Biomedical subjects

M J Spivey

Publications and source records attributed to M J Spivey.

5 recordsLinked to original sources

PubMed2001

Oculomotor mechanisms activated by imagery and memory: eye movements to absent objects.

It is hypothesized that eye movements are used to coordinate elements of a mental model with elements of the visual field. In two experiments, eye movements were recorded while observers imagined or recalled objects that were not present in the visual display. In both cases, observers spontaneously looked at particular blank regions of space in a systematic fashion, to manipulate and organize spatial relationships between mental and/or retinal images. These results contribute to evidence that interpreting a linguistic description of a visual scene requires a spatial (mental model) representation, and they support claims regarding the allocation of position markers in visual space for the manipulation of visual attention. More broadly, our results point to a concrete embodiment of cognition, in that a construction of a mental image is almost "acted out" by the eye movements, and a mental search of internal memory is accompanied by an ocolumotor search of external space.

Adult↗

PubMed2001

Linguistically mediated visual search.

During an individual's normal interaction with the environment and other humans, visual and linguistic signals often coincide and can be integrated very quickly. This has been clearly demonstrated in recent eye tracking studies showing that visual perception constrains on-line comprehension of spoken language. In a modified visual search task, we found the inverse, that real-time language comprehension can also constrain visual perception. In standard visual search tasks, the number of distractors in the display strongly affects search time for a target defined by a conjunction of features, but not for a target defined by a single feature. However we found that when a conjunction target was identified by a spoken instruction presented concurrently with the visual display, the incremental processing of spoken language allowed the search process to proceed in a manner considerably less affected by the number of distractors. These results suggest that perceptual systems specializedfor language and for vision interact more fluidly than previously thought.

Attention↗

PubMed2000

Representation, space and Hollywood Squares: looking at things that aren't there anymore.

It has been argued that the human cognitive system is capable of using spatial indexes or oculomotor coordinates to relieve working memory load (Ballard, D. H., Hayhoe, M. M., Pook, P. K., & Rao, R. P. N. (1997). Behavioral and Brain Sciences, 20(4), 723), track multiple moving items through occlusion (Scholl, D. J., & Pylyshyn, Z. W. (1999). Cognitive Psychology, 38, 259) or link incompatible cognitive and sensorimotor codes (Bridgeman, B., & Huemer, V. (1998). Consciousness and Cognition, 7, 454). Here we examine the use of such spatial information in memory for semantic information. Previous research has often focused on the role of task demands and the level of automaticity in the encoding of spatial location in memory tasks. We present five experiments where location is irrelevant to the task, and participants' encoding of spatial information is measured implicitly by their looking behavior during recall. In a paradigm developed from Spivey and Geng (Spivey, M. J., & Geng, J. (2000). submitted for publication), participants were presented with pieces of auditory, semantic information as part of an event occurring in one of four regions of a computer screen. In front of a blank grid, they were asked a question relating to one of those facts. Under certain conditions it was found that during the question period participants made significantly more saccades to the empty region of space where the semantic information had been previously presented. Our findings are discussed in relation to previous research on memory and spatial location, the dorsal and ventral streams of the visual system, and the notion of a cognitive-perceptual system using spatial indexes to exploit the stability of the external world.

Adult↗

PubMed2000

Selective visual attention modulates the direct tilt aftereffect.

One's being able to allocate attention to particular regions or properties of the visual field is fundamental to visual information processing. Visual attention determines what input is carefully analyzed and what input is more or less ignored. But at what stage of the visual system is this process evident? We describe three experiments that demonstrate an effect of voluntary spatial attention and voluntary object-based attention on an orientation illusion (the tilt aftereffect) that is believed to take place in primary visual cortex. This finding, in which selective visual attention influences adaptation to visual orientation information, contributes to mounting evidence for a view of visual perception in which mutual interaction takes place between high-level and low-level subsystems.

Adult↗

PubMed1998

Syntactic ambiguity resolution in discourse: modeling the effects of referential context and lexical frequency.

Sentences with temporarily ambiguous reduced relative clauses (e.g., The actress selected by the director believed that...) were preceded by discourse contexts biasing a main clause or a relative clause. Eye movements in the disambiguating region (by the director) revealed that, in the relative clause biasing contexts, ambiguous reduced relatives were no more difficult to process than unambiguous reduced relatives or full (unreduced) relatives. Regression analyses demonstrated that the effects of discourse context at the point of ambiguity (e.g., selected) interacted with the past participle frequency of the ambiguous verb. Reading times were modeled using a constraint-based competition framework in which multiple constraints are immediately integrated during parsing and interpretation. Simulations suggested that this framework reconciles the superficially conflicting results in the literature on referential context effects on syntactic ambiguity resolution.

Adult↗