The effect of a non-informative cueing signal in a three-choice reaction-time task

Summary Many studies have shown that in a simple reaction-time (RT) task a non-informative leading cue decreases RT to a subsequent target presented in the same region as the cue. This facilitation lasts about 150 ms; it is then replaced by a sustained inhibition. Experiment 1 tests the hypothesis that the initial facilitation is due to motor, rather than perceptual, processes by using choice RT. Facilitation is greater and lasts longer in choice than in simple tasks, thus supporting the hypothesis. Experiment 2 shows that facilitation occurs even when the subject actively orients his or her attention away from the cue.     

Operator behavior in a dynamic visual signal detection task

The effects of changes in signal-to-noise ratio (SIN) and feedback state on the operator’s detection behavior, particularly derived operator thresholds, were investigated using a discrete visual signal. It was found that: (1) the operator behaves as if he has established different thresholds as a function of S/N; (2) his decision thresholds are relatively independent of the presence or absence of feedback; and (3) the operator will change his threshold accordingly for a change from one S/N to another. A model of the operator’s behavior, which introduced the concept of “operator” noise. yielded predictions of detection and false alarm probabilities which were extremely close to the observed values.     

Sex composition and group performance in a visual signal detection task

Forty-eight Ss (24 males, 24 females) were run in groups of 4 on 720 trials of a 16-alternative forced-choice visual signal detection task requiring both individual and group decisions. Four types of groups were formed: all male, all female, mixed-alternate (seated in the order male-female-male-female), and mixed-adjacent (seated in the order male-male-female-female). There were no differences in performance between all-male and all-female groups, but mixed-sex groups had poorer performance, with mixed-adjacent groups having significantly lower sensitivity than homogeneous-sex groups. The results were interpreted as indicating that heterogeneity of groups with regard to sex interacts with seating pattern in affecting performance, probably due to the formation of information coalitions between like-sex group members when the seating pattern encourages such coalitions.     

Effect of subliminal visual material on an auditory signal detection task

An experiment assessed the effect of subliminally embedded, visual material on an auditory detection task. 22 women and 19 men were presented tachistoscopically with words designated as "emotional" or "neutral" on the basis of prior GSRs and a Word Rating List under four conditions: (a) Unembedded Neutral, (b) Embedded Neutral, (c) Unembedded Emotional, and (d) Embedded Emotional. On each trial subjects made forced choices concerning the presence or absence of an auditory tone (1000 Hz) at threshold level; hits and false alarm rates were used to compute non-parametric indices for sensitivity (A') and response bias (B"). While over-all analyses of variance yielded no significant differences, further examination of the data suggests the presence of subliminally "receptive" and "non-receptive" subpopulations.     

Residual sensory capacities of the deaf: a signal detection analysis of a visual discrimination task.

This experiment compared the visual sensory sensitivity of deaf and hearing subjects in a signal detection paradigm. Subjects (ns = 6) were required to give forced-choice responses to a brightness discrimination task under three stimulus probability conditions (0.25, 0.50, and 0.75). A total of 1,800 trials were given to each subject and utilized to construct isosensitivity functions and d' and Beta, indices for sensory sensitivity and response bias, respectively. The results showed that no enhanced sensory sensitivity is present for these deaf children and questions the classical sensory compensation hypothesis. Furthermore, the deaf subjects responded in a relatively bias-free manner to variations in stimulus probability.     

The effect of visual orientation uncertainty in a simultaneous detection-recognition task

This study concerned the processing of the outputs of visual orientation-sensitive mechanisms by higher order mechanisms. Ss performed a simultaneous detection-recognition task. Variation in the number of possible orientations of a single straight line produced only slight, if any, changes in detection or recognition performance as compared with findings from similar auditory frequency experiments. It was concluded that the outputs of all orientation-sensitive mechanisms are examined by higher order mechanisms. As the angular separation of two possible orientations increased, the data showed that recognition improved in keeping with other reported findings. Comparison of detection with recognition indicated that the latter, under certain conditions, was superior to the former.     

The effects of aging on reaction time in a signal detection task

The effects of aging on response time are examined in 2 simple signal detection tasks with young and older subjects (age 60 years and older). Older subjects were generally slower than young subjects, and standard Brinley plot analyses of response times showed typical results: slopes greater than 1 and (mostly) negative intercepts. R. Ratcliff, D. Spieler, and G. McKoon (2000) showed that the slopes of Brinley plots measure the relative standard deviations of the distributions of response times for older versus young subjects. Applying R. Ratcliff's (1978) diffusion model to fit the response times, their distributions, and response accuracy, it was found that the larger spread in older subjects' response times and their slowness relative to young subjects comes from a 50-ms slowing of the nondecision components of response time and more from conservative settings of response criteria.     

