Internal versus external references with respect to perception of stimuli on the body surface

Previous studies on the determinants of locus of perception of stimuli on the body have suggested that the position of the stimulus has a significant effect whether a subject perceives a tactile pattern as seen from inside or outside the body. However, it is possible that previous investigators confounded stimulus location--dorsal or frontal--and experimenter's position--behind or in front of the subject. Using 42 male subjects in a 2 X 2 design, the effects of experimenter's position and stimulus location were studied by a new technique for inferring locus of perception. Experimenter's position, rather than stimulus location, affects subjects' locus of perception. Perception of stimuli on the body involves three independent factors, the demand characteristics of the experiment, the manner in which an individual perceives the boundaries of his own body, and an individual's ability to adopt the experimenter's perceptual standpoint.     

Why can't we tickle ourselves?

When we tickle ourselves something prevents the sensation being as strong as when someone else does it. It is suggested that the "something" may be: (i) the predictability of the stimulus; (ii) the presence of feedback from the movement of the arm doing the tickling; (iii) the presence of a corollary discharge from the voluntary movement of the tickling arm; (iv) the absence of a social/sexual context. To study these, Ss rated perceived "tickle-strength" in situations where they were tickled: (a) with their eyes closed; (b) with their eyes open; (c) with their own arm doing the tickling, but being moved by someone else; (d) by themselves. One group of Ss was divided into same sex and different sex subject-experimenter pairs. The results showed significant effects of predictability and sensorimotor feedback.     

Facial expressions,smile types,and self-report during humour,tickle, and pain

The nature of ticklish smiling and the possible emotional state that accompanies it have been pondered since the ancient Greeks. The present study is arguably the first to systematically examine facial behaviour and self-reports of emotion in response to tickling. Using a within-participants design, 84 participants' responses to being tickled were compared to their responses when experiencing a painful stimulus and their responses to comedy. Overall results for both self-report and facial action coding showed that the tickle condition elicited both pleasure and displeasure. Facial action during tickling included “Duchenne” smiles plus movements associated with negative emotions. Results suggest that tickle-induced smiling can be dissociated from positive affect. Accounts of tickle are discussed.     

Autokinetic illusion as affected by suggestions of experimenter and observer.

Two experiments were done to examine whether an experimenter's suggestion and self-suggestion could affect the autokinetic illusion and to specify that effect. Exp. I compared the effect of a facilitative suggestion with a suppressive one, by measuring the moving latency, duration, frequency, and by analyzing the movement trace. Time and frequency did not detect any effects of marked individual differences. Trace analysis, on the other hand, showed that suggestions were effective in the expected direction for some subjects. Exp. II gave the suggestion for and against subjects' dominant direction of the movement and was designed to specify the effect. While effects indicated by time and frequency measures were not consistent, the movement trace showed the effect in suggested directions, which was more distinct for subjects whose nonsuggested illusion was not so markedly directed. These findings indicate that suggestion could affect the spatiotemporal aspect of the illusion, so the trace analysis may be useful for studies in this field.     

Can a machine tickle?

It has been observed at least since the time of Aristotle that people cannot tickle themselves, but the reason remains elusive. Two sorts of explanations have been suggested. Theinterpersonal explanation suggests that tickling is fundamentally interpersonal and thus requires another person as the source of the touch. Thereflex explanation suggests that tickle simply requires an element of unpredictability or uncontrollability and is more like a reflex or some other stereotyped motor pattern. To test these explanations, we manipulated the perceived source of tickling. Thirty-five subjects were tickled twice-once by the experimenter, and once, they believed, by an automated machine. The reflex view predicts that our “tickle machine” should be as effective as a person in producing laughter, whereas the interpersonal view predicts significantly attenuated responses. Supporting the reflex view, subjects smiled, laughed, and wiggled just as often in response to the machine as to the experimenter. Self-reports of ticklishness were also virtually identical in the two conditions. Ticklish laughter evidently does not require that the stimulation be attributed to another person, as interpersonal accounts imply.     

