Cognitive Psychology

The underrepresentation of women, people of color, and especially women of color—and the corresponding overrepresentation of white men—is more pronounced in philosophy than in many of the sciences. I suggest that part of the explanation for this lies in the role played by the idealized rational self, a concept that is relatively influential in philosophy but rarely employed in the sciences. The idealized rational self models the mind as consistent, unified, rationally transcendent, and introspectively transparent. I hypothesize that acceptance of (...) the idealized rational self leads philosophers to underestimate the influence of implicit bias on their own judgments and prevents them from enacting the reforms necessary to minimize the effects of implicit bias on institutional decision-making procedures. I consider recent experiments in social psychology that suggest that an increased sense of one’s own objectivity leads to greater reliance on bias in hiring scenarios, and I hypothesize how these results might be applied to philosophers’ evaluative judgments. I discuss ways that the idealized rational self is susceptible to broader critiques of ideal theory, and I consider some of the ways that the picture functions as a tool of active ignorance and color-evasive racism. (shrink)

According to the Standard Model account of religion, religious concepts tend to conform to “minimally counterintuitive” schemas. Laypeople may, to varying degrees, verbally endorse the abstract doctrines taught by professional theologians. But, outside the Sunday school exam room, the implicit representations that tend to guide people’s everyday thinking, feeling, and behavior are about minimally counterintuitive entities. According to the Standard Model, these implicit representations are the essential thing to be explained by the cognitive science of religion. It is argued here (...) that this theoretical orientation of mainstream CSR misses a whole dimension of religiosity—the acceptance of certain religious authorities, that is, the acceptance of other people’s superior expertise. Average believers tend to accept the authority of religious experts who espouse highly counterintuitive ideas that they understand in a distorted form, if at all.... (shrink)

In some visual cases, especially those in which one reasons from a visual model to a conclusion, it is tempting to think that some new normative base, perhaps a visual logic is in order. I show that, at least in the case of what I’ll call appeal to visual models, the same criteria are required in visual and verbal cases.

The paper presents research into the effects of the use of negations in directives. Three experiments are described that tested the effects of instructions formulated in various ways: direct and negated commands to focus the attention. Indicators of attention focusing that were used include: the correctness of answers to questions about a selection of comic book pages ; the time needed to name the colours of stimulus words and the level of recall of these words after completion of the colour (...) naming task. The results showed that a direct command influenced all indicators of attention focusing. However, a negated command increased the level of recall of details about the comic book pages, as well as the level of key word recall. Both the automatic process that generates the paradoxical effects of negated commands, as well as the controlled process of reasoning, may be responsible for the results of the memory task. (shrink)

This study explored the influence of the context-dependent effect of mood as well as individual differences in neuroticism and action vs. state/volatility orientation on predecisional processing in a multiattribute choice task. One hundred and twenty participants acquired information about choice options after filling out personality questionnaires. Results showed that participants in a positive mood processed the information longer in enjoy than in done-enough context. In turn, participants in a negative mood processed the information more selectively in enjoy than in done-enough (...) context. It also appeared that this effect is reinforced for participants with low neuroticism and volatility orientation, while it is weakened for those with low neuroticism and action orientation. Results were interpreted in accordance with the differential-processual approach. (shrink)

This article describes a qualitative inquiry into the historical reception of Flemish television fiction broadcast by the monopolistic Flemish broadcaster BRT between 1953 and 1989. This is a relatively homogeneous period, both in terms of broadcasting policies and fiction output. What do viewers remember of this period? Can patterns be discerned in these memories, and if so, why? To answer these questions, this research uses semi-structured interviews with older viewers. First, the article discusses the particular problems of this method, mostly (...) ‘faulty’ memory and nostalgic reinterpretation. Then, the findings are presented, reflecting on processes of memory formation. One clear finding concerns the selective and homogeneous nature of memories; the same few serials are remembered in similar ways by most, leading to clichéd memories of the past. (shrink)

