Using stop signals to inhibit chronic dieters' responses toward palatable foods

Palatable foods in the environment can unintentionally trigger reactions to obtain them, which may interfere with dieting attempts. We tested a strategy to facilitate dieting behavior that makes use of behavioral stop signals that should instantly inhibit chronic dieters’ responses toward palatable foods. Participants performed a go/no-go task in which go cues and no-go cues (i.e., the behavioral stop signals) were presented with pictures of palatable foods and control objects. In Study 1, we tested the immediate behavioral effect of presenting stop signals near palatable foods in a reaction time paradigm. In Study 2 we assessed consumption of palatable food that had either consistently been associated with no-go cues, or not. Results show that no-go cues instantly inhibited responses toward palatable foods especially among chronic dieters. Moreover, across a one day period chronic dieters consumed less of a food that had consistently been associated with no-go cues. Stop signals thus appear a promising tool for chronic dieters to control behavior to palatable foods, and we discuss the merits and potential applications of this tool for facilitating dieting behavior.     

Audiovisual integration increases the intentional step synchronization of side-by-side walkers

When people walk side-by-side, they often synchronize their steps. To achieve this, individuals might cross-modally match audiovisual signals from the movements of the partner and kinesthetic, cutaneous, visual and auditory signals from their own movements. Because signals from different sensory systems are processed with noise and asynchronously, the challenge of the CNS is to derive the best estimate based on this conflicting information. This is currently thought to be done by a mechanism operating as a Maximum Likelihood Estimator (MLE). The present work investigated whether audiovisual signals from the partner are integrated according to MLE in order to synchronize steps during walking. Three experiments were conducted in which the sensory cues from a walking partner were virtually simulated. In Experiment 1 seven participants were instructed to synchronize with human-sized Point Light Walkers and/or footstep sounds. Results revealed highest synchronization performance with auditory and audiovisual cues. This was quantified by the time to achieve synchronization and by synchronization variability. However, this auditory dominance effect might have been due to artifacts of the setup. Therefore, in Experiment 2 human-sized virtual mannequins were implemented. Also, audiovisual stimuli were rendered in real-time and thus were synchronous and co-localized. All four participants synchronized best with audiovisual cues. For three of the four participants results point toward their optimal integration consistent with the MLE model. Experiment 3 yielded performance decrements for all three participants when the cues were incongruent. Overall, these findings suggest that individuals might optimally integrate audiovisual cues to synchronize steps during side-by-side walking.     

Vestibular stimulation affects optic-flow sensitivity

Typically, multiple cues can be used to generate a particular percept. Our area of interest is the extent to which humans are able to synergistically combine cues that are generated when moving through an environment. For example, movement through the environment leads to both visual (optic-flow) and vestibular stimulation, and studies have shown that non-human primates are able to combine these cues to generate a more accurate perception of heading than can be obtained with either cue in isolation. Here we investigate whether humans show a similar ability to synergistically combine optic-flow and vestibular cues. This was achieved by determining the sensitivity to optic-flow stimuli while physically moving the observer, and hence producing a vestibular signal, that was either consistent with the optic-flow signal, eg a radially expanding pattern coupled with forward motion, or inconsistent with it, eg a radially expanding pattern with backward motion. Results indicate that humans are more sensitive to motion-in-depth optic-flow stimuli when they are combined with complementary vestibular signals than when they are combined with conflicting vestibular signals. These results indicate that in humans, like in nonhuman primates, there is perceptual integration of visual and vestibular signals.     

A psycho-ethological approach to social signal processing

The emerging field of social signal processing can benefit from a theoretical framework to guide future research activities. The present article aims at drawing attention to two areas of research that devoted considerable efforts to the understanding of social behaviour: ethology and social psychology. With a long tradition in the study of animal signals, ethology and evolutionary biology have developed theoretical concepts to account for the functional significance of signalling. For example, the consideration of divergent selective pressures responsible for the evolution of signalling and social cognition emphasized the importance of two classes of indicators: informative cues and communicative signals. Social psychology, on the other hand, investigates emotional expression and interpersonal relationships, with a focus on the mechanisms underlying the production and interpretation of social signals and cues. Based on the theoretical considerations developed in these two fields, we propose a model that integrates the processing of perceivable individual features (social signals and cues) with contextual information, and we suggest that output of computer-based processing systems should be derived in terms of functional significance rather than in terms of absolute conceptual meaning.     