Relation between self-paced and synchronized movement in persons with mental retardation

The relation between self-paced and synchronized tapping in 64 persons with mental retardation whose mental ages ranged from 2 to 11 years and chronological ages from 13 to 23 years was investigated. In a self-paced tapping task no stimulus was presented, and subjects' easy and spontaneous tapping was measured. In a synchronized tapping task their synchronous tapping with an auditory stimulus present at a quick or slow tempo was measured. Under both tempo conditions, the lower the subjects' mental age, the larger the errors in the intertap interval they made. The subjects of low mental age showed significantly larger errors in the intertap interval in the Slow than in the Quick Tempo condition and tended to tap at a rate near the self-paced tapping. These results may suggest that ability to adjust one's self pace is one of the key factors in the development of motor synchronization in persons with mental retardation.     

Verbal reports of stimulus effects on learning: Introspection revisited

The accuracy of subjects' verbal reports on the respective causal roles of relevant and irrelevant stimulus factors on learning was investigated. In two experiments, university undergraduates learned strings of letters that were either grammatically structured or unstructured (a causal variable) and either color coded or black (a salient but irrelevant variable). Results indicated that subjects reported more causal impact of color than structure on the learnability of lists, despite the fact that the latter variable and not color had an actual effect on learning. It was proposed that verbal reports of stimulus effects on one's own behavior can be regarded as a task in estimates of covariation rather than direct retrieval of memory traces.     

Sense of body and sense of action both contribute to self-recognition

Recognizing oneself, easy as it appears to be, seems at least to require awareness of one's body and one's actions. To investigate the contribution of these factors to self-recognition, we presented normal subjects with an image of both their own and the experimenter's hand. The hands could make the same, a different or no movement and could be displayed in various orientations. Subjects had to tell whether the indicated hand was theirs or not. The results showed that a congruence between visual signals and signals indicating the position of the body is one component on which self-recognition is based. Recognition of one's actions is another component. Subjects had most difficulty in recognizing their hand when movements were absent. When the two hands made different movements, subjects relied exclusively on the movement cue and recognition was almost perfect. Our findings are in line with pathological alterations in the sense of body and the sense of action.     

Bottlenosed dolphin and human recognition of veridical and degraded video displays of an artificial gestural language

2 bottlenosed dolphins proficient in interpreting gesture language signs viewed veridical and degraded gestures via TV without explicit training. In Exp. 1, dolphins immediately understood most gestures: Performance was high throughout degradations successively obscuring the head, torso, arms, and fingers, though deficits occurred for gestures degraded to a point-light display (PLD) of the signer's hands. In Exp. 2, humans of varying gestural fluency saw the PLD and veridical gestures from Exp. 1. Again, performance declined in the PLD condition. Though the dolphin recognized gestures as accurately as fluent humans, effects of the gesture's formational properties were not identical for humans and dolphin. Results suggest that the dolphin uses a network of semantic and gestural representations, that bottom-up processing predominates when the dolphin's short-term memory is taxed, and that recognition is affected by variables germane to grammatical category, short-term memory, and visual perception.     

The distribution of observing responses in a mixed FI-FR schedule,

In Exp I, three pigeons were trained on an observing response procedure where observing responses produced a stimulus correlated either with FI or with FR. Stimulus duration was 30 sec. During FR, the subjects completed the ratio before the stimulus terminated. During FI, the subjects usually observed the stimulus only once. Observing responses occurred immediately after food reinforcement. In Exp II, stimulus duration was shortened to 5 sec and the FR for food was increased. The results were similar to those of Exp 1. During most FIs and FRs, only one observing response occurred. The results of both experiments could be interpreted in a response competition framework. Immediately after food reinforcement, observing behavior is strong. When behavior on the food key begins it competes with further observing behavior.     