The present study provides evidence that the activation strength produced by emotional stimuli must pass a threshold level in order to be consciously perceived, contrary to the assumption of continuous quality of representation. An analysis of receiver operating characteristics for attentional blink performance was used to distinguish between two models of emotion perception by inspecting two different ROC’s shapes. Across all conditions, the results showed that performance in the attentional blink task was better described by the two-limbs ROC predicted by (...) the Krantz threshold model than by the curvilinear ROC implied by the signal-detection theory. (shrink)

This paper considers methodological issues of awareness during adult second language acquisition. Specifically, the paper deals with the issue of instructional orientations, the issue of biases in knowledge measurement, and the issue of reactivity in the online think-aloud protocol. Detailed reviews of prominent SLA research that has investigated the possibility of implicit SLA reveal that the instruction on implicit learning does not guarantee that learners engage in the implicit learning mode, that the majority of SLA research has employed only tests (...) of “explicit learning” such as untimed grammaticality judgment, and that there is some evidence that the online think-aloud protocol causes negative reactivity particularly when it is metalinguistic in nature. (shrink)

This article examines whether there are differences between older and younger adults in recall and liking of arousing television commercials. As hypothesized, the experiment demonstrated that older adults remembered brands and products in calm commercials better than in arousing commercials, and they also liked calm commercials more. In contrast, younger adults remembered brands and products in arousing commercials better and they liked these commercials more. In addition, linear relationships showed that for older adults arousal deteriorates their recall and liking, whereas (...) for younger adults arousal – up to a certain point – is beneficial. These findings strongly suggest that advertising effects found in younger samples are unlikely to be the same for older target groups. An important practical implication is that it currently seems wise to make commercials targeted towards older adults calm instead of arousing when the aim is to generate brand recall and liking. (shrink)

Attention-driven bias for threat-related stimuli in implicit memory. Preliminary results from the Posner cueing paradigm An implicit memory advantage for angry faces was investigated in this experiment by means of an additional cueing task. Participants were to assess the orientation of a triangle's peak, which side of presentation was cued informatively by angry and neutral face stimuli, after which they immediately completed an unexpected "old-new" task on a set of the previously presented faces and new, distractor-faces. Surprisingly, the RTs were (...) similarly long on the invalid trials for angry and neutral facial cues in the Posner task. However, performance on the "old-new" task was better for angry than neutral faces. A strong correlation between RTs in angry-invalid trials and confidence ratings for these angry faces was observed only in highly reactive participants. These results suggest that presentation of threatening material can induce enhanced incidental encoding which can result in stronger familiarity for such material, and this effect is driven by attentional bias in highly reactive individuals. (shrink)

The presented study investigates attitude change using a cross-modal evaluative conditioning paradigm. EC is a change in evaluative responses towards initially neutral stimulus due to its repeated pairing with affectively valenced stimulus. A positive scent of instant chocolate was used together with pictures of homeless people to change affective responses towards neutral names. We show that a classic EC effect, i.e. more negative CS evaluations after its pairing with negative images of the homeless, can be eliminated when a competitive US, (...) i.e. a positive chocolate scent, is present in the environment. Additionally, the study demonstrates chocolate scent selectively increased attitude towards homeless as measured by perceived distance to self and a self-report questionnaire. Moreover, this effect was not mediated by mood changes. We argue that scents can be used to change attitudes towards stigmatized groups. (shrink)

According to major cognitive theories of emotional disorders cognitive biases are partly responsible for their onset and maintenance. The direct test of this assumption is possible only if experimental method capable of altering a given form of cognitive bias is available. The purpose of the study was to examine the effectiveness of a novel implicit memory bias training procedure based on the emotional version of the classical Sternberg’s short-term memory task with negative, neutral and positive words. 108 participants, who completed (...) the PANAS and the CES-D questionnaires, were randomly assigned to the control group, the No-Negative group, in which the target words in the Sternberg’s task were either positive or neutral but never negative or the Negative-New group in which the negative target words in the modified Sternberg’s task were always new. This training was followed by the recollection stage. Only one of the training protocols resulted in significant effects at the recall stage - individuals in the No-Negative group recalled more positive words and fewer negative words than those in the control group. These results show that it may be possible to experimentally induce memory bias characteristic of non-depressed individuals. (shrink)