A psycho-ethological approach to social signal processing

The emerging field of social signal processing can benefit from a theoretical framework to guide future research activities. The present article aims at drawing attention to two areas of research that devoted considerable efforts to the understanding of social behaviour: ethology and social psychology. With a long tradition in the study of animal signals, ethology and evolutionary biology have developed theoretical concepts to account for the functional significance of signalling. For example, the consideration of divergent selective pressures responsible for the evolution of signalling and social cognition emphasized the importance of two classes of indicators: informative cues and communicative signals. Social psychology, on the other hand, investigates emotional expression and interpersonal relationships, with a focus on the mechanisms underlying the production and interpretation of social signals and cues. Based on the theoretical considerations developed in these two fields, we propose a model that integrates the processing of perceivable individual features (social signals and cues) with contextual information, and we suggest that output of computer-based processing systems should be derived in terms of functional significance rather than in terms of absolute conceptual meaning.     

The time windows of the sense of agency

The sense of agency depends on some internal cues that derive from action control, as well as external cues like contextual information and prior information (degree of contingency between an action and is effect). We assessed whether external agency cues are combined with internal agency cues to affect the sense of agency. In two experiments participants performed a movement (button press) that elicited, after a varying delay, an effect (ball appearing on a screen), and reported their sense of agency over the effect (full, partial or no-agency) while internal cues (premotor information) and external cues (contextual and prior information) were manipulated. We assessed the effect of agency cues on the delays at which the sense of agency varied. The delays were increased with premotor signals but were decreased with contextual information. These findings favour a model of integration of internal and external agency cues over time.     

The influence of partial-match cues on event-based prospective memory

In event-based prospective memory tasks people form an intention to respond when an environmental cue signals that conditions are appropriate to fulfil an intended activity. In the ongoing activity the authors embedded partial-match cues that only partially, but not completely, satisfied the conditions required to make a prospective response. The consequence of encountering these partial-match cues was to increase responses to appropriate prospective memory cues encountered later. This outcome occurred both with semantic and orthographic cues, but only the former led to longer processing latencies of the partial-match cues. This asymmetry suggests that partial-match cues may not need to be processed consciously in order to benefit event-based prospective memory. A parametric manipulation of the number of partial-match cues resulted in numerically but not statistically better prospective memory. Consequently, partial-match cues may function as overt reminders of the intention to respond or they may serve to engage participants in self-initiated remindings of the intention.     

The role of auditory memory traces in attention to frequency

Three cued signal detection experiments demonstrated a role for auditory memory traces in frequency selectivity. The extent to which the cue predicted the signal frequency affected the size of the advantage for signals at the cue frequency over those at distant frequencies when the cue-signal gap was 10 sec but not when it was 1 sec. Detection of occasional signals presented at uncued frequencies was enhanced when they matched the frequency of cues from recent trials. With "relative" cues, which were usually followed by signals at the musical fifth above the cue frequency, performance on occasional signals at the cue frequency was enhanced relative to other unexpected frequencies. These results suggest that, regardless of the listener's expectations and intentions, the detectability of a signal is enhanced if its frequency matches an existing memory trace. One form of voluntary attention to frequency may involve maintaining traces that would otherwise slowly decay.     

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.     

The influence of partial‐match cues on event‐based prospective memory

In event‐based prospective memory tasks people form an intention to respond when an environmental cue signals that conditions are appropriate to fulfil an intended activity. In the ongoing activity the authors embedded partial‐match cues that only partially, but not completely, satisfied the conditions required to make a prospective response. The consequence of encountering these partial‐match cues was to increase responses to appropriate prospective memory cues encountered later. This outcome occurred both with semantic and orthographic cues, but only the former led to longer processing latencies of the partial‐match cues. This asymmetry suggests that partial‐match cues may not need to be processed consciously in order to benefit event‐based prospective memory. A parametric manipulation of the number of partial‐match cues resulted in numerically but not statistically better prospective memory. Consequently, partial‐match cues may function as overt reminders of the intention to respond or they may serve to engage participants in self‐initiated remindings of the intention.     

Potency of food deprivation intensity cues as discriminative stimuli.

