propose how the brain accomplishes this feat. The model clarifies how the frequency components that correspond to a give acoustic source may be coherently grouped together into distinct streams based on pitch and spatial cues. The model also clarifies how multiple streams may be distinguishes and seperated by the brain. Streams are formed as spectral-pitch resonances that emerge through feedback interactions between frequency-specific spectral representaion of a sound source and its pitch. First, the model transforms a sound into a spatial pattern of frequency-specific activation across a spectral stream layer. The sound has multiple parallel representations at this layer. A sound's spectral representation activates a bottom-up filter that is sensitive to harmonics of the sound's pitch. The filter activates a pitch category which, in turn, activate a top-down expectation that allows one voice or instrument to be tracked through a noisy multiple source environment. Spectral components are suppressed if they do not match harmonics of the top-down expectation that is read-out by the selected pitch, thereby allowing another stream to capture these components, as in the "old-plus-new-heuristic" of Bregman. Multiple simultaneously occuring spectral-pitch resonances can hereby emerge. These resonance and matching mechanisms are specialized versions of Adaptive Resonance Theory, or ART, which clarifies how pitch representations can self-organize durin learning of harmonic bottom-up filters and top-down expectations. The model also clarifies how spatial location cues can help to disambiguate two sources with similar spectral cures. Data are simulated from psychophysical grouping experiments, such as how a tone sweeping upwards in frequency creates a bounce percept by grouping with a downward sweeping tone due to proximity in frequency, even if noise replaces the tones at their interection point. Illusory auditory percepts are also simulated, such as the auditory continuity illusion of a tone continuing through a noise burst even if the tone is not present during the noise, and the scale illusion of Deutsch whereby downward and upward scales presented alternately to the two ears are regrouped based on frequency proximity, leading to a bounce percept. Since related sorts of resonances have been used to quantitatively simulate psychophysical data about speech perception, the model strengthens the hypothesis the ART-like mechanisms are used at multiple levels of the auditory system. Proposals for developing the model to explain more complex streaming data are also provided.Air Force Office of Scientific Research (F49620-01-1-0397, F49620-92-J-0225); Office of Naval Research (N00014-01-1-0624); Advanced Research Projects Agency (N00014-92-J-4015); British Petroleum (89A-1204); National Science Foundation (IRI-90-00530); American Society of Engineering Educatio

TGD Inspired Theory of Consciousness

The basic ideas and implications of TGD inspired theory of consciousness are briefly summarized. The notions of quantum jump and self can be unified in the recent formulation of TGD relying on dark matter hierarchy characterized by increasing values of Planck constant. Negentropy Maximization Principle serves as a basic variational principle for the dynamics of quantum jump. The new view about the relation of geometric and subjective time leads to a new view about memory and intentional action. The quantum measurement theory based on finite measurement resolution and realized in terms of hyper-finite factors of type II1 justifies the notions of sharing of mental images and stereo-consciousness deduced earlier on basis of quantum classical correspondence. Qualia reduce to quantum number increments associated with quantum jump. Self-referentiality of consciousness can be understood from quantum classical correspondence implying a symbolic representation of contents of consciousness at space-time level updated in each quantum jump. p-Adic physics provides space-time correlates for cognition and intentionality

Action inhibition and affordances associated with a non-target object : An integrative review

This article reviews evidence for the special inhibitory mechanisms required to keep response activation related to affordances of a non-target object from evoking responses. This evidence presents that response activation triggered by affordances of a non-target are automatically inhibited resulting, for example, in decelerated response speed when the response is compatible with the affordance. The article also highlights the neural processes that differentiate these non-target-related affordance effects from other non-target-related effects such as the Eriksen flanker effect that-contrary to these affordance effects-present decelerated response speed when there is incompatibility between the non-target and the response. The article discusses the role of frontal executive mechanisms in controlling action planning processes in these non-target-related affordance effects. It is also proposed that overlapping inhibition mechanisms prevent executing impulsive actions relative to affordances of a target and exaggerate inhibition of response activation triggered by affordances of a non-target.Peer reviewe