Agoraphobia--a safety-signal perspective

The addition of a ‘safety perspective’ to the construal of agoraphobia as avoidance behaviour is proposed as a means of addressing several theoretical problems. Regarding agoraphobia as a balance between danger and safety signals enables one to re-examine the problem of the undue persistence of the avoidance behaviour component. It also opens for consideration the ‘non-exposure’ onset of agoraphobia (e.g. after loss or bereavements), the age of onset, the sex ratio, the role of trusted companions and talismen. A method for studying safety signals and safety factors is adumbrated, and some predictions are made. The advantages and limitations of the ‘safety perspective’ are considered.     

When Walking Makes Perception Better

ABSTRACT— When we move, the visual world moves toward us. That is, self-motion normally produces visual signals (flow) that tell us about our own motion. But these signals are distorted by our motion: Visual flow actually appears slower while we are moving than it does when we are stationary and our surroundings move past us. Although for many years these kinds of distortions have been interpreted as a suppression of flow to promote the perception of a stable world, current research has shown that these shifts in perceived visual speed may have an important function in measuring our own self-motion. Specifically, by slowing down the apparent rate of visual flow during self-motion, our visual system is able to perceive differences between actual and expected flow more precisely. This is useful in the control of action.     

AX+/BX- discrimination learning in the fear-potentiated startle paradigm in monkeys

Individuals with anxiety disorders often do not respond to safety signals and hence continue to be afraid and anxious. Consequently, it is important to develop paradigms in animals that can directly study brain systems involved in learning about, and responding to, safety signals. We previously developed a discrimination procedure in rats of the form AX+/BX-, where cues A and X presented together are paired with an aversive stimulus and cues B and X presented together predict the absence of an aversive stimulus. The present experiment adapted this procedure to the fear-potentiated startle paradigm in rhesus monkeys.     

A Computational Model of the Simplest Motor Program

A computational procedure (program) is defined to generate control signals for the motoneuron pools of agonist and antagonist muscles that will move a limb segment from one stationary position to another. The program accounts for the ability to move different distances with different inertial loads and for the influence of instructions concerning movement speed and accuracy. These motor commands allow the program to produce EMG patterns as well as force and kinematic trajectories that are consistent with much of the data found in the literature of these movements. The program is premised on the notion that kinematically defined tasks are accomplished by programming commands to the motoneuron pools, based on only a few cognitively recognized kinematic and dynamic features of the task. Most of the features found in EMG and kinematic patterns can be considered consequences of the program's algorithmic procedures rather than specifically planned features of those movements.     

Safety-signal therapy in agoraphobics: a preliminary test

It has been argued that persistent avoidance behaviour is strongly influenced by safety signals, and that agoraphobic avoidance behaviour is a clinical example of this influence. It was proposed that agoraphobic avoidance can be reduced by the judicious use of safety signals, and specifically, by training patients to travel towards rather than away from safety. A safety-signal technique in which the patient travelled towards the therapist at the most fear-inducing situations was compared with conventional therapist-assisted exposure. In the second part of the treatment programme, both groups of agoraphobics were given homework assignments. The safety-signal technique resulted in slightly better clinical gains than those achieved by therapist assisted exposure, but after these relatively brief programmes, the improvements in both groups were weak. Global clinical outcome was influenced by age, chronicity and long-term benzodiazepine use.     

Internalized homophobia in men: wanting in the first person singular, hating in the first person plural

This paper focuses on the expression of internalized homophobia in men, arguing that the most powerful clinical use of this term depends upon its applicability to any man, without limitation to those whose primary object choice is homosexual. A number of dynamic situations are described to which the term might apply, elaborated by examples from contemporary culture and clinical practice. A central dynamic elucidated here is the move from an anxiety-ridden, first person singular voice to the promised safety of a first person plural voice--that is, from the dangerous position of "I want" to the more protected "we hate."     

