The relationship between allocentric and egocentric frames of reference and categorical and coordinate spatial information processing

We report two experiments on the relationship between allocentric/egocentric frames of reference and categorical/coordinate spatial relations. Jager and Postma (2003) suggest two theoretical possibilities about their relationship: categorical judgements are better when combined with an allocentric reference frame and coordinate judgements with an egocentric reference frame (interaction hypothesis); allocentric/egocentric and categorical/coordinate form independent dimensions (independence hypothesis). Participants saw stimuli comprising two vertical bars (targets), one above and the other below a horizontal bar. They had to judge whether the targets appeared on the same side (categorical) or at the same distance (coordinate) with respect either to their body-midline (egocentric) or to the centre of the horizontal bar (allocentric). The results from Experiment 1 showed a facilitation in the allocentric and categorical conditions. In line with the independence hypothesis, no interaction effect emerged. To see whether the results were affected by the visual salience of the stimuli, in Experiment 2 the luminance of the horizontal bar was reduced. As a consequence, a significant interaction effect emerged indicating that categorical judgements were more accurate than coordinate ones, and especially so in the allocentric condition. Furthermore, egocentric judgements were as accurate as allocentric ones with a specific improvement when combined with coordinate spatial relations. The data from Experiment 2 showed that the visual salience of stimuli affected the relationship between allocentric/egocentric and categorical/coordinate dimensions. This suggests that the emergence of a selective interaction between the two dimensions may be modulated by the characteristics of the task.     

The relationship between allocentric and egocentric frames of reference and categorical and coordinate spatial information processing

We report two experiments on the relationship between allocentric/egocentric frames of reference and categorical/coordinate spatial relations. Jager and Postma (2003) suggest two theoretical possibilities about their relationship: categorical judgements are better when combined with an allocentric reference frame and coordinate judgements with an egocentric reference frame (interaction hypothesis); allocentric/egocentric and categorical/coordinate form independent dimensions (independence hypothesis). Participants saw stimuli comprising two vertical bars (targets), one above and the other below a horizontal bar. They had to judge whether the targets appeared on the same side (categorical) or at the same distance (coordinate) with respect either to their body-midline (egocentric) or to the centre of the horizontal bar (allocentric). The results from Experiment 1 showed a facilitation in the allocentric and categorical conditions. In line with the independence hypothesis, no interaction effect emerged. To see whether the results were affected by the visual salience of the stimuli, in Experiment 2 the luminance of the horizontal bar was reduced. As a consequence, a significant interaction effect emerged indicating that categorical judgements were more accurate than coordinate ones, and especially so in the allocentric condition. Furthermore, egocentric judgements were as accurate as allocentric ones with a specific improvement when combined with coordinate spatial relations. The data from Experiment 2 showed that the visual salience of stimuli affected the relationship between allocentric/egocentric and categorical/coordinate dimensions. This suggests that the emergence of a selective interaction between the two dimensions may be modulated by the characteristics of the task.     

The expectation of guilt and resistance to temptation

Children's expectations about the emotions that surround a moral transgression were examined. In experiment 1, children aged 4-6 years and 8-9 years listened to a story about a child who resisted but then yielded to the temptation to take a sweet without permission. In line with earlier findings (Nunner-Winkler and Sodian, 1988), older children were more likely than younger children to expect the wrongdoer to feel pleased at resisting, but to feel bad after yielding to, temptation. In experiment 2, the relation between expectations of emotion and actual resistance to temptation was studied. Children aged 5-6 years again made judgements about a story character who eventually yielded to temptation. Their own resistance to temptation was assessed by means of a cheating task: children were given an opportunity to cheat by peeking during the experimenter's absence. Children who did not peek were more likely to attribute morally oriented feelings to the story protagonist. The results suggest that children who readily anticipate the emotional consequences of wrongdoing are more likely to resist the temptation to transgress.     

