Developmental changes in infants’ visual short-term memory for location

To examine the development of visual short-term memory (VSTM) for location, we presented 6- to 12-month-old infants (N = 199) with two side-by-side stimulus streams. In each stream, arrays of colored circles continually appeared, disappeared, and reappeared. In the changing stream, the location of one or more items changed in each cycle; in the non-changing streams the locations did not change. Eight- and 12.5-month-old infants showed evidence of memory for multiple locations, whereas 6.5-month-old infants showed evidence of memory only for a single location, and only when that location was easily identified by salient landmarks. In the absence of such landmarks, 6.5-month-old infants showed evidence of memory for the overall configuration or shape. This developmental trajectory for spatial VSTM is similar to that previously observed for color VSTM. These results additionally show that infants’ ability to detect changes in location is dependent on their developing sensitivity to spatial reference frames.     

The role of form and meaning in the processing of written morphology: A priming study in French developing readers

Three visual priming experiments using three different prime durations (60 ms in Experiment 1, 250 ms in Experiment 2, and 800 ms in Experiment 3) were conducted to examine which properties of morphemes (form and/or meaning) drive developing readers’ processing of written morphology. French third, fifth, and seventh graders and adults (the latter as a control group) performed lexical decision tasks in which targets were preceded by morphological (e.g., tablette–TABLE, “little table–table”), pseudoderived (e.g., baguette–BAGUE, “little stick–ring”), orthographic control (e.g., abricot–ABRI, “apricot–shelter”), and semantic control (e.g., Tulipe–FLEUR, “tulip–flower”) primes. Across all groups, different patterns of priming were observed in both morphological and orthographic/semantic control conditions, suggesting that they all process morphemes as units when reading. In developing readers, the processing of written morphology is triggered by the form properties of morphemes, and their semantic properties are activated later in the time course of word recognition. In adults, patterns of priming were similar except that the activation of the form properties of morphemes decreased earlier in the time course of word recognition. Taken together, these findings indicate that French developing readers process both the form and meaning properties of morphemes when reading and support a progressive quantitative change in the development of morphological processing over the course of reading development.     

Young Children as Protagonists and the Role of Participatory, Visual Methods in Engaging Multiple Perspectives

How can the perspectives, insights and interests of young children, under 6 years‐old, be given status in processes of change? This paper will examine the contribution participatory and visual methods can make to enabling young children to document their experiences and to facilitate exchange with adults. Examples will be drawn from three research studies in educational settings which have developed a specific research method, the Mosaic approach (Clark and Moss 2001 ; Clark 2004 ; Clark 2005 ) which brings together visual and verbal research tools. This paper will discuss how researching with young children rather than on young children can redraw the boundaries between adults’ and children's roles in the research process including the relationship with the research audience.     

Fitts’ law holds for pointing movements under conditions of restricted visual feedback

Fitts’ law robustly predicts the time required to move rapidly to a target. However, it is unclear whether Fitts’ law holds for visually guided actions under visually restricted conditions. We tested whether Fitts’ law applies under various conditions of visual restriction and compared pointing movements in each condition. Ten healthy participants performed four pointing movement tasks under different visual feedback conditions, including full-vision (FV), no-hand-movement (NM), no-target-location (NT), and no-vision (NV) feedback conditions. The movement times (MTs) for each task exhibited highly linear relationships with the index of difficulty (r² > .96). These findings suggest that pointing movements follow Fitts’ law even when visual feedback is restricted or absent. However, the MTs and accuracy of pointing movements decreased for difficult tasks involving visual restriction.     

Perceiving the Present: Systematization of Illusions or Illusion of Systematization?

Mark Changizi et al. (2008) claim that it is possible systematically to organize more than 50 kinds of illusions in a 7 × 4 matrix of 28 classes. This systematization, they further maintain, can be explained by the operation of a single visual processing latency correction mechanism that they call “perceiving the present” (PTP). This brief report raises some concerns about the way a number of illusions are classified by the proposed systematization. It also poses two general problems—one empirical and one conceptual—for the PTP approach.     

