Directional Tuning Curves, Elementary Movement Detectors, and the Estimation of the Direction of Visual Movement

Both the insect brain and the vertebrate retina detect visual movement with neurons having broad, cosine-shaped directional tuning curves oriented in either of two perpendicular directions. This article shows that this arrangement can lead to isotropic estimates of the direction of movement: for any direction the estimate is unbiased (no systematic errors) and equally accurate (constant random errors). A simple and robust computational scheme is presented that accounts for the directional tuning curves as measured in movement sensitive neurons in the blowfly. The scheme includes movement detectors of various spans, and predicts several phenomena of movement perception in man.

Asymptotic Behavior of Strategies in the Repeated Prisoner's Dilemma Game in the Presence of Errors

We examine the asymptotic behavior of a finite, but error-prone population, whose agents can choose one of ALLD (always defect), ALLC (always cooperate), or Pavlov (repeats the previous action if the opponent cooperated and changes action otherwise) to play the repeated Prisoner's Dilemma. A novelty of the study is that it allows for three types of errors that affect agents' strategies in distinct ways: (a) implementation errors, (b) perception errors of one's own action, and (c) perception errors of the opponent's action. We also derive numerical results based on the payoff matrix used in the tournaments of Axelrod (1984). Strategies' payoffs are monitored as the likelihood of committing errors increases from zero to one, which enables us to provide a taxonomy of best response strategies. We find that for some range of error levels, a unique best response (i.e. a dominant strategy) exists. In all other, the population composition can vary based on the proportion of each strategist's type and/or the payoffs of the matrix. Overall, our results indicate that the emergence of cooperation is considerably weak at most error levels

A Brief Note on How Phenomenal Objects Relate to Objects Themselves

This brief note corrects some basic errors in Meijsing’s (2011) JCS paper on “The Whereabouts of Pictorial Space”, concerning the status of phenomenal objects in the reflexive model of perception. In particular I clarify the precise sense in which a phenomenal object relates to the object itself (the noumenal object) in visual perception

Spoken Language Intent Detection using Confusion2Vec

Decoding speaker's intent is a crucial part of spoken language understanding (SLU). The presence of noise or errors in the text transcriptions, in real life scenarios make the task more challenging. In this paper, we address the spoken language intent detection under noisy conditions imposed by automatic speech recognition (ASR) systems. We propose to employ confusion2vec word feature representation to compensate for the errors made by ASR and to increase the robustness of the SLU system. The confusion2vec, motivated from human speech production and perception, models acoustic relationships between words in addition to the semantic and syntactic relations of words in human language. We hypothesize that ASR often makes errors relating to acoustically similar words, and the confusion2vec with inherent model of acoustic relationships between words is able to compensate for the errors. We demonstrate through experiments on the ATIS benchmark dataset, the robustness of the proposed model to achieve state-of-the-art results under noisy ASR conditions. Our system reduces classification error rate (CER) by 20.84% and improves robustness by 37.48% (lower CER degradation) relative to the previous state-of-the-art going from clean to noisy transcripts. Improvements are also demonstrated when training the intent detection models on noisy transcripts

Drawing Mind Maps

{Excerpt} Mind maps are a visual means that represent, link, and arrange concepts, themes, or tasks, with connections usually extending radially from a central topic. They are used by individuals and groups (informally and intuitively) to generate, visualize, structure, and classify these. Intelligence is a potential, and thinking is the operating skill through which it acts upon experience. Outside highly technical matters, perception is the most important part of thinking. If most errors of thinking are errors of perception—that being colored by emotions and values—thinking as a skill can be improved by practice and education. Numerous straightforward yet powerful tools encourage creativity and flexibility, and help optimize different styles of reasoning (including analyzing, integrating, planning, and problem solving). They include APC, OPV, PMI, brainstorming, lateral thinking, and mind maps. After they are mastered, these tools can be applied explicitly. We usually write notes as sentences that we break into paragraphs, lists, or bullet points. A mind map is a circular, nonlinear way of organizing information: it shows the connections between a central topic and the relative importance of the concepts, themes, or tasks that one relates to it. It can be applied by individuals and groups to generate, visualize, structure, and classify these whenever clearer thinking and improved learning will enhance performance and effectiveness

On the internal target model in a tracking task

An optimal control model for predicting operator's dynamic responses and errors in target tracking ability is summarized. The model, which predicts asymmetry in the tracking data, is dependent on target maneuvers and trajectories. Gunners perception, decision making, control, and estimate of target positions and velocity related to crossover intervals are discussed. The model provides estimates for means, standard deviations, and variances for variables investigated and for operator estimates of future target positions and velocities

