When unexpected behavior is attributed to the environment

Two experiments were conducted to investigate a modification of the Jones and Davis (1965) analysis of attribution. Subjects were confronted with a situation in which there were two possible causes for an event, and differential information about these causes was provided such that subjects were much more informed about the nature of one potential cause than the other. This information also imparted to the subjects a definite expectancy about the forthcoming event. When the event disconfirmed subjects' expectancies, responsibility was attributed to the cause about which least was known. This result was found in both experiments. In addition, Experiment II offered some suggestive evidence that a disconfirmed expectancy will lead the person to direct his attention toward potential causes about which he is uninformed.     

Visual search for positional relationships between pattern elements

The purpose of these experiments was to illustrate how a search for positional relationships between the elements in a stimulus pattern is effortful and serial, whereas a search for pattern elements (without requiring any positional information) takes place rapidly and in parallel. In all three experiments of this study, the target and distractor patterns consisted of two vertical line segments. In the experiment concerning the search for positional relationships between pattern elements, one of the line segments in a line pair had a gap, and the observer's task was to indicate whether the positional order of the two lines was identical in all the line pairs of the display, or whether the line segments were in a mirror-image order in one line pair (the target). In the two experiments concerning the search for pattern elements (no positional information was required), the observer's task was to look for a line pair with one gap line (the target) among line pairs containing two broken lines or among line pairs with unbroken lines. In all three tasks, the reaction time for a correct target detection was measured. The results showed that the search in the first task was highly serial, and in the second and third tasks of "feature" searches, the search time was nearly independent of the number of distractor pairs. It is suggested that this dissociation may be interpreted in the context of the quality of information processing in extrafoveal vision, i. e. the elements of a stimulus pattern can be clearly visible outside the fovea, but it is not possible to perceive accurately the positional relationships between them.     

Serial deployment of attention during visual search

This study examined whether objects are attended in serial or in parallel during a demanding visual search task. A component of the event-related potential waveform, the N2pc wave, was used as a continuous measure of the allocation of attention to possible targets in the search arrays. Experiment 1 demonstrated that the relative allocation of attention shifts rapidly, favoring one item and then another. In Experiment 2, a paradigm was used that made it possible to track the absolute allocation of attention to individual items. This experiment showed that attention was allocated to one object for 100-150 ms before attention began to be allocated to the next object. These findings support models of attention that posit serial processing in demanding visual search tasks.     

Distractor ratio and grouping processes in visual conjunction search.

According to feature integration theory, conjunction search is conducted via a serial self-terminating search. However, effects attributed to search processes operating on the entire display may actually reflect search restricted to elements defined by a single feature. In experiment 1 this question is addressed in a reaction-time (RT) paradigm by varying distractor ratios within an array of fixed size. For trials in which the target was present in the array, RT functions were roughly symmetric, the shortest RTs being for extreme distractor ratios, and the longest RTs being for arrays in which there were an equal number of each distractor type. This result is superficially consistent with Zohary and Hochstein's interpretation that subjects search for only one distractor type and are able to switch search strategy from trial to trial. However, negative-trial data from experiment 1 case doubt on this interpretation. In experiment 2 the possible role of 'pop out' and of distractor grouping in visual conjunction search is investigated. Results of experiment 2 suggest that grouping may play a more important role than does distractor ratio, and point to the importance of the spatial layout of the target and of the distractor elements in visual conjunction search. Results of experiment 2 also provide clear evidence that groups of spatially adjacent homogeneous elements may be processed as a unit.     

Parallel and serial search in haptics

We propose a model that distinguishes between parallel and serial search in haptics. To test this model, participants performed three haptic search experiments in which a target and distractors were presented to their fingertips. The participants indicated a target's presence by lifting the corresponding finger, or its absence by lifting all fingers. In one experiment, the target was a cross and the distractors were circles. In another, the target was a vertical line and the distractors were horizontal lines. In both cases, we found a serial search pattern. In a final experiment, the target was a horizontal line and the distractors were surfaces without any contours. In this case, we found a parallel search pattern. We conclude that the model can describe our data very well.     

Predicting future affective states: How ease of retrieval and faith in intuition moderate the impact of activated content

Prior research suggests that duration bias—the tendency to overestimate the duration of affective states—is due to individuals' inordinate focus on event‐related information. We propose that the impact of focusing on event‐related (vs. unrelated) content is moderated by the ease with which the information is brought to mind. In the present experiment, participants thought about a possible future negative event and made affective forecasts after retrieving either few or many aspects in their life that would be affected (or unaffected) by the event. Participants estimated longer duration of affective consequences when they retrieved event‐related rather than event‐unrelated information. However, this effect was restricted to conditions where the respective information was brought to mind easily. Importantly, results also revealed that individual differences in faith in intuition moderated the effect of manipulated ease of retrieval. Copyright © 2008 John Wiley & Sons, Ltd.     

