Differences in adults’ spatial scaling based on visual or haptic information

The present study examined differences in adults’ spatial-scaling abilities across three perceptual conditions: (1) visual, (2) haptic, and (3) visual and haptic. Participants were instructed to encode the position of a convex target presented in a simple map without a time limit. Immediately after encoding the map, participants were presented with a referent space and asked to place a disc at the same location from memory. All spaces were designed as tactile graphics. Positions of targets varied along the horizontal dimension. The referent space was constant in size while sizes of maps were systematically varied, resulting in three scaling factor conditions: 1:4, 1:2, 1:1. Sixty adults participated in the study (M = 21.18; SD = 1.05). One-third of them was blindfolded throughout the entire experiment (haptic condition). The second group of participants was allowed to see the graphics (visual condition); the third group were instructed to see and touch the graphics (bimodal condition). An analysis of participants’ absolute errors showed that participants produced larger errors in the haptic condition as opposed to the visual and bimodal conditions. There was also a significant interaction effect between scaling factor and perceptual condition. In the visual and bimodal conditions, results showed a linear increase in errors with higher scaling factors (which may suggest that adults adopted mental transformation strategies during the spatial scaling process), whereas, in the haptic condition, this relation was quadratic. Findings imply that adults’ spatial-scaling performance decreases when visual information is not available.

The “cheerleader effect” in facial and bodily attractiveness: A result of memory bias and not perceptual encoding

Individual faces are rated as more attractive when presented in a group compared with when presented individually; a finding dubbed the “cheerleader effect.” As a relatively recent discovery, the conditions necessary to observe the effect are not clearly understood. We sought to better define these conditions by examining two parameters associated with the effect. Our first aim was to determine whether the effect is specific to faces or occurs also for human bodies. Both face and body images were rated as being more attractive when presented in groups than when presented in isolation, demonstrating that the cheerleader effect is not restricted to faces. Furthermore, the effect was significantly larger for bodies than faces. Our second aim was to determine whether the cheerleader effect originates from a bias in memory or occurs during perceptual encoding. Participants in the “memory” condition provided attractiveness ratings after images had been removed from the testing screen, whereas participants in the “perceptual” condition provided ratings while the images remained visible, thereby eliminating the memory components of the paradigm. Significant cheerleader effects were only observed in the memory condition. We conclude that the cheerleader effect for faces and bodies is due to a bias in memory and does not occur at an initial stage of perceptual encoding.

Quantifying Aphantasia through drawing: Those without visual imagery show deficits in object but not spatial memory

Congenital aphantasia is a recently characterized experience defined by the inability to form voluntary visual imagery, in spite of intact semantic memory, recognition memory, and visual perception. Because of this specific deficit to visual imagery, aphantasia serves as an ideal population for probing the nature of representations in visual memory, particularly the interplay of object, spatial, and symbolic information. Here, we conducted a large-scale online study of aphantasics and revealed a dissociation in object and spatial content in their memory representations. Sixty-one aphantasics and matched controls with typical imagery studied real-world scene images, and were asked to draw them from memory, and then later copy them during a matched perceptual condition. Drawings were objectively quantified by 2,795 online scorers for object and spatial details. Aphantasics recalled significantly fewer objects than controls, with less color in their drawings, and an increased reliance on verbal scaffolding. However, aphantasics showed incredibly high spatial accuracy, equivalent to controls, and made significantly fewer memory errors. These differences between groups only manifested during recall, with no differences between groups during the matched perceptual condition. This object-specific memory impairment in aphantasics provides evidence for separate systems in memory that support object versus spatial information.

Young children use and evaluate others’ arguments when forming and revising beliefs

What do young children understand about arguments? In particular, do they evaluate arguments critically when deciding whom to learn from? To address this question, the present study investigated children at age 4 to 5, a period in which capacities for basic selective social learning have been documented. In Studies 1a/b, children were asked to make an initial perceptual judgment regarding the location of an object under varying perceptual circumstances; then received advice by another informant who had either better or worse perceptual access than they themselves; and were then allowed to make their final judgment. The advice given by the other informant was sometimes accompanied by utterances of the form “I am certain … because I have seen it”. These utterances thus constituted good arguments in some conditions, but not in others. Results showed that children engaged in more belief-revision when the informant gave this argument only when her perceptual condition was high, and thus her argument, was good. In Study 2, children were asked to find out about different properties (color vs. texture) of an object, and received conflicting testimony from two informants who supported their claims by utterances of the form “because I have seen it” (good argument regarding color; poor regarding texture) or “because I have felt it” (vice versa). Again, children engaged in context-relative evaluation of argument quality. Taken together, these finding reveal that children from age 4 understand argument quality in sophisticated, context-relative ways, and use this understanding for selective learning and belief-revision.

Synaesthesia

Synaesthesia is the confusion or conflation of sensory modalities, where one sense is experienced or described in terms of another as in Charles Baudelaire’s simile "perfumes sweet as oboes, green as prairies." Synaesthesia captures an already existing tendency in language to blend the senses as in "sweet melody," "velvety voice," or "loud colors," and psychologists have conducted studies that show our shared experience of weak audiovisual associations between low pitch and darker colors, or high pitch and lighter colors. In a strictly neurological sense, synaesthesia is a perceptual condition in which the stimulation of one sensory system (for example, hearing) triggers sensations in another sensory system (for example, vision). Cross-sensory associations form one-to-one correspondences that are stable, delicately nuanced, and highly individual. For instance, a synaesthete may experience the timbre of violins as lime green, or the pitch A as burgundy. Synaesthetic associations occur as involuntary, automatic, and emotional responses to sensory stimuli. They persist throughout life and often aid memory: some synaesthetes reliably remember historical dates thanks to their color-to-number associations. The prevalence of synaesthesia has been contested over time, with varying ratios of synaesthetes to nonsynaesthetes of 1 in 2,000, 1 in 100 for colored letters and numbers in recent studies, and even 1 in 23 for all types of synaesthesia.