Speech perception in the elderly: errors analysis

OBJECTIVE: To analyze the errors made in a speech test in the presence of background noise for the elderly. METHOD: We performed a retrospective study with data collected from medical records of 55 elderly patients divided into control group (CG) and study group (SG), considering the tests Percentage Index of Speech Recognition (PISR) and Speech in Noise (S/R). RESULT: articulatory exchanges were more frequent test in the SG and in the /R test. Overall, there were more omissions of phonemes in initial position (/p/ and /b/) and final (/s/) of words, especially with the noise. There were omissions of words only in the SG. The words more exchanged in the CG were rir, dil, lhe, faz and rol, and in the SG, rir, dil, lhe, faz, pus and rol. CONCLUSION: the presence of normal pure tone thresholds did not prevent errors that occur in speech recognition and noise interfered negatively in this recognition, especially in the elderly with hearing loss. The phonemes / p /, / b / and / s / were most frequently omitted, especially in the presence of noise. The words rir, dil, lhe, faz and rol were the most confused in the groups, mainly in the presence of noise.OBJETIVO: analisar os erros apresentados em um teste de fala na presença de ruído competitivo de idosos. MÉTODO: foi realizado estudo retrospectivo com levantamento de dados de prontuário de 55 idosos divididos em grupo controle (GC) e grupo estudo (GE), considerando os testes Índice Percentual de Reconhecimento de Fala (IPRF) e Fala com Ruído (F/R). RESULTADO: as trocas articulatórias foram mais frequentes no GE e no teste F/R. De maneira geral, ocorreram mais omissões de fonemas na posição inicial (/p/ e /b/) e final (/s/) dos vocábulos, principalmente com o ruído. Houve omissões de vocábulos somente no GE. Os vocábulos mais trocados no GC foram rir , dil , lhe , faze rol , e no GE, rir , dil , lhe , faz , pue rol . CONCLUSÃO: a presença de limiares tonais normais não impediu que ocorressem erros no reconhecimento de fala e o ruído interferiu negativamente neste reconhecimento, principalmente no idoso com perda auditiva. Os fonemas /p/, /b/ e /s/ foram os mais frequentemente omitidos, principalmente na presença do ruído competitivo. Os vocábulos rir , dil , lhe , faze rolforam os mais trocados para os grupos avaliados, sobretudo na presença do ruído.Universidade Federal de São Paulo (UNIFESP) Curso de Pós-Graduação em Distúrbios da Comunicação HumanaPontifícia Universidade Católica de São Paulo Departamento de Clínica FonoaudiológicaUNIFESP, Curso de Pós-Graduação em Distúrbios da Comunicação HumanaSciEL

Effect of contrast on human speed perception

This study is part of an ongoing collaborative research effort between the Life Science and Human Factors Divisions at NASA ARC to measure the accuracy of human motion perception in order to predict potential errors in human perception/performance and to facilitate the design of display systems that minimize the effects of such deficits. The study describes how contrast manipulations can produce significant errors in human speed perception. Specifically, when two simultaneously presented parallel gratings are moving at the same speed within stationary windows, the lower-contrast grating appears to move more slowly. This contrast-induced misperception of relative speed is evident across a wide range of contrasts (2.5-50 percent) and does not appear to saturate (e.g., a 50 percent contrast grating appears slower than a 70 percent contrast grating moving at the same speed). The misperception is large: a 70 percent contrast grating must, on average, be slowed by 35 percent to match a 10 percent contrast grating moving at 2 deg/sec (N = 6). Furthermore, it is largely independent of the absolute contrast level and is a quasilinear function of log contrast ratio. A preliminary parametric study shows that, although spatial frequency has little effect, the relative orientation of the two gratings is important. Finally, the effect depends on the temporal presentation of the stimuli: the effects of contrast on perceived speed appears lessened when the stimuli to be matched are presented sequentially. These data constrain both physiological models of visual cortex and models of human performance. We conclude that viewing conditions that effect contrast, such as fog, may cause significant errors in speed judgments

An analysis and tabulation of word perception errors in the Scott, Foresman and Company basic readers: Curriculum Foundation Series, to discover the frequency and persistency of word perception errors in grades one and two.

Thesis (Ed.M.)--Boston Universit