How skin and object temperature influence touch sensation

Twenty subjects made magnitude estimations of the apparent heaviness of metallic stimulators of various masses and temperatures (cold, neutral, and warm). The stimulators were placed on the forearm at normal skin temperature (about 33°C), at elevated skin temperature (38°C), and at lowered skin temperature (25°C). Under neutral conditions, we replicated earlier studies: cold objects felt considerably heavier than neutral ones, warm objects somewhat heavier than neutral objects. Warming the skin essentially obliterated the intensifying effect of the warm objects but left unaltered the intensifying effect of the cold objects. Cooling the aim also essentially obliterated the intensifying effect of warm objects. It also diminished, but far from eliminated, the intensifying effect of cold objects. Cold intensification of touch sensation is a large and robust phenomenon and, unlike warm intensification, appears to characterize all body regions.     

TRAINING OF PERIPHERAL VISUAL ACUITY

An experiment was performed to investigate whether the duration of exposure and the size of the test objects are factors critical for obtaining a training effect in peripheral visual acuity. Contrary to previous results it is shown that considerable improvement may be obtained even under conditions of flash stimulation, provided that the test object used for training is sufficiently small to be just discriminable. The results are interpreted in terms of shifts in the maximum momentary level of attention from the central to the peripheral area of the visual field.     

Only “efficient” emotional stimuli affect the content of working memory during free-recollection from natural scenes

Emotional events are thought to have privileged access to attention and memory, consuming resources needed to encode competing emotionally neutral stimuli. However, it is not clear whether this detrimental effect is automatic or depends on the successful maintenance of the specific emotional object within working memory. Here, participants viewed everyday scenes including an emotional object among other neutral objects followed by a free-recollection task. Results showed that emotional objects—irrespective of their perceptual saliency—were recollected more often than neutral objects. The probability of being recollected increased as a function of the arousal of the emotional objects, specifically for negative objects. Successful recollection of emotional objects (positive or negative) from a scene reduced the overall number of recollected neutral objects from the same scene. This indicates that only emotional stimuli that are efficient in grabbing (and then consuming) available attentional resources play a crucial role during the encoding of competing information, with a subsequent bias in the recollection of neutral representations.     

One-trial learning and superior resistance to extinction of autonomic responses conditioned to potentially phobic stimuli.

Human subjects were exposed to pictures of potentially phobic (snakes) and supposedly neutral (houses) objects as conditioned stimuli (CSs) in a Pavlovian conditioning experiment with shock as unconditioned stimulus (US), and skin conductance and finger pulse volume as dependent variables. The skin conductance responses conditioned to phobic stimuli were acquired after one CS-US pairing, and showed practically no extinction, whereas the responses to neutral stimuli showed very little resistance to extinction after both 1 and 5 reinforcements. The superior resistance to extinction of the phobic condition was interpreted to be a specific associative effect. In general, the skin conductance acquisition data showed tendencies similar to those during extinction. For finger pulse volume responses, however, there were very weak conditioning effects, and no effect of stimulus.     

The development of emotional face and eye gaze processing

Recent research has demonstrated that infants' attention towards novel objects is affected by an adult's emotional expression and eye gaze toward the object. The current event-related potential (ERP) study investigated how infants at 3, 6, and 9 months of age process fearful compared to neutral faces looking toward objects or averting gaze away from objects. Furthermore, we examined how the processing of novel objects is affected by gaze direction and emotional expression. We hypothesized that an adult's fearful expression should be particularly salient when it is directed toward a referent in the environment. Furthermore, responses to objects should be increased if the face previously expressed fear toward the object. Three-month-olds did not show differential neural responses to fearful vs. neutral faces regardless of gaze direction. Six-month-olds showed an enhanced negative central (Nc) component for fearful relative to neutral faces looking toward objects, but not when eye gaze was averted away from the objects. Furthermore, 6-month-olds showed an enhanced Nc for objects that had been gaze-cued by a fearful compared to a neutral face. Nine-month-olds showed an enhanced Nc for fearful relative to neutral faces in both eye gaze conditions and showed an enhanced Nc for objects that had been gaze-cued by a neutral face. The findings are discussed in the context of social cognitive and brain development.     

