Gender, level of spatial ability, and lateralization of mental rotation

The present study indicates that some of the inconsistencies in studies of the lateralization of mental rotation may be a consequence of uncontrolled individual differences in the general level of spatial ability. In order to investigate the relation between spatial ability and the lateralization of mental rotation, 48 subjects (24 males and 24 females) were divided into three groups based on their performance on a standardized test of spatial ability. They then performed a lateralized two-dimensional mental rotation task. The results showed the typical mental rotation function in that angle of rotation and reaction time were linearly related. A significant spatial ability by visual field interaction indicated that subjects with low spatial ability had a left field advantage, whereas subjects with medium spatial ability showed no field advantage and subjects with high spatial ability showed a right field advantage. Gender also interacted with visual field, with males showing a left visual superiority and females an insignificant right visual field advantage. A significant three-way interaction of gender, spatial ability, and angle of rotation reflected the fact that low spatial males were more profoundly affected by rotation than the other groups. The results suggest that at least some of the inconsistent findings in studies of lateralization of mental rotation may be accounted for by differences in the level of spatial ability.     

Discrimination of possible and impossible objects in infancy

Adults can use pictorial depth cues to infer three-dimensional structure in two-dimensional depictions of objects. The age at which infants respond to the same kinds of visual information has not been determined, and theories about the underlying developmental mechanisms remain controversial. In this study, we used a visual habituation/novelty-preference procedure to assess the ability of 4-month-old infants to discriminate between two-dimensional depictions of structurally possible and impossible objects. Results indicate that young infants are sensitive to junction structures and interposition cues associated with pictorial depth and can detect inconsistent relationships among these cues that render an object impossible. Our results provide important insights into the development of mechanisms for processing pictorial depth cues that allow adults to extract three-dimensional structure from pictures of objects.     

Spatial localization of touch in the first year of life: early influence of a visual spatial code and the development of remapping across changes in limb position

Two experiments investigated infants' ability to localize tactile sensations in peripersonal space. Infants aged 10 months (Experiment 1) and 6.5 months (Experiment 2) were presented with vibrotactile stimuli unpredictably to either hand while they adopted either a crossed- or uncrossed-hands posture. At 6.5 months, infants' responses were predominantly manual, whereas at 10 months, visual orienting behavior was more evident. Analyses of the direction of the responses indicated that (a) both age groups were able to locate tactile stimuli, (b) the ability to remap visual and manual responses to tactile stimuli across postural changes develops between 6.5 and 10 months of age, and (c) the 6.5-month-olds were biased to respond manually in the direction appropriate to the more familiar uncrossed-hands posture across both postures. The authors argue that there is an early visual influence on tactile spatial perception and suggest that the ability to remap visual and manual directional responses across changes in posture develops between 6.5 and 10 months, most likely because of the experience of crossing the midline gained during this period.     

Visual neglect and left-sided context effects

Patients with visual neglect generally fail to respond to an item placed on the left of a target location, even when both stimuli are situated in the right visual field. Little is known, however, about the level of processing for the unattended items. Two patients with left visual neglect served as subjects in several experiments measuring passive contextual effects of a left-sided item on responses to a focal target. The results reveal that a neglected item may influence the speed of responding. The findings are interpreted relative to the loci of context effects in normal subjects.     

Task preparation in macaque monkeys (<Emphasis Type="Italic">Macaca mulatta</Emphasis>)

We investigated whether macaque monkeys possess the ability to prepare abstract tasks in advance. We trained two monkeys to use different stimulus-response (S-R) mappings. On each trial, monkeys were first informed with a visual cue which of two S-R mapping to use. Following a delay, a visual target was presented to which they would respond with a left or right button-press. We manipulated delay time between cue and target and found that performance was faster and more accurate with longer delays, suggesting that monkeys used the delay time to prepare each task in advance. Electronic Publication     

聋人阅读中的副中央凹视觉注意增强效应——来自消失文本的证据

为适应失聪后的复杂环境, 聋人视觉注意资源的空间分布发生改变, 这对聋人的阅读加工产生了影响。本研究尝试提出“聋人阅读中的副中央凹视觉注意增强效应”, 并采用消失文本范式考察这一效应对聋人读者副中央凹及中央凹处词汇信息视觉编码效率的影响。结果发现, 在词n+1短暂呈现时, 聋生快速编码副中央凹处文本信息的加工效率与其生理年龄匹配组相近, 高于阅读能力匹配组; 但在词n短暂呈现时, 聋生快速编码中央凹处文本信息的加工效率落后于健听控制组, 其词汇通达和总阅读效率均受阻。综上所述, 本研究证实了聋人阅读中的副中央凹视觉注意增强效应, 表现为副中央凹加工效率增强, 但中央凹加工效率受阻。     

