The naked truth: Positive,arousing distractors impair rapid target perception

Emotional stimuli tend to capture and hold attention more than non-emotional stimuli do. Aversive pictures have been found to impair perception of visual targets even after the emotional information has disappeared. The benefits of such interlinked emotion and attention systems have sometimes been discussed within an evolutionary framework, with a survival advantage attributed to early detection of threatening stimuli. However, consistent with recent suggestions that attention is drawn to arousing stimuli regardless of whether they are positive or negative, the current investigation found that erotic distractors—generally rated as both pleasing and arousing—consistently elicited a transient “emotion-induced blindness” similar to that caused by aversive distractors (Experiment 1). This effect persisted despite performance-based monetary incentives to ignore the distractors (Experiment 2), and following attentional manipulations that reduced interference from aversive images (Experiment 3). The findings indicate that positively arousing stimuli can spontaneously cause emotion-induced deficits in visual processing, just as aversive stimuli can.     

Internet and Facebook related images affect the perception of time

Even though there is a wealth of research on addiction and implicit measures, the effects of addiction on time perception are still unclear. Internal clock models separate the effects of attention and arousal which could have important implications for addiction research. This study investigated whether Internet related stimuli can lead to distorted time perception. We found evidence that Internet and Facebook related stimuli can distort time perception due to attention and arousal related mechanisms. This highlights that Facebook related stimuli lead to an overestimation of time compared to Internet related stimuli, and both Facebook and Internet related stimuli were associated with better discriminability of time compared to matched neutral stimuli. Implications of these findings on addiction are discussed.     

Selective attention to global and local information: Effects of visual angle,exposure duration,and eccentricity on processing dominance

Abstract

The size and exposure duration of stimuli have been found to be relevant factors to the issue of processing dominance. Nevertheless, the relation between these two factors and their possible effects on processing dominance have never been studied. The aim of the present research was twofold: (a) to examine whether size and the exposure duration of stimuli affect processing dominance; (b) to examine whether these effects depend on the same/different eccentricity of global and local levels. Stimuli were presented at three exposure durations: 140 msec, 70 msec, and 40 msec. The overall sizes of stimuli were varied at three levels: small (3[ddot]), intermediate (6[ddot]) and large (12[ddot]). In Experiment 1 stimuli were used whose global and local levels were at different eccentricity (Hs and Ss stimuli). In Experiment 2 stimuli whose global and local levels were at the same eccentricity (Cs stimuli) were used. The results showed that the effects of visual angle on processing dominance are independent of the exposure duration of stimuli used. The transition from global to local dominance as visual angle is increased depends on the eccentricity of global and local information: It only appears when the eccentricity is different and biased towards the local level (Hs and Ss stimuli). Finally, the size of the effect is modulated by the visual angle subtended by the stimuli: the size of the effect of global advantage was inversely related to visual angle. The size of the interference effect from the local level to the global level was directly related to the visual angle, whereas that from the global level to the local level was inversely related to the visual angle subtended by the stimuli.     

Sequence learning by action and observation: Evidence for separate mechanisms

In the Serial Reaction Time (SRT) task, participants respond to a set of stimuli the order of which is apparently random, but which consists of repeating sub‐sequences. Participants can become sensitive to this regularity, as measured by an indirect test of reaction time, but can remain apparently unaware of the sequence, as measured by direct tests of prediction or recognition. Some researchers have claimed that this learning may take place by observation alone. We suggest that observational learning may be due to explicit acquired knowledge of the sequence, and is not mediated by the same processes which give rise to learning by action. In Expt 1, we show that it is very difficult to acquire explicit sequence knowledge under dual task conditions, even when participants are told that a regular sequence exists. In Expt 2, we use the same conditions to compare actors, who respond to the sequence during learning, and observers, who merely watch the stimuli. Furthermore, we manipulate the salience of the sequence, in order to encourage learning. There is no evidence of observational learning in these conditions, despite the usual effects of learning being demonstrated by actors. In Expt 3, we show that observational learning does occur, but only when observers have no secondary task and even then only reliably for a sequence which has been made salient by chunking subcomponents. We conclude that sequence learning by observation is mediated by explicit processes, and is eliminated under conditions which support learning by action, but make it difficult to acquire explicit knowledge.     