Binding neutral information to emotional contexts: Brain dynamics of long-term recognition memory

There is abundant evidence in memory research that emotional stimuli are better remembered than neutral stimuli. However, effects of an emotionally charged context on memory for associated neutral elements is also important, particularly in trauma and stress-related disorders, where strong memories are often activated by neutral cues due to their emotional associations. In the present study, we used event-related potentials (ERPs) to investigate long-term recognition memory (1-week delay) for neutral objects that had been paired with emotionally arousing or neutral scenes during encoding. Context effects were clearly evident in the ERPs: An early frontal ERP old/new difference (300–500 ms) was enhanced for objects encoded in unpleasant compared to pleasant and neutral contexts; and a late central-parietal old/new difference (400–700 ms) was observed for objects paired with both pleasant and unpleasant contexts but not for items paired with neutral backgrounds. Interestingly, objects encoded in emotional contexts (and novel objects) also prompted an enhanced frontal early (180–220 ms) positivity compared to objects paired with neutral scenes indicating early perceptual significance. The present data suggest that emotional—particularly unpleasant—backgrounds strengthen memory for items encountered within these contexts and engage automatic and explicit recognition processes. These results could help in understanding binding mechanisms involved in the activation of trauma-related memories by neutral cues.     

Reduced visual acuity is mirrored in low vision imagery

Research has examined the nature of visual imagery in normally sighted and blind subjects, but not in those with low vision. Findings with normally sighted subjects suggest that imagery involves primary visual areas of the brain. Since the plasticity of visual cortex appears to be limited in adulthood, we might expect imagery of those with adult-onset low vision to be relatively unaffected by these losses. But if visual imagery is based on recent and current experience, we would expect images of those with low vision to share some properties of impaired visual perception. We examined key parameters of mental images reported by normally sighted subjects, compared to those with early- and late-onset low vision, and with a group of subjects with restricted visual fields using an imagery questionnaire. We found evidence that those with reduced visual acuity report the imagery distances of objects to be closer than those with normal acuity and also depict objects in imagery with lower resolution than those with normal visual acuity. We also found that all low vision groups, like the normally sighted, image objects at a substantially greater distance than when asked to place them at a distance that ‘just fits’ their imagery field (overflow distance). All low vision groups, like the normally sighted, showed evidence of a limited visual field for imagery, but our group with restricted visual fields did not differ from the other groups in this respect. We conclude that imagery of those with low vision is similar to that of those with normal vision in being dependent on the size of objects or features being imaged, but that it also reflects their reduced visual acuity. We found no evidence for a dependence on imagery of age of onset or number of years of vision impairment.     

Emotional valence modulates the preference for curved objects

Previous studies have shown that people prefer objects with curved contours over objects with sharp contours. However, those studies used stimuli that were mainly neutral in emotional valence. We tested here the interplay between visual features and general valence as positive or negative. After replicating curvature preferences for neutral objects, we used positive (cake, chocolate) and negative (snake, bomb) stimuli to examine if emotional valence-through response prioritisation-modulates the preference for curved objects. We found that people indeed preferred the curved versions of objects to the sharp versions of the same objects, but only if the objects were neutral or positive in emotional valence. There were no difference in liking for objects with negative emotional valence. This is evidence that the aesthetic response is adaptive, in this case prioritising valence over contour as demanded by the general semantic classification.     

Fingertip skin conformance accounts, in part, for differences in tactile spatial acuity in young subjects, but not for the decline in spatial acuity with aging

The ability of the skin to conform to the spatial details of a surface or an object is an essential part of our ability to discriminate fine spatial features haptically. In this study, we examined the extent to which differences in tactual acuity between subjects of the same age and between younger and older subjects can be accounted for by differences in the properties of the skin. We did so by measuring skin conformance and tactile spatial acuity in the glabrous skin at the fingertip in 18 younger (19-36 years old) and 9 older (61-69 years old) subjects. Skin conformance was measured as the degree to which the skin invaded the spaces in the psychophysical stimuli. There were several findings. First, skin conformance accounted for 50% of the variance in our measure of tactile spatial acuity (the threshold for grating orientation discrimination) between the younger subjects. The subjects with more compliant skin had substantially lower thresholds than did the subjects with stiffer skin. Second, the skin of the younger subjects was more compliant across than along the skin ridges, and this translated into significantly greater performance when the gratings were oriented along than when oriented across the skin. Third, skin conformance was virtually identical in the younger and the older subjects. Consequently, skin conformance cannot account for the loss of spatial acuity reported in earlier studies and confirmed in this study. We infer that the loss must be neural in origin.     