The effects of advance location cueing on latencies in a single-letter recognition task

Summary This study investigates facilitating effects of foreknowledge of position in single-letter recognition tasks with latency as the dependent variable. Three kinds of cue are used: symbolic cues, location cues and neutral cues. For the effects of symbolic and location cues the following predictions are derived from the literature: increasing benefits with increasing SOAs for symbolic cues and constant benefits with increasing SOAs for location cues.Cue-detection times and letter-recognition times with the different cues were determined in three experiments. In the experiments the same general paradigm was used. In Experiment 1 cue-detection times appeared to differ as a function of cue eccentricity; in Experiments 2 and 3 cues were adjusted in such a way that cue-detection times were about the same. Cues reliably indicated the target position in Experiments 1 and 2; in Experiment 3 cue validity was reduced to 50%.The cueing results conformed partly to the predictions. All experiments suggested a small benefit under symbolic cueing and a larger benefit under location cueing. Except for the smallest SOA used, for both types of cue benefits were invariant over SOAs. The implications of these results in relation to other single-letter recognition studies are briefly discussed.     

The effect of orthographic structure on word recognition in a visual search task

The effect of the orthographic structure of the stimulus field on the visual search performance of third graders (8-8 years), sixth graders (11-7 years) and adults was investigated in three experiments. In Experiment 1, where the predesignated target was one word, subjects of all ages searched equally fast through fields consisting of words, pseudowords, and nonwords. In contrast, subjects of all ages displayed effects of orthographic structure when searching for instances of a semantic category (Experiment 2) or for three words (Experiment 3). Subjects searched faster through nonwords than through pseudowords and faster through pseudowords than through words. The use of orthographic structure to facilitate search did not increase with age, suggesting that children of the youngest age group were already making maximal use of intraword redundancy.     

Contextual cueing of visual attention

Visual context information constrains what to expect and where to look, facilitating search for and recognition of objects embedded in complex displays. This article reviews a new paradigm called contextual cueing, which presents well-defined, novel visual contexts and aims to understand how contextual information is learned and how it guides the deployment of visual attention. In addition, the contextual cueing task is well suited to the study of the neural substrate of contextual learning. For example, amnesic patients with hippocampal damage are impaired in their learning of novel contextual information, even though learning in the contextual cueing task does not appear to rely on conscious retrieval of contextual memory traces. We argue that contextual information is important because it embodies invariant properties of the visual environment such as stable spatial layout information as well as object covariation information. Sensitivity to these statistical regularities allows us to interact more effectively with the visual world.     

Implicit learning for probable changes in a visual change detection task

Previous research demonstrates that implicitly learned probability information can guide visual attention. We examined whether the probability of an object changing can be implicitly learned and then used to improve change detection performance. In a series of six experiments, participants completed 120–130 training change detection trials. In four of the experiments the object that changed color was the same shape (trained shape) on every trial. Participants were not explicitly aware of this change probability manipulation and change detection performance was not improved for the trained shape versus untrained shapes. In two of the experiments, the object that changed color was always in the same general location (trained location). Although participants were not explicitly aware of the change probability, implicit knowledge of it did improve change detection performance in the trained location. These results indicate that improved change detection performance through implicitly learned change probability occurs for location but not shape.     

The effect of visual guidance on the acquisition of a simple motor task

Subjects were required to learn to depress a bar using concurrent visual feedback, which was removed for test. The overshooting found in test is attributed to visual dominance of the feedback traces; the way in which it occurs is not clear, since the reduction of the ratio of movement to display gain from 1:15 to 1:7.5 did not reduce overshooting. Performance improved after extended practice, but the direction of error remained positive. The results are discussed in terms of motor programming and feedback control of movement and are interpreted as evidence against Adams' (1971) two-trace theory.     

The effect of auditory and visual models on acquisition of a timing task

While research on observational learning has typically employed visual models of correct performance, the characteristics of perceptual systems support the suggestion that an auditory model may be more effective in developing a cognitive representation of tasks for which timing is essential. Therefore, it was the purpose of this study to compare the relative effectiveness of auditory and visual models in the acquisition of a timing task. Subjects were provided with an auditory model, a visual model, a combined auditory and visual model, or no model of correct performance. There were significant main effects of groups and trials during acquisition. While performance of all groups improved during acquisition, the audio and audiovisual groups had generally better performance. The same effects were significant on immediate transfer, again reflecting the superior performance of the two auditory model groups. The results suggest an important role for audition in the development of a cognitive representation of movement timing.     

