Cutaneous coding of optical signals: the optohapt

Attention, Perception, & Psychophysics - Means of transmuting optical signals into cutaneous patterns are sufficiently rare to warrant a fresh attempt at devising one. An instrument called the...     

Inevitable contradictory relationship of psychoanalytic thought with the "Zeitgeist". A plea for reclaiming the sovereignity of psychoanalytic thought

Psychoanalysis is by its nature a sturdy procedure. It does not fit into the frame of contemporary thought patterns and should not, in the author's opinion, be made into something that its conceptual basis does not allow it to become: a partisan instrument. The author extends a discussion that was opened by Paul Parin's article on social criticism in the interpretive process.     

Electronic AVTA: Signal processing for automatic vocal transaction analysis

An integrated circuit device that simplifies computer acquisition of the sound-silence patterns of vocalization in dyadic conversations is described. The unit converts analog voice signals into digital form, handles the problem of cross talk that occurs when persons seated close together are recorded on separate microphones, and adds a smoothing constant to fill in brief pauses within and between vocalizations.     

On the role of space and time in auditory processing

Unlike visual and tactile stimuli, auditory signals that allow perception of timbre, pitch and localization are temporal. To process these, the auditory nervous system must either possess specialized neural machinery for analyzing temporal input, or transform the initial responses into patterns that are spatially distributed across its sensory epithelium. The former hypothesis, which postulates the existence of structures that facilitate temporal processing, is most popular. However, I argue that the cochlea transforms sound into spatiotemporal response patterns on the auditory nerve and central auditory stages; and that a unified computational framework exists for central auditory, visual and other sensory processing. Specifically, I explain how four fundamental concepts in visual processing play analogous roles in auditory processing.     

A two-dimensional computer-controlled visual stimulator

A computer-controlled instrument that creates complex two-dimensional patterns on a CRT monitor is described. These patterns are used to elicit visual evoked responses. Patterns are produced on a raster that is rotatable about its center. It is possible to assign to arbitrary regions in the raster any of four independent one-dimensional spatial-temporal functions. For each spatial-temporal function, the experimenter can select an arbitrary spatial profile, the spatial frequency of the profile, the starting phase of the profile, the temporal function, and the depth of modulation.     

The Study of Interpersonal Problems: A Leary Legacy

The Inventory of Interpersonal Problems (IIP) is an instrument based on Leary's original theory that has been used to identify dysfunctional patterns in a person's interpersonal interactions. Interpersonal problems can be organized. in 2 dimensions, and the 2-dimensional space can be divided into 8 equal sector's (octants). Subscale of the IIP describe problems in each of these octants. The instrument has been used to identify interpersonal problems that are discussed most often in a brief dynamic psychotherapy and problems that are treated most easily. The results show that problems in the exploitable octant improve most frequently, whereas problems in the dominating, vindictive, and cold octants do not improve as readily. We have also examined people's attachment styles in adulthood (following a model proposed by Bowlby) ,and found that different attachment styles correspond to different types of interpersonal problems.     

Using State-Space Model with Regime Switching to Represent the Dynamics of Facial Electromyography (EMG) Data

Facial electromyography (EMG) is a useful physiological measure for detecting subtle affective changes in real time. A time series of EMG data contains bursts of electrical activity that increase in magnitude when the pertinent facial muscles are activated. Whereas previous methods for detecting EMG activation are often based on deterministic or externally imposed thresholds, we used regime-switching models to probabilistically classify each individual’s time series into latent “regimes” characterized by similar error variance and dynamic patterns. We also allowed the association between EMG signals and self-reported affect ratings to vary between regimes and found that the relationship between these two markers did in fact vary over time. The potential utility of using regime-switching models to detect activation patterns in EMG data and to summarize the temporal characteristics of EMG activities is discussed.     

Species identity and the temporal characteristics of fish acoustic signals

Analyses of the acoustic signals of fish show that fine-scale temporal patterns of signals are what vary among species. A growing body of research addressing the topic of species differences in fish acoustic signals suggests that these differences are related to mate choice or species isolation. However, little behavioral work has been done to determine whether these temporal differences are actually used in discriminating conspecific sounds from interspecific sounds. In this article, the authors review three cases--Centrachids, Mormyrids, and Pomancentrids--for which species specificity in both signal production and differential response to acoustic signals have been demonstrated. Work done on damselfish (Dascyllus albisella) is an especially good example and thus may serve as a model for future work.     

Populations of spiking neurons for reservoir computing: Closed loop control of a compliant quadruped

Compliant robots can be more versatile than traditional robots, but their control is more complex. The dynamics of compliant bodies can however be turned into an advantage using the physical reservoir computing framework. By feeding sensor signals to the reservoir and extracting motor signals from the reservoir, closed loop robot control is possible. Here, we present a novel framework for implementing central pattern generators with spiking neural networks to obtain closed loop robot control. Using the FORCE learning paradigm, we train a reservoir of spiking neuron populations to act as a central pattern generator. We demonstrate the learning of predefined gait patterns, speed control and gait transition on a simulated model of a compliant quadrupedal robot.     