Left of centre: asymmetries for the horizontal vertical line illusion

This study explored the mechanisms that underlie asymmetries for the horizontal vertical illusion (HVI), which deceives length perception, so that a vertical line is perceived as longer than a horizontal line of equivalent length. In Experiment 1, university students (n = 14) made length judgements for vertical and horizontal lines. The vertical line was shifted in eight steps from the far left of the horizontal line (⌊) to the far right (⌋). An HVI was observed for the medial positions (⊥), which diminished towards the lateral positions. The HVI was also stronger when the vertical line was on the left. Because the left/right asymmetry changed as a function of lateral/medial position, the asymmetry within the HVI stimulus is most likely the result of pseudoneglect, which affects judgements of horizontal length. In Experiment 2, participants (n = 15) made judgements for HVI stimuli presented to the left- and right-hemispace and the midline. The HVI was stronger in the left hemispace. Because the asymmetry between the left- and right-hemispaces did not interact with the asymmetry within the stimuli, it was concluded that the asymmetry between hemispatial positions was the result of right hemisphere susceptibility to illusory geometrical effects whereas the asymmetry within the stimulus is related to an object-centred attentional asymmetry. The HVI is affected by asymmetries in length judgements and susceptibility to illusions and may provide interesting insights into attentional disorders in clinical populations, such as neglect.     

Absolute and relative perceptual codes in young children

Three experiments were conducted to ascertain whether young children's perceptual codes, as evidenced by choice reaction times, were related to either the absolute difference or the ratio between stimuli. In Experiments 1 and 2, children were shown pairs of line lengths and were asked to choose either the longer or shorter line within each pair. In Experiment 3, children chose which of two birds on a map was closer to themselves or to the experimenter. In all three experiments, children's reaction times were related to both the absolute differences and ratios between pairs of stimuli. The findings suggest that perceptual judgments in young children may be based on both absolute and relational codes.     

When do auditory/visual differences in duration judgements occur?

Four experiments examined judgements of the duration of auditory and visual stimuli. Two used a bisection method, and two used verbal estimation. Auditory/visual differences were found when durations of auditory and visual stimuli were explicitly compared and when durations from both modalities were mixed in partition bisection. Differences in verbal estimation were also found both when people received a single modality and when they received both. In all cases, the auditory stimuli appeared longer than the visual stimuli, and the effect was greater at longer stimulus durations, consistent with a “pacemaker speed” interpretation of the effect. Results suggested that Penney, Gibbon, and Meck's (2000) “memory mixing” account of auditory/visual differences in duration judgements, while correct in some circumstances, was incomplete, and that in some cases people were basing their judgements on some preexisting temporal standard.     

When do auditory/visual differences in duration judgements occur?

Four experiments examined judgements of the duration of auditory and visual stimuli. Two used a bisection method, and two used verbal estimation. Auditory/visual differences were found when durations of auditory and visual stimuli were explicitly compared and when durations from both modalities were mixed in partition bisection. Differences in verbal estimation were also found both when people received a single modality and when they received both. In all cases, the auditory stimuli appeared longer than the visual stimuli, and the effect was greater at longer stimulus durations, consistent with a “pacemaker speed” interpretation of the effect. Results suggested that Penney, Gibbon, and Meck's (2000) “memory mixing” account of auditory/visual differences in duration judgements, while correct in some circumstances, was incomplete, and that in some cases people were basing their judgements on some preexisting temporal standard.     

Is subjective shortening in human memory unique to time representations?

Three experiments compared forgetting of the duration of a bar-like visual stimulus with forgetting of its length. The main aim of the experiments was to investigate whether subjective shortening (a decrease in the subjective magnitude of a stimulus as its retention interval increased) was observable in length judgements as well as in time judgements, where subjective shortening has been often observed previously. On all trials of the three experiments, humans received two briefly presented coloured bars, separated by adelay ranging from 1 to 10 s, and the bars could differ in length, duration of presentation, or both. In Experiment 1 two groups of subjects made either length or duration judgements, and subjective shortening-type forgetting functions were observed only for duration. Experiments 2 and 3 used the same general procedure, but the stimuli judged could differ both in length and duration within a trial, and different subject groups (Experiment 2) or the same subjects in two conditions (Experiment 3) made either length or duration judgements of stimuli, which were on average physically identical. Subjective shortening was only found with duration, and never with length, supporting the view that subjective shortening may be unique to time judgements.     

