Overt head movements and persuasion: a self-validation analysis

The authors report 3 experiments that examine a new mechanism by which overt head movements can affect attitude change. In each experiment, participants were induced to either nod or to shake their heads while listening to a persuasive message. When the message arguments were strong, nodding produced more persuasion than shaking. When the arguments were weak, the reverse occurred. These effects were most pronounced when elaboration was high. These findings are consistent with the "self-validation" hypothesis that postulates that head movements either enhance (nodding) or undermine (shaking) confidence in one's thoughts about the message. In a 4th experiment, the authors extended this result to another overt behavior (writing with the dominant or nondominant hand) and a different attitude domain (self-esteem).     

The impact of socially conveyed norms on the reporting of sexual behavior and attitudes by men and women

This study explored the impact of verbally-conveyed social norms on college students’ reports of sexual behavior and attitudes. Some participants overheard a staged conversation that enforced conservative or permissive social norms. Men and women in the permissive condition were more likely to report extradyadic involvement than those in the conservative condition. Men in the conservative condition reported an older age at first intercourse and fewer lifetime and one-time only sexual partners than did men who did not overhear a conversation. Men’s and women’s reports of sexual attitudes were unaffected by the manipulation. That a transient social norm had an impact on reports of sexual behavior lends support to the notion that some apparent sex differences in sexual behavior are at least partially reporting differences due to the influence of differential social norms. Sexual attitudes were less influenced by the social context, suggesting that attitudinal sex differences may be more robust.     

Ambulatory accelerometry to quantify involuntary movements and tics in the syndrome of Gilles de la Tourette

Gilles de la Tourette syndrome is a chronic neuropsychiatric disorder characterizedby recurrent and involuntary tics, in addition to complex behavioral symptoms. Objective quantification of the nonspecific movements in Tourette patients can contribute much to understanding the pathophysiology of this disease. We used three accelerometersto characterizehead movement patterns and to objectively quantify head motility in the lateral, sagittal, and transversal planes in 9 Tourette patients and 14 controls during periods of rest, conversation, and watching a videotape with an entertaining program. Characteristic head movement patterns can be documented by means of accelerometry. Head motility levels in the lateral, sagittal, and transversal planes were significantly higher in the patients than in the controls during all the procedures. The patients and the controls showed a similar significant increase in head motility during conversation, but not during video watching. This first study shows that for both standardized and ambulatory research, accelerometry may provide an objective tool by which to quantify the severity and temporal dynamics of tics or nonspecific movements.     

Vection during conflicting multisensory information about the axis, magnitude, and direction of self-motion

We examined the vection induced by consistent and conflicting multisensory information about self-motion. Observers viewed displays simulating constant-velocity self-motion in depth while physically oscillating their heads left-right or back-forth in time with a metronome. Their tracked head movements were either ignored or incorporated directly into the self-motion display (as an added simulated self-acceleration). When this head oscillation was updated into displays, sensory conflict was generated by simulating oscillation along: (i) an orthogonal axis to the head movement; or (ii) the same axis, but in a non-ecological direction. Simulated head oscillation always produced stronger vection than 'no display oscillation'--even when the axis/direction of this display motion was inconsistent with the physical head motion. When head-and-display oscillation occurred along the same axis: (i) consistent (in-phase) horizontal display oscillation produced stronger vection than conflicting (out-of-phase) horizontal display oscillation; however, (ii) consistent and conflicting depth oscillation conditions did not induce significantly different vection. Overall, orthogonal-axis oscillation was found to produce very similar vection to same-axis oscillation. Thus, we conclude that while vection appears to be very robust to sensory conflict, there are situations where sensory consistency improves vection.     

Effects of relative immobilization on the speaker's nonverbal behavior and on the dialogue imagery level

People generally display an important amount of gestural and motoric activity when speaking. Since recent data have shown the limits of an explanation of this activity in terms of nonverbal or bodily communication, the present study attempted to explore what would happen if subjects were impeded from making the principal movements they normally perform during a conversation. Subjects were led to hold a 50-minute conversation while sitting in an armchair devised to restrain their movements of the head, arms, hands, legs, and feet during part of the experiment. The main dependent variables consisted of nonverbal activity in body zones that remained free to vary: eyebrows, eyes, mouth, and fingers. During the phase of movement restriction, highly significant increases in activity were recorded in these zones, with subsequent return to base levels when the subject recovered free movements. Also, significant interactions of conditions of movements and subject's conversational role (speaker vs. listener) were observed for most of the variables. Samples of dialogues submitted to a computerized technique of content analysis revealed a significant decrease in the vividness of imagery during movement restriction.     

