Error-driven knowledge restructuring in categorization

Knowledge restructuring occurs when people shift to a new strategy or representation during learning. Although knowledge restructuring can frequently be experimentally encouraged, there are instances in which people resist restructuring and continue to use an expedient but imperfect initial strategy. The authors report 3 category learning experiments that reconciled those conflicting outcomes by postulating that, for restructuring to occur, learners must be dissatisfied with their knowledge and a usable alternative must be available. In line with expectation, restructuring was elicited only when an alternative strategy was pointed out and when people's initial expedient strategy entailed performance error. Neither error nor information about the alternative strategy by itself was sufficient to induce restructuring.     

Color term knowledge does not affect categorical perception of color in toddlers

Categorical perception of color is shown when colors from the same category are discriminated less easily than equivalently spaced colors that cross a category boundary. The current experiments tested various models of categorical perception. Experiment 1 tested for categorical responding in 2- to 4-year-olds, the age range for the onset establishment of color term knowledge. Experiment 2 tested for categorical responding in Himba toddlers, whose language segments the color space differently from the way in which the English language does so. Experiment 3 manipulated the conditions of the task to explore whether the categorical responding in Experiments 1 and 2 was equivalent to categorical perception. Categorical perception was shown irrespective of naming and was not stronger in those children with more developed color term knowledge. Cross-cultural differences in the extent of categorical perception were not found. These findings support universalistic models of color categorization and suggest that color term knowledge does not modify categorical perception, at least during the early stages of childhood.     

Acquired dyslexia in Spanish: a review and some observations on a new case of deep dyslexia

Readers and writers of Spanish use an orthography that is highly transparent. It has been proposed that readers of Spanish can rely on grapheme-phoneme correspondences, alone, to access meaning or phonology from print. In recent years, a number of case studies have yielded evidence inconsistent with this idea. We review these studies with particular focus on those that report evidence for reading based on direct lexical mappings between print, orthographic representations, and meaning or phonology. We report a new case of acquired literacy impairment in Spanish, MJ, who presents a pattern of preserved abilities and deficits symptomatic of deep dyslexia. The patient is unable to read nonwords, but can read a substantial number of words. Her reading is characterized by the production of semantic, visual, and derivational errors. We argue that MJ has a deficit in her lexical selection ability, common to both her reading and her naming problems. We propose that MJ, and the other cases we review, demonstrate that lexical reading is adopted by skilled readers even in a transparent language.     

Subjective experience and the attentional lapse: task engagement and disengagement during sustained attention

Three experiments investigated the relationship between subjective experience and attentional lapses during sustained attention. These experiments employed two measures of subjective experience (thought probes and questionnaires) to examine how differences in awareness correspond to variations in both task performance (reaction time and errors) and psycho-physiological measures (heart rate and galvanic skin response). This series of experiments examine these phenomena during the Sustained Attention to Response Task (SART, Robertson, Manly, Adrade, Baddeley, & Yiend, 1997). The results suggest we can dissociate between two components of subjective experience during sustained attention: (A) task unrelated thought which corresponds to an absent minded disengagement from the task and (B) a pre-occupation with one's task performance that seems to be best conceptualised as a strategic attempt to deploy attentional resources in response to a perception of environmental demands which exceed ones ability to perform the task. The implications of these findings for our understanding of how awareness is maintained on task relevant material during periods of sustained attention are discussed.     

Living in the “space of reasons”: The “rationality debate” revisited

Two questions are central to the “rationality debate” in the philosophy of social science. First, should we acknowledge differences in basic norms of epistemic and agential rationality, or in the content of perceptual experience, as the “best explanation” of radical differences in belief and practice? Second, can genuine understanding be achieved between cultures and research traditions that so differ in their beliefs and practices? I survey a number of responses to these questions, and suggest that one of these, “dialogical optimism”, while attractive, is in need of further clarification. Such clarification may be forthcoming if we attend to recent work by John McDowell. McDowell claims that perceptual experience, as our primary mode of epistemic access to the world, must be located within what Sellars termed the “space of reasons” if we are to make sense of our conception of ourselves as thinking creatures. I develop a reading of this claim in terms of a fundamental duality in human perceptual experience, and use this conception of experience to illuminate the dialogical optimist strategy in the rationality debate.     

The impact of character attribution on composite production: A real world effect?

Facial memory draws upon both veridical detail and beliefs based upon prior knowledge and stereotypes. Shepherd, Ellis, McMurran, and Davies (1978) demonstrated that subjects' perception and subsequent reconstruction of a face using the “Photofit” kit was significantly influenced by whether they believed the person to be a multiple murderer or a local hero. The current study explored whether similar effects would occur when the face involved was one of four male celebrities about which subjects held pronounced positive or negative views and where reconstruction was accomplished using the computerised “E-fit” composite system. Semantic differential ratings showed significant influences of liking on subjects' perception and reconstruction of the faces involved, though the pattern of effects was not always readily predictable. Liking also influenced accuracy of reconstruction; ranking and naming data showed that the best composites were made by subjects who disliked the target and made their reconstructions with the aid of a photograph.     

The impact of character attribution on composite production: A real world effect?

Facial memory draws upon both veridical detail and beliefs based upon prior knowledge and stereotypes. Shepherd, Ellis, McMurran, and Davies (1978) demonstrated that subjects' perception and subsequent reconstruction of a face using the “Photofit” kit was significantly influenced by whether they believed the person to be a multiple murderer or a local hero. The current study explored whether similar effects would occur when the face involved was one of four male celebrities about which subjects held pronounced positive or negative views and where reconstruction was accomplished using the computerised “E-fit” composite system. Semantic differential ratings showed significant influences of liking on subjects' perception and reconstruction of the faces involved, though the pattern of effects was not always readily predictable. Liking also influenced accuracy of reconstruction; ranking and naming data showed that the best composites were made by subjects who disliked the target and made their reconstructions with the aid of a photograph.