Inferences about guessing and knowing by chimpanzees (Pan troglodytes)

The visual perspective-taking ability of 4 chimpanzees (Pan troglodytes) was investigated. The subjects chose between information about the location of hidden food provided by 2 experimenters who randomly alternated between two roles (the guesser and the knower). The knower baited 1 of 4 obscured cups so that the subjects could watch the process but could not see which of the cups contained the reward. The guesser waited outside the room until the food was hidden. Finally, the knower pointed to the correct cup while the guesser pointed to an incorrect one. The chimpanzees quickly learned to respond to the knower. They also showed transfer to a novel variation of the task, in which the guesser remained inside the room and covered his head while the knower stood next to him and watched a third experimenter bait the cups. The results are consistent with the hypothesis that chimpanzees are capable of modeling the visual perspectives of others.     

Can blindsight be superior to 'sighted-sight'?

DB, the first blindsight case to be tested extensively (Weiskrantz, 1986) has demonstrated the ability to detect and discriminate a range of visual stimuli presented within his perimetrically blind visual field defect. In a temporal two alternative forced choice (2AFC) detection experiment we have investigated the limits of DB's detection ability within his field defect. Blind field performance was compared to his sighted field performance and to an age-matched control group (n=6). DB reliably detected the presence of a small (2 degrees ), low contrast (7%), 4.6c/ degrees Gabor patch with the same space-averaged luminance as the background presented within his blind field but performed at chance levels at the same eccentricity (11.3 degrees ) within his sighted field. Investigation of detection as a function of stimulus contrast revealed DB's ability to detect the presence of an 8% contrast stimulus within his blind field, compared to 12% in his sighted field. No significant difference in detection performance between DB's sighted field and the performance of six age-matched control participants suggests poor sighted field performance does not account for the results. Monocular testing also rules out differences between the eyes as an explanation, suggesting that DB demonstrates superior detection for certain stimuli within his visual field defect compared to normal vision.     

Pupillometry system for use in social psychology

It is now relatively easy to implement pupillometry in social psychological research. We describe a system in which a Macintosh computer presents visual and auditory stimuli to subjects while monitoring an infrared pupillometer. The computer records information on subject, task, and pupil diameter into a data file for input into standard statistical analysis programs. Pupil diameter is measured continuously while subjects respond to stimuli that last for several seconds or minutes. A demonstration experiment verifies the usefulness of the system. The ability of the Macintosh computer to easily handle visual and auditory stimuli and to record responses lasting a considerable length of time makes the system well suited for studying pupil responses to complex social stimuli. This system is also well suited for the researcher initiating a research program using pupillometry. Ease of operation makes using a large number of subjects feasible.     

Visual field size necessary for length comparison

Influence of visual field size upon acuity for comparing lengths of two lines was investigated. The visual field was effectively narrowed to any desired size by use of a TV display system. The TV screen presented a portion of the test stimulus, the position of which was controlled by the subject’s eye movement so that his fixation point always coincided with the center of the portion. The test stimulus was composed of two lines arranged horizontally, one of which had a length of 81 mm and the other a slightly different value. Sizes of the narrowed visual field were 20, 40, 70, 100, 150, and 340 mm wide. The comparison acuity dropped rapidly as the visual field was narrowed to and below 70 mm which was about the same extent as one of the two lines. The implication is that our excellent ability for length comparison is only possible when we can observe the whole line at one time.     

Color singleton pop-out does not always poop out: An alternative to visual search

Folk psychology suggests that when an observer views a scene, a unique item will stand out and draw attention to itself. This belief stands in contrast to numerous studies in visual search that have found that a unique target item (e.g., a unique color) is not identified more quickly than a nonunique target. We hypothesized that this finding is the result of task demands of visual search, and that when the task does not involve visual search, uniqueness will pop out. We tested this hypothesis in a task in which observers were presented an array of letters and asked to respond aloud, as quickly as possible, with the identity of any one of the letters. The observers were significantly more likely to respond with a uniquely colored letter than would be expected by chance. In a task in which observers blurt out the first thing that they see, unique pop-out does not poop out.     