Motion parallax judgements of depth as a function of the direction and type of head movement

We compared the relative effectiveness of rotating or translating the head, either horizontally or vertically, on the perception of depth resulting from motion parallax. Using Rogers and Graham's (1979) paradigm, we yoked the movement of random dots on a screen to movements of the head, simulating a corrugated surface. In two experiments, subjects nulled the apparent depth or motion seen in the display. Horizontal head movements yielded the most precise depth judgements, irrespective of whether the head translated or rotated. Motion thresholds were higher than those for depth and were independent of direction of head movement. In a third experiment, suprathreshold stimuli that simulated differing amounts of depth were used, and the subjects' perception of depth was virtually the same for all types and directions of head movement. In our stimulus situation, rotating or translating the head either vertically or horizontally produced motion parallax cues for depth that were equally effective. Our results also showed that, within a range, retinal image motion from head movement is converted into a depth signal and that above that range location constancy breaks down and motion is seen.     

Adaptation in the constancy of visual direction measured by a one-trial method

Adaptation to field displacement during head movements in the direction with the head rotation and in the direction against it was produced under otherwise identical conditions and compared; the field displacement rate was also varied. A rapid training procedure was used, and a novel one-trial test was employed that could measure the adaptation well enough to compare the effects of various training conditions. The one-trial test measured the magnitude of one of the manifestations of adaptation, the apparent displacement of a stationary target during head movements. This apparent horizontal target displacement was transformed into an oblique one by having the head movements that brought forth the apparent target displacement simultaneously cause an objective vertical target displacement. The slant of the resultant apparent motion path varied with the magnitude of the apparent horizontal target displacement. It was measured by having S reproduce its slant angle. It was found that adaptation to field displacement in the direction with the head rotation was consistently greater than adaptation to the opposite displacement conditions. An explanation for this result is offered.     

Control of a virtual vehicle influences postural activity and motion sickness

Everyday experience suggests that drivers are less susceptible to motion sickness than passengers. In the context of inertial motion (i.e., physical displacement), this effect has been confirmed in laboratory research using whole body motion devices. We asked whether a similar effect would occur in the context of simulated vehicles in a visual virtual environment. We used a yoked control design in which one member of each pair of participants played a driving video game (i.e., drove a virtual automobile). A recording of that performance was viewed (in a separate session) by the other member of the pair. Thus, the two members of each pair were exposed to identical visual motion stimuli, but the risk of behavioral contagion was minimized. Participants who drove the virtual vehicle (drivers) were less likely to report motion sickness than participants who viewed game recordings (passengers). Data on head and torso movement revealed that drivers tended to move more than passengers, and that the movements of drivers were more predictable than the movements of passengers. Before the onset of subjective symptoms of motion sickness movement differed between participants who (later) reported motion sickness and those who did not, consistent with a prediction of the postural instability theory of motion sickness. The results confirm that control is an important factor in the etiology of motion sickness and extend this finding to the control of noninertial virtual vehicles.     

Motion, not masking, provides the medium for feature attribution

ABSTRACT— Understanding the dynamics of how separate features combine to form holistic object representations is a central problem in visual cognition. Feature attribution (also known as feature transposition and feature inheritance) refers to the later of two stimuli expressing the features belonging to the earlier one. Both visual masking and apparent motion are implicated in feature attribution. We found that when apparent motion occurs without masking, it correlates positively with feature attribution. Moreover, when apparent motion occurs with masking, feature attribution remains positively correlated with apparent motion after the contribution of masking is factored out, but does not correlate with masking after the contribution of apparent motion is similarly factored out. Hence, motion processes on their own provide the effective medium for feature attribution. Our results clarify the dynamics of feature binding in the formation of integral and unitary object representations in human vision.     

The effect of perceived distance on perceived movement

Equations were developed to predict the apparent motion of a physically stationary object resulting from head movement as a function of errors in the perceived distances of the object or of its parts. These equations, which specify the apparent motion in terms of relative and common components, were applied to the results of two experiments. In the experiments, the perceived slant of an object was varied with respect to its physical slant by means of perspective cues. In Experiment I, O reported the apparent motion and apparent distance of each end of the object independently. The results are consistent with the equations in terms of apparent relative motion, but not in terms of apparent common motion. The latter results are attributed to the tendency for apparent relative motion to dominate apparent common motion when both are present simultaneously. In Experiment II, a direct report of apparent relative motion (in this case, apparent rotation) was obtained for illusory slants of a physically frontoparallel object. It was found that apparent rotations in the predicted direction occurred as a result of head motion, even though under these conditions no rotary motion was present on the retina.     

