Allocation of attention according to informativeness in visual recognition

In visual identification, is visual attention attracted to more informative elements, i.e. to elements which are more critical for identification? This question was investigated by having subjects detect some visual probes while performing a primary task that involved identification. The probes were located in the neighbourhood of highly or poorly informative parts of the identified stimuli. Three experiments that followed this rationale were conducted. In Experiment I, it was found that when subjects searched for a target letter in lines of identical background letters, they detected more dots near the feature that distinguished between the target and the background letters. In Experiment 11, it was found that native Hebrew-speaking subjects detected more lines above a letter that distinguished between two English words. Experiment III showed that the effect was reduced but did not vanish when spatial uncertainty was introduced. On the whole, the data are interpreted as suggesting that more attention may indeed be directed to informative regions, and that this effect cannot be solely attributed to retinal factors.     

Is three greater than five: The relation between physical and semantic size in comparison tasks

In this study, subjects were asked to judge which of two digits (e.g., 3 5) was larger either in physical or in numerical size. Reaction times were facilitated when the irrelevant dimension was congruent with the relevant dimension and were inhibited when the two were incongruent (size congruity effect). Although judgments based on physical size were faster, their speed was affected by the numerical distance between the members of the digit pair, indicating that numerical distance is automatically computed even when it is irrelevant to the comparative judgment being required by the task. This finding argues for parallel processing of physical and semantic information in this task.     

Competition between endogenous and exogenous orienting of visual attention

The relation between reflexive and voluntary orienting of visual attention was investigated with 4 experiments: a simple detection task, a localization task, a saccade toward the target task, and a target identification task in which discrimination difficulty was manipulated. Endogenous and exogenous orienting cues were presented in each trial and their validity was manipulated orthogonally to examine whether attention mechanisms are mediated by separate systems and whether they have additive and independent effects on visual detection and discrimination. The results showed that each orienting mechanism developed its typical and independent effect in every case except for the difficult identification task. A theoretical framework for understanding the relationship between endogenous and exogenous orienting of attention is proposed, tested, and confirmed.     

Auditory imagery from musical notation in expert musicians

Anecdotal evidence has suggested that musical notation can trigger auditory images. Expert musicians silently read scores containing well-known themes embedded into the notation of an embellished phrase and judged if a tune heard aloud thereafter was the original theme (i.e., melodic target) or not (i.e., melodic lure). Three experiments were conducted employing four score-reading conditions: normal nondistracted reading, concurrent rhythmic distraction, phonatory interference, and obstruction by auditory stimuli. The findings demonstrate that phonatory interference impaired recognition of original themes more than did the other conditions. We propose that notational audiation is the silent reading of musical notation resulting in auditory imagery. The research suggests that it also elicits kinesthetic-like phonatory processes.     

Is there a “strength effect” in automatic semantic priming?

According to spreading activation models of automatic priming, highly related associates should yield stronger priming effects than weakly related associates. The strength of relations is usually based on word association norms. However, this strength effect has been found in some studies but not in others. The present study suggests that one factor that might be responsible for this inconsistency is whether the weak associate is the primary or nonprimary response in the word association norms This possibility was explored by comparing priming effects of weak nonprimary and primary associates with those of strong primary associates. Comparable priming effects were found for the strong and weak primary associates whereas the weak nonprimary associates did not yield any priming effects. These results were obtained both in paired (Experiment 1) and single (Experiment 2) presentation priming procedures. Thus, the rank of the associate is an important factor in predicting the magnitude of the priming effect.     

Effects of non-symbolic numerical information suggest the existence of magnitude-space synesthesia

In number-space synesthesia, numbers are visualized in spatially defined arrays. In a recent study (Gertner et al. in Cortex, doi: 10.1016/j.cortex.2012.03.019 , 2012), we found that the size congruency effect (SiCE) for physical judgments (i.e., comparing numbers' physical sizes while ignoring their numerical values, for example, 8) was modulated by the spatial position of the presented numbers. Surprisingly, we found that the neutral condition, which is comprise solely of physical sizes (e.g., 3), was affected as well. This pattern gave rise to the idea that number-space synesthesia might entail not only discrete, ordered, meaningful symbols (i.e., Arabic numbers) but also continuous non-symbolic magnitudes (i.e., sizes, length, luminance, etc.). We tested this idea by assessing the performance of two number-space synesthetes and 12 matched controls in 3 comparative judgment tasks involving symbolic and non-symbolic stimuli: (1) Arabic numbers, (2) dot clusters, and (3) sizes of squares. The spatial position of the presented stimuli was manipulated to be compatible or incompatible with respect to the synesthetic number-space perceptions. Results revealed that for synesthetes, but not for controls, non-symbolic magnitudes (dot clusters) as well as symbolic magnitudes (i.e., Arabic numbers) interacted with space. Our study suggests that number-space synesthetes might have a general magnitude-space association that is not restricted to concrete symbolic stimuli. These findings support recent theories on the perception and evaluation of sizes in numerical cognition.     

Cue and target processing modulate the onset of inhibition of return

Inhibition of return (IOR) is modulated by task set and appears later in discrimination tasks than in detection tasks. Several hypotheses have been suggested to account for this difference. We tested three of these hypotheses in two experiments by examining the influence of cue and target level of processing on the onset of IOR. In the first experiment, participants were required to respond to both the cue and target. The pattern of results showed that deeper processing of the cue or target advanced the onset of IOR. In the second experiment, participants were not required to respond to the cue and a reverse pattern of results emerged, which replicated the general findings in cuing tasks. We conclude that in more-demanding tasks, an additional process slows down the processing of a nonpredictive cue in order to enhance the processing of the target.