Does the Motor System Facilitate Spatial Imagery?

Recent studies have ascertained a link between the motor system and imagery in children. A motor effect on imagery is demonstrated by the influence of stimuli-related movement constraints (i. e., constraints defined by the musculoskeletal system) on mental rotation, or by interference effects due to participants’ own body movements or body postures. This link is usually seen as qualitatively different or stronger in children as opposed to adults. In the present research, we put this interpretation to further scrutiny using a new paradigm: In a motor condition we asked our participants (kindergartners and third-graders) to manually rotate a circular board with a covered picture on it. This condition was compared with a perceptual condition where the board was rotated by an experimenter. Additionally, in a pure imagery condition, children were instructed to merely imagine the rotation of the board. The children’s task was to mark the presumed end position of a salient detail of the respective picture. The children’s performance was clearly the worst in the pure imagery condition. However, contrary to what embodiment theories would suggest, there was no difference in participants’ performance between the active rotation (i. e., motor) and the passive rotation (i. e., perception) condition. Control experiments revealed that this was also the case when, in the perception condition, gaze shifting was controlled for and when the board was rotated mechanically rather than by the experimenter. Our findings indicate that young children depend heavily on external support when imagining physical events. Furthermore, they indicate that motor-assisted imagery is not generally superior to perceptually driven dynamic imagery.

Nanotechnology: The Endgame of Materialism

Imagine that one could arrange atoms in any form one wanted: What would one create? What kind of mind would it take to change the world through this metamorphosis of rearrangement and design? The ultimate endgame of our current technological capability to make material things is determined by our own creativity. The author examines how technological interfaces join the human mind to objects of experience from the nanometric to the planetary scale and theorizes the impact this perceptual condition will have on the personal and collective psyche.

Functional Anatomy of Perceptual and Semantic Processing for Odors

The functional anatomy of perceptual and semantic processings for odors was studied using positron emission tomography (PET). The first experiment was a pretest in which 71 normal subjects were asked to rate 185 odorants in terms of intensity, familiarity, hedonicity, and comestibility and to name the odorants. This pretest was necessary to select the most appropriate stimuli for the different cognitive tasks of the second experiment. The second one was a PET experiment in which 15 normal subjects were scanned using the water bolus method to measure regional cerebral blood flow (rCBF) during the performance in three conditions. In the first (perceptual) condition, subjects were asked to judge whether an odor was familiar or not. In the second (semantic) condition, subjects had to decide whether an odor corresponded to a comestible item or not. In the third (detection) condition, subjects had to judge whether the perceived stimulus was made of an odor or was just air. It was hypothetized that the three tasks were hierarchically organized from a superficial detection level to a deep semantic level. Odorants were presented with an air-flow olfactometer, which allowed the stimulations to be synchronized with breathing. Subtraction of activation images obtained between familiarity and control judgments revealed that familiarity judgments were mainly associated with the activity of the right orbito-frontal area, the subcallosal gyrus, the left inferior frontal gyrus, the left superior frontal gyrus, and the anterior cingulate (Brodmann's areas 11, 25, 47, 9, and 32, respectively). The comestibility minus familiarity comparison showed that comestibility judgments selectively activated the primary visual areas. In contrast, a decrease in rCBF was observed in these same visual areas for familiarity judgments and in the orbitofrontal area for comestibility judgments. These results suggest that orbito-frontal and visual regions interact in odor processing in a complementary way, depending on the task requirements.

Hearing in the Mind's Ear: A PET Investigation of Musical Imagery and Perception

Neuropsychological studies have suggested that imagery processes may be mediated by neuronal mechanisms similar to those used in perception. To test this hypothesis, and to explore the neural basis for song imagery, 12 normal subjects were scanned using the water bolus method to measure cerebral blood flow (CBF) during the performance of three tasks. In the control condition subjects saw pairs of words on each trial and judged which word was longer. In the perceptual condition subjects also viewed pairs of words, this time drawn from a familiar song; simultaneously they heard the corresponding song, and their task was to judge the change in pitch of the two cued words within the song. In the imagery condition, subjects performed precisely the same judgment as in the perceptual condition, but with no auditory input. Thus, to perform the imagery task correctly an internal auditory representation must be accessed. Paired-image subtraction of the resulting pattern of CBF, together with matched MRI for anatomical localization, revealed that both perceptual and imagery. tasks produced similar patterns of CBF changes, as compared to the control condition, in keeping with the hypothesis. More specifically, both perceiving and imagining songs are associated with bilateral neuronal activity in the secondary auditory cortices, suggesting that processes within these regions underlie the phenomenological impression of imagined sounds. Other CBF foci elicited in both tasks include areas in the left and right frontal lobes and in the left parietal lobe, as well as the supplementary motor area. This latter region implicates covert vocalization as one component of musical imagery. Direct comparison of imagery and perceptual tasks revealed CBF increases in the inferior frontal polar cortex and right thalamus. We speculate that this network of regions may be specifically associated with retrieval and/or generation of auditory information from memory.