Disentangling the relationship between hemispheric asymmetry and cognitive performance

It is widely believed that advantages of hemispheric asymmetries originated in better cognitive processing, hence it is often implied that the relationship between hemispheric asymmetry and cognitive performance is linearly positive: the higher the degree of lateralization in a specific cognitive domain, the better the performance in a corresponding task. Yet, the empirical evidence for this notion is mixed and the statistical methods to analyze this relationship have been criticized. The present study therefore investigated the relationship between hemispheric asymmetries and cognitive performance in two behavioral tasks (a left-lateralized word-matching task and a right-lateralized face-decision task) in 230 participants (140 women, 90 men) by using two different approaches. Both methods correspondingly revealed that a relationship between hemispheric asymmetries and cognitive performance does exist. Contrary to a positive (linear) relationship however, the data could be best described by an inverted U-shaped curve. Although the optimal degree of lateralization seemed to be task-specific, a slight or moderate degree of hemispheric asymmetry achieved best cognitive performance in all tasks. Moreover, performances deteriorated towards extreme ends of lateralization (i.e., participants with either extreme left or right hemispheric biases). Taken together, the present study provides evidence against the notion that higher lateralization is related to enhanced cognitive performance.     

High regularities in eye-movement patterns reveal the dynamics of the visual working memory allocation mechanism

With only two to five slots of visual working memory (VWM), humans are able to quickly solve complex visual problems to near optimal solutions. To explain the paradox between tightly constrained VWM and impressively complex human visual problem-solving ability, we propose several principles for dynamic VWM allocation. In particular, we propose that complex visual information is represented in a temporal manner using only a few slots of VWM that include global and local visual chunks. We built a model of human traveling salesman problem solving based on these principles of VWM allocation and tested the model with eye-movement data. Exactly as the model predicted, human eye movements during traveling salesman problem solving have precise quantitative regularities with regard to both the general statistical pattern of attentional fixations and how they vary across individuals with different VWM capacities. Even though VWM capacity is very limited, eye movements dynamically allocate VWM resources to both local and global information, enabling attention to fine details without loss of the big picture.     

Attentional processes and meditation

Visual attentional processing was examined in adult meditators and non-meditators on behavioral measures of change blindness, concentration, perspective-shifting, selective attention, and sustained inattentional blindness. Results showed that meditators (1) noticed more changes in flickering scenes and noticed them more quickly, (2) counted more accurately in a challenging concentration task, (3) identified a greater number of alternative perspectives in multiple perspectives images, and (4) showed less interference from invalid cues in a visual selective attention task, but (5) did not differ on a measure of sustained inattentional blindness. Together, results show that regular meditation is associated with more accurate, efficient, and flexible visual attentional processing across diverse tasks that have high face validity outside of the laboratory. Furthermore, effects were assessed in a context separate from actual meditation practice, suggesting that meditators’ better visual attention is not just immediate, but extends to contexts separate from meditation practice.     

Subjective discriminability of invisibility: A framework for distinguishing perceptual and attentional failures of awareness

Conscious visual perception can fail in many circumstances. However, little is known about the causes and processes leading to failures of visual awareness. In this study, we introduce a new signal detection measure termed subjective discriminability of invisibility (SDI) that allows one to distinguish between subjective blindness due to reduction of sensory signals or to lack of attentional access to sensory signals. The SDI is computed based upon subjective confidence in reporting the absence of a target (i.e., miss and correct rejection trials). Using this new measure, we found that target misses were subjectively indistinguishable from physical absence when contrast reduction, backward masking and flash suppression were used, whereas confidence was appropriately modulated when dual task, attentional blink and spatial uncertainty methods were employed. These results show that failure of visual perception can be identified as either a result of perceptual or attentional blindness depending on the circumstances under which visual awareness was impaired.     

"I know what I like": stability of aesthetic preference in Alzheimer's patients

Two studies explored the stability of art preference in patients with Alzheimer's disease and age-matched control participants. Preferences for three different styles of paintings, displayed on art postcards, were examined over two sessions. Preference for specific paintings differed among individuals but AD and non-AD groups maintained about the same stability in terms of preference judgments across two weeks, even though the AD patients did not have explicit memory for the paintings. We conclude that aesthetic responses can be preserved in the face of cognitive decline. This should encourage caregivers and family to engage in arts appreciation activities with patients, and reinforces the validity of a preference response as a dependent measure in testing paradigms.