Reasoning in the hooded rat

A problem situation was devised to test Deutsch's (1956) theory of reasoning. In this situation various problems can be set the rat and these problems admit of various equally rational solutions. Predictions from the theory were made, not only that the animals would solve the problems, but also which particular solution they would adopt. These predictions are confirmed. The rats were trained to run to two goal-boxes, one near, the other more distant. The near one had two paths of equal length leading to it, the more distant goal only one. After training, the animals chose the near goal-box on the first trial of the day. On the test trials the near goal-box was left empty, or the chosen path blocked, or a mesh placed across the goal-box, with the food accessible via the other short path.     

A test of the neo-behaviouristic theory of extinction

A test between Moltz's and Deutsch's theory of extinction was devised. Animals were trained to go to the same goal-box via two different paths. Then they were divided into two groups. The first found the goal-box empty, the second found the entrance into the goal-box blocked. The choices of the animals on the next trial were observed. The results are those predicted by Deutsch.     

Caudate-putamen lesions in the rat may impair or potentiate maze learning depending upon availability of stimulus cues and relevance of response cues

In Experiment 1 rats were required to learn a Y-maze in which reward was made available after a given response (e.g. a left turn) regardless of which arm was used as the start-box. Subjects with lesions of the caudate-putamen showed a deficit on this response-learning task compared with control subjects (unoperated animals and rats having lesions of the posterior cortex). In Experiment 2 rats with caudate-putamen lesions were unimpaired when the direction of the turn required to reach the correct goal-box (identified by means of a salient visual intra-maze cue) varied from trial to trial. In the absence of salient intramaze cues, but with enriched room (extra-maze) cues, the rats with caudate-putamen lesions were superior to controls on this task. It is argued that caudate-putamen lesions disrupt a mechanism responsible for processing information about responses, but that the other (spatial) mechanisms responsible for maze-learning remain intact and that caudate-putamen lesions may enhance performance on spatial tasks for which information about responses is irrelevant.     

Regulatory fit effects in a choice task

This article examines the interface between motivation and choice. In category learning, a regulatory fit has been shown to increase exploration of alternative response strategies even when exploration is suboptimal. In the present study, promotion- and prevention-focused subjects performed a choice task that required them to choose from one of two decks of cards on each trial. They either gained or lost points with each draw. In Experiment 1, optimal performance required an exploratory response pattern that entailed sampling from a deck that initially appeared disadvantageous but ultimately became advantageous. In Experiment 2, optimal performance required an exploitative response pattern. A softmax action selection model that includes an exploitation parameter was applied to each subject’s data from both experiments and revealed greater exploration of alternative strategies for people with a regulatory fit. This response strategy was optimal in Experiment 1 and led to superior performance, but was suboptimal in Experiment 2 and led to inferior performance.     

The effect of set on encoding and rehearsal processes in memory

An experiment was conducted to determine the effect of manipulating S’s preparation for what he will see on a given trial on his ability to mentally keep track of the number of occurrences of each of several different stimuli in a sequence. It was found that, when the same stimuli were used from trial to trial, performance was significantly better than when different stimuli were used. Foreknowledge of the specific stimuli to be used on a given trial did little to improve performance per se, but it did reduce labeling errors. The results were discussed in terms of the “spatial window” model of keeping-track performance.     

Blocking the incorrect alley in a two-drive learning situation

This experiment was designed to test the effect of blocking the path to an irrelevant reward on the subject's later performance when motivated for that reward, with a view to clarifying a well-known problem-situation.

An experimental group of 17 hooded rats was run in a two-choice maze, with food in one goal-box and water in the other, being motivated alternately for one or the other. The wrong goal-box was always blocked. Their performance on the first trial of the daily series was significantly poorer than that of a control group of 18 hooded rats, for which both boxes were always open. This difference persisted when, in a second period of training, the rhythm of motivation was altered for both groups.

It is concluded that blocking an irrelevant reward can have a disturbing effect and that this may be relevant to the problem-situation. It is also shown that such a result is to be predicted from Deutsch's (1953, 1956) theory.     