Conversing while driving: The importance of visual information for conversation modulation

Multiple studies have shown an increased accident risk due to telephoning while driving. On the other hand, driving with passengers leads to a decreased accident risk. One explanation is a conversation modulation by passengers in cars which leads to a different conversation pattern which is not so detrimental to driving as that when phoning. A driving simulator study was conducted in order to examine this conversation modulation more closely and to find out more about the factors involved in this modulation, especially about the role of visual information available to the passenger. In a within-subject design the conversational patterns of 33 drivers and passengers in different in-car settings (passenger as usual, passenger without front view or passenger without view of the driver) were compared to a hands-free cell phone and to a hands-free cell phone with additional visual information either about the driving situation or the driver. Participants were instructed to have a naturalistic small-talk with a friend. Results of the drivers’ speaking behavior showed a reduction of speaking while driving. Compared to a conversation partner on the cell phone, a passenger in the car varies his speaking rhythm by speaking more often but shorter. Further analyses showed that this effect is also found with a cell phone when providing the conversation partner additional visual information either about the driving situation or the driver. This latter finding supports the idea that conversation modulation is not triggered by being in the car but by the visual information about the driver’s state and the driving situation.     

Frequency, phase, and colour coding in apparent motion.

We present some results which indicate that the known spatiotemporal limits for apparent motion are consistent with the motion being sinusoidal or a result of filtering. Given this we investigated how two such motions interact as a function of their relative temporal phase differences. This was accomplished by inducing two independent motions from complementary coloured event pairs. Results indicated critical phase limits for perceiving the two motions (red and green) which were consistent with the frequency specificity of the effect. The results are discussed within the framework of a filtering process for the perception of apparent motion.     

Development of social perception: a conversation study of 6-, 12- and 36-month-old children

A conversation is made up of visual and auditory signals in a complex flow of events. What is the relative importance of these components for young children's ability to maintain attention on a conversation? In the present set of experiments the visual and auditory signals were disentangled in four filmed events. The visual events were either accompanied by the speech sounds of the conversation or by matched motor sounds and the auditory events by either the natural visual turn taking of the conversation or a matched turn taking of toy trucks. A cornea-reflection technique was used to record the gaze-pattern of subjects while they were looking at the films. Three age groups of typically developing children were studied; 6-month-olds, 1-year-olds and 3-year-olds. The results show that the children are more attracted by the social component of the conversation independent of the kind of sound used. Older children find spoken language more interesting than motor sound. Children look longer at the speaking agent when humans maintain the conversation. The study revealed that children are more attracted to the mouth than to the eyes area. The ability to make more predictive gaze shifts develops gradually over age.     

Visual Attention in Real-World Conversation: Gaze Patterns Are Modulated by Communication and Group Size

Gaze behavior both initiates and maintains conversations, playing a crucial role in real-world collaboration. Hitherto, most findings on social attention stem from research using pictures of faces in the laboratory, however, attention operates differently in the real world. Thus, we know little of how gaze behavior operates in naturalistic interactions. To bridge this gap, we applied mobile eye-tracking to investigate the gaze patterns present in naturalistic conversations. Specifically, we examined gaze behavior of participants in a group of two or five, either sitting together in silence, or engaging in a conversation, in which they took turns either listening or speaking to each other. Results show that participants looked more frequently towards others when the group was communicating compared to when remaining silent, and that they looked at others more frequently when listening compared to when speaking. Furthermore, being part of a dyad led to more social attention being afforded during conversation compared to the group situation, regardless of whether subjects were listening or speaking. Meanwhile, when sitting in silence subjects showed less social gazing in a dyad than in a group of five. Our results provide qualitative and quantitative insights into the patterns of visual attention during dynamic naturalistic conversations.     

Accurate intelligence assessments in social interactions: mediators and gender effects

Research indicates that people can assess a stranger's measured intelligence more accurately than expected by chance, based on minimal information involving appearance and behavior. The present research documents behavioral correlates of perceived and measured intelligence and identifies behaviors that mediate the relationship between perceived and measured intelligence. In particular, when judges rated targets with video and auditory stimuli available, responsiveness to conversation partner, eye-gaze, and looking at partner while speaking were each significant mediators in the accurate assessment of intelligence. Each of those behaviors, as well as the percentage of looking at partner while speaking as a function of the target's own speaking time, were significant mediators in the video silent condition. Additionally, judge and target gender contributed to accurate intelligence assessments.     

Efference,perceived movement,and illusory displacement

Implications of the efferent signal associated with voluntary eye movements as a mechanism of perceived motion are reviewed. This signal normally subserves motion perception during pursuit eye movements and is also present when the pursuit is activated to prevent loss of fixation. Such efferent signals are the basis of a number of illusory motion and displacement phenomena. The contribution of efferent motion mechanisms to the oculogyral and apparent concomitant motion illusions is discussed. The phenomenon of roll-induced tilt is analysed in terms of illusory motion and displacement associated with voluntary cyclotorsional eye movements.     