The spacing illusion: a spatial aperture problem?

A geometrical illusion in which the horizontal spacing between adjacent parallel lines in a row is underestimated when the lines are tilted away from vertical in a chevron configuration was investigated in two experiments. The perceived spacing was found to decrease as the tilt angle increased, consistent with the idea that separation judgements are influenced by the normal spacing between lines ie at right angles to the line orientation. It is proposed that this illusion reveals an analogue in spatial perception to the well-known aperture problem in motion perception. In establishing the separation of nearby or overlapping shapes in an image, the visual system cannot only rely upon the normal separation of contours belonging to each shape (as would be visible through small spatial apertures or receptive fields), since this varies with contour orientation. The system is therefore faced with a spatial aperture problem. The spacing illusion may arise because information usually available to solve the problem is absent in the illusion figure, or it may reflect a bias in favour of the orthogonal, which is adopted in the face of the ambiguity.     

Parallel development of ERP and behavioural measurements of visual segmentation

Visual segmentation, a process in which elements are integrated into a form and segregated from the background, is known to differ from adults at infancy. The further developmental trajectory of this process, and of the underlying brain mechanisms, during childhood and adolescence is unknown. The aim of the study was to investigate the developmental trajectory of ERP reflections of visual segmentation, and to relate this to behavioural performance. One hundred and eleven typically developing children from 7 to 18 years of age were divided into six age groups. Each child performed two visual tasks. In a texture segmentation task, the difference in event‐related potential (ERP) response to homogeneous (no visual segmentation) and checkered stimuli (visual segmentation) was investigated. In addition, behavioural performance on integration of elements into contours was measured. Both behavioural and ERP measurements of visual segmentation differed from adults in 7–12 year‐old children. Behaviourally, young children were less able to integrate elements into a contour than older children. In addition, a developmental change was present in the ERP pattern evoked by homogeneous versus checkered stimuli. The largest differences in behaviour and ERPs were found between 7–8‐ and 9–10‐, and between 11–12‐ and 13–14‐year‐old children, indicating the strongest development between those age groups. Behavioural as well as ERP measurements at 13–14 years of age showed similar results to those of adults. These results reveal that visual segmentation continues to develop until early puberty. Only by 13–14 years of age, children do integrate and segregate visual information as adults do. These results can be interpreted in terms of functional connectivity within the visual cortex.     

The effect of orthographic uniqueness and deviation points on lexical decisions: evidence from unilateral and bilateral-redundant presentations

Words with an early or late orthographic uniqueness point and nonwords with an early or late orthographic deviation point were presented to the left, right, or both visual fields simultaneously. In Experiment 1, 20 participants made lexical decision judgements to horizontal stimulus presentations. In Experiment 2, a further 20 participants completed the task using vertical presentations to control for attentional biases. Consistent with previous research, words with earlier orthographic uniqueness points prompted faster responses across visual fields, regardless of stimulus orientation. Although research has suggested that the left hemisphere's superiority for language processing stems from a comparatively parallel processing strategy, with the right hemisphere reliant upon a serial mechanism, left and right visual field presentations were not differentially affected by orthographic uniqueness point. This suggests that differential sequential effects previously reported result during processes other than retrieval from the lexicon. The overall right visual field advantage observed using horizontal presentations disappeared when stimuli were presented vertically. Contrary to expectations, there was a facilitatory effect of late orthographic deviation point for horizontal nonword presentations. Overall, the results were interpreted as being consistent with predictions of a cohort model of word recognition, and they highlighted the effect of stimulus orientation on left and right hemisphere word recognition.     