Use of prior beliefs in the assignment of causal roles: Causal powers versus regularity-based accounts

There is a tradition of models of causal judgment in which causes and other causal roles are defined and identified in terms of empirical patterns of association with effects. In the present experiments, results conflicting with the predictions of such models were obtained. In one experiment, subjects judged that an interpretation in which a factor constantly present was identified as the cause was more likely than was an interpretation in which a perfect positive covariate was identified as the cause. In a second experiment, possible effects of prior beliefs about covariation were controlled and similar findings were obtained in two out of three scenarios. These results favor the idea that people make causal judgments by applying preexisting beliefs framed in terms of causal concepts, such as causal powers, and in ways that cannot be accounted for by models in the empiricist tradition.     

Information becomes evidence when an explanation can incorporate it into a causal framework

Recognizing information as evidence is central to the development of scientific reasoning. When does information about an event come to be treated as evidence relevant to explaining the event? We asked whether this was increasingly likely to happen when an explanation becomes available that can incorporate both the event and the information into a single causal framework. In three studies, we presented participants with events for which there were two possible and plausible explanations (a baseline and one of two alternative explanations), as well as with two pieces of background information. While all explanations could account for the event, only one alternative explanation (the “target” explanation) could incorporate both the event and the background information into a single causal framework. The results indicated that information is more likely to be seen as evidentially relevant to an event when there is an explanation available that can accommodate both the event and the information into a single casual framework than when such an explanation is lacking. Furthermore, the presence of this information renders the target alternative increasingly plausible. That is, it is the interdependence of explanation or theory and evidence that allows us to realize that some information is likely to be evidential. However, for this to happen, the relation between explanation and information must be made salient, either by explicitly asking about it (as we did in Study 1) or by fleshing out the target explanation (as we did in Study 3).     

Search performance without eye movements

Visual search performance (with sets chosen to elicit both serial and parallel search patterns) under two conditions that precluded saccades was compared to the typical situation in which visual inspection of the array is possible. In one condition, the display duration was so brief that any saccades that were executed would be too late to bring the targeted portion of the array into the fovea. In the other, the display remained present until the subject's response, but eye position was monitored and trials with shifts in fixation were excluded from analysis. The latter condition produced search latencies that were nearly identical to those with free inspection. Brief exposure, in contrast, did not produce the pattern typical of serial search, presumably because of strategies induced to deal with the rapid decay of the visual array. It is concluded that saccadic eye movements play little role in the patterns of performance used to infer serial and parallel search, and that brief exposure is not a satisfactory technique for exploring the role of saccadic eye movements in visual search.     

Target detection in one visual field in the presence or absence of stimuli in the contralateral field by right- and left-handed subjects

Marked differences in detectability are observed as a function of retinal locus when subjects are required to find a briefly exposed target pattern of uncertain location in the presence of a number of discriminably different nontarget patterns. Our previous studies using this search paradigm have attributed these detectability differences, and the right visual field detectability superiority associated with them, to a serial (scanning) mechanism which tends to examine stimuli in the right field earlier than those in the left. The present experiment, performed on large groups of right- and left-handed subjects, was designed to test the hypothesis that there are two independent serial processors, one in each hemisphere--an hypothesis which might account for the differences in detectability within and between the two half-fields in terms of hemispheric processing differences. The results are inconsistent with the dual independent serial processor hypothesis but are fully consistent with a single serial processor, a scanning mechanism, which has access to the information presented to both visual half-fields.     

Effect of starting position on reproduction of movement: further evidence of interference between location and distance information

Two experiments done with a short-term memory paradigm examined the influence of shifts in the starting position on the reproduction of kinesthetic location (Exp. 1) and on distance cues (Exp. 2). We assessed possible causes of the systematic pattern of undershooting and overshooting as related to the shift in the starting position. In each experiment, two groups of 10 students were given 25 trials, and each had criterion and reproduction tasks involving linear-positioning movements with a 10-sec. retention interval. Each experiment had two independent variables, the group of subjects and the shift in the starting position. The two groups differed in the possible sources of information, the distance moved (Exp. 1) or the end-location (Exp. 2), which were assumed to cause undershooting and overshooting during reproduction. Analysis showed that the information about the distance moved may produce undershooting and overshooting in reproduction of the end-location (Exp. 2). Also, the information about the end-location may produce undershooting and overshooting in reproduction of the distance moved (Exp. 2). The findings were further evidence of interference between location and distance cues in motor short-term memory.     