Is There a "Language of the Eyes"? Evidence from Normal Adults,and Adults with Autism or Asperger Syndrome

Previous work suggests that a range of mental states can be read from facial expressions, beyond the “basic emotions”. Experiment 1 tested this in more detail, by using a standardized method, and by testing the role of face parts (eyes vs. mouth vs. the whole face). Adult subjects were shown photographs of an actress posing 10 basic emotions (happy, sad, angry, afraid, etc.) and 10 complex mental states (scheme, admire, interest, thoughtfulness, etc.). For each mental state, each subject was shown the whole face, the eyes alone, or the mouth alone, and were given a forced choice of two mental state terms. Results indicated that: (1) Subjects show remarkable agreement in ascribing a wide range of mental states to facial expressions, (2) for the basic emotions, the whole face is more informative than either the eyes or the mouth, (3) for the complex mental states, seeing the eyes alone produced significantly better performance than seeing the mouth alone, and was as informative as the whole face. In Experiment 2, the eye-region effect was re-tested, this time using an actor's face, in order to test if this effect generalized across faces of different sex. Results were broadly similar to those found in Experiment 1. In Experiment 3, adults with autism or Asperger Syndrome were testedusing the same procedure as Experiment1. Results showed a significant impairment relative to normal adults on the complex mental states, and this was most marked on the eyes-alone condition. The results from all three experiments are discussed in relation to the role or perception in the use of our everyday “theory of mind”, and the role of eye-contact in this.     

虚拟路径整合的学习效应

路径整合指通过自身运动信息对自身位置进行更新的过程。本研究使用头盔式虚拟现实系统和分段式迷宫, 在两个实验中检验在同样布局的外出路径上重复地进行路径完成任务是否会改善被试的反应表现。实验1中的外出路径具有相对较简单的空间布局, 实验结果表明, 男性和女性被试均在反应时、位置误差、角度误差上表现出了学习效应, 即第二次在同样空间布局的外出路径上进行路径完成任务时的表现比第一次有了显著的改善。实验2中的外出路径具有更复杂多样化的空间布局, 而实验结果表明, 男性和女性被试均在反应时和比例位置误差上表现出了学习效应, 但是路径更复杂时要求更多次数的重复才可以提高路径整合成绩。这些研究结果为路径整合能力训练的可行性提供了初步的实证依据。     

The Hull-Leeper drive discrimination situation-a control experiment

An experiment was conducted testing the author's explanation of the discrepancy between results obtained by Hull and Leeper in a similar situation. Animals were run either hungry or thirsty to obtain the appropriate reward by making one response when hungry and another when thirsty. For all groups the reward was in the same goal-box. The first group (Leeper) had the goal-box divided with each side being accessible only if the animal had made the correct response initially. The second group (Hull) had the same goal-box for both rewards, but if the wrong path was taken the animal was prevented from reaching the goal by a block. The third group had the same goal-box for both rewards again, but the animal could reach the goal-box even if the wrong path was taken and discovered the unwanted reward in the goal-box. The results confirm the predictions made from the author's theory.     

The threshold for successiveness

In Experiment 1, three stimuli were presented on each trial; the second and third were simultaneous. Ss said which of the three they saw first and then made a different second guess. Second guesses were correct more often than chance when first guesses were wrong, contradicting the predictions of a psychological moment theory. Psychometric functions are inconsistent with a theory which holds that Ss can order their perceptions and that errors result from lack of correspondence between this order and that of the stimuli. In Experiment 2, two pairs of stimuli, each simultaneous or successive, were presented on each trial, the interval between their onsets varying, and Ss guessed whether each was successive. A moment-like cyclic process affecting the perception of successive stimuli should raise the correlation between responses when both pairs were successive and beginning at the same time; this was not found.     

Attention to primes modulates affective priming of pronunciation responses

In studies on affective priming of pronunciation responses, two words are presented on each trial and participants are asked to read the second word out loud. Whereas some studies revealed shorter reaction times when the two words had the same valence than when they had a different valence, other studies either found no effect of affective congruence or revealed a reversed effect. In the present experiments, a significant effect of affective congruence only emerged when filler trials were presented in which the prime and target were identical and participants were instructed to attend to the primes (Experiment 2). No effects were found when participants were merely instructed to attend to or ignore the primes (Experiment 1), or when affectively incongruent filler trials were presented and participants were instructed to ignore the primes (Experiment 2).     

The influence of retrieval on retention

Four experiments tested the hypothesis that successful retrieval of an item from memory affects retention only because the retrieval provides an additional presentation of the target item. Two methods of learning paired associates were compared. In the pure study trial (pure ST condition) method, both items of a pair were presented simultaneously for study. In the test trial/study trial (TTST condition) method, subjects attempted to retrieve the response term during a period in which only the stimulus term was present (and the response term of the pair was presented after a 5-sec delay). Final retention of target items was tested with cued-recall tests. In Experiment 1, there was a reliable advantage in final testing for nonsense-syllable/number pairs in the TTST condition over pairs in the pure ST condition. In Experiment 2, the same result was obtained with Eskimo/English word pairs. This benefit of the TTST condition was not apparently different for final retrieval after 5 min or after 24 h. Experiments 3 and 4 ruled out two artifactual explanations of the TTST advantage observed in the first two experiments. Because performing a memory retrieval (TTST condition) led to better performance than pure study (pure ST condition), the results reject the hypothesis that a successful retrieval is beneficial only to the extent that it provides another study experience.     

