Attention capture by episodic long-term memory.

Everyday behavior depends upon the operation of concurrent cognitive processes. In visual search, studies that examine memory-attention interactions have indicated that long-term memory facilitates search for a target (e.g., contextual cueing), but the potential for memories to capture attention and decrease search efficiency has not been investigated. To address this gap in the literature, five experiments were conducted to examine whether task-irrelevant encoded objects might capture attention. In each experiment, participants encoded scene-object pairs. Then, in a visual search task, 6-object search displays were presented and participants were told to make a single saccade to targets defined by shape (e.g., diamond among differently colored circles; Experiments 1, 4, and 5) or by color (e.g., blue shape among differently shaped gray objects; Experiments 2 and 3). Sometimes, one of the distractors was from the encoded set, and occasionally the scene that had been paired with that object was presented prior to the search display. Results indicated that eye movements were made, in error, more often to encoded distractors than to baseline distractors, and that this effect was greatest when the corresponding scene was presented prior to search. When capture did occur, participants looked longer at encoded distractors if scenes had been presented, an effect that we attribute to the representational match between a retrieved associate and the identity of the encoded distractor in the search display. In addition, the presence of a scene resulted in slower saccade deployment when participants made first saccades to targets, as instructed. Experiments 4 and 5 suggest that this slowdown may be due to the relatively rare and therefore, surprising, appearance of visual stimulus information prior to search. Collectively, results suggest that information encoded into episodic memory can capture attention, which is consistent with the recent proposal that selection history can guide attentional selection.

Eye movements are captured by a perceptually simple conditioned stimulus in the absence of explicit contingency knowledge.

Past reports suggest that threatening materials can impact the efficiency of goal-directed behavior. However, questions remain about whether a conditional stimulus (CS) can capture attention as previous results may have been influenced by voluntary prioritization of a to-be-ignored CS. In 2 experiments, eye tracking was used to evaluate whether neutral, perceptually simple materials capture attention when they take on aversive properties via probabilistic fear conditioning with strict methods in place to eliminate voluntary CS prioritization. During training, participants attempted to fixate search targets (i.e., horizontally or vertically oriented rectangles) as quickly as possible to avoid shock. In reality, shock administration was related to rectangle orientation so that 1 rectangle (CS+) predicted shock more often than the other (CS-). Subsequently rectangles became distractors and were to be ignored. At this point, participants were instructed to fixate a new target and incidences of CS capture were examined. Results showed that saccades were made more quickly to the CS+ than the CS- as training progressed, and that oculomotor capture by irrelevant rectangles occurred more often for the CS+ than the CS-. An independent physiological index (skin conductance response) confirmed that contingencies had been learned, as SCR magnitude was greater for CS+ than CS- trials early in the test phase. These effects were documented despite the absence of explicit contingency knowledge, assessed using a postexperimental questionnaire. Collectively, these outcomes indicate that a CS can capture attention despite being task-irrelevant, and that these effects do not depend on conscious awareness of learned contingencies. (PsycINFO Database Record

Eye Movements Index Implicit Memory Expression in Fear Conditioning.

The role of contingency awareness in simple associative learning experiments with human participants is currently debated. Since prior work suggests that eye movements can index mnemonic processes that occur without awareness, we used eye tracking to better understand the role of awareness in learning aversive Pavlovian conditioning. A complex real-world scene containing four embedded household items was presented to participants while skin conductance, eye movements, and pupil size were recorded. One item embedded in the scene served as the conditional stimulus (CS). One exemplar of that item (e.g. a white pot) was paired with shock 100 percent of the time (CS+) while a second exemplar (e.g. a gray pot) was never paired with shock (CS-). The remaining items were paired with shock on half of the trials. Participants rated their expectation of receiving a shock during each trial, and these expectancy ratings were used to identify when (i.e. on what trial) each participant became aware of the programmed contingencies. Disproportionate viewing of the CS was found both before and after explicit contingency awareness, and patterns of viewing distinguished the CS+ from the CS-. These observations are consistent with "dual process" models of fear conditioning, as they indicate that learning can be expressed in patterns of viewing prior to explicit contingency awareness.