Category Instances Research Articles

De la "naturalité" des catégories sémantiques : des catégories d'objets naturels aux catégories lexicales

About the "naturalness " of semantic categories — From categories of "natural objects" to lexical categories This paper examines the notion of naturality developed in the framework of the theory of natural categories and the natural process of categorization. We first analyze the seminal work of Rosch on focal colors as instances of natural categories. We then track the extension of the notion of natural categories to natural objects, from natural categories to artefacts and to any object categorized on the basis of typicality. Finaly we point to the consequences of such a concept on cognitive linguistics based on the naturalization of lexical semantic categories. The polysémie use of the notion of naturality is subsumed by the epistemic function of preserving the principles of universality of cognition against cultural determination.

Mapping the perceptual magnet effect for speech using signal detection theory and multidimensional scaling.

Recent experiments have demonstrated that the category goodness of speech sounds strongly influences perception in both adult and infants [Kuhl, Percept. Psychophys. 50, 93-107 (1991); Kuhl et al., Science 255, 606-608 (1992)]. Stimuli judged as exceptionally good instances of phonetic categories (prototypes) make neighboring tokens in the vowel space seem more similar, exhibiting a perceptual magnet effect. Three experiments further examined the perceptual magnet effect in adults. Experiment 1 collected goodness and identification judgments for 13 variants of the vowel /i/. Experiment 2 used signal detection theory to assess the discrimination of these tokens using a bias-free measure (d'). Experiment 3 employed multidimensional scaling (MDS) to geometrically model the distortion of the perceptual space due to the magnet effect. The results demonstrated a strong relationship between category goodness and discrimination. Vowel tokens receiving high goodness ratings in experiment 1 were more difficult to discriminate in experiment 2 and were more tightly clustered in the MDS solutions of experiment 3. These findings support the existence of a perceptual magnet effect, and may help explain some aspects of first language learning in infants and second language learning in adults.

Facilitation and matching bias in the abstract selection task

Abstract The present study examined performance on Wason's abstract selection task. Specifically, it explored further our hypothesis that the difficulty of the task can be traced to two sources: selective encoding of the problem information, and inadequate analytic processing of the encoded information. The results of Experiment 1 replicated our earlier finding of good performance when an explicated rule with categorical elements is used along with violation selection instructions and a decision justification format. In addition, Experiment 1 demonstrated that the type of elements used in the rule (categories vs specific instances of categories) did not influence the rate of correct performance. Experiment 2 examined the effects of explicated rules that allow matching bias to operate. The rate of correct selections was lowered, but only significantly so for the categorical rules. Performance in both cases, however, was still well above baseline. The results are discussed in terms of our selective encoding...

Causal models and the acquisition of category structure.

This article proposes that learning of categories based on cause-effect relations is guided by causal models. In addition to incorporating domain-specific knowledge, causal models can be based on knowledge of such general structural properties as the direction of the causal arrow and the variability of causal variables. Five experiments tested the influence of commoncause models and common-effect models on the ease of learning linearly separable and nonlinearly separable categories. The results show that causal models guide the interpretation of otherwise identical learning inputs, and that learning difficulty is determined by the fit between the structural implications of the causal models and the structure of the learning domain. These influences of the general properties of causal models were obtained across several different content domains, including domains for which subjects lacked prior knowledge. Tasks as apparently diverse as classical conditioning, category learning, and causal induction often require the learner to combine multiple cues in order to elicit a response. The cues may be conditioned stimuli (in conditioning), features of category instances (in category learning), or possible causes (in causal induction). Numerous learning models have been proposed in each of these areas, and a great deal of theoretical interest has focused on the extent to which common learning mechanisms may operate across these formally similar tasks. Most of these theories model learning as a domain-general process, bottom-up and basically associative in nature, that applies across diverse domains. Recently, more top-down or theory-based approaches have been proposed, which view learning as guided by domain-specific theories. In the present article we outline a position that is intermediate between these two views. We claim that a major subset of learning situations—

Improvement in cognitive functions and psychiatric symptoms in treatment-refractory schizophrenic patients receiving clozapine

Cognitive functions and psychopathology were assessed in 36 treatment-refractory schizophrenic patients before initiation of clozapine, and at 6 weeks and 6 months, thereafter. Before treatment, cognitive impairment was found in each measure of memory, attention, and executive function as compared with 26 normal controls. After both 6 weeks and 6 months of treatment, significant improvement occurred in the Controlled Oral Word Association Test, a measure of retrieval from reference memory. Improvement was also noted as 6 months in the Category Instance Generation Test, another measure of retrieval from reference memory, and in some, but not all, tests of executive function, attention, and recall memory. Clozapine treatment also resulted in significant improvement in Brief Psychiatric Rating Scale (BPRS) Total and Positive symptom scores at both 6-week and 6-month assessment points. There was some evidence for a relationship between improvement in psychopathology and cognitive function. The improvement in cognitive function during clozapine treatment could have consequences for capacity to work and social function.