A developmental study of visual attention: Issues of filtering efficiency and focus

A forced-choice reaction time (RT) task was used to assess developmental changes in filtering and the concomitant ability to narrow the focus of the attentional lens. Participants included 20 children in each of four age groups (4, 5, 7, and 9 years), as well as 20 adults between the ages of 21 and 29 years. Conditions varied with regard to the presence or absence of distractors and their proximity to a target stimulus, and the presence or absence of a visual window within which the target stimulus was presented. Age-related differences in the ability to filter task-irrelevant stimuli were found. The performance of 4-year-old children was adversely affected with the presence of distractors located at both 5.7° and 0.95° of visual angle from target stimuli, whereas that of children aged 5, 7, and 9 was negatively affected only with distractors 0.95° of visual angle from the target. Adults' performance was not adversely affected by the presence of distractors. Developmental differences in focusing attention were further highlighted by the finding that the presence of a visual window cue was only associated with faster RTs among 4-year-old children. These results are discussed in terms of the zoom-lens metaphor of visual attention, and the development of the ability to vary the size of an attentive zoom-lens in response to task requirements.     

Parallel discrimination of subjective contours defined by offset gratings.

Recent physiological studies (von der Heydt & Peterhans, 1989) suggest that the orientation of subjective contours is encoded very early in the visual system (V2 in monkey). This result is seemingly at odds with existing psychophysical data which suggest that the detection of subjective contours involves selective attention. It is argued that certain subjective contours are registered in a reflexive (bottom-up) manner by the visual system but that selective attention may be needed to gain access to this representation. To assess this suggestion, a visual-search task was used in which subjects were to detect the presence of a horizontal (vertical) subjective contour (defined by offset gratings) in a variable number of vertical (horizontal) subjective contours (also defined by offset gratings). When there were no competing organizations within the display, detection was indeed independent of the number of nontarget distractors, that is, selective attention was unnecessary. In a second experiment, we found that a curved form (a crescent defined by subjective contours) was easier to detect in a background of vertical bars (also defined by subjective contours) than vice versa, namely, a search asymmetry paralleling those found by Treisman and Gormican (1988). A final experiment showed that when the horizontal and vertical bars of the first experiment formed textured regions, they could be discriminated at very brief display durations (30-120 msec). However, when the line terminations aligned along the subjective contour were tapered rather than abrupt, discrimination dropped off with the degree of tapering. The latter result is consistent with the assumption that the registration of subjective contours in V2 involves the integration of responses from aligned, end-stopped cells found in V1 (von der Heydt & Peterhans, 1989).     

Influence of auditory and audiovisual stimuli on the right–left prevalence effect

When auditory stimuli are used in two-dimensional spatial compatibility tasks, where the stimulus and response configurations vary along the horizontal and vertical dimensions simultaneously, a right–left prevalence effect occurs in which horizontal compatibility dominates over vertical compatibility. The right–left prevalence effects obtained with auditory stimuli are typically larger than that obtained with visual stimuli even though less attention should be demanded from the horizontal dimension in auditory processing. In the present study, we examined whether auditory or visual dominance occurs when the two-dimensional stimuli are audiovisual, as well as whether there will be cross-modal facilitation of response selection for the horizontal and vertical dimensions. We also examined whether there is an additional benefit of adding a pitch dimension to the auditory stimulus to facilitate vertical coding through use of the spatial-musical association of response codes (SMARC) effect, where pitch is coded in terms of height in space. In Experiment 1, we found a larger right–left prevalence effect for unimodal auditory than visual stimuli. Neutral, non-pitch coded, audiovisual stimuli did not result in cross-modal facilitation, but did show evidence of visual dominance. The right–left prevalence effect was eliminated in the presence of SMARC audiovisual stimuli, but the effect influenced horizontal rather than vertical coding. Experiment 2 showed that the influence of the pitch dimension was not in terms of influencing response selection on a trial-to-trial basis, but in terms of altering the salience of the task environment. Taken together, these findings indicate that in the absence of salient vertical cues, auditory and audiovisual stimuli tend to be coded along the horizontal dimension and vision tends to dominate audition in this two-dimensional spatial stimulus–response task.     