Rats were trained to use stimuli arising from 0 and 24 hr without food as discriminative signals for shock. In Experiment 1, one group was shocked under 0-hr food deprivation and not shocked under 24-hr food deprivation. Another group received the reverse contingency. The groups received only 3 training trials under each deprivation level. Learning was revealed in a test phase when greater extinction of freezing was observed under the nonshocked than under the shocked deprivation level for both groups. A similar pattern of results was obtained in Experiment 2 when auditory cues were also relevant throughout training. Furthermore, prior training with food deprivation cues seemed to reduce learning about auditory cues subsequently trained in compound with deprivation stimuli. The results indicate that food deprivation intensity cues can be potent discriminative stimuli. The idea that deprivation cues function as conditioned modulatory stimuli cues is also discussed.     

The interactive effect of vehicle signals and sensation-seeking on driver hazard perception

Does sensation seeking—as a personality trait that is closely related to risky driving—affect a driver's hazard perception, and if so, under what circumstances? Using hazard locations and vehicle signals as cues, this study classifies traffic situations into four types: danger ahead with cues, danger ahead without cues, danger behind with cues, and danger behind without cues. Based on these classifications, we examine the characteristics of hazard perception, decision-making criteria, sensitivity, and visual attention patterns of drivers with different sensation-seeking tendencies. Fifty-two experienced drivers were recruited for experiments in Dalian, China. Using computer, participants were shown videos taken from the driver's perspective and were asked to respond to hazards by pressing keys on the left mouse button. Their eye movements were recorded, and a multi-dimensional driving-style scale was used to divide participants into higher and lower sensation-seeking groups. The results showed that the higher sensation-seeking drivers had a lower hazard detection rate, fewer fixation counts, and shorter glances when there were cues, and they responded more slowly when there was danger ahead. For dangers ahead with cues and dangers behind without cues, the more attention the higher sensation-seeking drivers paid to the danger, the slower their response and the lower their hazard detection rate. The results indicated that higher sensation-seeking drivers have poor hazard perception in situations when there are vehicle signals as prompting clues and dangers ahead. In particular, for a danger with clues, the visual agility of the higher sensation-seeking drivers was worse than that of the lower sensation-seeking drivers. The more attention they paid to the danger the worse their hazard perception. The results of this study can provide guidance to teach drivers hazard-perception skills.     

Velocity constancy in a virtual reality environment

During everyday life the brain is continuously integrating multiple perceptual cues in order to allow us to make decisions and to guide our actions. In this study we have used a simulated (virtual reality--VR) visual environment to investigate how cues to speed judgments are integrated. There are two sources that could be used to provide signals for velocity constancy: temporal-frequency or distance cues. However, evidence from most psychophysical studies favours temporal-frequency cues. Here we report that two depth cues that provide a relative object--object distance--disparity and motion parallax--can provide a significant input to velocity-constancy judgments, particularly when combined. This result indicates that the second mechanism can also play a significant role in generating velocity constancy. Furthermore, we show that cognitive factors, such as familiar size, can influence the perception of object speed. The results suggest that both low-level cues to spatiotemporal structure and depth, and high-level cues, such as object familiarity, are integrated by the brain during velocity estimation in real-world viewing.     

Cuing mechanisms in autitory signal detection

Detection of auditory signals under frequency uncertainty can be improved by presenting cues to the listeners. Since various cues have been found to differ in effectiveness, three conceivable mechanisms were considered which might account for these differences. Cuing might reduce the number and/or width of the employed auditory filters or listening bands. Also, cues could modulate the precision of frequency tuning of the filters. Psychometric functions were collected in a detection experiment with frequency uncertainty employing three kinds of cues: pure tones whose frequency was identical to that of the signal (iconic cues), complex tones with a missing fundamental equal to the signal (complex cues), and pure tones with a certain frequency relation to the signal (relative cues). Compared with a no-cue condition, all cue types improved detection performance. Fitting models to the data suggests that in the no-cue condition as well as the complex-cue condition, multiple bands were utilized, and that the iconic and relative cues induced single-band listening. There is no indication that accuracy of frequency tuning was responsible for cue-efficiency differences.     

Identifying the distress cues that influence support provision: a paired comparison approach

Just as chemistry has methods for determining the composition of unknown substances, psychology needs, but has lacked, effective methods for identifying the "active ingredients" of social stimuli. We describe such a method and apply it to identify the verbal and nonverbal distress cues that serve as signals prompting others to provide social support. This method allowed us to identify 55 such cues. Furthermore, the cues that were salient in the minds of potential support providers depended on their goals. For example, when deciding whether someone needed support, negative nonverbal cues (e.g., distressed persons' fidgeting) were more salient, but when deciding whether one was willing to provide support, cues that suggested a positive outcome for the support seeker (e.g., distressed persons' positive attitude and open-mindedness) were more salient.     