Fear and anxiety modulate mental rotation

We used an emotional priming paradigm to investigate whether fear and anxiety modulate mental rotation of abstract three-dimensional objects (i.e., Shepard-Metzler figures). On each trial, participants viewed pairs of objects and decided whether the objects had the identical shape by mentally rotating the one on the right into congruence with the one on the left. The participants viewed a picture of a face—fearful or neutral—briefly before the pairs of objects appeared. Participants with high state anxiety, and not those with low state anxiety, rotated the objects more quickly after they saw fearful faces than after they saw neutral faces. This result not only documents that fear can improve mental rotation but also shows that this effect is modulated by the emotional arousal of the participants.     

Residual effects of emotion are reflected in enhanced visual activity after sleep

Research has investigated how sleep affects emotional memory and how emotion enhances visual processing, but these questions are typically asked by re-presenting an emotional stimulus at retrieval. For the first time, we investigate whether sleep affects neural activity during retrieval when the memory cue is a neutral context that was previously presented with either emotional or nonemotional content during encoding. Participants encoded scenes composed of a negative or neutral object on a neutral background either in the morning (preceding 12 hours awake; wake group) or evening (preceding 12 hours including a night of sleep; sleep group). At retrieval, participants viewed the backgrounds without their objects, distinguishing new backgrounds from those previously studied. Occipital activity was greater within the sleep group than the wake group specifically during the successful retrieval of neutral backgrounds that had been studied with negative (but not neutral) objects. Moreover, there was enhanced connectivity between the middle occipital gyrus and hippocampus following sleep. Within the sleep group, the percentage of REM sleep obtained correlated with activity in the middle occipital gyrus, lingual gyrus, and cuneus during the successful retrieval of neutral backgrounds previously paired with negative objects. These results confirm that emotion affects neural activity during retrieval even when the cues themselves are neutral, and demonstrate, for the first time, that this residual effect of emotion on visual activity is greater after sleep and may be maximized by REM sleep.     

Talking emotions: vowel selection in fictional names depends on the emotional valence of the to-be-named faces and objects

One prestudy based on a corpus analysis and four experiments in which participants had to invent novel names for persons or objects (N?=?336 participants in total) investigated how the valence of a face or an object affects the phonological characteristics of the respective novel name. Based on the articulatory feedback hypothesis, we predicted that /i:/ is included more frequently in fictional names for faces or objects with a positive valence than for those with a negative valence. For /o:/, the pattern should reverse. An analysis of the Berlin Affective Word List – Reloaded (BAWL-R) yielded a higher number of occurrences of /o:/ in German words with negative valence than in words with positive valence; with /i:/ the situation is less clear. In Experiments 1 and 2, participants named persons showing a positive or a negative facial expression. Names for smiling persons included more /i:/s and fewer /o:/s than names for persons with a negative facial expression. In Experiments 3 and 4, participants heard a Swahili narration and invented pseudo-Swahili names for objects with positive, neutral, or negative valence. Names for positive objects included more /i:/s than names for neutral or negative objects, and names for negative objects included more /o:/s than names for neutral or positive objects. These finding indicate a stable vowel-emotion link.     

Visual acuity improvement following fading and feedback training—II. Relationship to changes in refractive error

The present study evaluated the effects of behavioral training on visual acuity and refractive error in myopic adults. Twenty volunteers were matched on the basis of refractive error and one member of each matched pair was randomly assigned to either Fading and Feedback training or a no-treatment control condition. Visual acuity was measured with both recognition and resolution measures. Refractive error was measured subjectively using the LaserSpec optometer, and objectively by two retinoscopic examinations performed by an ophthalmologist with and without cycloplegia. The results indicated significant increases in recognition visual acuity, but not resolution visual acuity for trained subjects compared to the no-treatment controls. Trained subjects did not show improvement in refractive error on any measure, and refractive error changes were not correlated with changes in either measure of visual acuity. These data suggest that the visual acuity improvements typically found with behavioral training are not associated with changes in refractive error.     

Looking away from death: Defensive attention as a form of terror management

Previous research has suggested that the physical aspects of human nature in general, and physical human frailties in particular become disagreeable and repugnant following death primes. The current research tested this hypothesis in two studies using an eye-tracking methodology. Participants were subliminally primed with death or with a control word and then viewed a series of arrays containing four pictures each, during which their eye-movements were monitored. In Study 1, the arrays included pictures of physical injury or neutral objects, and in Study 2 pictures of physical injury, threatening images, and neutral objects. The results indicated that in both studies death primes significantly decreased gaze duration towards pictures of physical injury, and did not have a significant effect on gaze duration towards neutral images. However, in Study 2 death primes increased gaze duration towards threatening images. The discussion examines the role of motivated unconscious attention in terror management processes.     

