The influence of clause order,congruency, and probability on the processing of conditionals

Conditional information can be equally asserted in the forms if p, then q (e.g., “if I am ill, I will miss work tomorrow”) and q, if p (e.g., “I will miss work tomorrow, if I am ill”). While this type of clause order manipulation has previously been found to have no influence on the ultimate conclusions participants draw from conditional rules, we used self-paced reading to examine how it affects the real time incremental processing of everyday conditional statements. Experiment 1 revealed that clause order interacts with presuppositional congruency as readers hypothetically represent counterfactual statements. When if p, then q counterfactuals contained a presupposition that was incongruent with prior context, these statements took longer to read than when the presupposition was congruent, but for q, if p conditionals there was no such congruency effect. Experiment 2 revealed that reading times were influenced by the subjective probability of an indicative conditional regardless of clause order, with a penalty observed for low-probability statements relative to high-probability statements in both conditional clause orders. These data reveal a dissociation whereby clause order mediates the effect of suppositional congruency on reading times, but does not mediate the effect of subjective probability.     

On the processing of canonical word order during eye fixations in reading: Do readers process transposed word previews?

Whether readers always identify words in the order they are printed is subject to considerable debate. In the present study, we used the gaze-contingent boundary paradigm (Rayner, 1975) to manipulate the preview for a two-word target region (e.g., white walls in My neighbor painted the white walls black). Readers received an identical (white walls), transposed (walls white), or unrelated preview (vodka clubs). We found that there was a clear cost of having a transposed preview compared to an identical preview, indicating that readers cannot or do not identify words out of order. However, on some measures, the transposed preview condition did lead to faster processing than the unrelated preview condition, suggesting that readers may be able to obtain some useful information from a transposed preview. Implications of the results for models of eye movement control in reading are discussed.     

Training attention: Interactions between central cues and reflexive attention

Three experiments are reported in which we investigate whether the recently reported interactions between central cues (e.g., arrows) and reflexive attention are attributable to the overlearned spatial properties of certain central cues. In all three experiments, a nonpredictive cue with arbitrary spatial properties (a colour patch) is presented prior to a detection target in the left or right visual field. Reaction times to detect targets are compared before and after a training session in which participants are trained to associate each colour patch with left and right space, either via a target detection task in which colour predicts target location 100% of the time (Experiments 1 and 3), or via a left/right motor movement as a function of colour (Experiments 2 and 3). In the first two experiments, a small but highly significant training effect is observed. Participants are approximately 10 ms faster to detect targets at congruent locations relative to incongruent locations after training relative to before training, despite the fact that cue colour was nonpredictive during the test sessions. In Experiment 3, the length of the training session is increased and the magnitude of the training effect also increases as a result. Implications for the interaction between central cues and reflexive attention, as well as premotor theory of attention, are discussed.     

Attention can operate on semantic objects defined by individual Chinese characters

Attention can select perceptual objects, but it is less clear whether attention can operate on objects defined by higher level cognition, such as semantic associations. Recent studies have shown that attention may be based on objects defined by Chinese two-character compound words, suggesting that attention can operate on semantic objects. In the present study, object-based attention (OBA) effect was investigated at the level of individual Chinese characters, and the role of character structure and radical order in OBA was explored by using a spatial cueing paradigm. In Experiment 1, we found OBA effect for conditions that had legal radical order, but not for other conditions in which the radical order information was disrupted. Character structure, however, had no influence on the OBA effect. In Experiment 2, we observed OBA effect for all conditions after enhancing the radical order and character structure information by adding perceptual cues. The results extend previous findings of a “semantic object”-based attention effect from the two-character word level to the individual character level. Moreover, we found that radical order but not character structure was important for this semantic OBA effect. We conclude that visual attention can be based on semantic objects at the level of individual characters, and that the development of semantic objects is affected by the perceptual grouping of the radicals.     

Children's Understanding of Second‐Order False Belief: Comparisons of Content and Method of Assessment

This research examined children's performance on second‐order false belief tasks as a function of the content area for the belief and the method of assessing understanding. A total of 70 kindergarten and first‐grade children responded to four second‐order stories. On two stories, the task was to judge a belief about a belief, and on two, the task was to judge a belief about an emotion. On one trial within each group, the task was to predict the target's belief, and on one trial, the task was to explain the belief. Older children outperformed younger children on the prediction measure. Differences as a function of content area and method of assessment were limited; when they did occur, performance was generally better with belief than with emotion as the target, and better with prediction than with explanation as the response criterion. Finally, there was no relation between number of siblings and performance.     