Sense of agency: Sensorimotor signals and social context are differentially weighed at implicit and explicit levels

Sense of agency (SoA) describes the experience of being the author of an action. Cue integration approaches divide SoA into an implicit level, mostly relying on prospective sensorimotor signals, and an explicit level, resulting from an integration of sensorimotor and contextual cues based on their reliability. Integration mechanisms at each level and the contribution of implicit to explicit SoA remain underspecified. In a task of movements with visual outcomes, we tested the effect of social context (contextual cue) and sensory prediction congruency (retrospective sensorimotor cue) over implicit (intentional binding) and explicit (verbal judgments) SoA. Our results suggest that prospective sensorimotor cues determine implicit SoA. At the explicit level, retrospective sensorimotor cues and contextual cues are partly integrated in an additive way, but contextual cues can also act as a heuristic if sensorimotor cues are highly unreliable. We also found no significant association between implicit and explicit SoA.     

Cues and control strategies in visually guided tracking

Detailed quantitative models are required to investigate the neurological basis of motor behavior. Previous studies of visually guided manual tracking have either identified a variety of control signals (cues) for planning tracking movements or analyzed how a single cue is used (i.e., one-tracking strategy). A systematic, quantitative analysis of the effects and interactions of cues in terms of human manual-tracking performance is presented here together with measurements of concomitant eye movements. These measurements help define the routes by which information reaches the CNS, and the analysis elucidates how the control signals are processed and combined. The results quantify not only the large improvement in performance observed when the target waveform being tracked is predictable but also the extent to which this improvement depends on the availability of current information about target movements and positional error. Target information is shown to provide short-term prediction independent of the error signals used in on-line negative feedback control.     

Frog embryos use multiple levels of temporal pattern in risk assessment for vibration-cued escape hatching

Animal Cognition - Stereotyped signals can be a fast, effective means of communicating danger, but animals assessing predation risk must often use more variable incidental cues. Red eyed-treefrog,...     

The communication of friendly and hostile attitudes by verbal and non-verbal signals

Two experiments are reported here in which Ss were asked to rate videotapes of a performer reading friendly, neutral and hostile messages in a friendly, neutral or hostile non-verbal style. These messages and non-verbal styles had previously been presented independently to a separate group of Ss jor rating, in order to obtain an estimate of their individual strengths in terms of six rating scales, and thus permit a matching of verbal (messages) and non-verbal (styles) cues in the experiment where both types of cues were presented in combination. The results of both experiments indicate that non-verbal cues had a greater effect on ratings made on 7-point scales, such as hostile-friendly, than verbal cues. The magnitude of this greater effect of non-verbal cues, however, was dependent on the relative strength of non-verbal as opposed to verbal cues. In the first experiment, both types of cues were approximately equal in strength when ruted alone; here non-verbal cues accounted for 12.5 times us much variance us verbal cues, and produced 5.7 times as much shift on the ratitig scales. In the second experiment the verbal cues were much stronger than the non-verbal cues when rated alone. Here the relative effect of non-verbal cues in the second experiment was diminished; the ratio of non-verbal : verbal variance was now 1.67:1. When verbal and non-verbal signals were inconsistent, the performance was rated as insincere, unstable and confusing - which was not found in earlier experiments on the superior-inferior dimension.     

Identifying the Distress Cues that Influence Support Provision: A Paired Comparison Approach

ABSTRACT

Just as chemistry has methods for determining the composition of unknown substances, psychology needs, but has lacked, effective methods for identifying the “active ingredients” of social stimuli. We describe such a method and apply it to identify the verbal and nonverbal distress cues that serve as signals prompting others to provide social support. This method allowed us to identify 55 such cues. Furthermore, the cues that were salient in the minds of potential support providers depended on their goals. For example, when deciding whether someone needed support, negative nonverbal cues (e.g., distressed persons' fidgeting) were more salient, but when deciding whether one was willing to provide support, cues that suggested a positive outcome for the support seeker (e.g., distressed persons' positive attitude and open-mindedness) were more salient.