A comparative analysis of global and local processing of hierarchical visual stimuli in young children (Homo sapiens) and monkeys (Cebus apella)

Results obtained with preschool children (Homo sapiens) were compared with results previously obtained from capuchin monkeys (Cebus apella) in matching-to-sample tasks featuring hierarchical visual stimuli. In Experiment 1, monkeys, in contrast with children, showed an advantage in matching the stimuli on the basis of their local features. These results were replicated in a 2nd experiment in which control trials enabled the authors to rule out that children used spurious cues to solve the matching task. In a 3rd experiment featuring conditions in which the density of the stimuli was manipulated, monkeys' accuracy in the processing of the global shape of the stimuli was negatively affected by the separation of the local elements, whereas children's performance was robust across testing conditions. Children's response latencies revealed a global precedence in the 2nd and 3rd experiments. These results show differences in the processing of hierarchical stimuli by humans and monkeys that emerge early during childhood.     

结果预期与结果反应对儿童意图认知和道德判断的影响

考察了结果预期与结果反应对儿童意图认知和道德判断的影响。结果表明,结果预期影响幼儿园和小学儿童的意图认知,结果反应仅影响幼儿园儿童的意图认知;结果预期和结果反应显著地影响幼儿园和小学儿童的道德判断,但结果预期对小学儿童道德判断的影响要比结果反应大。     

A comparison of the Ponzo illusion with a textural analogue

The inappropriate constancy scaling notion of geometric illusions was explored by employing a textural analogue of the Ponzo figure. Ten Ss estimated the length of a horizontal line by equating it with varying companion lines in the context of the Ponzo figure, a textural analogue, and a baseline control in which the lines appeared with no surrounding contours. The textural analogue had the added feature of imposing no contours at the ends of the horizontal lines. It was found that length estimates were significantly different between the horizontals of the Ponzo figure and control stimuli, but not between the texture figure and a context-free control. The results suggest that inappropriate constancy scaling plays a minor role at best in the perception of geometric illusions.     

Movement cues and body orientation in recall of locations by blind and sighted children

Experiment 1 tested blind children's recall of locations with repeated and changed recall movements under normal and out-of-line body-to-target orientation. Changed movements produced target undershooting and inaccurate path-keeping by the older blind, particularly for horizontal directions. Errors by the younger blind depended more on body orientation.

Experiment 2 tested blindfolded sighted children under the same conditions, with four forms of coding instructions. The sighted showed no effect of body orientation, but changed movements had similar effects on target localization as for the older blind, regardless of instructions. Different forms of instructions affected bias from movement directions in near and far sectors of the display differently, and instructions to code by reference to the shape of the display surround eliminated the differences.

It was argued that blind and sighted children use extent and direction cues from the positioning movement in locating targets, and that these are not automatic effects but result from children's assessment of the informational conditions.     

Parallel discrimination of subjective contours defined by offset gratings

Recent physiological studies (von der Heydt & Peterhans, 1989) suggest that the orientation of subjective contours is encoded very early in the visual system (V2 in monkey). This result is seemingly at odds with existing psychophysical data which suggest that the detection of subjective contours involves selective attention. It is argued that certain subjective contours are registered in a reflexive (bottom-up) manner by the visual system but that selective attention may be needed to gain access to this representation. To assess this suggestion, a visual-search task was used in which subjects were to detect the presence of a horizontal (vertical) subjective contour (defined by offset gratings) in a variable number of vertical (horizontal) subjective contours (also defined by offset gratings). When there were no competing organizations within the display, detection was indeed independent of the number of nontarget distractors, that is, selective attention was unnecessary. In a second experiment, we found that a curved form (a crescent defined by subjective contours) was easier to detect in a background of vertical bars (also defined by subjective contours) than vice versa, namely, a search asymmetry paralleling those found by Treisman and Gormican (1988). A final experiment showed that when the horizontal and vertical bars of the first experiment formed textured regions, they could be discriminated at very brief display durations (30–120 msec), However, when the line terminations aligned along the subjective contour were tapered rather than abrupt, discrimination dropped off with the degree of tapering. The latter result is consistent with the assumption that the registration of subjective contours in V2 involves the integration of responses from aligned, end-stopped cells found in VI (von der Heydt & Peterhans, 1989).