从中药的安全性谈中药产业的危机管理

药物的安全性是药物评价的首要标准。《欧盟传统药品法案》对中药的技术壁垒和我国对某些中药的毒副作用的披露,使得中药的安全性问题日益突出,使得中药产业面临前所未有的危机。对中药安全性的理性认识是扩大其国内市场占有率、走向国际市场所必须突破的瓶颈,也是中药产业危机管理的必由通道。这是一场深刻的文化革命。     

Extraretinal and retinal amplitude and phase errors during Filehne illusion and path perception

Pursuit eye movements give rise to retinal motion. To judge stimulus motion relative to the head, the visual system must correct for the eye movement by using an extraretinal, eye-velocity signal. Such correction is important in a variety of motion estimation tasks including judgments of object motion relative to the head and judgments of self-motion direction from optic flow. The Filehne illusion (where a stationary object appears to move opposite to the pursuit) results from a mismatch between retinal and extraretinal speed estimates. A mismatch in timing could also exist. Speed and timing errors were investigated using sinusoidal pursuit eye movements. We describe a new illusion--the slalom illusion--in which the perceived direction of self-motion oscillates left and right when the eyes move sinusoidally. A linear model is presented that determines the gain ratio and phase difference of extraretinal and retinal signals accompanying the Filehne and slalom illusions. The speed mismatch and timing differences were measured in the Filehne and self-motion situations using a motion-nulling procedure. Timing errors were very small for the Filehne and slalom illusions. However, the ratios of extraretinal to retinal gain were consistently less than 1, so both illusions are the consequence of a mismatch between estimates of retinal and extraretinal speed. The relevance of the results for recovering the direction of self-motion during pursuit eye movements is discussed.     

Accuracy of stereomotion speed perception with persisting and dynamic textures

It has been established that the motion in depth of stimuli visible to both eyes may be signalled binocularly either by a change of disparity over time or by the difference in the velocity of the images projected on each retina, known as an interocular velocity difference. A two-interval forced-choice stereomotion speed discrimination experiment was performed on four participants to ascertain the relative speed of a persistent random dot stereogram (RDS) and a dynamic RDS undergoing directly approaching or receding motion in depth. While the persistent RDS pattern involved identical dot patterns translating in opposite directions in each eye, and hence included both changing disparity and interocular velocity difference cues, the dynamic RDS pattern (which contains no coherent monocular motion signals) specified motion in depth through changing disparity, but no motion through interocular velocity difference. Despite an interocular velocity difference speed signal of zero motion in depth, the dynamic RDS stimulus appeared to move more rapidly. These observations are consistent with a scheme in which cues that rely on coherent monocular motion signals (such as looming and the interocular velocity difference cue) are less influential in dynamic stimuli due to their lack of reliability (i.e., increased noise). While dynamic RDS stimuli may be relatively unaffected by the contributions of such cues when they signal that the stimulus did not move in depth, the persistent RDS stimulus may retain a significant and conflicting contribution from the looming cue, resulting in a lower perceived speed.     

Segregation of cognitive and motor aspects of visual function using induced motion

Targets were displaced to cancel an apparent displacement induced by a step motion of a background or were held stationary while appearing to jump in an induced displacement. Target and background were then extinguished, and the subject pointed to the target’s last position. When the target had appeared to move but did not, background position did not significantly affect pointing; when the target had moved but appeared to remain stationary (displacement canceled by opposite induced displacement), pointing depended upon the target’s egocentric position. A similar result was obtained with sinusoidal motion. In terms of a two visual-systems hypothesis, the motor system uses more veridical spatial information and is less affected by relative changes in two retinal signals than is the cognitive system.     