Priming effects in prospective memory

The objective of this study was to examine whether an increased activation of knowledge structures facilitates memory for future actions. Priming effects were manipulated by giving subjects a category fluency task for half of the target categories used in the subsequent prospective memory task. In this task, younger and older adults performed an action whenever an instance of a given semantic category occurred in the context of a free association task. The degree of retrieval support was varied by using typical and atypical category instances as targets. Although reliable priming effects were observed for both age groups, the magnitude of priming interacted with the degree of retrieval support. Older adults showed priming effects for typical targets only, whereas the opposite pattern of results was obtained for younger adults. These findings indicate that, in addition to retrieval-related factors, the operations performed at the time of planning also contribute to optimal prospective remembering.

A connectionist approach to the prefrontal cortex.

Recent data from studies of the prefrontal cortex (PFC) in humans and laboratory animals are reviewed with particular reference to the anatomical substrates of prefrontal neuropsychological function in health and disease. The PFC has been shown to have a unique pattern of supramodal connectivity with intracortical and subcortical circuits that place the PFC in an anatomical position to subserve "executive" cognitive functions and modulate limbic information to relate to basal ganglia circuits in a highly specific manner and to uniquely control the neurochemical elements of attention and reward. PFC connectivity is also consistent with current hypotheses about prefrontal neuropsychology, which emphasize conscious, goal-directed behavior guided by past experience. PFC connectivity explains the frequency with which prefrontal dysfunction is seen in disease states, which, on the basis of neuroimaging and neuropathology data, can be categorized as either intrinsic or dysconnection disorders.

Acute Exercise Facilitates Semantically Cued Memory in Nursing Home Residents

To study the acute effects of non-strenuous physical exercise on memory retrieval and visuo-motor performance in old-old nursing home residents. A randomized control trial. A nursing home. Ambulatory volunteers from the nursing home, with all 20 shown to be normal on mental status. Three were male and 17 female, with a means of 84.5 years for age and 9.3 years for education. They were divided at random into an exercise and a control group. A single 15-minute standardized bout of non-strenuous exercise administered independently to each participant in the exercise group. Control group participants watched a video of similar exercises for 15 minutes. Two measures requiring the retrieval of category instances with semantic or initial consonant cues. Retrieval time was 60 seconds for each of four categories per measure. Visuo-motor performance was measured by Symbol Digit coding. Testing sessions were held before exercise, immediately post-exercise and 30 minutes post-exercise. The group-by-time interaction was significant only for semantically cued memory (P < 0.01), with higher retrieval at post-testing only in the exercised group. The higher retrieval was mainly attributable to more new items retrieved by the exercise group at the immediate post-test (P < 0.05). This study provides preliminary support for the hypothesis that non-strenuous physical exercise has positive acute effects on meaningfully cued memory.

Slot-filler and Conventional Category Organisation in Young Korean Children

Previous research has found that young English-speaking children rely on event schema knowledge in forming object categories and using them in verbal tasks. The present study examined category knowledge in young Korean children. In Experiment 1, 5and 8-year-olds produced category instances under either slot-filler or taxonomic instructions. Five-year-olds produced more instances in the slot-filler condition, whereas 8-year-olds produced more in the taxonomic condition. In Experiment 2, children were presented with a list of words composed of either slot-filler category items or taxonomic category items for either free or cued recall. For the 5-year-olds, slot-filler categories led to superior recall, higher levels of organisation, and shorter latencies than taxonomic categories in both recall conditions, and led to increased recall when script cues were provided. These findings support the view that slot-filler categories represent a closer match to the categorical structures of the young child's semantic organisation than taxonomic categories, and that slot-filler categories are combined into larger taxonomic categories as the child develops and learns.

Part-instance association in the categorization of acts.

Rips and Conrad (1989) found a kind-part reciprocal effect in models of the mind, in that one mental activity is part of another if the second is a kind of the first, and vice versa. In the present paper, we hypothesize that a formally analogous effect occurs at the level of activity instances. In particular, we hypothesize that an act is judged to be an instance of an act category referred to by an activity verb if the activity is judged to be an important part of the act, and vice versa. Empirical support for this hypothesis is found in three studies with activity verbs. The converse part-instance relation is further noted to parallel the part-instance association for a specific type of metonymically defined categories. Rips and Conrad's kind-part reciprocal effect is shown to be a logical consequence of the converse part-instance relation.