Long-term facilitation of return: A response-retrieval effect

The present study used a target–target procedure to examine the extent to which perceptual and response factors contribute to inhibition of return (IOR) in a visual discrimination task. When the target was perceptually identical to the previous target and the required response was the same, facilitation was observed for both standard and long-term target–target stimulus onset asynchronies (SOAs). When the color of the previous target differed from that of the current target but the response remained the same, facilitation was reduced in both the standard SOA and long-term SOA conditions. Finally, IOR was observed for both standard and long-term SOAs only in the condition in which there was a change in response. This pattern of inhibition and facilitation provides new evidence that the responses previously associated with a location play an important role in the ability to respond to a stimulus. We interpret this finding as consistent with a framework in which the involuntary retrieval of bound stimulus–response episodes contributes to response compatibility effects in visual stimulus discrimination.     

Attentional capture by globally defined objects.

The abrupt appearance of a new perceptual object in the visual field typically captures visual attention. However, if attention is focused in advance on a different location, onsets can fail to capture attention (Yantis & Jonides, 1990). In the present experiments, we investigated the extent to which the deployment of attention to the local level of a hierarchical scene may be affected by the abrupt appearance of a new object at the global level. Participants searched for a semi-disk target in an array of randomly oriented segmented disks ("pacmen"). On half the trials, a subset of the segmented disks induced a subjective square. On these critical trials, participants were significantly slower to respond to the presence of a local target even though the local features of the display were qualitatively identical across all conditions. This slowing was absent when outline pacmen were used (which do not induce subjective figures) and when the subjective square was perceptually old. When the participants' task was defined at the global level of the display, a new local element failed to capture attention, suggesting an asymmetry in the ability of objects at different levels of a hierarchical scene to capture attention. In a control experiment, a new local element captured attention, however, when the participants' task was defined at the local level, indicating that the local item was in principle capable of capturing attention. It is argued that global objects capture attention because they convey important information about the environment that is not available at the local level.     

Attentional capture by globally defined objects

The abrupt appearance of a new perceptual object in the visual field typically captures visual attention. However, if attention is focused in advance on a different location, onsets can fail to capture attention (Yantis & Jonides, 1990). In the present experiments, we investigated the extent to which the deployment of attention to the local level of a hierarchical scene may be affected by the abrupt appearance of a new object at the global level. Participants searched for a semi-disk target in an array of randomly oriented segmented disks (“pacmen”). On half the trials, a subset of the segmented disks induced a subjective square. On these critical trials, participants were significantly slower to respond to the presence of a local target even though the local features of the display were qualitatively identical across all conditions. This slowing was absent when outline pacmen were used (which do not induce subjective figures) and when the subjective square was perceptually old. When the participants’ task was defined at the global level of the display, a new local element failed to capture attention, suggesting an asymmetry in the ability of objects at different levels of a hierarchical scene to capture attention. In a control experiment, a new local element captured attention, however, when the participants’ task was defined at the local level, indicating that the local item was in principle capable of capturing attention. It is argued that global objects capture attention because they convey important information about the environment that is not available at the local level.     

EFFECTS OF WITHIN-STIMULUS AND EXTRA-STIMULUS PROMPTING ON DISCRIMINATION LEARNING IN AUTISTIC CHILDREN1

Two different prompting procedures to teach visual and auditory discriminations to autistic children were compared. The first involved presenting an added cue as an extra-stimulus prompt. This required the child to respond to both prompt and training stimulus. The second involved the use of a within-stimulus prompt. This consisted of an exaggeration of the relevant component of the training stimulus and thus did not require that the child respond to multiple cues. The results indicated that (1) children usually failed to learn the discriminations without a prompt, (2) children always failed to learn when the extra-stimulus prompt was employed but usually did learn with the withinstimulus prompt, and (3) these findings were independent of which modality (auditory or visual) was required for the discrimination.     

Hemispheric asymmetry in the processing of absolute versus relative spatial frequency.