Motion versus position in the perception of head-centred movement

Abstract. Observers can recover motion with respect to the head during an eye movement by comparing signals encoding retinal motion and the velocity of pursuit. Evidently there is a mismatch between these signals because perceived head-centred motion is not always veridical. One example is the Filehne illusion, in which a stationary object appears to move in the opposite direction to pursuit. Like the motion aftereffect, the phenomenal experience of the Filehne illusion is one in which the stimulus moves but does not seem to go anywhere. This raises problems when measuring the illusion by motion nulling because the more traditional technique confounds perceived motion with changes in perceived position. We devised a new nulling technique using global-motion stimuli that degraded familiar position cues but preserved cues to motion. Stimuli consisted of random-dot patterns comprising signal and noise dots that moved at the same retinal 'base' speed. Noise moved in random directions. In an eye-stationary speed-matching experiment we found noise slowed perceived retinal speed as 'coherence strength' (ie percentage of signal) was reduced. The effect occurred over the two-octave range of base speeds studied and well above direction threshold. When the same stimuli were combined with pursuit, observers were able to null the Filehne illusion by adjusting coherence. A power law relating coherence to retinal base speed fit the data well with a negative exponent. Eye-movement recordings showed that pursuit was quite accurate. We then tested the hypothesis that the stimuli found at the null-points appeared to move at the same retinal speed. Two observers supported the hypothesis, a third partially, and a fourth showed a small linear trend. In addition, the retinal speed found by the traditional Filehne technique was similar to the matches obtained with the global-motion stimuli. The results provide support for the idea that speed is the critical cue in head-centred motion perception.     

Motion capture depends on signal strength

When flickering dots are superimposed onto a drifting grating, the dots appear to move coherently with the grating. In this study we examine: (i) how the perceived direction of a compound stimulus composed of superimposed grating and dots, moving in opposite directions with equal speeds, is influenced by the relative strength of the motion signals; (ii) how the perceived speed of a compound stimulus composed of superimposed grating and dots, moving in the same direction but at different speeds, is influenced by the relative strength of the motion signals; and (iii) whether this stimulus is discriminable from its metameric speed match. Dot signal strength was manipulated by using different proportions of signal dots in noise and different dot lifetimes. Both the perceived direction and speed of these compound stimuli depended upon the relative motion-signal strengths of the grating and the dots. Those compound stimuli that appeared coherent were not discriminable from the speed-matched metameric compound stimuli. When the signals were completely integrated into a coherent compound stimulus, the local motion signals were no longer perceptually available, though both contributed to the global percept. These data strongly support a weighted-combination model where the relative weights depend on signal strength, instead of a winner-takes-all model.     

The time course of attentional bias to cues of threat and safety

It is well known that relative to neutral stimuli, attention is biased towards processing stimuli that convey threat. In a previous study in which a particular stimulus (e.g. a blue diamond) was associated with the delivery of an electrical shock, the presence of the fear-conditioned stimulus interfered with the execution of voluntary eye movements to other locations. Here, we show that this effect not only occurs early in time, but remains present long after the fear-conditioned stimulus was removed from the screen. In a subsequent experiment, we associated the presence of a particular stimulus with safety, that is, when this stimulus was present it was certain that no electrical shock would be delivered. The presence of the safety signalling stimulus also interfered with the execution of voluntary saccades, but only when the time between stimulus and cue presentation was relatively long. The results indicate that both signals of threat and signals of safety interfere with execution of a saccade long after the source of threat or safety has been removed. However, only threatening stimuli affect saccade execution early in time, suggesting that threatening stimuli drive selection exogenously.     

From Melancholia to Meaning How to Live the Past in the Present

Freud's theory of melancholia has lately experienced a renaissance among those interested in the creative potentialities of the psyche. In this essay, I consider the ways in which melancholia can contribute to the actualization of these potentialities by preparing the ground in which inspiration can later take root. I also outline the circumstances in which the melancholy subject's refusal to abandon its lost objects represents an entirely valid response to loss. At the same time, I propose that if the subject is to develop an affirmative and imaginatively supple relationship to its psychic history, it must in the end move from melancholia to meaning production. Insofar as melancholia signals the psyche's inability or stubborn unwillingness to move forward, its powers by necessity remain dormant until the subject is able to exchange its sadness for the versatile meaning-making capacities of the signifier. I moreover argue that it is only when the subject is able to transcend its melancholia enough to begin to desire new objects that it can develop loving and responsible relationships with others—that it can begin to welcome others in their own terms rather than reducing them to its own narcissistic image.     