Attentional bias and emotion in older adults: Age-related differences in responses to an emotional Stroop task The purpose of the study was to examine whether older adults show an emotional interference effect in a Stroop task, and whether their RTs differ with regard to age, gender and tendencies of mood regulation. The sample consisted of 60 participants at the age from 65 to 85. Emotional version of Stroop task and the Mood Regulation Scales were used. The results showed no significant (...) differences in RTs to emotional and neutral words. Unexpectedly, a speeding effect was observed with the age of women. It appeared also that the effect of mood regulation tendencies was not significant for RTs. The last two effects are not consistent with the literature on cognitive and emotional aging. (shrink)

Retrieval Induced Forgetting refers to the finding that the retrieval of some items from memory impairs the retrieval of related items. The RIF effect is indicated by a comparison of RP- with unrelated but also tobe- remembered items. Since RIF appears during intentional memorizing of words, therefore we checked whether it depends on attentional control involved in goal maintenance, and also if implicit evaluations of to-be-remembered contents moderate this process. In three experiments, each including AC as the independent variable, we (...) found AC to be related to the RIF effect. Only high but not low AC subjects showed the presence of RIF. The results of the affective priming procedure showed that implicit evaluations of NRP items moderate the relationship of high AC and the RIF effect. The explanation why temporarily devaluated NRP could enhance the RIF effect and suggestion concerning future research summarize the article. (shrink)

The purpose of the study was to compare the visuospatial decision-making error scores related to the perception of biological motion of individuals categorized as field dependent or field independent. A sample of 69 participants aged 18-27 years that included 33 males and 36 females completed the experiment. Cognitive style was assessed using the Group Embedded Figure Test. Perception of biological motion was evaluated using two different point-light stimuli developed from video images of a ballet dancer’s performance of a correct and (...) incorrect turn in the fifth position. The results showed that individuals classified as field independent made significantly fewer visuospatial processing errors. The findings are considered and discussed in relation to theoretical perspectives associated with both cognitive processing and cognitive style. (shrink)

The aim of this study was to investigate the association between temperament and social support and the level of quantitatively rated PTSD symptoms in a sample of HIV+ and HIV/aids men and women. A total of 310 men and women, including 182 HIV+ and 128 HIV/aids, were studied. Social support was assessed with the Berlin Social Support Scales. Temperament was assessed with the Formal Characteristics of Behaviour - Temperament Inventory. Intensity of PTSD symptoms was assessed with the PTSDF. The best (...) predictors of intensity of PTSD symptoms in HIV+ participants were support seeking and sensory sensitivity. Support seeking was positively associated, and sensory sensitivity was negatively associated with intensity of PTSD symptoms. (shrink)

Psychometric properties of Attentional Control Scale: The preliminary study on a Polish sample The presented study was focused primarily on a psychometric analysis of the Attentional Control Scale, but they also enhanced the understanding of the role of effortful attentional skills in determining the individual well-being, general adaptation or emotional disorders. The analyses included basic item and scale descriptions as well as convergent and discriminant validity. 218 Polish undergraduate students completed the battery of the self-report techniques and two paper —pencil (...) attentional tests. Data revealed a unidimensional of a 20-item ACS. It can be used validly to assess long-term individual differences in attentional skills related to the voluntary executive functions. The analysis of content, internal and construct validity as well as reliability provided evidence of the scale's significant convergent and discriminant validity when correlated with attentional tests and other personality techniques. We found strong, systematic relations between the attentional control and selected measures of temperament, arousal, emotionality, and motivation. The results allow assuming that good attentional control, may protect individuals from the emotional disorders by regulating perceptual, conceptual, and response processing. (shrink)

Mindfulness/mindlessness as a new factor influencing false memories: evidence from imagination inflation and modified premature cognitive commitment study Two effects that can influence the creation of false memories were investigated. First, the classic effect of imagination inflation was investigated. Second, the effect of exposure to modified premature cognitive commitment procedure, in which subjects apply bias correction in order to be opposed to suggested information. 24 subjects were asked to perform, imagine or hear simple action statements. Then half of the subjects (...) imagined performing some other actions. One week later half of the subjects were exposed to false information that they have the tendency to underestimate the quantity of many occurrences in everyday life. The surprising finding was that imagination inflation effect had not emerged. Nevertheless, the exposure to information about fictitious deficit led to bias correction and to source monitoring errors in which actions that had not been presented were recollected as having been imagined or heard. (shrink)