The Role of Sketching States in the Stimulation of Idea Generation: An Eye Movement Study

Sketching is widely used in design to generate creative ideas. Design studies present stimuli during sketching to enhance creativity. This study examines the effect of stimuli presented during different sketching states, especially of those presented during the stuck period. It conducted a sketching experiment that enrolled 41 students with an average of 5.7 years’ practice in industrial design. The sketching with stimuli presented at regular intervals, those with stimuli presented during the stuck period, and those without stimulus were compared. Eye movements during the sketching processes were recorded. The attention to stimuli, and the direct applications of stimuli to design ideas, and the idea connection and idea differentiation were analyzed. Participants sketching with stimuli presented during the stuck period had a higher sketching quality, compared with those in other experimental conditions. They fixated longer on stimuli, built more links among related ideas, and had a more differentiated and balanced exploration. This study then proposed the mechanisms of stimuli processing. The stimuli presented at regular intervals were stored and acted as additional memory. The stimuli presented during the stuck period were dissected and acted as supporter, inducing a more creative sketching.     

Retrieval dynamics in self-terminated memory search

Attended stimuli are perceived as occurring earlier than unattended stimuli. This phenomenon of prior entry is usually identified by a shift in the point of subjective simultaneity (PSS) in temporal order judgements (TOJs). According to its traditional psychophysical interpretation, the PSS coincides with the perception of simultaneity. This assumption is, however, questionable. Technically, the PSS represents the temporal interval between two stimuli at which the two alternative TOJs are equally likely. Thus it also seems possible that observers perceive not simultaneity, but uncertainty of temporal order. This possibility is supported by prior-entry studies, which find that perception of simultaneity is not very likely at the PSS. The present study tested the percept at the PSS in prior entry, using peripheral cues to orient attention. We found that manipulating attention caused varying temporal perceptions around the PSS. On some occasions observers perceived the two stimuli as simultaneous, but on others they were simply uncertain about the order in which they had been presented. This finding contradicts the implicit assumption of most models of temporal order perception, that perception of simultaneity inevitably results if temporal order cannot be discriminated.     

Film clips and narrative text as subjective emotion elicitation techniques

Film clips and narrative text are useful techniques in eliciting emotion in a laboratory setting but have not been examined side-by-side using the same methodology. This study examined the self-identification of emotions elicited by film clip and narrative text stimuli to confirm that selected stimuli appropriately target the intended emotions. Seventy participants viewed 30 film clips, and 40 additional participants read 30 narrative texts. Participants identified the emotion experienced (happy, sad, angry, fearful, neutral—six stimuli each). Eighty-five percent of participants self-identified the target emotion for at least two stimuli for all emotion categories of film clips, except angry (only one) and for all categories of narrative text, except fearful (only one). The most effective angry text was correctly identified 74% of the time. Film clips were more effective in eliciting all target emotions in participants for eliciting the correct emotion (angry), intensity rating (happy, sad), or both (fearful).     

Shape Integration for Visual Object Recognition and Its Implication in Category-Specific Visual Agnosia

A series of experiments was conducted on a patient (ELM) with bilateral inferior temporal lobe damage and category-specific visual agnosia in order to specify the nature of his functional impairment. In Experiment 1, ELM performed a task of picture/word matching that used line drawings of fruits and vegetables as stimuli. The pattern of confusions exhibited by the patient suggested a failure in processing the full range of shape features necessary for the unique specification of the target relative to other structurally related items. This hypothesis of a shape integration impairment was tested and verified by subsequent visual recognition experiments (Experiments 2-4), which used synthetic stimuli with shapes precisely defined on the dimensions of elongation, curvature, and tapering. Furthermore, it was determined (Experiment 5) that the integration deficit is specific to the retrieval of shape knowledge from memory and does not affect the encoding of the properties of visual stimuli. It is argued that these findings have critical implications for cognitive theories of visual object recognition and for an interpretation of the visual function of the inferior temporal cortex. Finally, it was shown that the patient's deficit for structural knowledge integration is modulated by the semantic properties of the objects (Experiment 6), thereby demonstrating the applicability of the present findings to an explanation of category-specific visual agnosia.     

