Scene perception, gaze behavior, and perceptual learning in virtual environments.

More and more immersive environments are developed to provide support for learning or training purposes. Ecological validity of such environments is usually based on learning performance comparisons between virtual environments and their genuine counterparts. Little is known about learning processes occurring in immersive environments. A new technique is proposed for testing perceptual learning during virtual immersion. This methodology relies upon eye-tracking technologies to analyze gaze behavior recorded in relation to virtual objects' features and tasks' requirements. It is proposed that perceptual learning mechanisms engaged could be detected through eye movements. In this study, nine subjects performed perceptual learning tasks in virtual immersion. Results obtained indicated that perceptual learning influences gaze behavior dynamics. More precisely, analysis revealed that fixation number and variability in fixation duration varied with perceptual learning level. Such findings could contribute in shedding light on learning mechanisms as well as providing additional support for validating virtual learning environments.     

Reappraising Past and Future Transitional Events: The Effects of Mental Focus on Present Perceptions of Personal Impact and Self‐Relevance

This research examined how instructions to focus on the concrete details (experience focus) versus broader life significance (coherence focus) influence present perceptions of transitional impact and self‐relevance for past and future transitional events. Participants (Study 1, N = 119; Study 2, N = 251) selected a past or future transition and wrote about it using either an experiential or coherence focus. Participants then rated the event on transitional impact, self‐relevance, and other phenomenological characteristics. Individuals instructed to use a coherence focus on a past transition reported higher levels of material and psychological impact and rated the event as more self‐relevant, compared to those instructed to use an experiential focus. The manipulation did not influence ratings for future events. Controlling for temporal distance and emotional valence did not alter the findings. Future transitions were regarded as more personally important than past transitions. Appraisals of the impact and self‐relevance of transformative past events (but not future events) are affected by the mental focus adopted at retrieval. The findings are considered in light of essential differences between remembering and forecasting and support the notion that a coherence focus promotes adaptive self‐reflection by affording people the cognitive means with which to reconcile transitional experiences.     

Is egocentric space automatically encoded?

Using the criteria defined by Hasher and Zacks [Hasher, L., & Zacks, R. T. (1979). Automatic and effortful processes in memory. Journal of Experimental Psychology: General, 108(3), 356-388], three studies examined the effects of intent of memorization, dual task interference, old age, practice and individual differences on memory for egocentric positions. Results showed that dual task interference and old age slightly influenced memory for egocentric positions. Small but significant individual differences were also observed. However, intent of memorization and practice had no influence on accuracy. The findings demonstrate that encoding of egocentric space works rather automatically but nevertheless requires minimal attentional resources.     

Role of proprioceptive information in movement programming and control in 5 to 11-year old children

The role of proprioceptive inputs in the control of goal-directed movements was examined, by means of the tendon vibration technique, in 5 to 11-year old children performing a serial pointing task. Children pointed, with movements of various amplitudes and at various positions, by alternating wrist flexions and extensions. Tendon vibration was applied to both agonist and antagonist muscles to perturb relevant muscular proprioceptive inputs during the static or dynamic phase of the task, i.e., during stops on targets or during movement execution. Constant and variable amplitude errors as well as constant position error were evaluated. Vibratory perturbation applied during movement execution resulted in a similar reduction in movement amplitude, yielding an increased constant error in all age groups and a systematic position error in the direction of the movement starting point. Perturbing proprioception during static phases preceding movement resulted in an age-related increase in the variable amplitude error, which was maximal in 5-year old children performing extension movements. The results were interpreted in terms of the use of proprioceptive information in the feedforward and feedback based components of movement control in children. In particular, the results indicated (1) developmental changes in the relative weighting of each component, (2) an increased capacity to move from one strategy to the other, depending on the availability of information, and (3) developmental changes from an alternated to an integrated control of amplitude and position in serial pointing.     

The effect of old age on the learning of supraspan sequences

Two experiments examined age-related differences in sequence learning using computerized versions of the D. O. Hebb (1961) paradigm. In this learning task, the participant executes immediate serial recall of 24 supraspan sequences. Without the participants' knowledge, 1 sequence is presented several times. Repetition leads to improved recall of this repeated sequence relative to random sequences. Results showed a dissociation in age-related learning deficits depending on the nature of the to-be-remembered material. The effect of repetition is similar for younger and older adults with familiar and unfamiliar verbal material (words and pseudowords) but is significantly reduced in older adults when learning is assessed with a visuospatial version of Hebb's supraspan learning task (P. M. Corsi, 1972).     

Manual pointing to remembered targets...but also in a remembered visual context

In this paper we investigated whether visual background information available during target presentation influences manual pointing to remembered targets. Younger and older participants manually pointed with their unseen hands to remembered or visible targets that were presented or not over a structured visible background. The results indicated that a structured visual background biased movement planning processes, but did not influence motor control processes, regardless of the fact that target location and the background were visible or remembered. How one uses visual background information for movement planning is not modified by aging.     

Age-related differences in the visual processes implied in perception and action: distance and location parameters

The aim of the two present experiments was to examine the ontogenetic development of the dissociation between perception and action in children using the Duncker illusion. In this illusion, a moving background alters the perceived direction of target motion. Targets were held stationary while appearing to move in an induced displacement. In Experiment 1, 30 children aged 7, 9, and 12 years and 10 adults made a perceptual judgment or pointed as accurately as possible, with their index finger, to the last position of the target. The 7-year-old children were more perceptually deceived than the others by the Duncker illusion but there were no differences for the goal-directed pointing movements. In Experiment 2, 50 children aged 7, 8, 9, 10, and 11 years made a perceptual judgment or reproduced as accurately as possible, with a handle, the distance traveled by the target. Participants were perceptually deceived by the illusion, judging the target as moving although it was stationary. When reproducing the distance covered by the target, children were unaffected by the Duncker illusion. Our results suggest that the separation of the allocentric visual perception pathway from the egocentric action pathway occurs before 7 years of age.     

Modeling developmental cognitive neuroscience

In the past few years connectionist models have greatly contributed to formulating theories of cognitive development. Some of these models follow the approach of developmental cognitive neuroscience in exploring interactions between brain development and cognitive development by integrating structural change into learning. We describe two classes of these models. The first focuses on experience-dependent structural elaboration within a brain region by adding or deleting units and connections during learning. The second models the gradual integration of different brain areas based on combinations of experience-dependent and maturational factors. These models provide new theories of the mechanisms of cognitive change in various domains and they offer an integrated framework to study normal and abnormal development, and normal and impaired adult processing.