Presented studies investigated the specificity of visual and auditory modalities in attentional processing of emotion, and its association with temperamental dimensions and trait-like attentional control. During preliminary study 30 participants were presented with the paper-pencil visual search task and emotional prosody detection tasks. Results revealed visual happiness superiority and auditory sadness superiority. During the main study, in addition to attentional performance, 51 subjects were administrated two questionnaires: EPQ-R and Attentional Control Scale. Introducing individual differences into analysis limited the general pattern (...) of modality distinctiveness in attentional processing of emotional stimuli obtained in the preliminary study. Findings for all personality traits studied separately showed that Extraversion and low Neuroticism were associated with the visual sadness superiority. Whereas interactional analysis indicated effective visual threat processing in extraverts with good AC and effective friendly prosody detection when Neuroticism and AC remain in inverse relationship. Hence, we have found that processing emotional targets in both modalities is associated with temperament dimensions and their interactions with attentional control. Additionally, findings from both studies suggest that general psychological laws might be challenged by individual differences. (shrink)

In this article I introduce the term ‘theatrical latency’ as a pleasurable effect experienced when listening to sound in relation to visual perception. Latency refers to both the phenomena of audio delay and a theatrical sensation that comes from the reanimation of visual environments through aural framing. In this configuration, the notion of latency takes on a double meaning as both a recorded phenomenon and the retrieval of something dormant within physical objects, sites or materials. These ideas will be introduced (...) through my experience of walking Katrina Palmer’s site-specific audio work The Loss Adjusters on the island of Portland. The audio tracks create an extended meditation on Portland, interweaving specific locations and histories with fictional characters and ghosts of the island. (shrink)