Imagery and Recognition: Dissociable Measures of Memory?

An assumption of many theories of visual cognition is that imagery tasks and picture recognition tasks tap the same kind of memory processes (i.e. visual), implying that these two types of tests can be used as interchangeable measures of visual memory. In this paper, we investigated whether articulatory suppression—a variable known to improve imagery performance—has a similar effect on picture recognition performance. In Experiment 1, subjects performed either an imagery task or a recognition task while engaging or not in articulatory suppression; in Experiment 2, the same subjects performed first the imagery task, and then the recognition task, while engaging or not in articulatory suppression. When the type of task was manipulated between subjects (Experiment 1), imagery performance was significantly improved by articulatory suppression. In contrast, recognition performance was significantly impaired by the introduction of articulatory suppression. In accordance with results of Experiment 1, in Experiment 2 imagery and recognition performance were found to be unrelated. However, when the same subjects performed both tasks, the opposite effect of articulatory suppression on imagery vs recognition performance was observed only on the first item. It does appear that when the imagery task and the picture recognition task are performed in isolation, performance is found to be independent, suggesting that the two tasks are mediated by different mechanisms. However, when a within-subjects design is used, performance in one task can be contaminated by the presence of the other task.     

Spatial contiguity facilitates Pavlovian second-order conditioning

Two experiments investigated the effects of spatial contiguity upon the formation of second-order conditioning in pigeon subjects. Experiment 1 used an autoshaping procedure to pair two visual stimuli, S2 and S1, after S1 had previously been paired with food. The resulting second-order conditioning of S2 was superior when both stimuli appeared on the same response key within a trial, compared with their appearing on different keys. Experiment 2 found a similar importance of spatial contiguity between S2 and S1 in a conditioned suppression paradigm. In addition, consistently presenting S2 and S1 in the same spatial location produced superior conditioning compared with varying their spatial relation from trial to trial. The design of these experiments was such as to imply that spatial contiguity facilitates performance by improving the formation of association rather than by promoting stimulus generalization or pseudoconditioning. Moreover, the observation of a facilitative effect of spatial contiguity between S1 and S2 in two different paradigms that use qualitatively different unconditioned stimuli and evoke different responses implies some generality for these findings. Consequently, these results suggest that spatially contiguous stimuli are especially associable in Pavlovian conditioning paradigms.     

Orthographic congruency effects in the suprasegmental domain: Evidence from Thai

The influence of orthographic knowledge on lexical tone processing was examined by manipulating the congruency between the tone and the tone marker of Thai monosyllabic words presented in three metalinguistic tasks. In tone monitoring (Experiment 1) and same–different tone judgement (Experiment 2)—that is, tasks that require an explicit analysis of tone information—an orthographic congruency effect was observed: Better performance was found when both tone and tone marker led to the same response than when they led to opposite, competing responses. In rhyme judgement (Experiment 3), a metaphonological task that allows tone to be processed in a more natural way since it does not require explicit analysis of tone, the orthographic effect emerged only when the interstimulus interval was lengthened from 30 to 1,200 ms. In addition to demonstrating the generalization of the orthographic congruency effect to the suprasegmental domain in Thai, the present data also suggest relatively late and task-dependent activation of orthographic representations of tone.     

Preschoolers' extension of familiar adjectives

In two experiments, we examined the role of labels in guiding preschoolers' extension of three types of familiar adjectives: emotional state adjectives, physiological state adjectives, and trait adjectives. On each trial, we labeled a target animal with one of the three different types of adjectives and asked whether these terms could apply to a subordinate-level match, a basic-level match, a superordinate-level match, or an inanimate object. In Experiment 1, participants extended trait adjectives, but not emotional or physiological adjectives, to members of the same basic-level category, regardless of whether an explicit basic-level label was provided for the target animal. Similarly, children in Experiment 2 also extended trait adjectives to the members of the same basic-level category, even when explicit superordinate- and subordinate-level labels were provided for the target animals. Together, these results demonstrate that children appreciate that emotional and physiological adjectives cannot be generalized to the same extent as can trait adjectives, and the results document the privileged status of basic-level categories in preschoolers' extension of trait adjectives.     