Time of day and semantic category effects on late components of the visual ERP

The N100, P200, N400 and P600 components of the visual event-related potential were recorded from 11 female subjects every 2 h from 09:00 to 21:00 hours using a semantic categorization task. All subjects scored as “Intermediate” or marginal “Evening” types on a Morningness-Eveningness questionnaire. Amplitude and latency of components, tympanic temperature, and performance measures for positive and negative category instances were assessed. Amplitude of P200 increased across the day. Amplitude of N400 was larger, and latency of P600 was longer, for negative category instances, but neither component varied with time of day. N100 was unaffected by time of day. The results suggest that previous reports of diurnal variations in visual N100–P200 were due to variations in P200 alone, and that diurnal variations in P200 may reflect diurnal variations in underlying arousal levels. In addition, overlap with P600 may have obscured time of day effects for N400.

Equivalent impairment of spatial and nonspatial memory following damage to the human hippocampus.

The hippocampus has sometimes been proposed to function as a cognitive map, a memory system that stores information about allocentric space. Work with experimental animals and memory-impaired patients has raised difficulties with this view by showing that the hippocampus is not performing an exclusively spatial function. However, the possibility has remained that the hippocampus plays a special role in spatial memory or a disproportionately large role in spatial memory compared to other kinds of memory. This study compared spatial and nonspatial memory in amnesic patients with lesions of the hippocampal formation or diencephalon. Subjects studied an array of 16 toy objects and were subsequently tested for object recall, object recognition, and memory for the location of the objects. Control subjects were tested after long retention intervals in order to equate their object memory performance with that of the patients. The main finding was that, when the performance of amnesic patients on the object memory tests was matched to the object memory performance of control subjects, spatial memory performance of the amnesic patients also matched the spatial memory performance of the control subjects. The results were the same for the two groups of patients. These findings suggest that the hippocampus is not especially involved in spatial memory. Spatial memory is simply one instance of a broader category of memory that requires the hippocampus. While cognitive mapping in its most abstract sense may describe hippocampal function, our results support alternative formulation, suggesting that the hippocampus is necessary for the rapid acquisition of relational, configural, or declarative (as opposed to purely spatial) information.

Semantic Memory Retrieval: Deadlining the Typicality Effect

Corbett and Wickelgren (1978), employing a speed–accuracy tradeoff method for verifying category membership, found that while the estimated strength of the category–instance association was higher for category examples given more frequently as instances of the category (i.e. higher instance dominance), retrieval dynamics did not vary across levels of instance dominance. The Corbett and Wickelgren data challenged the claims of models of speeded sentence verification that postulated differences in the retrieval processes of high- and low-dominance category-instance associations (e.g. Smith, Shoben, &amp; Rips, 1974). We argued that Corbett and Wickelgren very probably used category instances of debatable membership status in their low-instance dominance category examples, thus making it impossible to decide which responses to these items were correct. This, in turn, rendered their low-instance dominance data uninterpretable. Two partial replications of the Corbett and Wickelgren study were carried out, each with four subjects, and 10 variable lags between the stimulus presentation and the response signal. When care was taken that each category instance clearly belonged to its respective category, an estimate of the rate at which information accumulated towards its asymptote was greater for high-dominance, high-typicality items than for low-dominance, medium-typicality items. However, there were no dominance or typicality differences in the estimates of this asymptotic strength. In contrast, in the study in which low-dominance, low-typicality items were of questionable category membership, the results were similar to those obtained by Corbett and Wickelgren. These data support the idea that there is a continuous accumulation of information in the semantic memory sentence verification task.

Induction from a single instance: Formation of a novel category

This study examines whether preschoolers can use information from a known category to induce a characteristic attribute of a novel, contrasting category based on a single instance. We showed 32 four-year-olds three instances of a Given Category and one instance of a Target Category. These objects could vary along two attribute dimensions, such as color and shape. All instances of the Given Category shared identical values of one attribute (e.g., all were blue), but could have different values of the other attribute (e.g., a circle, a square, and a triangle). The single instance of the Target Category was different from the Given on both attribute dimensions (e.g., a red diamond). Children gave yes/no judgments as to whether additional objects were instances of the Target Category. There were two possible sources of information about the relevance of an attribute to classification: explicit (labeling) and implicit (variation in the Given Category). There were four conditions such that each source of information was either available or not. Both types of information were effective in eliciting inductions of the relevant kind of attribute and the characteristic value of this attribute in the novel category (explicit: p = .0004; implicit: p = .031). This suggests that children use an inductive bias that the instances of two related but distinct categories tend to be alike in the same way.