Relationships between exploratory behaviour and fear: a review

Two main theories of the relationship between exploratory behaviour and anxiety or fearfulness are: (a) ‘Two-factor theory’, according to which novel stimuli evoke both curiosity and fear/anxiety, with exploration as the outcome of competing tendencies to approach and avoid, and (b) the ‘Halliday-Lester theory’, where the fear aroused by novelty results in either approach (low fear) or avoidance (high fear). Relevant evidence comes from animal studies varying fear by manipulating either environmental or intrinsic factors. This evidence is largely compatible with the two-factor theory and some results which have been presented as critical support for the Halliday-Lester theory are actually equivocal.     

Feature-based inhibition underlies the affective consequences of attention

Rapid selection of a target in the presence of similar distractors can cause subsequent affective evaluation of a distractor to be more negative than that for the selected object. This distractor devaluation effect has previously been attributed to an association of attentional inhibition with the distractor's representation. Here, we investigated whether the associated inhibition leading to distractor devaluation is object based or feature based. Using colour-tinted face and building stimuli in a two-item simple visual search, followed by evaluation of face stimuli on a trustworthiness scale, we report that emotional evaluation was modified by prior attention whenever the search stimuli and the to-be-evaluated face shared the distractor feature, regardless of whether face identity seen in the two successive tasks matched or not. These data support the notion that inhibition can be feature-based and show that such inhibition can have emotional consequences.     

Developing auditory stimulus control: A note on methodology

This paper concerns the problem of teaching people with intellectual handicaps to respond reliably to spoken words and other auditory instructional stimuli. We describe how microcomputer technology can be applied to implement effective auditory stimulus control shaping methods. With hardware and software currently available, it is now possible to adapt procedures that have been previously successful in stimulus control programming with visual stimuli. We describe several techniques for programming gradual stimulus changes (e.g., stimulus fading, stimulus shaping) to promote auditory discrimination learning. Teaching studies with two individuals with severe mental retardation provide illustrative applications and data supporting the feasibility and potential utility of auditory stimulus control shaping methodology.     

Comparing the effects of static and dynamic signals during multiple schedules

The extent to which multiple schedules are an effective schedule thinning method following functional communication training (FCT) relies on the control the schedule-correlated stimuli exert over behavior. Thus, the stimuli used to signal the schedule in place (e.g., reinforcement and extinction) in a multiple schedule arrangement require special attention. To date, the majority of the research on multiple schedules has evaluated the use of different arbitrary signals as schedule-correlated stimuli (e.g., poster boards). These signals are considered static as they lack movement. More recently, some studies have successfully used dynamic signals, which include movement or animation, within multiple schedule arrangements. However, the extent to which one type of signal may result in faster stimulus control over behavior has not been evaluated. Thus, the purpose of this study was to compare the use of static and dynamic signals as schedule-correlated stimuli in multiple schedules used within the context of FCT. Four children diagnosed with autism spectrum disorder participated in the study. The results suggest that no differences in discriminated manding were observed for three out of four participants. Only dynamic signals resulted in discriminated manding for one participant.     

Biased attention and dysphoria: Manipulating selective attention reduces subsequent depressive symptoms

Selective attention for dysphoric stimuli has been observed in individuals with depression and those at risk for depression. To date, no studies have investigated the effects of directly manipulating selective attention for dysphoric stimuli on depressive symptoms. Mild to moderately depressed college students (N=34) were randomly assigned to complete 4 sessions of either attention training (AT) or no training (NT) during a two-week period. Participants completed self-reported assessments of depressive symptoms at baseline, post-training, and follow-up. Participants in the AT condition had a significantly greater decrease in depressive symptoms from baseline to follow-up than participants in the NT condition. This group difference was mediated by change in attention bias. Our findings suggest that biased attention may have a causal role in the maintenance of depressive symptoms.     

