Parola parlata: convenzioni e tecniche di resa nella narrativa araba classica

Numero monografico: L’oralità nella scrittura. Modalità di rappresentazione della parola orale nel testo scritto”, a cura di Maria Teresa Biaso

Dwelling on simple stimuli in visual search

Research and theories on visual search often focus on visual guidance to explain differences in search. Guidance is the tuning of attention to target features and facilitates search because distractors that do not show target features can be more effectively ignored (skipping). As a general rule, the better the guidance is, the more efficient search is. Correspondingly, behavioral experiments often interpreted differences in efficiency as reflecting varying degrees of attentional guidance. But other factors such as the time spent on processing a distractor (dwelling) or multiple visits to the same stimulus in a search display (revisiting) are also involved in determining search efficiency. While there is some research showing that dwelling and revisiting modulate search times in addition to skipping, the corresponding studies used complex naturalistic and category-defined stimuli. The present study tests whether results from prior research can be generalized to more simple stimuli, where target-distractor similarity, a strong factor influencing search performance, can be manipulated in a detailed fashion. Thus, in the present study, simple stimuli with varying degrees of target-distractor similarity were used to deliver conclusive evidence for the contribution of dwelling and revisiting to search performance. The results have theoretical and methodological implications: They imply that visual search models should not treat dwelling and revisiting as constants across varying levels of search efficiency and that behavioral search experiments are equivocal with respect to the responsible processing mechanisms underlying more versus less efficient search. We also suggest that eye-tracking methods may be used to disentangle different search components such as skipping, dwelling, and revisiting

The Mona Lisa Illusion—scientists see her looking at them though she isn’t

Horstmann G, Loth S. The Mona Lisa Illusion—scientists see her looking at them though she isn’t. i-Perception. 2019;10(1): 2041669518821702.If the person depicted in an image gazes at the camera or painter, a viewer perceives this as being gazed at. The viewers’ perception holds irrespectively of their position relative to image. This is the Mona Lisa effect named after the subject of Leonardo’s famous painting La Gioconda. The effect occurs reliably but was not tested with Mona Lisa herself. Remarkably, viewers judged Mona Lisa’s gaze as directed to their right-hand side irrespectively of the image zoom, its horizontal position on screen, and the distance of the ruler that was used for measuring the gaze direction

Distractor Dwelling, Skipping, and Revisiting Determine Target Absent Performance in Difficult Visual Search

Horstmann G, Herwig A, Becker SI. Distractor Dwelling, Skipping, and Revisiting Determine Target Absent Performance in Difficult Visual Search. Frontiers in Psychology. 2016;7: 1152.Some targets in visual search are more difficult to find than others. In particular, a target that is similar to the distractors is more difficult to find than a target that is dissimilar to the distractors. Efficiency differences between easy and difficult searches are manifest not only in target-present trials but also in target-absent trials. In fact, even physically identical displays are searched through with different efficiency depending on the searched-for target. Here, we monitored eye movements in search for a target similar to the distractors (difficult search) versus a target dissimilar to the distractors (easy search). We aimed to examine three hypotheses concerning the causes of differential search efficiencies in target-absent trials: (a) distractor dwelling (b) distractor skipping, and (c) distractor revisiting. Reaction times increased with target similarity which is consistent with existing theories and replicates earlier results. Eye movement data indicated guidance in target trials, even though search was very slow. Dwelling, skipping, and revisiting contributed to low search efficiency in difficult search, with dwelling being the strongest factor. It is argued that differences in dwell time account for a large amount of total search time differences

Top-down contingent feature-specific orienting with and without awareness of the visual input

In the present article, the role of endogenous feature-specific orienting for conscious and unconscious vision is reviewed. We start with an overview of orienting. We proceed with a review of masking research, and the definition of the criteria of experimental protocols that demonstrate endogenous and exogenous orienting, respectively. Against this background of criteria, we assess studies of unconscious orienting and come to the conclusion that so far studies of unconscious orienting demonstrated endogenous feature-specific orienting. The review closes with a discussion of the role of unconscious orienting in action control

Distractor dwelling, skipping, and revisiting determine target absent performance in difficult visual search

Some targets in visual search are more difficult to find than others. In particular, a target that is similar to the distractors is more difficult to find than a target that is dissimilar to the distractors. Efficiency differences between easy and difficult searches are manifest not only in target-present trials but also in target-absent trials. In fact, even physically identical displays are searched through with different efficiency depending on the searched-for target. Here, we monitored eye movements in search for a target similar to the distractors (difficult search) versus a target dissimilar to the distractors (easy search). We aimed to examine three hypotheses concerning the causes of differential search efficiencies in target-absent trials: (a) distractor dwelling (b) distractor skipping, and (c) distractor revisiting. Reaction times increased with target similarity which is consistent with existing theories and replicates earlier results. Eye movement data indicated guidance in target trials, even though search was very slow. Dwelling, skipping, and revisiting contributed to low search efficiency in difficult search, with dwelling being the strongest factor. It is argued that differences in dwell time account for a large amount of total search time differences

Visual search for schematic affective faces: Stability and variability of search slopes with different instances

Horstmann G. Visual search for schematic affective faces: Stability and variability of search slopes with different instances. COGNITION & EMOTION. 2009;23(2):355-379.The threat-advantage hypothesis that threatening or negative faces can be discriminated preattentively has often been tested in the visual search paradigm with schematic stimuli. The results have been heterogeneous, suggesting that the choice of particular stimuli have profound effects on search efficiency. Because this conclusion is hampered by differences in experimental procedure, I selected examples from past literature and presented replicas of stimulus pairs (schematic positive and negative faces) in a within-participants design. Although there was a consistent advantage for angry-face targets, search efficiency varied between 8 and 35 ms/item, yielding no clear evidence for the threat-advantage hypothesis. Furthermore, search efficiency for negative- and positive-face targets was highly correlated over stimulus pairs, which implies that whatever complicates the search for the negative face of a pair also complicates the search for the positive face. This results pattern argues against the hypothesised preattentive detector

What do facial expressions convey: feeling states, behavioral intentions, or action requests?

Horstmann G. What do facial expressions convey: feeling states, behavioral intentions, or action requests? Emotion. 2003;3(2):150-166.Emotion theorists assume certain facial displays to convey information about the expresser's emotional state. In contrast, behavioral ecologists assume them to indicate behavioral intentions or action requests. To test these contrasting positions, over 2,000 online participants were presented with facial expressions and asked what they revealed-feeling states, behavioral intentions, or action requests. The majority of the observers chose feeling states as the message of facial expressions of disgust, fear, sadness, happiness, and surprise, supporting the emotions view. Only the anger display tended to elicit more choices of behavioral intention or action request, partially supporting the behavioral ecology view. The results support the view that facial expressions communicate emotions, with emotions being multicomponential phenomena that comprise feelings, intentions, and wishes

Biasing attention by a expectancy discrepant stimuli

Horstmann G. Biasing attention by a expectancy discrepant stimuli. Presented at the ZiF Conference "Competitive Visual Processing across Space and Time: Interactions with Memory", Bielefeld