Simulated angular head oscillation enhances vection in depth

Research has shown that adding simulated linear head oscillation to radial optic flow displays enhances the illusion of self-motion in depth (ie linear vection). We examined whether this oscillation advantage for vection was due to either the added motion parallax or retinal slip generated by insufficient compensatory eye movement during display oscillation. We constructed radial flow displays which simulated 1 Hz horizontal linear head oscillation (generates motion parallax) or angular head oscillation in yaw (generates no motion parallax). We found that adding simulated angular or linear head oscillation to radial flow increased the strength of linear vection in depth. Neither type of simulated head oscillation significantly reduced vection onset latencies relative to pure radial flow. Simultaneous eye-movement recordings showed that slow-phase ocular following responses (OFRs) were induced in both linear and angular viewpoint oscillation conditions. Vection strength was significantly reduced by active central fixation when viewing displays which simulated angular, but not linear, head oscillation. When these displays with angular oscillation were viewed without stable fixation, vection strength was found to increase with the velocity and regularity of the OFR. We conclude that vection improvements observed during central viewing of displays with angular viewpoint oscillation depend on the generation of eye movements.     

Virtual social interactions in social anxiety--the impact of sex, gaze, and interpersonal distance

In social interactions, interpersonal distance between interaction partners plays an important role in determining the status of the relationship. Interpersonal distance is an important nonverbal behavior, and is used to regulate personal space in a complex interplay with other nonverbal behaviors such as eye gaze. In social anxiety, studies regarding the impact of interpersonal distance on within-situation avoidance behavior are so far rare. Thus the present study aimed to scrutinize the relationship between gaze direction, sex, interpersonal distance, and social anxiety in social interactions. Social interactions were modeled in a virtual-reality (VR) environment, where 20 low and 19 high socially anxious women were confronted with approaching male and female characters, who stopped in front of the participant, either some distance away or close to them, and displayed either a direct or an averted gaze. Gaze and head movements, as well as heart rate, were measured as indices of avoidance behavior and fear reactions. High socially anxious participants showed a complex pattern of avoidance behavior: when the avatar was standing farther away, high socially anxious women avoided gaze contact with male avatars showing a direct gaze. Furthermore, they showed avoidance behavior (backward head movements) in response to male avatars showing a direct gaze, regardless of the interpersonal distance. Overall, the current study proved that VR social interactions might be a very useful tool for investigating avoidance behavior of socially anxious individuals in highly controlled situations. This might also be the first step in using VR social interactions in clinical protocols for the therapy of social anxiety disorder.     

Neuropsychological functions of hand movements and gestures change in the presence or absence of speech

In order to address previous controversies whether hand movements and gestures are linked to mental concepts or solely to the process of speaking, in the present study we investigate the neuropsychological functions of the entire spectrum of unimanual and bimanual hand movements and gestures when they either accompany speaking or when they act as the only means to communicate in the absence of speech. The results showed that the hand movement activity regarding all types of hand movements and gestures stayed constant with and without speaking. The analysis of the Structure of hand movements showed that executions shifted from in space hand movements with a phase structure during the condition without speech to more irregular on body hand movements without a phase structure during the co-speech condition. The gestural analysis revealed that pantomime gestures increase under conditions without speech whereas emotional motions and subject-oriented actions primarily occur when speaking. The present results provide evidence that the overall hand movement activity does not differ between co-speech conditions and conditions without speech, but that the hands adopt different neuropsychological functions. We conclude that the hands primarily externalise mental concepts in conditions without speaking but that their use shifts to more self-regulation and to endorsing verbal output with emotional connotations when they accompany speech.     

Conversation Orientation and Cognitive Processes: A Comparison of U.S. Students in Initial Interaction With Native‐ Versus Nonnative‐Speaking Partners

The present study compares thought patterns, perceptions of interaction (perceived interaction smoothness and interaction involvement), and conversation orientation of U.S. students (N = 60) in dyadic interaction with a partner who is either another American or a non‐American nonnative speaker of English. As hypothesized, U.S. participants with nonnative‐speaking partners perceived interaction as more difficult, or less smooth, than did their counterparts with native‐speaking partners. U.S. participants with nonnative‐speaking partners also displayed different thought patterns, having more thoughts showing confusion, as well as more thoughts focused on the partner and less on the content of the ongoing conversation, than those with fellow native‐speaking partners. U.S. participants with a nonnative‐speaking partner also exhibited a different conversation orientation pattern, focusing more on understanding of the other's message, less on clarifying their own message, and less on displaying their own involvement. Specific thought categories and perceived interaction smoothness were correlated with conversation orientation indices for participants in interactions between native and nonnative speakers. Finally, interaction involvement was found to contribute most to variation in perceived interaction smoothness for both U.S. and non‐U.S. participants in interactions between native and nonnative speakers. Implications of the findings are discussed.