Repetition, not number of sources, increases both susceptibility to misinformation and confidence in the accuracy of eyewitnesses

Are claims more credible when made by multiple sources, or is it the repetition of claims that matters? Some research suggests that claims have more credibility when independent sources make them. Yet, other research suggests that simply repeating information makes it more accessible and encourages reliance on automatic processes—factors known to change people's judgments. In Experiment 1, people took part in a “misinformation” study: people first watched a video of a crime and later read eyewitness reports attributed to one or three different eyewitnesses who made misleading claims in either one report or repeated the same misleading claims across all three reports. In Experiment 2, people who had not seen any videos read those same reports and indicated how confident they were that each claim happened in the original event. People were more misled by—and more confident about—claims that were repeated, regardless of how many eyewitnesses made them. We hypothesize that people interpreted the familiarity of repeated claims as markers of accuracy. These findings fit with research showing that repeating information makes it seem more true, and highlight the power of a single repeated voice.     

Fighting the Past: Perceptions of Control,Historical Misperceptions,and Corrective Information in the Israeli‐Palestinian Conflict

What makes people deny wrongdoing that their group has inflicted on others? Prior research argues that refusing to acknowledge past misbehavior contributes to intergroup conflict, making historical misinformation important to understand and address. In particular, feeling a lack of control may make people more vulnerable to these misperceptions—a claim we test in a preregistered survey experiment examining beliefs about the Palestinian exodus during the creation of the state of Israel. Consistent with expectations, Jewish Israelis who were asked to recall an event in which they lacked control were more vulnerable to arguments (incorrectly) denying any Jewish responsibility for the exodus. By contrast, corrective information successfully reduced misperceptions regardless of feelings of control. However, corrections had no effect on attitudes toward the outgroup or support for the peace process, which suggests that historical misperceptions may be more of a symptom of intergroup conflict than a cause of its persistence.     

Task relevance modulates processing of distracting emotional stimuli

Relatively little is known about the integration of people's fear-related dispositions and their expectations about stressful events. This research used information integration theory to examine how participants’ anxiety sensitivity and event expectancy are integrated to determine their social anxiety. Three studies were conducted—two with university students and one with anxiety clinic patients—in which participants were presented with multiple scenarios of a socially embarrassing event, each representing a different degree of event probability, from which subjective expectancies were derived. Independent variables included anxiety sensitivity (low, moderate, high) and event expectancy (low, medium, high, no probability information). Participants were asked to indicate their anxiety (dependent measure) in each expectancy condition in this 3 × 4 mixed, quasi-experimental design. The results of all three studies strongly suggest that anxiety sensitivity and event expectancy are integrated additively to produce social anxiety. Additional results and their implications for the treatment of anxiety-related disorders are also discussed.     

Probabilistic judgements in deluded and non-deluded subjects

An experiment is described in which deluded subjects were compared with a non-deluded psychiatric control group and a normal control group on a probabilistic inference task. Deluded subjects were found to request less information before reaching a decision and to express higher certainty levels than either control group. They also exhibited over-confidence on estimates of the probability of a future event.

Delusion. A false personal belief based on incorrect inference about external reality and firmly sustained in spite of what almost everyone else believes and in spite of what constitutes incontrovertible and obvious proof or evidence to the contrary. The belief is not one ordinarily accepted by other members of the person's subculture. [American Psychiatric Association, 1980]     

The Representation of Mortality Statistics and the Perceived Importance of Causes of Death

This study investigated how different methods of presenting mortality statistics may influence subjective impressions of the importance of a given cause of death. Subjects were 214 students from the fifth year of a comprehensive school (average age 15). Each subject rated one of six causes of death on a scale labeled "extremely minor–extremely major cause of death" before and after receiving accurate information concerning the number of deaths per annum in the United Kingdom resulting from the cause in question. This information was presented in one of five forms: (a) a statement of what proportion of all deaths resulted from the specified cause; (b) a statement of what percentage of all deaths were so caused; (c) a pie chart representing the proportion pictorially; (d) a bar chart representing the proportion pictorially; and (e) a statement of absolute number of deaths from the specified cause without information on total number of deaths from all causes combined. Analysis showed that subjects discriminated between the different causes both before and after presentation of the information but their ratings were imperfectly calibrated with actual frequencies. Also, the changes in ratings following the information depended significantly on the mode of presentation. Except when subjects were told the absolute frequency, the changes were in the direction of decrease in perceived importance. This decrease was most marked in the bar chart and pie chart conditions. The data are interpreted in relation to the literature on statistical inference processes and on judgmental contrast.     