Respiratory phase and visual signal detection

Previous studies have implicated respiration as a source of intra-S variation in visual signal detection tasks. In the present study, pneumographic respiration records were obtained on 22 female undergraduates during a visual signal detection task. The analysis of signal detection with respect to respiration phase showed that signals presented during exhalation were detected more frequently than those presented during inhalation. These findings suggest that the intra-S variation in signal detection performance may be partially accounted for by respiratory behavior at the moment of signal presentation.     

Attentional and intentional cueing in a Simon task: An EEG-based approach

Advance information about the location of a stimulus (attentional cueing) does not affect the Simon effect (a shortening of manual response times whenever the position of a stimulus that is irrelevant for the task corresponds to the side of the response). However, advance information about the side of a response (intentional cueing) enhances the Simon effect. At first sight, these well-established results contradict two important assumptions about the origin of the Simon effect: (a) the effect originates at least in part in a covert shift of visual attention that forces the preparation of a response towards the location of the attentional shift and (b) interference between stimulus location and response side takes place within a response selection stage. We replicated the behavioral finding in a study that measured event-related potentials (ERPs) of the EEG. ERPs indicated that the mechanisms causing the Simon effect remain widely unaffected by advance information. Clear evidence for both response preparation and attentional shifts in the cue-target interval was found. Additionally, ERPs suggested that the increment of the Simon effect by intentional cueing might be due to perceptual factors rather than to an alteration in the mechanisms involved in the generation of a regular Simon effect. The implications of these data for the role of attention and of response selection in Simon tasks are discussed.     

选择性注意机制在情景线索效应中的作用

情景线索效应是指个体在视觉搜索过程中通过学习重复不变的情景信息提高搜索效率的现象。本文从情景线索效应相关行为特征、眼动特征及大脑神经活动等三个方面探讨了情景线索效应与选择性注意机制的交互作用,发现现有研究中存在着许多互相冲突的现象,增加了理解注意机制的难度。未来研究应结合认知神经科学技术寻找更多的实证数据,探索注意机制对情景线索效应的影响,以进一步完善情景线索效应中的注意机制理论。     

Colour and spatial cueing in low-prevalence visual search

In visual search, 30-40% of targets with a prevalence rate of 2% are missed, compared to 7% of targets with a prevalence rate of 50% (Wolfe, Horowitz, & Kenner, 2005). This "low-prevalence" (LP) effect is thought to occur as participants are making motor errors, changing their response criteria, and/or quitting their search too soon. We investigate whether colour and spatial cues, known to improve visual search when the target has a high prevalence (HP), benefit search when the target is rare. Experiments 1 and 2 showed that although knowledge of the target's colour reduces miss errors overall, it does not eliminate the LP effect as more targets were missed at LP than at HP. Furthermore, detection of a rare target is significantly impaired if it appears in an unexpected colour-more so than if the prevalence of the target is high (Experiment 2). Experiment 3 showed that, if a rare target is exogenously cued, target detection is improved but still impaired relative to high-prevalence conditions. Furthermore, if the cue is absent or invalid, the percentage of missed targets increases. Participants were given the option to correct motor errors in all three experiments, which reduced but did not eliminate the LP effect. The results suggest that although valid colour and spatial cues improve target detection, participants still miss more targets at LP than at HP. Furthermore, invalid cues at LP are very costly in terms of miss errors. We discuss our findings in relation to current theories and applications of LP search.     

Colour and spatial cueing in low-prevalence visual search

People are able to judge the current position of occluded moving objects. This operation is known as motion extrapolation. It has previously been suggested that motion extrapolation is independent of the oculomotor system. Here we revisited this question by measuring eye position while participants completed two types of motion extrapolation task. In one task, a moving visual target travelled rightwards, disappeared, then reappeared further along its trajectory. Participants discriminated correct reappearance times from incorrect (too early or too late) with a two-alternative forced-choice button press. In the second task, the target travelled rightwards behind a visible, rectangular occluder, and participants pressed a button at the time when they judged it should reappear. In both tasks, performance was significantly different under fixation as compared to free eye movement conditions. When eye movements were permitted, eye movements during occlusion were related to participants' judgements. Finally, even when participants were required to fixate, small changes in eye position around fixation (<2°) were influenced by occluded target motion. These results all indicate that overlapping systems control eye movements and judgements on motion extrapolation tasks. This has implications for understanding the mechanism underlying motion extrapolation.