小学生近似数量系统敏锐度的发展趋势及其与数学能力的关系：抑制控制的中介作用

采用测量法和问卷法考察了172名小学生近似数量系统敏锐度的发展,以及抑制控制在近似数量系统敏锐度与数学能力关系中的中介效应。结果表明：(1)随着年龄增长,小学生的近似数量系统敏锐度逐渐提高;(2)近似数量系统敏锐度(负相关序列中的韦伯系数)和抑制控制均能显著正向预测小学生的数学能力;(3)抑制控制在小学生近似数量系统敏锐度(负相关序列中的韦伯系数)与数学能力的关系中起部分中介作用。     

Hand position alters vision by biasing processing through different visual pathways

The present study investigated the mechanisms responsible for the difference between visual processing of stimuli near and far from the observer's hands. The idea that objects near the hands are immediate candidates for action led us to hypothesize that vision near the hands would be biased toward the action-oriented magnocellular visual pathway that supports processing with high temporal resolution but low spatial resolution. Conversely, objects away from the hands are not immediate candidates for action and, therefore, would benefit from a bias toward the perception-oriented parvocellular visual pathway that supports processing with high spatial resolution but low temporal resolution. We tested this hypothesis based on the psychophysical characteristics of the two pathways. Namely, we presented subjects with two tasks: a temporal-gap detection task which required the high temporal acuity of the magnocellular pathway and a spatial-gap detection task that required the spatial acuity of the parvocellular pathway. Consistent with our prediction, we found better performance on the temporal-gap detection task and worse performance on the spatial-gap detection task when stimuli were presented near the hands compared to when they were far from the hands. These findings suggest that altered visual processing near the hands may be due to changes in the contribution of the two visual pathways.     

Pigeons' recognition of partially occluded objects depends on specific training experience

DiPietro et al (2002 Perception 31 1299-1312) reported a dramatic improvement in pigeons' recognition of partially occluded objects after the birds had been trained to recognize objects that were placed on top of another surface. Here, we investigated whether training with partially erased stimuli or with notched stimuli that had a thin gap between the object and another surface would similarly enhance pigeons' recognition of partially occluded objects. We found that erased training had no effect on the birds' recognition of partially occluded objects. Training pigeons to recognize notched objects improved their performance with the same objects when they were partially occluded; but this improvement did not transfer to novel objects, a result that DiPietro et al reported after on-top training. Together, the present results and those of DiPietro et al implicate prior experience as a key factor in pigeons' recognition of partially occluded objects. Training experiences which improve recognition of partially occluded objects may do so because they improve decomposition of complex two-dimensional scenes by pigeons into separate entities.     

Enhanced perceptual priming for neutral stimuli in a traumatic context: A pathway to intrusive memories?

Clinical observations suggest that re-experiencing symptoms are triggered by stimuli that are perceptually similar to those present shortly before the trauma or its worst moments. Two experiments investigated the possible role of perceptual priming in this phenomenon. Volunteers (N = 28, N = 62) watched a series of "traumatic" and neutral picture stories, and completed blurred object identification (priming) and recognition memory tasks. Neutral objects that immediately preceded the "traumatic" stories were more strongly primed, but not better recognised, than objects from neutral stories. Enhanced priming predicted subsequent re-experiencing symptoms. The results support the role of perceptual priming in re-experiencing.     

Orienting and maintenance of gaze to facial expressions in social anxiety

In 2 experiments, the authors tested predictions from cognitive models of social anxiety regarding attentional biases for social and nonsocial cues by monitoring eye movements to pictures of faces and objects in high social anxiety (HSA) and low social anxiety (LSA) individuals. Under no-stress conditions (Experiment 1), HSA individuals initially directed their gaze toward neutral faces, relative to objects, more often than did LSA participants. However, under social-evaluative stress (Experiment 2), HSA individuals showed reduced biases in initial orienting and maintenance of gaze on faces (cf. objects) compared with the LSA group. HSA individuals were also relatively quicker to look at emotional faces than neutral faces but looked at emotional faces for less time, compared with LSA individuals, consistent with a vigilant-avoidant pattern of bias.