Temporal order perception of auditory stimuli is selectively modified by tonal and non-tonal language environments

The close relationship between temporal perception and speech processing is well established. The present study focused on the specific question whether the speech environment could influence temporal order perception in subjects whose language backgrounds are distinctively different, i.e., Chinese (tonal language) vs. Polish (non-tonal language). Temporal order thresholds were measured for both monaurally presented clicks and binaurally presented tone pairs. Whereas the click experiment showed similar order thresholds for the two language groups, the experiment with tone pairs resulted in different observations: while Chinese demonstrated better performance in discriminating the temporal order of two “close frequency” tone pairs (600 Hz and 1200 Hz), Polish subjects showed a reversed pattern, i.e., better performance for “distant frequency” tone pairs (400 Hz and 3000 Hz). These results indicate on the one hand a common temporal mechanism for perceiving the order of two monaurally presented stimuli, and on the other hand neuronal plasticity for perceiving the order of frequency-related auditory stimuli. We conclude that the auditory brain is modified with respect to temporal processing by long-term exposure to a tonal or a non-tonal language. As a consequence of such an exposure different cognitive modes of operation (analytic vs. holistic) are selected: the analytic mode is adopted for “distant frequency” tone pairs in Chinese and for “close frequency” tone pairs in Polish subjects, whereas the holistic mode is selected for “close frequency” tone pairs in Chinese and for “distant frequency” tone pairs in Polish subjects, reflecting a double dissociation of function.     

不同反应线索条件下调节匹配对建议采纳的影响

研究的目的是为了探究不同反应线索条件下调节匹配对建议采纳的影响。实验中有两个反应线索：言语性反应线索(实验一)与非言语性反应线索(实验二), 两个实验均采用2(调节取向：促进/防御)×2(建议策略：渴望/警惕)的混合设计。实验一、二的被试分别是81和79名在校大学生, 年龄均在19~25岁之间。实验结果表明, 在言语反应线索条件下, 调节匹配时人们对建议的采纳程度更高; 在非言语性反应线索条件下, 防御取向时, 调节匹配时人们显著提高了建议的采纳程度, 但促进取向条件人们对建议的采纳程度无明显差异。结果表明在促进取向下非言语性反应线索对调节匹配具有干扰作用, 这个结果值得进一步研究。     

Do squirrel monkeys (<Emphasis Type="Italic">Saimiri sciureus</Emphasis>) and capuchin monkeys (<Emphasis Type="Italic">Cebus apella</Emphasis>) predict that looking leads to touching?

Squirrel monkeys (Saimiri sciureus) and capuchin monkeys (Cebus apella) were tested using an expectancy violation procedure to assess whether they use an actors gaze direction, signaled by congruent head and eye orientation, to predict subsequent behavior. The monkeys visually habituated to a repeated sequence in which the actor (a familiar human or a puppet) looked at an object and then picked it up, but they did not react strongly when the actor looked at an object but then picked up another object. Capuchin monkeys responses in the puppet condition were slightly more suggestive of expectancy. There was no differential responding to congruent versus incongruent look–touch sequences when familiarization trials were omitted. The weak findings contrast with a strongly positive result previously reported for tamarin monkeys. Additional evidence is required before concluding that behavior prediction based on gaze cues typifies primates; other approaches for studying how they process attention cues are indicated.This revised version was published online in March 2004 with corrections to Fig. 2. The number 1 in the bottom left panel should be a cross and was, moreover, misaligned.     

Second-order schedules of token reinforcement with pigeons: implications for unit price

Four pigeons were exposed to second-order schedules of token reinforcement, with stimulus lights serving as token reinforcers. Tokens were earned according to a fixed-ratio (token-production) schedule, with the opportunity to exchange tokens for food (exchange period) occurring after a fixed number had been produced (exchange-production ratio). The token-production and exchange-production ratios were manipulated systematically across conditions. Response rates varied inversely with the token-production ratio at each exchange-production ratio. Response rates also varied inversely with the exchange-production ratio at each token-production ratio, particularly at the higher token-production ratios. At higher token-production and exchange-production ratios, response rates increased in token-production segments closer to exchange periods and food. Some conditions were conducted in a closed economy, in which the pigeons earned all their daily ration of food within the session. Relative to comparable open-economy conditions, response rates in the closed economy were less affected by changes in token-production ratio, resulting in higher levels of food intake and body weight. Some of the results are consistent with the economic concept of unit price, a cost-benefit ratio comprised of responses per unit of food delivery, but most are well accounted for by a consideration of the number of responses required to produce exchange periods, without regard to the amount of reinforcement available during those exchange periods.     

Domestic dogs (Canis familiaris) use a physical marker to locate hidden food

Dogs can use the placement of an arbitrary marker to locate hidden food in an object-choice situation. We tested domestic dogs (Canis familiaris) in three studies aimed at pinning down the relative contributions of the human’s hand and the marker itself. We baited one of two cups (outside of the dogs’ view) and gave the dog a communicative cue to find the food. Study 1 systematically varied dogs’ perceptual access to the marker placing event, so that dogs saw either the whole human, the hand only, the marker only, or nothing. Follow-up trials investigated the effect of removing the marker before the dog’s choice. Dogs used the marker as a communicative cue even when it had been removed prior to the dog’s choice and attached more importance to this cue than to the hand that placed it although the presence of the hand boosted performance when it appeared together with the marker. Study 2 directly contrasted the importance of the hand and the marker and revealed that the effect of the marker diminished if it had been associated with both cups. In contrast touching both cups with the hand had no effect on performance. Study 3 investigated whether the means of marker placement (intentional or accidental) had an effect on dogs’ choices. Results showed that dogs did not differentiate intentional and accidental placing of the marker. These results suggest that dogs use the marker as a genuine communicative cue quite independently from the experimenter’s actions.