In the following sections, English summaries of the three studies presented in this dissertation are given. For a detailed German synopsis of the present work, see chapter 8. Research in the field of aging and dementia is a main concern as the population of elderly people is growing continuously due to increasing life expectancy and thus, an accumulative number of people who live well beyond 65 years of age run a risk of developing age-associated neurodegenerative disorders of cognitive function, such (...) as Alzheimer’s disease, emerging as a major health problem. The present work is based on growing evidence that deficits in visual selective attention occur early in the progression to AD and therefore might be present as the first non-memory deficits at the early prodromal stage of mild cognitive impairment. The present dissertation was performed to contribute to the still ongoing debate as to whether certain aspects of visual selective attention are par-ticularly vulnerable or preserved, especially at the stage of MCI, and whether attentional func-tioning might be qualitatively and/ or quantitatively different from attentional performance at the AD stage on the one hand or normal functioning on the other hand. As theoretical basis, Bundesen’s theory of visual attention was employed to assess several latent, mathematically independent and quantitative parameter es-timates which are derived from two highly comparable paradigms – computerized whole re-port and partial report of briefly presented visual letter arrays. Central conclusions arising out of TVA-based investigations point at four central strengths of this tool for attentional assessment – the quality criteria sensitivity, specificity, reliability and validity. Study 1: In AD, the amyloid cascade hypothesis assumes that rising plaque and tangle burden invokes loss of nerve cells through direct and indirect effects on synaptic, neuronal and neuritic function, resulting in progressive intellectual decline. Thus, sensitive biomarkers loading functionally on the neural alterations invoked by AD from early on, might improve the possibility to identify at risk subjects in time, providing a chance for effective treatment. The first study examined whether cognitive parameters for estimating the capacity of visual attention might serve that purpose. Based on Bundesen’s TVA, visual information uptake was analyzed in 18 subjects with probable AD, 18 subjects with amnestic MCI, and 18 healthy elderly control subjects. Groups were matched for gender, age, and education. From a whole report task requiring ver-bal report of briefly presented letters, four parameters were derived, characterizing different aspects of visual processing capacity: perceptual threshold t0, iconic memory μ, processing speed C, and visual short-term memory storage capacity K. Comparison of these attentional parameters between groups revealed an elevation of the per-ceptual threshold already in MCI subjects, while processing speed and VSTM storage capacity showed a significant decline for AD patients, only. AD patients on medication with acetyl-choline esterase inhibitors had higher processing speed, but were still below the level of MCI patients. Perceptual threshold values were significantly correlated with disease duration, but not with cognitive measures. Conversely, speed and VSTM were significantly related to cog-nitive scores, but not to disease duration. In particular, VSTM storage was related to neurop-sychological tasks applying visual material, while speed showed an additional relationship also to measures of verbal memory. These results indicate a staged pattern of deficits affecting pre-attentive visual processing in MCI, and attentive processing in AD. They fit into the amyloid cascade hypothesis according to which the neuropathology of AD is characterized by a net accumulation and deposition of β-amyloid in the initial phase, giving rise to neuronal and neuritic dysfunction. Later, gradual neuronal loss and transmitter disturbances finally cause the increasing intellectual de-cline during further progression of the disease. A threshold elevation may thus be considered as a possible index of impaired neuronal functioning prior to cell death, while speed and VSTM deficits may be indicative already of a substantial loss of neuronal cell assemblies and a degeneration of neurotransmitter systems. Study 2: AD is the most frequent form of dementia which appears both as a familial and a sporadic va-riant. In the by far more frequent sporadic form, a genetic risk factor is also implicated, in that carriers of the apolipoprotein E ε4 allele have a 3 to 15 times higher risk of develop-ing the disease, compared to non-carriers. Using an identical TVA-based partial report paradigm as in the present study, Finke et al. had found a close relationship between the severity of the underlying genetic pathology in another neurodegenerative, namely Huntington’s, disease and the direction and degree of spatial attentional weighting. Sensitive tools for assessing selective visual attention might serve as early cognitive markers in the course of AD and therefore enhance the identification rate of at-risk subjects at the MCI stage as well as of subjects with underlying genetic risk. The second study aimed at examining whether attentional parameters of visuospatial and task-related selection are appropriate means for that purpose. Visual selective attention was investigated in 32 patients with amnestic MCI, 16 patients with probable AD, and 36 healthy elderly control subjects. Groups were matched for age, gender and educational level. In combination with Bundesen’s TVA, two mathematically in-dependent and quantitative parameter estimates were derived from a partial report of briefly presented letter arrays: top-down control of attentional selection, representing task-related at-tentional weighting for prioritizing relevant visual objects, and spatial distribution of atten-tional weights across the left and right visual hemifield. Compared to controls, MCI patients showed significantly reduced top-down controlled selec-tion which further deteriorated in AD subjects. Moreover, attentional weighting was signifi-cantly unbalanced across hemifields in MCI and tended to be more lateralized in AD. The ma-jority of patients was biased to the left. Across MCI and AD patients, ApoE4 carriers revealed a leftward spatial bias. The leftward bias was the more pronounced the younger the ApoE4-positive patients and the earlier disease onset. ApoE4-negative subjects showed balanced attentional weighting. These results indicate that impaired top-down control may be linked to early dysfunction of cortico-cortical networks connecting parietal and frontal lobes. Accompanying, an early inter-hemispheric asymmetry in temporo-parietal cortical interactions might cause a pathological spatial bias. As the inheritance of ApoE4 is associated with an interhemispheric imbalance in parietal cortical interactions, a pathological spatial bias may function as early cognitive marker for detecting subjects at risk for probable AD. Study 3: In the latter study, the TVA-based partial report paradigm proved to be a sensitive tool for ve-rifying that both, deficits in task-related selection and a pathological attentional imbalance, are already present at the early stage of amnestic MCI and increase further at the AD stage. It was hypothesized that these deficiencies in selective attention may result from an early disconnection syndrome and an interhemispheric imbalance in cortical interactions, respectively, in the fronto-parietal attention network, before gradual neuronal loss leads to further decline in selective attentional and intellectual functions at later stages. In the third study, these hypotheses were tested by investigat-ing the relationship of both partial report parameters, top-down control α and especially the laterality index of attentional weighting wλ, to regional glucose metabolism measured by rest-ing-state positron emission tomography in a sample of 30 amnestic MCI or mild AD patients. Hypometabolism across all patients was slightly increased in the left hemisphere. Interestingly, the more reduced the metabolism in the left temporo-parietal junction the more pro-nounced was the top-down control deficit. Accordingly, hypometabolism in the left TPJ pre-dicted the magnitude of the spatial bias. Furthermore, relative hypometabolism in the left TPJ and left inferior parietal lobe as compared to the right TPJ and right IPL, respectively, was correlated with direction and degree of spatial bias. Taken together, PET imaging results support the hypotheses that, one the one hand, early def-icits in task-related weighting may result from a fronto-parietal disconnection syndrome al-ready at the stage of MCI. On the other hand, very early AD seems to be also associated with an interhemispheric imbalance of metabolism, particularly in the temporo-parietal cortices, resulting in a correspondingly directed and distinctive visuo-spatial attentional bias. Conclusions and outlook: This dissertation intended to investigate the probable valuable contribution of the whole and partial report of briefly presented letter arrays based on Bundesen’s theory of visual attention in assessing am-nestic MCI and AD patients in comparison to healthy elderly control subjects. The results of the three presented studies suggest a staging model of visual selective atten-tional impairments in MCI and AD. Deficits of pre-attentive processing, task-related and spatial weighting were already detectable in MCI patients, while aspects of processing capacity were still intact. At a later stage of the disease, further deterioration of top-down control α and increasing lateralization of spatial weighting wλ accompanied impairments in perceptual processing speed C and VSTM storage capacity K. In conclusion, the TVA-based assessment of selective visual attention proved to be a sensitive diagnostic tool for revealing subtle deficits already at the stage of MCI which might exhibit the capability of an early cognitive marker for the identification of subjects at risk of AD. To address this question, this survey needs to be complemented by longitudinal studies. (shrink)