The cognitive implications of asymmetric color generalization in honeybees

Generalization occurs when a conditioned response formed to one stimulus is also elicited by other stimuli which have not been used in the course of conditioning. Here, we studied color generalization in honeybees Apis mellifera trained to two rewarded colors, S₁+ and S₂+. After training, bees were tested with non-rewarded novel stimuli, which lay between the trained stimuli in a honeybee color space (Int) or outside the range defined by the trained stimuli (E ₁ and E ₂). We analyzed whether bees interpolated their choice to Int and/or extrapolated it to E ₁ and E ₂. We compared the performances of the group trained with S₁+ and S₂+ to those of control groups trained only with S₁+ or S₂+. Bees trained with S₁+ and S₂+ responded similarly and highly to all test stimuli. These results do not allow discerning between generalization models based on the presence of interpolation and/or extrapolation. Nevertheless, bee’s performance was consistent with a linear summation of the two generalization gradients generated by S₁+ and S₂+, respectively. These gradients were asymmetric because control bees responded to the test stimuli as if these belonged to different similarity classes in spite of the fact that they had similar perceptual distances separating them. Stimuli treated as similar were located in the same half of the color spaces, whereas stimuli treated as different were located in opposite halves. Our results suggest that color categories could exist in honeybees and may underlie the performance of the control groups. Under this assumption, color categories would be also present in simpler nervous systems, and would not require factors such as language to be expressed.     

Perception of biological motion in common marmosets (Callithrix jacchus): by females only

The ability to perceive biological motion (BM) has been demonstrated in a number of species including humans but the few studies of non-human primates have been relatively inconclusive. We investigated whether common marmosets (Callithrix jacchus) are able to perceive biological motion, using a novel method to test non-human primates. Marmosets (7 male and 7 female) were trained to remove a cover from a container and look inside it, revealing a computer screen. Then they were presented with images on this computer screen consisting of a novel BM pattern (a walking hen) and 4 manipulations of that pattern (a static frame of this pattern and inverted, scrambled, and rotating versions of the pattern). The behavioural responses of the marmosets were recorded and used to assess discrimination between stimuli. BM was attended to by females but not males, as shown by active inspection behaviour, mainly movement of the head towards the stimulus. Females paid significantly less attention to all of the other stimuli. This indicates the females’ ability to attend to biological motion. Females showed slightly more attention to the inverted BM than to the static, scrambled, and rotating patterns. The males were less attentive to all of the stimuli than were the females and, unlike the females, responded to all stimuli in a similar manner. This sex difference could be due to an inability of males to recognise BM altogether or to a lesser amount of curiosity. Considered together with the findings of previous studies on chicks and humans, the results of the present study support the notion of a common mechanism across species for the detection of BM.     

The larger the cause,the larger the effect: evidence of speed judgment biases in causal scenarios

ABSTRACT

When two motions appear to be causally related, the spatiotemporal features of motions are sometimes distorted in order to increase the consistency with causal impressions. Here, in four experiments, we tested if varying the speed of an object A could affect the judged speed of an object B that appeared to be causally related to A. Participants were presented with classic launching stimuli (Experiment 1), a variant of launching stimuli in which A could move with uniformly accelerated or decelerated motion (Experiment 2), non-launching stimuli that elicited a causal impression (Experiment 3), and stimuli showing a three-object launching event (Experiment 4). Main results showed that the judged speed of B was systematically biased towards the speed of A, and moreover that the judged speed of B depended on the average speed of A, rather than on the speed of A at the moment of collision as it would be predicted by Newtonian mechanics. The results are consistent with the hypothesis that internal representations of causal events based on property transmission (for instance, impetus) can affect judgments of the low-level properties of causal scenarios.     