Programming saccadic eye movements

This article addresses questions about the preparatory processes that immediately precede saccadic eye movements. Saccade latencies were measured in a task in which subjects were provided partial advance information about the spatial location of a target fixation. In one experiment, subjects were faster in initiating saccades when they knew either the direction or amplitude of the required movement in advance compared to a condition with equal uncertainty about the number of potential saccade targets but without knowledge of the parameters required to execute the movement. These results suggest that the direction and amplitude for an upcoming saccade were calculated separately, and not in a fixed serial order. In another experiment, subjects appear to have programmed the saccades more holistically--with computations of direction and amplitude parameters occurring simultaneously. The implications of these results for models of eye movement preparation are discussed.     

Inferences about unobserved causes in human contingency learning

Estimates of the causal efficacy of an event need to take into account the possible presence and influence of other unobserved causes that might have contributed to the occurrence of the effect. Current theoretical approaches deal differently with this problem. Associative theories assume that at least one unobserved cause is always present. In contrast, causal Bayes net theories (including Power PC theory) hypothesize that unobserved causes may be present or absent. These theories generally assume independence of different causes of the same event, which greatly simplifies modelling learning and inference. In two experiments participants were requested to learn about the causal relation between a single cause and an effect by observing their co-occurrence (Experiment 1) or by actively intervening in the cause (Experiment 2). Participants' assumptions about the presence of an unobserved cause were assessed either after each learning trial or at the end of the learning phase. The results show an interesting dissociation. Whereas there was a tendency to assume interdependence of the causes in the online judgements during learning, the final judgements tended to be more in the direction of an independence assumption. Possible explanations and implications of these findings are discussed.     

Do apes know that they could be wrong?

When confronted with uncertain or incomplete information in decision-making situations, monkeys and apes opt for either escaping the situation or seeking additional information. These responses have been interpreted as evidence of metacognitive abilities. However, this interpretation has been challenged. On the one hand, studies using the information-seeking paradigm have been criticized because subjects may simply engage in a search for information routine (e.g., search until spot the reward) without any metacognitive involvement. On the other hand, studies using the escape response paradigm have been criticized because subjects may not recognize their own state of uncertainty but have learned to use the escape response in the presence of certain stimuli configurations that create uncertainty. The current study attempted to address these two criticisms by presenting great apes (seven gorillas, eight chimpanzees, four bonobos, seven orangutans) with a seeking information task whose basic procedure consisted of presenting two hollow tubes, baiting one of them and letting subjects choose. Conditions varied depending on whether subjects had visual access to the baiting, the cost associated with seeking information, the time interval between baiting and choosing, the food quality and the additional information offered regarding the food’s location. Although subjects showed a high retrieval accuracy when they had witnessed the baiting, they were more likely to check inside the tube before choosing when high stakes were involved (Experiment 3) or after a longer period of time had elapsed between the baiting and the retrieval of the reward (Experiment 2). In contrast, providing subjects with indirect auditory information about the food’s location or increasing the cost of checking reduced checking before choosing (Experiment 1). Taken together, these findings suggest that subjects knew that they could be wrong when choosing.     

What is learned about nontarget items in simple visual search?

Human sensitivity to correlational structure between nontargets and likelihood of target presence in a visual letter-search task were studied in two experiments. In each of these experiments, the performance of subjects for whom the nontarget information was altered in the final trial block was compared with the performance of subjects for whom the nontarget information did not change. When stimulus strings were presented individually on a computer screen and subjects were required to make a yes-no decision about target presence (Experiment 1), the change in nontarget structure resulted in increased reaction times for target-absent trials. When subjects searched simultaneously for three possible targets (Experiment 2), the change in nontarget structure produced increased error rates and increased reaction times for both target-absent and target-present trials. Correlations between the amount of predictive information in individual stimulus strings and reaction times also showed that both switching and nonswitching subjects were sensitive to the nontarget context. However, neither self-reports of strategy nor postexperiment choices between context-consistent and -inconsistent letter strings indicated any explicit knowledge of the predictive information in the nontarget stimuli. Subjects can thus acquire and benefit from, apparently without awareness, information about subtle correlational structure in nontarget elements in simple visual search.