We analysed location priming effects, and thus the ability to integrate visual information across subsequent trials in the three studies presented in the following chapters. Based on previous findings in healthy subjects priming effects occur under conditions that require no attentional shifts in-between subsequent trials, i.e. with the subject’s fixation maintained and the search displays presented at retinotopically equal locations with respect to the fixation cross. In study 1 we tested whether location-based priming effects would outlive spatial shifts of attention (...) in healthy subjects. The basic assumption, derived from Pisella and Mattingley´s account was they would, and that the outliving would be based on intact spatial remapping mechanisms operating in healthy subjects along with attention shifts. The aim of study 1 in view of further investigations in patients, i.e. in studies 2 and 3 was to test the suitability of the priming paradigm to serve our purpose to investigate spatial remapping abilities, and furthermore, in patients, purported deficits. To test whether priming effects would outlive saccadic shifts of overt attention, subjects had to re-fixate the fixation cross in turns on the left and on the right side of the monitor between subsequent trials. In two separate experiments priming effects were measured at post-saccadically retinotopic and spatiotopic locations, respectively, and compared to effects in a control experiment requiring no attention shifts. The experiments were also applied in study 2. To test whether priming effects would outlive covert shifts of attention subjects´ attention was distracted between subsequent trials while their fixation was maintained. In two separate experiments priming effects were measured after exogenous and endogenous distraction, respectively, and compared to a control experiment without distraction. The experiments were also applied in study 3. The presence of priming effects despite interfering attention shifts could be taken as evidence that processes that integrate visual information along with attention shifts, i.e. spatial remapping mechanisms, operate flawlessly in healthy subjects. The aim of study 2 was to test whether the parietal cortex provides the neural correlate of spatial remapping as assumed by Pisella and Mattingley. To that end, we tested whether spatial remapping deficits would occur after saccadic shifts of overt attention in patients with right parietal lesions. Deficits were expected to be indicated by altered or disturbed priming effects in those patients as compared to priming effects in healthy control subjects and furthermore, in patients with right-hemispheric lesions not involving the parietal lobe. Latter patients were tested, to control for and differentiate between deficits occurring more generally after right-hemispheric damages and specific deficits occurring after right parietal damages. Moreover, given the crucial role of priming for visual search disturbed priming as an indicator of deficient spatial remapping would provide support for the assumption made by Pisella and Mattingley that spatial remapping deficits contribute to visual search impairments as they are often observed in patients with right parietal lesions. The aim of study 3 was to test the model’s assumption that spatial remapping is required after spatial shifts of covert attention. Again, we compared priming effects of patients with right parietal lesions to those of patients with right-hemispheric lesions without parietal involvement, and healthy subjects. We expected priming effects to be disturbed in patients with right parietal lesions provided that covert attention shifts induce spatial remapping requirements, and that the anatomical site of spatial remapping mechanisms operating to integrate visual information across spatial shifts of covert attention is located in the parietal lobe. (shrink)

