Oculomotor Evidence for Top-Down Control following the Initial Saccade

The goal of the current study was to investigate how salience-driven and goal-driven processes unfold during visual search over multiple eye movements. Eye movements were recorded while observers searched for a target, which was located on (Experiment 1) or defined as (Experiment 2) a specific orientation singleton. This singleton could either be the most, medium, or least salient element in the display. Results were analyzed as a function of response time separately for initial and second eye movements. Irrespective of the search task, initial saccades elicited shortly after the onset of the search display were primarily salience-driven whereas initial saccades elicited after approximately 250 ms were completely unaffected by salience. Initial saccades were increasingly guided in line with task requirements with increasing response times. Second saccades were completely unaffected by salience and were consistently goal-driven, irrespective of response time. These results suggest that stimulus-salience affects the visual system only briefly after a visual image enters the brain and has no effect thereafter

Memory for structural information across eye movements

The visual world extends before us in all directions, but there are limitations on how much of the world can be perceived at any one time. To compensate, the eyes move around from point to point in space, and can be directed to objects or regions of interest. Since information is picked up from the world only during eye fixations, these intervening eye movements (i.e., saccades) disrupt the inflow of information, thereby requiring that the information received from the world be combined across separate eye fixations. Memory for information retained from one fixation to the next has been called transsaccadic memory. Previous research has demonstrated that visual information is retained transsaccadically at a more abstract level than a point-by-point buffer. The results of 3 experiments using different tasks show that one of the ways in which visual information is represented is in the form of structural descriptions, and that these structural descriptions are used in transsaccadic memory in the same manner as they are used in visual short term memory. These results lend support to the idea that the memory store that retains information transsaccadically is in fact visual short term memory (Irwin, 1991).U of I OnlyETDs are only available to UIUC Users without author permissio

Object Orientation Affects Spatial Language Comprehension

Burigo M, Sacchi S. Object Orientation Affects Spatial Language Comprehension. Cognitive Science. 2013;37(8):1471-1492.Typical spatial descriptions, such as The car is in front of the house, describe the position of a located object (LO; e.g., the car) in space relative to a reference object (RO) whose location is known (e.g., the house). The orientation of the RO affects spatial language comprehension via the reference frame selection process. However, the effects of the LO's orientation on spatial language have not received great attention. This study explores whether the pure geometric information of the LO (e.g., its orientation) affects spatial language comprehension using placing and production tasks. Our results suggest that the orientation of the LO influences spatial language comprehension even in the absence of functional relationships