Observers indicated whether a stimulus presented to one visual field or the other consisted of two sine-wave gratings (the baseline stimulus) or those same two gratings with the addition of a 2 cycle per degree (cpd) component. When the absolute spatial frequencies of the baseline stimulus were low (0.5 and 1.0 cpd), there was a left visual field-right hemisphere (LVF-RH) advantage in reaction time (RT) to respond to the baseline stimulus which disappeared when the 2 cpd component was added (i.e., the stimulus consisted of 0.5, 1.0, and 2.0 cpd components). When the absolute spatial frequencies of the baseline stimulus were moderate to high (4.0 and 8.0 cpd), a right visual field-left hemisphere advantage in RT to respond to the baseline stimulus approached significance and shifted to a significant LVF-RH advantage when the 2 cpd component was added (i.e., the stimulus consisted of 2.0, 4.0, and 8.0 cpd components. That is, adding the same 2 cpd component caused opposite shifts in visual laterality depending on whether 2 cpd was a relatively high or relatively low frequency compared to the baseline.     

Cognitive arithmetic: Evidence for right hemispheric mediation in an elementary component stage

Earlier studies involving the lateralization of arithmetic abilities have provided evidence for both right and left hemisphere superiorities. It is argued here that part of this inconsistency could be due to the complexity of the arithmetic computations which have been examined. The present studies examined a subprocess shown to be involved in more complex tasks, such as subtraction. The subprocess is the identification of which of two numbers is greater, and was tested by the flashing of a pair of digits to either the left or right visual field. Errors, reaction-times to make a decision, and examination of hand × visual field interactions all indicated that this subprocess is mediated by the right hemisphere. Correlational analysis was used to identify the operations underlying the observed lateralization of this ability. This analysis indicated that an operation indexed by the spatial order in which the digits were presented was effective in the right hemisphere but not the left hemisphere. Speculations on the nature of these operations were presented.     

Hippocampus lesions impair landmark array spatial learning in homing pigeons: a laboratory study

Hippocampal (HF)-lesioned pigeons display impaired homing ability when flying over familiar terrain, where they are presumably relying on a map-like representation of familiar landmarks to navigate. However, research carried out in the field precludes a direct test of whether hippocampal lesions compromise the ability of homing pigeons to navigate by familiar landmarks. To examine more thoroughly the relationship between hippocampus and landmark spatial learning, control, neostriatum-lesioned, and HF-lesioned homing pigeons were trained on two open field, laboratory, conditional discrimination tasks. One was a visual landmark array task, and the other was a room color discrimination task. For the tasks, the correct of three differently colored food bowls was determined by the spatial relationship among a group of five landmarks and room color, respectively. Intact control birds successfully learned both tasks, while neostriatum-lesioned birds successfully learned the landmark array task-the only task on which they were trained. By contrast, HF-lesioned birds successfully learned the room color task but were unable to learn the landmark array task. The data support the hypothesis that homing performance deficits observed in the field following hippocampal lesions are in part a consequence of an impairment in the ability of lesioned pigeons to use familiar visual landmarks for navigation.     

Perceiving Affective Content in Ambiguous Visual Stimuli: A Component of Emotional Intelligence

Emotional intelligence involves the accurate appraisal and expression of emotions in oneself and others and the regulation of emotion in a way that enhances living. One aspect of emotional intelligence is the ability to recognize the consensually agreed upon emotional qualities of objects in the environment. One hundred thirty-nine adults viewed 18 reproductions of faces, color swatches, and abstract designs and rated the emotional content of these visual stimuli. Three scores were extracted, including consensual accuracy, amount, and range of emotion perceived. These scores were compared with other aspects of emotional intelligence such as empathy and related to constructs such as alexithymia and neuroticism. A general ability to perceive consensual emotional content in visual stimuli was found, and it was most strongly associated with the ability to respond empathically to others.     

Perceiving affective content in ambiguous visual stimuli: a component of emotional intelligence

Emotional intelligence involves the accurate appraisal and expression of emotions in oneself and others and the regulation of emotion in a way that enhances living. One aspect of emotional intelligence is the ability to recognize the consensually agreed upon emotional qualities of objects in the environment. One hundred thirty-nine adults viewed 18 reproductions of faces, color swatches, and abstract designs and rated the emotional content of these visual stimuli. Three scores were extracted, including consensual accuracy, amount, and range of emotion perceived. These scores were compared with other aspects of emotional intelligence such as empathy and related to constructs such as alexithymia and neuroticism. A general ability to perceive consensual emotional content in visual stimuli was found, and it was most strongly associated with the ability to respond empathically to others.