In this updated and extended edition of their book, Goodale and Milner explore one of the most extraordinary neurological cases of recent years--one that profoundly changed scientific views on the visual brain. Taking us on a journey into the unconscious brain, this book is a fascinating illustration of the power of the 'unconscious' mind.

I examine the impact of human metarepresentational abilities on human memory.

This study investigates a new experimental paradigm called the Modified Traveling Salesman Problem. This task requires subjects to visit once and only once n invisible targets in a 2D display, using a virtual vehicle controlled by the subject. Subjects can only see the directions of the targets from the current location of the vehicle, displayed by a set of oriented segments that can be viewed inside a circular window surrounding the vehicle. Two conditions were compared. In the “allocentric” condition, subjects (...) see the vehicle move across the screen and change orientation under their command. The “egocentric” condition is similar except for how the information is provided: the position and orientation of the vehicle icon remains fixed at the center of the screen and only target directions, as indicated by the oriented segments, change as the subject “moves” the vehicle. The unexpected finding was that this task can be performed, in either condition, for up to 10 targets. We consider two possible strategies that might be used, a location-based strategy and a segment strategy. The location-based strategy relies on spatial memory and attempts to infer the locations of all the targets. The segment strategy is more local and focuses on the directional segments themselves, keeping track of the ones that represent already-visited targets. A number of observations suggest that the segment strategy was used, at least for larger numbers of targets. According to our hypothesis, keeping track of the segments requires one to use indexical reference for associating the segments with their status in the task - given by current status predicates Visited or Not-visited -, perhaps using visual indexes, deictic pointers, or object files. (shrink)

This article puts forward an hypothesis on the aesthetic use of attention. Some artistic situations favour such a use of attention and may contribute to the conscious access to cognitive and emotional contents and effects, as well as to their discussion in the public sphere.

Last year at VSS, Bullot, Droulez & Pylyshyn reported studies using a Modified Traveling Salesman Paradigm in which a virtual vehicle had to visit up to 10 targets once and only once, and in which the invisible targets were identified only by line segments pointing from the vehicle toward each target. We hypothesized that subjects used two distinct strategies: A “location-based strategy”, which kept track of where targets were located in screen coordinates, and a “segment-based strategy” that kept track of (...) which segments corresponded to visited targets. We report new studies that further explore these two strategies. Subjects passively observed a computer-controlled virtual vehicle that visited a number of targets. Two forms of display were used: an “Allocentric” display, in which the vehicle moved and the targets remained fixed in screen coordinates, and an “Egocentric” display, in which the vehicle's position on the screen remained fixed while the targets moved -- as if the environment were being viewed by an observer on the vehicle. At the end of each trial, the directional segments were extended to the edge of the screen and subjects were asked to perform two tasks by referring to these segments. In the “status task” observers had to indicate for each segment whether the corresponding target had been visited or not. In the “locating task” they had to locate each target along its directional segment. Performance on these two tasks measures the use of the two hypothesized strategies. Results showed that observers do well on the status task with 4 or 6 targets in both display conditions, but do poorly on the locating task, especially in the egocentric condition when there are more targets. These results are consistent with the hypothesis that in the egocentric condition the MTSP task is carried out primarily by segment-tracking, which can be viewed as a deictic strategy. (shrink)

According to the two visual systems model, the visual processing of objects divides into semantic and pragmatic processing. We provide various criteria for this distinction. Further, we argue that both the semantic and pragmatic processing of visual information about objects should be divided into low-level processing and high-level processing. Finally, we re-evaluate the contribution of the human parietal lobe to the concious visual perception of spatial relations among objects.