Infant categorization: Memory for category-level and specific item information

In an attempt to determine whether it is necessary to postulate abstraction processes in infant categorization, three experiments assessed retention of category-level information and information specific to category members. Using a visual recognition memory procedure, 10- and 13-month-old infants were familiarized with category instances containing both shared dimensional information and idiosyncratic features. The addition of idiosyncratic features to members of the familiarization category enhanced specific item memory for 13-month-old infants. However, this was not the case for the younger infants. The results of within-category test comparisons indicated that 10-month-old infants regarded information common to all members of the category as more familiar than information specific to individual exemplars. This occurred despite evidence that specific item information was retained in memory and available for retrieval during recognition tests. The findings are discussed in relation to exemplar and abstraction models of categorization.

The revelation effect: When disguising test items induces recognition.

Documented here is a bias whereby items are more likely to be judged as having been presented beforehand if they are disguised in some way and so have to be discovered or "revealed." The bias was found for test words that were unfolded letter by letter (Experiments 1 and 3), presented with their letters either transposed (Experiments 2 and 3), or individually rotated (Experiments 4 and 5), or rotated as a whole (Experiment 5), and for test numbers that were presented in the form of roman numerals (Experiment 6) or equations (Experiment 7). The bias occurred both for items that were presented beforehand and for those that were not. No bias was found when words were judged, not for prior occurrence, but for typicality as category instances (Experiment 8), lexicality (Experiment 9), frequency of general usage (Experiment 10), or number of times encountered during the preceding week (Experiment 11).

Generation enhances semantic processing? The role of distinctiveness in the generation effect.

The goal of the present study was to investigate the locus of the memory advantage for words that are generated according to a nonsemantic rule (letter transposition) over words that are presented intact (read words). In the first two experiments, a category instance generation task was used to test the possibility that the semantic features of generated words are more readily available than those of read words. This possibility was not supported. In Experiment 3, generation effects were found to depend on the level of meaningfulness of words in recall, but not in recognition. In Experiment 4, a between-list design eliminated the generation effect found in recall, but did not affect the generation effect in recognition. Taken together, these findings suggest that generating a target according to a letter transposition rule enhances the distinctiveness of the word along a nonsemantic dimension.

The effect of prior sleep on retrieval

Sleeping immediately prior to learning impaires subsequent retention. The purpose of this study was to ascertain if relatively short-term (0 to 20 mins) retention deficits are the result of impaired retrieval at the time of testing. 24 young women students were randomly allocated to two groups: prior sleep and awake. The prior sleep group was required to generate (retrieve) instances of specified categories immediately upon awakening from the first hour or so of nocturnal sleep and repeated the task again after a delay of 20 minutes. The awake control group performed the task at exactly the same times of night but without having had any prior sleep. The prior sleep group retrieved significantly fewer category instances immediately upon awakening and at delayed testing. However, retrieval had significantly improved during the 20 mins delay. It was concluded that the detrimental effects of prior sleep on retention over relatively short intervals may in part be due to retrieval difficulties at the time of testing but that longer-term retention deficits (<20 mins) are more likely to be due to impaired memory consolidation.

Judgments of Category Size: Now You Have Them, Now You Don't

To provide at least a partial explanation for the level-of-processing effect in frequency judgments, in three experiments we explored the role of covert elicitations of events on subsequent frequency judgments. Subjects were asked to judge the number of category instances that had been presented, when cued at retrieval by the category name. In these experiments we hoped to carry the argument regarding the importance of covert occurrences to its extreme. That is, we sought to show that in the absence of covert occurrences of the category label during encoding, judgments of category size would be impossible. Alternatively, when covert occurrences of those category labels were encouraged during encoding, frequency judgments would be possible. We were successful in two experiments, but only moderately successful in another.

Uncanny Narration in Moby-Dick

THE word strange appears in nearly every chapter of MobyDick. Why? To what effects? Is repetition of strange itself strange? Three arguments developed from Freud's essay, Uncanny, will orient following discussion. (i) The structure of uncanny is structure of repression. Phenomenologically, uncanny is experienced as a certain frightful feeling: it belongs all that is terrible, Freud says, to all that arouses dread and . . . creeping horror.' This uncanny emotionality, however, functions within an economy of knowledge. On one hand, the 'uncanny' is that class of terrifying which leads back long known us, once very familiar but now forgotten. On other hand, everything is uncanny that ought have remained hidden and secret, and yet comes light.2 The uncanny signals a return of repressed. This is Freud's interest: not affective topography of uncanny but its signifying character, that was known and will be known again. (2) Freud identifies this something as the dread of and, in his analysis of Hoffman's Sand Man, locates it in child's castration complex. However, if one were understand cutting off of a part of body in castration as a particular instance of a larger category of severings, and if one were understand certain of infant's early experiences of separations from mother as experiences of being cut off, then one would be able conceptualize uncanny in preoedipal as well as oedipal terms.