Face processing in cotton-top tamarins (Saguinus oedipus)

Current research on face processing in primates has focused on a few species, mostly macaques and chimpanzees; to date, only one New World monkey, the squirrel monkey, has been tested. We explored face processing, and the inversion effect in particular, in a New World primate species, the cotton-top tamarin (Saguinus oedipus). In phase 1 of our study, we trained subjects to discriminate between two faces and two scrambled faces; we then presented the tamarins with a series of novel probes in order to determine the features underlying classification. Results showed that the tamarins relied on the external contour of the face for discrimination more than the internal features and their configuration. Statistical analyses revealed no differences in accuracy or response times to upright versus inverted stimuli, and thus no inversion effect. In phase 2, we provided subjects with additional training on the face versus scrambled face discrimination task in order to focus their attention on the configuration of the internal features. Accuracy data revealed individual differences in how tamarins classified these stimuli, even though each subject was trained in the same way. In phase 3, we tested for generalization to a new set of face stimuli, as well as for the capacity to show an inversion effect. For one subject who attended to the configuration of internal features, we found significant evidence of generalization, but no evidence for an inversion effect. Electronic Publication     

Serial position effects in semantic memory: reconstructing the order of verses of hymns

Serial position effects (primacy and recency) have been consistently demonstrated in both short- and long-term episodic memory tasks. The search for corresponding effects in semantic memory tasks (e.g., reconstructing the order of U.S. presidents) has been confounded by factors such as differential exposure to stimuli. In the present study, the stimuli were six-verse hymns that would have been sung from the first to the last verse by churchgoers on numerous occasions. Participants were presented with the verses of each hymn in random order and were required to reconstruct the correct order. Primacy and recency effects were significantly more evident for churchgoers than for nonchurchgoers. Moreover, error gradients were steeper than chance for churchgoers but not for nonchurchgoers; in other words, churchgoers' errors were more likely to be close to the correct position than further away. These findings provide the first unequivocal demonstration of serial position effects in semantic memory.     

Categorization behaviour in adults,adolescents, and attention-deficit/hyperactivity disorder adolescents: A comparative investigation

Although significant progress has been made with respect to our understanding of categorization and concept learning behaviour in adults, much less is known about how this key capacity plays out with respect to more restrictive populations. This is unfortunate because much may be revealed about the nature of concept learning by examining the limits exhibited by special populations. With this tenet in mind, in what follows, we investigated key aspects of concept learning in terms of the unexplored comparative performance of three populations—adults, adolescents, and adolescents with attention-deficit/hyperactivity disorder (ADHD). To do so, we employed a novel parainformative experimental task involving categorical stimuli with four objects defined over three dimensions. The learning difficulty ordering for these types of three-dimensional stimuli has proven robust and has been replicated by several researchers. Indeed, in our experiment, we observed the same concept learning ordering in adults and adolescents, but not in ADHD adolescents: For example, the latter group showed greatly impaired categorization performance on stimuli characterized by an “exclusive-or” rule. However, categorization performance on such type of stimuli indicated good reliability in discriminating between adolescents with and without ADHD (receiver-operating characteristic, ROC?=?.82). We accurately predicted and accounted for these results using generalized invariance structure theory (GIST; Vigo, 2013. The GIST of concepts. Cognition, 129, 138–162), which posits that organisms detect invariance patterns in stimuli that are necessary precursors to concept formation.     

Processing of order information for numbers and months

Despite a great deal of research on the processing of numerical magnitude (e.g., the quantity denoted by the number 5), few studies have investigated how this magnitude information relates to the ordinal properties of numbers (e.g., the fact that 5 is the fifth integer). In the present study, we investigated order-related processing of numbers, as well as months of the year, with a novel ordering task to see whether the processing of order information differs from the processing of magnitude information. In Experiments 1 and 2, participants were shown three numbers (Experiment 1) or three months (Experiment 2) and were required to indicate whether the stimuli were in the correct order. In Experiment 3, participants were again shown three numbers; however, now they were instructed to indicate whether the three numbers were ordered in a forward, backward, or mixed direction. Whereas number comparison tasks typically reveal distance effects (comparisons become easier with increased distance between two numbers), these three experiments reveal a different pattern of results. There were reverse distance effects when the stimuli crossed a boundary (i.e., when numbers crossed a decade or months crossed the year boundary) and no effect of distance when the stimuli did not cross a boundary (i.e., when numbers were within a decade and months were within the January—December calendar year). These data suggest that additional mechanisms are involved in the processing of order information: a scanning mechanism and a long-term memory checking mechanism.