Brain potentials related to seeing one''s own name

Subjects were assigned an assumed name and then shown a series of statements of the form, "My name / is / X", where X was the assumed name, their own first name, or one of a set of other false names. Their task was to respond positively to the "assumed" name and reject as false all other names, including their own. An N380 feature of the averaged task-related brain potentials, considered to be inversely related to the degree of contextual priming, was greatly enhanced for the false names compared to the assumed name. The N380 to one's own name was more similar to that of the false than the assumed name, indicating that the sentence context's priming of various names was under the subjects' attentional control, and that the late negativity could be modulated by this attention. In contrast, a large P510 feature distinguished one's own name from the false name, and this difference was unaffected by practice. Even in cases, then, where the context allows anticipation of one verbal event (here, the assumed name), a highly overlearned and salient stimulus such as one's own name continues to produce a distinctive neural response.     

Inhibition of return is composed of attentional and oculomotor processes.

Response time can be delayed if a target stimulus appears at a location or object that was previously cued. This inhibition of return (IOR) phenomenon has been attributed to a delay in activating attentional or motor processes to a previously cued stimulus. Two experiments required subjects to localize or identify a target stimulus. In Experiment 1, the subjects' eyes were not monitored. In Experiment 2, the subjects' eyes were monitored, and the subjects were instructed to either execute or withhold an eye movement to a target stimulus. The results indicated that IOR was always present for location and identification responses, supporting an attentional account of IOR. However, IOR was larger when eye movements were executed, indicating that a motor component can contribute to IOR. Finally, when eye movements were withheld, IOR was larger when a target was presented alone than when it was presented with a distractor, suggesting that IOR is larger for exogenous than for endogenous covert orienting. Together, the data indicate that IOR is composed of both an oculomotor component and an attentional component.     

Now you see me,now you don't: evidence that chimpanzees understand the role of the eyes in attention

Chimpanzees appear to understand something about the attentional states of others; in the present experiment, we investigated whether they understand that the attentional state of a human is based on eye gaze. In all, 116 adult chimpanzees were offered food by an experimenter who engaged in one of the four experimental manipulations: eyes closed, eyes open, hand over eyes, and hand over mouth. The communicative behavior of the chimpanzees was observed. More visible behaviors were produced when the experimenter's eyes were visible than when the experimenter's eyes were not visible. More vocalizations were produced when the experimenter's eyes were closed than when they were open, but there were no differences in other attention getting behaviors. There was no effect of age or rearing history. The results suggest that chimpanzees use the presence of the eyes as a cue that their visual gestures will be effective.     

年龄和知识学习对国家分类的影响

通过两个自由分类实验探讨年龄和知识学习对国家分类的影响。实验1探讨年龄对国家分类的影响。结果表明,不同年龄的人对国家分类基本一致,但有一定差异。实验2探讨分类前的知识学习对国家分类的影响。结果表明,知识学习能有效地影响分类。阅读文章的主题影响被试的分类标准。整个研究表明,社会概念的分类是事物特征、知识经验和分类情境相互作用的产物。分类既受事物特征的影响,也受人的知识经验影响,还受分类情境影响,从而支持一种权变的观点。     

The impact of body-part-naming training on the accuracy of imitative performances in 2- to 3-year-old children

A series of three experiments explored the relationship between 3-year-old children's ability to name target body parts and their untrained matching of target hand-to-body touches. Nine participants, 3 per experiment, were presented with repeated generalized imitation tests in a multiple-baseline procedure, interspersed with step-by-step training that enabled them to (i) tact the target locations on their own and the experimenter's bodies or (ii) respond accurately as listeners to the experimenter's tacts of the target locations. Prompts for on-task naming of target body parts were also provided later in the procedure. In Experiment 1, only tact training followed by listener probes were conducted; in Experiment 2, tacting was trained first and listener behavior second, whereas in Experiment 3 listener training preceded tact training. Both tact and listener training resulted in emergence of naming together with significant and large improvements in the children's matching performances; this was true for each child and across most target gestures. The present series of experiments provides evidence that naming--the most basic form of self-instructional behavior--may be one means of establishing untrained matching as measured in generalized imitation tests. This demonstration has a bearing on our interpretation of imitation reported in the behavior analytic, cognitive developmental, and comparative literature.     