Haptic shape perception from force and position signals varies with exploratory movement direction and the exploring finger

We investigated how exploratory movement influences signal integration in active touch. Participants judged the amplitude of a bump specified by redundant signals: When a finger slides across a bump, the finger’s position follows the bump’s geometry (position signal); simultaneously, it is exposed to patterns of forces depending on the gradient of the bump (force signal). We varied amplitudes specified by force signals independently of amplitudes specified by position signals. Amplitude judgment was a weighted linear function of the amplitudes specified by both signals, under different exploratory conditions. The force signal’s contribution to the judgment was higher when the participants explored with the index finger, as opposed to the thumb, and when they explored along a tangential axis, as opposed to a radial one (pivot ≌ shoulder joint). Furthermore, for tangential, as compared with radial, axis exploration, amplitude judgments were larger (and more accurate), and amplitude discrimination was better. We attribute these exploration-induced differences to biases in estimating bump amplitude from force signals. Given the choice, the participants preferred tangential explorations with the index finger—a behavior that resulted in good discrimination performance. A role for an active explorer, as well as biases that depend on exploration, should be taken into account when signal integration models are extended to active touch.     

Steps and pips in the history of the cumulative recorder

From its inception in the 1930s until very recent times, the cumulative recorder was the most widely used measurement instrument in the experimental analysis of behavior. It was an essential instrument in the discovery and analysis of schedules of reinforcement, providing the first real-time analysis of operant response rates and patterns. This review traces the evolution of the cumulative recorder from Skinner's early modified kymographs through various models developed by Skinner and his colleagues to its perfection in the 1950s, and then into the 1960s when it proliferated as different scientific instrument companies began marketing their own models of the cumulative recorder. With the rise of digital computers, the demise of the cumulative recorder as a scientific instrument was inevitable; however, the value of the cumulative record as a monitoring device to assess schedule control of behavior continues. The cumulative recorder remains, along with the operant conditioning chamber, an icon of Skinner's approach to psychology.     

Detecting structure in glass patterns: an interocular transfer study

Glass patterns are visual stimuli used here to study how local orientation signals are spatially integrated into global pattern perception. We measured a form aftereffect from adaptation to both static and dynamic Glass patterns and calculated the amount of interocular transfer to determine the binocularity of the detectors responsible for the perception of global structure. Both static and dynamic adaptation produced significant form aftereffects and showed a very high degree of interocular transfer, suggesting that Glass-pattern perception involves cortical processing beyond primary visual cortex. Surprisingly, dynamic adaptation produced significantly greater interocular transfer than static adaptation. Our results suggest a functional interaction between local orientation processing and global motion processing that contributes to form perception.     

Discrimination of acoustic communication signals by grasshoppers (Chorthippus biguttulus): temporal resolution, temporal integration, and the impact of intrinsic noise

A characteristic feature of hearing systems is their ability to resolve both fast and subtle amplitude modulations of acoustic signals. This applies also to grasshoppers, which for mate identification rely mainly on the characteristic temporal patterns of their communication signals. Usually the signals arriving at a receiver are contaminated by various kinds of noise. In addition to extrinsic noise, intrinsic noise caused by stochastic processes within the nervous system contributes to making signal recognition a difficult task. The authors asked to what degree intrinsic noise affects temporal resolution and, particularly, the discrimination of similar acoustic signals. This study aims at exploring the neuronal basis for sexual selection, which depends on exploiting subtle differences between basically similar signals. Applying a metric, by which the similarities of spike trains can be assessed, the authors investigated how well the communication signals of different individuals of the same species could be discriminated and correctly classified based on the responses of auditory neurons. This spike train metric yields clues to the optimal temporal resolution with which spike trains should be evaluated.     

A test-signal generator for low-frequency instrumentation

An instrument for generating simultaneous sinusoidal test signals m the range of 1–32 Hz for EEG equipment checkout procedures is described. A composite signal is produced by a method that separates the functions of waveform generation and control of output frequencies at which that waveform appears. The general technique may be applicable in a number of situations involving low-frequency instrumentation, as with other types of physiological monitoring. Possibilities and methods for elaboration or modification of the circuit are suggested.     

Spatial coding of auditory signals

Sequences of nine binary auditory signals (dots and dashes) were presented to 20 subjects in Experiment I. The subjects were instructed to internally organize the signals into two-dimensional arrays. Visual patterns (letters) could be recognized in these imaginary arrays in both upright and rotated orientations. In Experiment II, a group of nine subjects, which was instructed to use spatial imagery of this kind, reproduced significantly longer sequences of signals than nine control subjects. By means of internal spatial organization, experimental subjects were able to reproduce sequences up to 45 signals in length, whereas control subjects recalled near the chance level for portions of sequences longer than nine signals. Three levels of information processing were postulated to account for the results, with spatial organization occupying a mediating level between acoustic and verbal levels.     