Safer driver responses at intersections with green signal countdown timers

Traffic signal countdown timers (TSCTs) are innovative, practical, and cost effective technologies with the potential to improve safety at signalized intersections. The purpose of these devices is to assist motorists in decision-making at signalized intersections by providing them with real-time signal duration information. This study examines US driver responses in the presence of a green signal countdown timer (GSCT) and the implications those responses have on intersection safety. A driving simulator study was conducted to record driver responses to virtual GSCTs. Fifty-five participants (32 male and 23 female) responded to 1100 simulated traffic signals, half of which had GSCTs. A predictive model was developed and validated to estimate the change in driver’s probability to stop at different distances from the stop line in the presence of a GSCT. The presence of a GSCT increased average driver stopping probability in the dilemma zone by 13.10%, while decreasing average driver deceleration rates by 1.50 ft/s². These results suggest that GSCTs may contribute to improved intersection safety in the US.     

The simple constitutivist move

A common feature of all versions of constitutivism is the “simple constitutivist move” to the effect that engagement in any enterprise requires respecting the constitutive standards of the enterprise on pain of failing to engage in it. The move is both trivial and powerful in addressing skeptical challenges. I argue that this move only helps transmitting the robust authority of standards that are externally grounded, even when applied to functional items or constitutive aims. This is not a problem for modest versions of constitutivism, but more ambitious constitutivists seems to require supplementation to ground robust or authoritative normativity. Unfortunately, the usual appeal to inescapability is at best a defensive move. Ambitious constitutivism needs to look elsewhere in its search for a positive explanation of the source of robust normativity. The simple constitutivist move, even when combined with inescapability, is indeed too simple.     

Two-factor theory has strong empirical evidence of validity.

Traditional two-factor theory is supported by parallels in the clinical literature. Theoretical problems with two-factor theory are obviated by the role of safety signals, which serve as positive conditioned reinforcers and retard the extinction of conditioned fear.     

Motor Planning Influences the Perceived Timing of Vibrotactile Stimuli in an Amplitude-Dependent Manner

The authors characterized how motor planning influences temporal order judgment (TOJ) tasks. They examined this by applying vibrotactile stimulation during the planning stages of a bimanual arm movement that would bring the arms into a crossed configuration. The authors have previously shown that planning to cross the arms induces a subjective reversal of spatially defined temporal order judgments that evolves over the course of the planning period. It was unclear, however, whether this effect is modulated by the extent to which the arms would be crossed after movement. The authors examined this issue by having participants plan to move to 4 different targets that would leave the arms in crossed configurations of varying extents. The results demonstrate that even though cutaneous stimuli were applied before the movements, if participants were planning to move into a more crossed configuration, performance on the TOJ task worsened depending on where they were in the planning process. This data suggest the brain uses planning signals to predict sensations from impending movements in a context-dependent manner.     

Letting Diasporic Voices Be Heard

More than 68.5 million people were forced to move from their countries, according to the UN Refugee Agency, UNHCR, in 2018. Forced displacements are caused by poverty, war, and lack of safety. Since 2015, Europe has been experiencing a so‐called refugee crisis that calls European values and policies into question. Beyond data, there are the experiences of those who are on the move. The number of people arriving on the continent has made integration a decisive topic. This research aims to discover the portrayal of refugees and migrants in media. This goal includes the challenge of making European media evaluate their work to improve the treatment given to complex subjects such as migration. This article is the result of research derived from the project Refugees Reporting in 2017, coordinated by the Europe Region of the World Association for Christian Communistories ancation and the Churches' Commission for Migrants in Europe.     

Self-of-the-Therapist Work: A Balance Between Removing Restraints and Identifying Resources

The authors propose that self-of-the-therapist work is most productive when therapists and supervisors approach family of origin issues and historical life events in a balanced way and suggest that they move to an approach that ideally liberates restraints posed by self-of-the-therapist issues, while at the same time accesses resources available to therapists because of the same issues. This is a shift from the primarily restraint focus that has dominated self-of-the-therapist work. This paper also provides personal experiences of the authors, guidelines on how to create safety and balance, as well as practical examples of self-of-the-therapist exercises.