数字概念的视知觉无意识语义启动效应

研究了数字概念大小判断任务中的无意识语义启动效应。被试为天津师范大学本科生和研究生 5 6名。仪器为 pentiumIII高分辨率计算机 ,程序用E prime心理实验软件系统编制而成。在实验一中 ,用信号检测论技术发现 ,当启动数字呈现为 30ms时 ,被试是不能觉知到启动数字的 ;在实验二中 ,启动数字和靶数字使用相同的刺激序列 ,用MANOVA分析了启动数字和靶数字属于不同字体时的启动效应 ,发现启动数字对靶数字加工有促进或抑制作用 ;在实验三中 ,启动数字和靶数字使用两个不同的刺激序列 ,同样发现类似的启动效应。实验证据提示 ,无意识知觉能够达到语义水平上的加工     

Amer-Ind versus ASL: recognition and imitation in aphasic subjects

The imitation and recognition ability of brain-damaged and normal subjects was tested for 30 pairs of semantically matched ASL signs and corresponding Amer-Ind gestures. Subjects were rated according to severity and site of lesion. They were 6 nonaphasic, right-hemisphere brain-damaged subjects, 12 aphasic subjects, and 12 non-brain-damaged geriatric subjects. Results indicated that the Amer-Ind gestures were significantly easier to imitate and to recognize than the matched ALS signs. The relationships between these gestural abilities and severity of aphasia, site of lesion, Amer-Ind transparency ratings, and subjects' performance on a standardized aphasia test are outlined. The theoretical implications that concern the neural systems which mediate spoken and limb gestures are discussed.     

JUDGING WEIGHT UNDER GROUP PRESSURE

Subjects judged weights after hearing the judgments of four 'confederates' whose responses had been predetermined by the experimenter. Although the actual stimulus weight was held constant (500 grams), the confederates' judgments increased systematically from 500 to 900 (Exp. I), or decreased from 500 to 100 grams (Exp. II). The subjects' judgments followed those of the confederates very closely, and this group-induced change appeared to be accepted privately in most cases.     

Spatial stimulus-response compatibility and coding of tactile motor events: influence of distance between stimulated and responding body parts, spatial complexity of the task and sex of subject

We studied spatial stimulus response compatibility in the somatosensory modality by instructing 16 men and 16 women to press a key using the left or the right thumb in response to a nonnoxious electric stimulation delivered either to the left or to the right little finger or, in different blocks, to the left or to the right malleolar region. The task was performed in compatible (stimulus and key-response on the same side of the corporeal midline) and in incompatible conditions (stimulus and key-response on opposite sides of the corporeal midline). In Exp. 1 subjects were tested while keeping their limbs in anatomic position; in Exp. 2 subjects performed the task while keeping the left upper and lower limbs on the right side and the right limbs on the left side of the bodily midline (crossed position). The compatibility effect was observed in both experiments and was higher for stimuli delivered to the little finger than to the malleolar region. This suggests that the cost of inhibiting compatible responses is maximal when stimulated and responding body parts are contiguous. Moreover, in the spatially most demanding task (Exp. 2) men outperformed women for both speed and accuracy suggesting a sex related specialisation in the spatial processing of somatosensory information.     

Subvocalization rate versus other predictors of the memory span

Two experiments were performed to determine how accurately the immediate memory span may be predicted from the subject's subvocalization rate, as compared with other subject and stimulus variables. In the first, span and free-recall measures were obtained for 24 subjects, each tested with four types of spoken material (nonsense syllables, random words, fourth-order approximations to English, and normal prose). Silent subvocalization rate, whispered subvocalization rate, speaking rate, and silent reading rate were also measured for each subject. The span (3.9-14 items) showed the highest zero-order correlation with silent subvocalization rate: r = .80. Multiple regression analysis confirmed this as the span's best predictor, partial r = .31. Similar results were found for free-recall scores. In Exp. 2 the digit span was correlated against measures of age, intelligence, subvocalization rate, perceptual speed, and memory search rate, for 40 subjects aged 7 to 17 yr. The best zero-order predictor was age (.62), followed by subvocalization rate (.57) and intelligence (.39). Multiple regression analysis indicated that the span was best predicted by age, partial r = .37, and subvocalization rate, partial r = .29. The span appears more closely related to subjects' internal speech rate than to other cognitive functions.