This article presents data and theory concerning the fundamental question of how the brain achieves a balance between integrating and separating perceptual information over time. This theory was tested in the domain of word reading by examining brain responses to briefly presented words that were either new or immediate repetitions. Critically,…

Egon Brunswik (1903-1955) first made an interesting distinction between perception and explicit reasoning, arguing that perception included quick estimates of an object's size, nearly always resulting in good approximations in uncertain environments, whereas explicit reasoning, while better at achieving exact estimates, could often fail by wide…

Adults have little difficulty perceiving objects as complete despite occlusion, but newborn infants perceive moving partly occluded objects solely in terms of visible surfaces. The developmental mechanisms leading to perceptual completion have never been adequately explained. Here, the authors examine the potential contributions of oculomotor…

Prior work suggests that active experience affects infants' understanding of simple actions. The present studies compared the impact of active and observational experience on infants' ability to identify the goal of a novel tool-use event. Infants either received active training and practice in using a cane to retrieve an out-of-reach toy or had…

This study examined three visual strategies for timing the initiation of the landing flare based on perceptions of either: (a) a critical height above ground level; (b) a critical runway width angle ([psi]); or (c) a critical time-to-contact (TTC) with the runway. Visual displays simulated landing approaches with trial-to-trial variations in…

An example of the auditory-visual illusion in speech perception, first described by McGurk and MacDonald, is the perception of [ta] when listeners hear [pa] in synchrony with the lip movements for [ka]. One account of the illusion is that lip-read and heard speech are combined in an articulatory code since people who mispronounce words respond…

This account of practice discusses the learning of a set that met for five years as part of undertaking a research degree. It focuses on questions relating to the role of the facilitator that emerge from the experience of an action learning set that was first helped by an external facilitator and that, after 18 months, became self-facilitating.…

Testing sensory characteristics on herpetological species has been difficult due to a range of properties related to physiology, responsiveness, performance ability, and the type of reinforcer used. Using the Jacky lizard as a model, we outline a successfully established procedure in which to test the visual sensitivity to motion characteristics.…

Data from lesion studies suggest that the ability to perceive speech sounds, as measured by auditory comprehension tasks, is supported by temporal lobe systems in both the left and right hemisphere. For example, patients with left temporal lobe damage and auditory comprehension deficits (i.e., Wernicke's aphasics), nonetheless comprehend isolated…

Alaryngeal speakers (speakers in whom the larynx has been removed) have inconsistent control over acoustic parameters such as F[subscript 0] and duration. This study investigated whether proficient tracheoesophageal and oesophageal speakers consistently convey phrase boundaries. It was further investigated if these alaryngeal speakers used the…

It has been hypothesised that autism is an extreme version of the male brain, caused by high levels of prenatal testosterone (Baron-Cohen 1999). To test this proposal, associations were assessed between three visuo-spatial tasks and prenatal testosterone, indexed in second-to-fourth digit length ratios (2D:4D). The study included children with…

The cognitive underpinnings of arithmetic calculation in children are noted to involve working memory; however, cognitive processes related to arithmetic calculation and working memory suggest that this relationship is more complex than stated previously. The purpose of this investigation was to examine the relative contributions of processing…

Purpose: To examine age-related differences in auditory speech recognition and visual text recognition performance for parallel sets of stimulus materials in the auditory and visual modalities. In addition, the effects of variation in rate of presentation of stimuli in each modality were investigated in each age group. Method: A mixed-model design…

Applying optimal stimulation theory, the present study explored the development of sustained attention as a dynamic process. It examined the interaction of modality and temperament over time in children and adults. Second-grade children and college-aged adults performed auditory and visual vigilance tasks. Using the Carey temperament…

This is the fifth in a series of technical research reports by Harvard Project Zero which study artistic creation and comprehension as a means toward better art education. The three papers in this report all concern the bearing of projective geometry on the perceptual processes by which pictures are "read" for spatial information. The…