Effects of opiate antagonists on spatial memory in young and aged rats

The effects of post-training opiate antagonist administration on spatial memory were assessed in young and aged male Long Evans rats. In Experiment I rats were trained to visit each arm of an eight-arm radial maze once in a session to obtain a food reward placed at the end of each arm. During training aged rats required significantly more trials to achieve criterion performance when compared to young mature rats. However, administration of the opiate antagonist naloxone (2.0 mg/kg) immediately after each training trial did not significantly alter the rate of achieving accurate performance in either age group. In Experiment II young and aged rats that were previously trained to a comparable criterion on the radial maze were tested on the same maze apparatus in novel spatial environments. When animals were exposed to novel spatial information, the effects of post-trial opiate antagonists were examined using a within-subjects counter-balanced design. In Experiment IIa naloxone (2 mg/kg) enhanced the performance of both young and aged rats. In Experiment IIB naltrexone (1.0 mg/kg) was found to have a comparable effect of enhancing the performance of both age groups. In addition, in Experiment IIb a significant age-related deficit was found in rats tested in novel spatial environments. These results indicate that opiate antagonists are capable of improving memory for new spatial information in both young and aged rats on a task that is sensitive to behavioral deficits during normal aging.     

Successive and conditional discrimination learning in pigs

We studied the ability of pigs to discriminate tone cues using successive and conditional discrimination tasks. Pigs (n = 8) were trained in a successive discrimination Go/No-Go task (Experiment 1) to associate a Go-cue with a reward at the end of a runway and a No-Go-cue with the absence of reward. Latency to reach the goal-box was recorded for each cue-type. Learning of a conditional discrimination task was compared between low-birthweight (LBW, n = 5) and normal-birthweight (NBW, n = 6) pigs (Experiment 2) and between conventional farm (n = 7) and Göttingen miniature (n = 8) pigs (Experiment 3). In this active-choice task, one cue signalled a response in a right goal-box was correct and a second cue signalled a response in a left goal-box was correct. Cues were differentially rewarded. The number of sessions to learn the discrimination and number of correct choices per cue-type were recorded. In Experiment 1, four out of eight pigs showed learning on the task, that is, a higher latency to respond to the No-Go-cue, within 25 sessions. In Experiment 2, eight out of 11 pigs learned the discrimination within 46 sessions. LBW learners learned faster than NBW learners. In Experiment 3, all 15 pigs learned the task within 16 sessions. Göttingen miniature pigs learned faster than conventional farm pigs. While some methodological issues may improve the Go/No-Go design, it is suggested that an active-choice task yields clearer and more consistent results than one relying on latency alone.     

The effect of temporal delay and spatial differences on cross-modal object recognition

In a series of experiments, we investigated the matching of objects across visual and haptic modalities across different time delays and spatial dimensions. In all of the experiments, we used simple L-shaped figures as stimuli that varied in either the x or the y dimension or in both dimensions. In Experiment 1, we found that cross-modal matching performance decreased as a function of the time delay between the presentation of the objects. We found no difference in performance between the visual-haptic (VH) and haptic-visual (HV) conditions. Cross-modal performance was better when objects differed in both the x and y dimensions rather than in one dimension alone. In Experiment 2, we investigated the relative contribution of each modality to performance across different interstimulus delays. We found no differential effect of delay between the HH and VV conditions, although general performance was better for the VV condition than for the HH condition. Again, responses to xy changes were better than changes in the x or y dimensions alone. Finally, in Experiment 3, we examined performance in a matching task with simultaneous and successive presentation conditions. We failed to find any difference between simultaneous and successive presentation conditions. Our findings suggest that the short-term retention of object representations is similar in both the visual and haptic modalities. Moreover, these results suggest that recognition is best within a temporal window that includes simultaneous or rapidly successive presentation of stimuli across the modalities and is also best when objects are more discriminable from each other.     

Metacognitive monitoring during category learning: how success affects future behaviour

The purpose of this study was to see how people perceive their own learning during a category learning task, and whether their perceptions matched their performance. In two experiments, participants were asked to learn natural categories, of both high and low variability, and make category learning judgements (CLJs). Variability was manipulated by varying the number of exemplars and the number of times each exemplar was presented within each category. Experiment 1 showed that participants were generally overconfident in their knowledge of low variability families, suggesting that they considered repetition to be more useful for learning than it actually was. Also, a correct trial, for a particular category, was more likely to occur if the previous trial was correct. CLJs had the largest increase when a trial was correct following an incorrect trial and the largest decrease when an incorrect trial followed a correct trial. Experiment 2 replicated these results, but also demonstrated that global CLJ ratings showed the same bias towards repetition. These results indicate that we generally identify success as being the biggest determinant of learning, but do not always recognise cues, such as variability, that enhance learning.