Time-place learning by pigeons, Columba livia

In each of two experiments, 2 pigeons received discrimination training in which food reinforcement for key pecking was conditional upon both spatial and temporal cues. In Experiment 1, food was available for periods of 30 s at each of three locations (pecking keys) during trials that lasted 90 s. In Experiment 2, food was available for periods of 15 min at each of four locations (pecking keys) during a 60-min trial. In both experiments, pigeons' key pecking was jointly controlled by the spatial and temporal cues. These data, and other recent experiments, suggest that animals learn relationships between temporal and spatial cues that predict stable patterns of food availability.     

词切分的韵律学线索

本文是关于汉语普通话词切分的一个实验报告。用无意文重复句和合成句作语音材料,探讨音节时长分布、基频曲线、音节强度以及共振峰等韵律学线索在词切分中的作用。得到的主要结果是,在排除语义和音段层面信息的条件下,听者能够根据句子的韵律学特征进行句子结构的判断和词的切分;在对切分有效的韵律学线索中,最重要的是音节的时长分布模式,其次是基频曲线,音节的强度和共振峰变化对切分没有贡献。     

IMPROVED CURVEBALL HITTING THROUGH THE ENHANCEMENT OF VISUAL CUES

This study investigated the effectiveness of using visual cues to highlight the seams of baseballs to improve the hitting of curveballs. Five undergraduate varsity baseball team candidates served as subjects. Behavior change was assessed through an alternating treatments design involving unmarked balls and two treatment conditions that included baseballs with 1/4-in. and 1/8-in. orange stripes marking the seams of the baseballs. Results indicated that subjects hit a greater percentage of marked than unmarked balls. These results suggest that the addition of visual cues may be a significant and beneficial technique to enhance hitting performance. Further research is suggested regarding the training procedures, effect of feedback, rate of fading cues, generalization to live pitching, and generalization to other types of pitches.     

Eyewitness testimony and memory distortion

Abstract: Do memories change as we acquire new information? Recent research on memory distortion using implicit tests along with research using confidence is reviewed and new studies are presented. Two new studies asked misinformed subjects to provide reasons for their answers. In each study 15% to 27% of subjects said they remembered seeing items they had only read about. In another study subjects were asked to identify the source of misleading items they had seen in slides or read in misleading questions. Subjects were more likely to say they had seen in slides something they read about in the questions than they were to confuse information from two nearly identical sets of slides. Recent work shows that, not only is it possible to distort memory for events, it is possible to implant an entire memory for something that never happened. The evidence is now clear that we can become mentally tricked into making large as well as small changes in the way we recall the past.     

Counterexample Search in Diagram-Based Geometric Reasoning

Topological relations such as inside, outside, or intersection are ubiquitous to our spatial thinking. Here, we examined how people reason deductively with topological relations between points, lines, and circles in geometric diagrams. We hypothesized in particular that a counterexample search generally underlies this type of reasoning. We first verified that educated adults without specific math training were able to produce correct diagrammatic representations contained in the premisses of an inference. Our first experiment then revealed that subjects who correctly judged an inference as invalid almost always produced a counterexample to support their answer. Noticeably, even if the counterexample always bore a certain level of similarity to the initial diagram, we observed that an object was more likely to be varied between the two drawings if it was present in the conclusion of the inference. Experiments 2 and 3 then directly probed counterexample search. While participants were asked to evaluate a conclusion on the basis of a given diagram and some premisses, we modulated the difficulty of reaching a counterexample from the diagram. Our results indicate that both decreasing the counterexample density and increasing the counterexample distance impaired reasoning performance. Taken together, our results suggest that a search procedure for counterexamples, which proceeds object-wise, could underlie diagram-based geometric reasoning. Transposing points, lines, and circles to our spatial environment, the present study may ultimately provide insights on how humans reason about topological relations between positions, paths, and regions.     

Scale sensitivity in the multiplicative AHP and SMART

We consider first a variant of the analytic hierarchy process (AHP) with a one-parametric class of geometric scales to quantify human comparative judgement and with a multiplicative structure: logarithmic regression to calculate the impact scores of the alternatives at the first evaluation level and a geometric-mean aggregation rule to calculate the final scores at the second level. We demonstrate that the rank order of the impact scores and final scores is scale-independent. Finally we show that the multiplicative AHP is an exponential version of the simple multi-attribute rating technique (SMART). In fact, the multiplicative AHP is concerned with ratios of intervals on the dimension of desirability, whereas SMART analyses differences in the corresponding orders of magnitude.     

The effects of mood and retrieval cues on semantic memory and metacognition

We investigated whether the previously established effect of mood on episodic memory generalizes to semantic memory and whether mood affects metacognitive judgments associated with the retrieval of semantic information. Sixty-eight participants were induced into a happy or sad mood by viewing and describing IAPS images. Following mood induction, participants saw a total of 200 general knowledge trivia items (50 open-ended and 50 multiple-choice after each of two mood inductions) and were asked to provide a metacognitive judgment about their knowledge for each item before providing a response. A sample trivia item is: Author – – To kill a mockingbird. Results indicate that mood affects the retrieval of semantic information, but only when the participant believes they possess the requested semantic information; furthermore, this effect depends upon the presence of retrieval cues. In addition, we found that mood does not affect the likelihood of different metacognitive judgments associated with the retrieval of semantic information, but that, in some cases, having retrieval cues increases accuracy of these metacognitive judgments. Our results suggest that semantic retrieval processes are minimally susceptible to the influence of affective state but does not preclude the possibility that affective state may influence encoding of semantic information.     

Listen to your mother! The role of talker familiarity in infant streaming

Little is known about the acoustic cues infants might use to selectively attend to one talker in the presence of background noise. This study examined the role of talker familiarity as a possible cue. Infants either heard their own mothers (maternal-voice condition) or a different infant's mother (novel-voice condition) repeating isolated words while a female distracter voice spoke fluently in the background. Subsequently, infants heard passages produced by the target voice containing either the familiarized, target words or novel words. Infants in the maternal-voice condition listened significantly longer to the passages containing familiar words; infants in the novel-voice condition showed no preference. These results suggest that infants are able to separate the simultaneous speech of two women when one of the voices is highly familiar to them. However, infants seem to find separating the simultaneous speech of two unfamiliar women extremely difficult.     

Seeing to hear better: evidence for early audio-visual interactions in speech identification

Lip reading is the ability to partially understand speech by looking at the speaker's lips. It improves the intelligibility of speech in noise when audio-visual perception is compared with audio-only perception. A recent set of experiments showed that seeing the speaker's lips also enhances sensitivity to acoustic information, decreasing the auditory detection threshold of speech embedded in noise [J. Acoust. Soc. Am. 109 (2001) 2272; J. Acoust. Soc. Am. 108 (2000) 1197]. However, detection is different from comprehension, and it remains to be seen whether improved sensitivity also results in an intelligibility gain in audio-visual speech perception. In this work, we use an original paradigm to show that seeing the speaker's lips enables the listener to hear better and hence to understand better. The audio-visual stimuli used here could not be differentiated by lip reading per se since they contained exactly the same lip gesture matched with different compatible speech sounds. Nevertheless, the noise-masked stimuli were more intelligible in the audio-visual condition than in the audio-only condition due to the contribution of visual information to the extraction of acoustic cues. Replacing the lip gesture by a non-speech visual input with exactly the same time course, providing the same temporal cues for extraction, removed the intelligibility benefit. This early contribution to audio-visual speech identification is discussed in relationships with recent neurophysiological data on audio-visual perception.