General software for an on-line eye-movement recording system

A general on-line eye-movement recording system is described which consists basically of (a) some on-line instrument capable of displaying a visual scene, (b) a device to measure eye position and output position information in the form of electrical signals (c) an analogue-to-digital converter, and (d) a computer. General software for such a system is discussed with emphasis on subroutines which perform calibration and which continuously monitor eye position.     

Hidden patterns of play interaction in soccer using SOF-CODER

Traditional methods for quantifying sport performances are limited in their capacity to describe the complex interactions of events that occur within a performance over time. The following article outlines a new approach to the study of actions between players in team sports—mainly, soccer. Since the observational design is nomothetic, point, and multidimensional, an observational and data-collecting instrument has been developed. The instrument is mixed and combines a field format with a category system for game events, as well as an ad hoc instrument that considers the game actions of one or both teams, each recorded according to the same criteria. The article also outlines a new approach to the analysis of time-based event records—in this case, sports performance—known as T-pattern detection. The relevant elements of the T-pattern detection process are explained, and exemplar data from analyses of soccer matches are presented to highlight the potential of this form of data analysis. The results suggest that it is possible to identify new kinds of profiles for both individuals and teams on the basis of observational criteria and a further analysis of temporal behavioral patterns detected within the performances.     

音高模式加工的大脑偏侧化研究

作为一种超音段成分,音高在言语的理解和产生过程中承担着重要作用,这些作用主要包括:区别不同声调的词汇意义,区别陈述、疑问等不同的语调,标志话语的情绪色彩等。音段、语义和句法信息的加工具有左脑优势,但音高模式加工的单侧优势及其机制还存在很多争论,本文从音高模式加工的两个主要理论———功能假设和声音信号假设出发,对相关研究加以评述。     

A hidden markov model-based analysis framework using eye-tracking data to characterise re-orientation strategies in minimally invasive surgery

Natural Orifice Translumenal Endoscopic Surgery (NOTES) represents a new paradigm in minimally invasive surgery whereby an operator uses a flexible instrument to navigate within an anatomical space. The flexible instrument is introduced via a natural body orifice such as the mouth to perform an operative intervention controlled by the surgeon without making incisions in the anterior abdominal wall. It differs from laparoscopic (traditional keyhole) surgery in two main ways: (1) the instruments used in NOTES are not rigid as in laparoscopic surgery and not specifically designed for this application; and (2) there are no incisions in the anterior abdominal wall. Disorientation during NOTES is a significant problem because as in laparoscopic surgery the operator typically uses a 2D camera-monitor interface for visualisation by the camera at the site of the operation. Furthermore, the positional cue offered by the external component (outside the body) of the camera is absent, and camera navigation is more cumbersome. When the operator is disorientated, it is important to be able to re-orientate quickly to minimise potential surgical errors. It is hypothesised that when surgeons become disorientated, there exist discrete patterns in psychophysical behaviour which are associated with effective re-orientation, and that these patterns are recognisable. In this study, we examine visual re-orientation behaviour in 18 subjects using eye-tracker data in a model comprised of selective image manipulation of everyday objects in a box trainer. We characterise effective behaviour using a fixation sequence similarity-based hidden Markov model. We show that the output of this algorithm is reliable in differentiating visual behavioural sequences, and that there are specific behavioural patterns and strategies associated with successful re-orientation in this model. Good re-orientation strategy appears to rely on identification and focus on a central object within the scene and judging position of its surrounding peripheral objects, suggesting integration of both geometric and feature information in a systematic way. Using selective, inconsistent feature cues for re-orientation were associated with less effective performance.     

Relative sensitivities to large-field optic-flow patterns varying in direction and speed

Motion in depth results in radial optic-flow patterns. Forward motion results in radially expanding patterns, whereas backward motion generates contracting patterns. Radial optic-flow patterns are typically represented with a positive speed gradient, ie zero speed at the point of fixation, and maximum speed at the periphery. However, the actual speed profile in such a stimulus will depend upon the relative depth of objects in the scene. Using large-field stimuli (82 deg diameter) we determined relative sensitivities to radial expansion and contraction patterns and also to various types of speed gradients: positive, negative, random, and flat. We found that, even when large-field stimuli are used, observers are more sensitive to radially contracting patterns than to expanding patterns. Sensitivity to the positive speed gradient was not consistently different from either the negative or random gradients. Sensitivity to the flat gradient depended upon the speed of the stimuli. The finding of greater sensitivity to radial contraction is discussed in terms of the functional requirements involved in the use of optic-flow signals in maintaining balance. On the basis of the present findings, the utility of comparing psychophysical results based on thresholds against physiological data based on suprathreshold stimuli is also discussed.